High Power Rocketry Certification Program · 2019. 1. 3. · High Power Rocketry Certification...

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High Power Rocketry Certification Program The NAR was created in 1957 as an advocate of the model rocketry hobby. Over the past four decades the hobby has grown to encompass rocket motor types and performance unavailable to the modeler at the NAR's inception. In response to this growth the NAR offers a certification process, which permits individuals to purchase and use rocket motors whose physical constraints and performance exceed traditional model rocket boundaries. Rocket motors which exceed model rocketry motor definitions and the models that use these motors are collectively referred to as high power rocketry. The following pages provide the following:

1. A copy of the NAR High Power Certification Application for Level 1, 2 and 3 (Which may be photocopied for use of your members.)

2. A description of the High Power Certification Program

3. The current "Pool of Test Questions" used in the written test. (Latest revision of March,

1999) Not all of the questions from the pool are used, but all questions in the test are chosen from the Test Question Pool. This section will probably be the most frequently updated section of this manual.

Steve Lubliner is in charge of maintaining the question pool. In the 1995 December issue of The Model Rocketeer, Steve offers the following:

Please contact me if you have issues with the questions or are seeking other information about the NAR High Power Certification. I can be reached at (520)-296-1689, or by mail at 9968 E. Domenic Lane, Tucson, AZ 85730. (e-mail: [email protected])

Editor's note: Suggest you contact Steve before a test session to make sure that this question pool is still in effect. If not, Steve can get you a more current list. Also, a practice area is available on the NAR Web Site ( http://www.nar.org). Certification for high power rocketry consists of three progressive levels:

Level 1 allows the purchase and use of H and I impulse class motors.

Level 2 allows the purchase and use of J, K, and L impulse class motors and hybrid rocket motors.

Level 3 certification allows the purchase and use of M, N, and O impulse class rocket

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motors. The procedures for Level 1 and Level 2 certification are documented below. Level 3 certification requires in-process reviews of the certification model design and construction prior to flight. Level 3 certification is covered in an application separate from the Level 1 and Level 2 paperwork. Please note that the NAR high power certification is only one consideration when purchasing and using high power rocket motors. Compliance with local and state laws as well as federal regulations (e.g. FAA FAR Part 101) is also required. High power certification is intended to provide a measure of the modeler's competence to avoid gross violations of good modeling practice and safe model operation. The program is not foolproof. A single demonstration of a modeler's skills does not guarantee consistent safe performance. The certification program does not replace competent range personnel (note that high power range safety officers will require high power certification per NFPA 1127) to provide assurance of safe models and operating practices. Levels 1 and 2 1. Minimum Requirements

1. 1.1 The individual seeking high power certification must be a minimum of 18 years old at the time of certification. A driver's license or a birth certificate is an acceptable proof of age. Note: Other requirements, e.g. 21 years old minimum age, U.S. citizenship, and/or no felony convictions, are imposed by federal, state, or local authorities. Federal requirements for a Low Explosives Users Permit (LEUP) are not satisfied by NAR high power certification. This document does not supersede any requirements imposed by the authorities having jurisdiction.

1.2 The individual must be a member in good standing with the National Association of

Rocketry (NAR) at the time of certification. Evidence of NAR membership will be requested prior to the certification attempt. Acceptable evidence of membership includes the NAR membership card, a canceled check indicating payment of membership fees, or participation in a NAR event where membership status is verified and indicated on the event materials.

1.3 Motors used for certification attempts must be currently certified by either the NAR or

other organizations (e.g. Tripoli) with a recognized certification program. Manufacturer's designations, not certification test data, will be used to identify suitability for the certification level being attempted (e.g. an H128 is an H, a G75 is a G).

2. Certification Teams

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2.1 The certification team consists of two individuals who are a minimum of 18 years old and are members in good standing in the NAR. The certification team members must be unrelated to the applicant. Members of Tripoli, unless they are also members of the NAR, cannot participate on a certification team.

2.2 At least one of the team members must be already certified to a level equal to the

certification level being attempted, e.g. a team member must be certified at Level 1 to judge another individual's Level 1 certification attempt.

2.3 Level 1 certifications, may be administered by a single NAR Level 2 certified individual.

The two certified individuals requirement is waived in this case.

2.4 Certification attempts and written tests must be witnessed in person by the certification team.. Video recordings of a certification flight are not acceptable.

3. Certification Process and Documentation

3.1 Certification may be accomplished at any launch where sufficient individuals meeting the requirements of paragraph 2 are available.

3.2 FAA regulations requiring notification or waivers must be complied with. The launch

site must have a FAA waiver for high power models (greater than 3.3 pounds launch weight and/or 4.4 ounces of propellant) in effect at the time of launch. All conditions and restrictions imposed by the FAA must be satisfied and followed.

3.3 The individual attempting certification must complete a NAR High Power Certification

Application prior to his certification attempt. If Level 2 certification is desired the individual must provide proof of previous Level 1 certification. Proof of previous certification includes the high power certification card or a NAR membership card showing the Level 1 certification level.

3.4 The model will be subjected to a safety inspection prior to flight. The safety inspection

form is on the back of the NAR High Power Certification Application. During the safety inspection the modeler will be expected to orally answer technical questions related to the safety and construction of his model. The questions may include (but not limited to) identification of the model's center of gravity and center of pressure, methods used to determine model stability, and interpretation of the rocket motor's designation. The certification team will initial (or check) the blocks indicating that model safety, motor certification, and the existence of a FAA waiver (if required) in effect were verified prior to flight.

3.5 The individual will fly his model. The flight must be witnessed by the certification team

members. Stability, deployment of the recovery system, and safe recovery should be considered when evaluating safety of the flight. Models experiencing a catastrophic failure of either the airframe, rocket motor and/or recovery system (e.g. shock cord

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separation) will not be considered as having a safe flight. 3.6 The model must be returned to the certification team after flight and be inspected to

verify engine retention and for evidence of flight induced damage. The certification team will initial the blocks indicating that a safe flight was made and that the post-flight inspection was satisfactory.

3.7 The certification team will sign the certification sheet to indicate that the certification

attempt was successfully completed. Both the certification sheet and the certification card must be signed. The certification card and the certification sheet are normally returned to the certifying individual after the flight. At club launches or NAR sponsored activities (e.g. NARAM, NSL) the certification sheets may be retained by the event sponsors to be sent to NAR Headquarters as a group. In that event, only the certification card is returned to the certifying individual.

3.8 The certification sheets and Level 2 written tests (if applicable) are returned to NAR

Headquarters. No fees are required. The certification sheets with tests must be returned by the certified individual or the event sponsors to NAR Headquarters to allow updating the NAR database. A new NAR membership card will be issued showing the certification level upon receipt of the certification paperwork.

3.9 The certification card is valid for one year after the certification date or until the end

the NAR member's membership, which ever comes first. The card is recognized as proof of the certification level. The certification card should be destroyed upon receipt of a new NAR membership card, which shows the certification level.

3.10 Falsification of data or statements by the certifying individual will result in revocation of

the high power certification. Falsification of data or statements by the certification team, e.g. failure to secure a FAA waiver, can result in revocation of the team members' NAR memberships.

4. Level 1 high power certification (160.01 to 640.00 Newton-seconds impulse)

4.1 The modeler must demonstrate his ability to build and fly a rocket containing at least one H or I impulse class motor. Cluster or staged models used for certification may not contain over 640.00 Newton seconds total impulse. Single use or reloadable (no hybrids) technology motors are permitted. The modeler must assemble the reloadable motor, if used, in the presence of a certification team member.

4.2 No written examination is required.

4.3 Certification at this level permits single or multiple motor rocket flights with motors

having a maximum total impulse of 640.00 Newton seconds. 5. Level 2 high power certification (640.01 to 5120.00 Newton-seconds impulse)

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5.1 The modeler must demonstrate his ability to build and fly a rocket containing at least

one J, K, or L impulse class motor. Cluster or staged models used for certification may not contain over 5120.00 Newton seconds total impulse. Single use, reloadable, and hybrid technology motors are permitted. The modeler must assemble the reloadable or hybrid motor, if used, in the presence of a certification team member.

5.2 A written examination is required to demonstrate knowledge of the regulations and laws

pertaining to high power rocketry. Questions concerning basic rocket technical knowledge, e.g. center of pressure and center of gravity relationships, will also be included.

5.2.1 The examination will contain 33 questions in the multiple choice format.

5.2.2 The questions will come from a 50 to 100 question pool of previously published

questions and answers.

5.2.3 The passing grade is 88%.

5.2.4 The test may be taken only once in a 30 day period.

5.2.5 The test must be completed prior to the flight attempt. The flight attempt should be made as soon as reasonably and safely possible after successful test completion. The written test will not have to be repeated if the flight attempt is completed within 1 year of taking the written test. Tests should be retained until the completion of the certification flight and sent with the application form to NAR Headquarters.

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5.2.6 Tests are available from: Stephen Lubliner 9968 E. Domenic Lane Tucson, AZ 85730 (520) 296-1689 (home) [email protected]

Tests will typically be provided to a certification team member or to a Section officer (e.g. advisor, president). Tests can be provided to the individual on a case by case basis to be evaluated when the test is requested. The tests are sealed to prevent accidental disclosure of the questions. The tests should remain sealed until taken. Allow one week minimum prior to a certification attempt to receive the test in the mail.

Section advisors or officers can request a supply of tests (typically three to 12 tests) in advance of launches or Section events. Address requests to the above address.

5.3 Certification at this level permits single or multiple motor rocket flights with motors

having a maximum total impulse of 5120.00 Newton seconds. 6. Administrative Items

6.1 NAR members who are currently Tripoli members and are Tripoli Level 1 certified may grandfather at the NAR Level 1 by completing a NAR high power application and attaching proof of Tripoli certification.

6.2 NAR members who are currently Tripoli members and are Tripoli Level 2 certified may

grandfather at the NAR Level 2 by completing a NAR high power application and attaching proof of Tripoli certification.

6.3 Tripoli certifications will be honored at NAR launches.

6.3.1 A current Tripoli consumer confirmation card is required as evidence of Tripoli high

power certification at launches.

6.4 Lapses in the NAR membership over one year will void all certifications. Certifications will have to be repeated starting with Level 1.

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Formal Certification Procedure Level 3 1. Flyer Requirements

1.1 Any individual attempting NAR Level 3 Certification must be a Level 2 high power certified NAR member in good standing.

2. Rocket Requirements

2.1. The certification rocket must be substantially built by certifying flyer. Individuals using rockets with substantial "prefabricated" components will be required to demonstrate suitable construction knowledge to the satisfaction of the Certification Committee. Only the builder of the rocket may use that rocket for a certification attempt. Rockets built by other than the certifying flyer are specifically disallowed. Certification rockets may be built from commercially available kits and may contain components built to the specifications of the certifying flyer but fabricated by others.

2.2. Multiple stage rockets are specifically disallowed for certification flights.

2.3. The rocket must contain a redundant mechanism for performing the initial recovery

event. For single event recovery, the main parachute must have redundant mechanisms for ejection. For drogue-main recovery systems, the drogue parachute must have multiple mechanisms for ensuring drogue deployment. Motor ejection charges may be used as a redundant ejection mechanism, but rockets depending primarily on motor ejection for any recovery event are specifically disallowed.

2.4. The capability must exist to externally disarm all pyrotechnic devices in the rocket. In

this context, "disarm" means the ability to physically break the connection between a pyrotechnic device and the power source to its igniter. Simply turning off the device controlling the pyrotechnic(s) is not sufficient.

2.5. The rocket must conform in all respects to any restrictions imposed by the NAR High

Power Safety Code and NFPA 1127. 3. Certification Procedures

3.1. The flyer must obtain and fill out a NAR Level 3 Certification Form. This form documents the certification procedure steps. The flyer must also prepare a Certification Package as defined in these requirements.

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3.2. During the construction of the rocket, the flyer must complete the Rocket Construction section of the Certification Form. This package will consist of one of the following three options:

a. The flyer may present the rocket for inspection to one member of the Level 3

Certification Committee (L3CC) prior to its final assembly. The purpose of the inspection is to verify, to the satisfaction of the L3CC member, that the rocket is being constructed in a manner suitable for the stresses encountered in a Level 3 flight. The L3CC member performing the inspection will sign his/her approval on the Certification Form.

b. The flyer may prepare a construction packet with descriptions of the construction

techniques, and including photos and/or diagrams. If a construction packet is used in lieu of a physical inspection, this package must be approved and signed by one member of the L3CC.

c. The flyer may build and document a test flight of the rocket. The test flight must utilize

a Level 2 motor with thrust characteristics similar to the intended Level 3 certification motor. The flyer must be able to show that the rocket received stresses approaching that anticipated in the Level 3 flight (either by flight simulation or by recording altimeter or accelerometer).

3.3 The L3CC member accepting the Construction Package will sign the Level 3

Certification Form at the indicated location.

3.4. Prior to the certification flight, the flyer must present a Recovery Systems Package to one L3CC member. This document package must contain the following components:

a. A description of the recovery system components, including the type of electronics,

where redundancy is employed, the type and size of pyrotechnic devices, and the sizes of parachutes or streamers being utilized.

b. A schematic/wiring diagram of the ejection control system. This diagram should show

the wiring between the ejection devices, disarming "switches" and controlling electronics/power source(s).

c. Description of expected descent rate with the main recovery device deployed and

explanation of how the descent rate was determined, or other description explaining why the main recovery device is suitably sized for the certification rocket (manufacturer's recommendation, etc.).

d. Documentation describing how the basic functioning of the recovery electronics has

been demonstrated prior to the certification flight (use of untested ejection control electronics is not permitted). This may be accomplished by either of two methods:

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The flyer may document a Level 2 test flight utilizing the recovery components intended

for use in the Level 3 certification flight, including the primary ejection electronics to be used in the certification flight.

The flyer may document the ground testing of the recovery electronics.

3.5. The L3CC member accepting the Recovery Systems Package will sign the Level 3

Certification Form at the indicated location.

3.6. At the time of the Certification Flight, the flyer will present a completed Certification Package for approval as described in the Certification Package Guidelines.

3.7. Upon approval of the Certification Package, the flyer must make a successful

certification flight as described in Certification Flight Requirements.

3.8. Upon successful completion of the certification flight, the completed, approved certification package will be sent to NAR headquarters for final processing as described in Final Procedures After Certification.

3.9. If the certification flight fails or is disallowed, one of the Flight Witnesses will complete

and send in the Certification Form as described in Failed Certification Procedures. 4. Certification Package Requirements The Level 3 Certification Package will contain all of the following:

1. The certification rocket Construction and Recovery packages.

2. A scale drawing of the certification rocket showing major dimensions, calculated center of pressure, and expected center of gravity in Level 3 certification flight configuration.

3. A description of the expected flight profile using the intended certification motor(s). This

profile should include at a minimum estimates for the following: Maximum expected altitude Maximum expected acceleration Maximum expected velocity Velocity as the rocket leaves the launch system

4. A pre-launch checklist covering rocket and motor preparation and setup.

5. A post-recovery checklist for "safing" the rocket in case of a failure. This would include

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steps required for disarming pyrotechnics, removal of unfired igniters, etc. 5. Certification Flight Requirements

5.1. Prior to the Certification Flight, the flyer will present the certification rocket and Certification Package to two senior members of the NAR, who will act as Flight Witnesses, for pre-flight inspection. Both of the Flight Witnesses must be at least Level 2 high power certified. One of the Flight Witnesses must be a member of the L3CC. Both Flight Witnesses must approve the rocket for flight.

5.2. The actual flight must meet all of the following requirements:

The rocket must use at least one motor with total impulse greater than 5120NS. The flight must be made while a suitable FAA waiver is in effect. The rocket must make a stable, safe flight. The rocket must fully deploy its recovery system. The rocket must remain intact, with no separation of parts that do not deploy their own

recovery device(s). The rocket must be returned for post-flight inspection.

5.3. If the recovered rocket is plainly visible but not retrievable (such as hung in high power lines or in an inaccessible location) the flyer may direct the Flight Witnesses to the location of the rocket for visual inspection at that location.

5.4. By signing for final approval on the Certification Package, the Flight Witnesses are also

certifying that they have looked over the entire Certification Package and to the best of their knowledge, it is complete and acceptable.

5.5. Different Certification Committee members may be used for Construction/Recovery

Package approval and Flight witnesses.

5.6. Either Flight Witness may disallow the certification attempt if, in his or her opinion:

a. The flight did not demonstrate the flyer's ability to successfully fly a Level 3 High Power rocket.

b. The rocket did not fully meet all of the flight requirements for Level 3 certification. 6. Final Certification Procedures

6.1. The flyer will remove and keep the signed, lower section of the Certification Form. This may be used as temporary proof of Level 3 certification.

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6.2. One of the Flight Witnesses will return the completed Certification Form to NAR Headquarters.

6.3. The flyer will receive an updated NAR membership card, showing the new Level 3

certification level, by return mail. 7. Failed Certification Procedures

7.1 One of the Witnesses shall fill out the Failed Certification Flight section on the Level 3 Certification Form. The form shall then be mailed to NAR headquarters, in its entirety.

7.2. These forms will not be used to track failures by individuals. Failed certification attempts

do not count against an individual. The forms will be used to track the effectiveness of the NAR Level 3 certification procedures. They will also be used to track the frequency and types of failures. This information is needed in order to improve the certification procedures over time.

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National Association of Rocketry Level 2 ("J"/"K"/"L") Certification Test Question Pool

Section A - Applicable Regulations (11 questions) A1) Which of the following National Fire

Protection Association standards provides a code for high power rocketry?

A) NFPA 1122 B) NFPA 1127 C) NFPA 1123 D) NFPA 1124

The answer is "B". NFPA 1127 is the Code for High Power Rocketry. NFPA 1122 is the Code for Model Rocketry; NFPA 1123 is the Code for Outside Display of Fireworks; NFPA 1124 is the Code for the Manufacture, Transportation, and Storage of Fireworks.

A2) What part of the Federal Aviation

Administration Federal Aviation regulations govern rocket activity?

A) Part 95 B) Part 97 C) Part 101 D) Part 125

The answer is "C". Rocket activity is codified in Part 101, Moored Balloons, Kites, Unmanned Rockets, and Unmanned Free Balloons.

A3) What is the maximum launch weight

allowable for a rocket which does not require FAA notification or waiver?

A) 4 ounces (113 grams) B) 4.4 ounces (125 grams) C) 1 pound (453 grams)

D) 3.3 pounds (1500 grams) The answer is "C". Part 101 does not govern the operation of model rockets weighing under 16 ounces (1 pound).

A4) What is the maximum propellant

weight allowable for a rocket which does not require FAA notification or waiver?

A) 4 ounces (113 grams) B) 4.4 ounces (125 grams) C) 1 pound (453 grams) D) 3.3 pounds (1500 grams)

The answer is "A". Part 101 does not govern the operation of model rockets using not more than 4 ounces of propellant.

A5) What is the maximum total impulse

allowable for a rocket which does not require FAA notification or waiver?

A) 80 Newton seconds B) 160 Newton seconds C) 320 Newton seconds D) There is no impulse limit.

The answer is "D". Part 101 does not specify any impulse limits.

A6) What is the maximum launch weight

allowable for a rocket when complying with the FAA notification requirements?


The answer is "D". Part S101.22 allows

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operation of rockets weighing no more than 1500 grams (3.3 pounds) provided an individual complies with the notification requirements in part S101.25.

A7) What is the maximum propellant

weight allowable for a rocket when complying with the FAA notification requirements?


The answer is "B". Part S101.22 allows operation of rockets using not more than 125 grams (4.4 ounces) of propellant provided an individual complies with the notification requirements in part S101.25.

A8a) High power rocket motors, motor

reloading kits, and pyrotechnic modules shall be stored at least ____ away from smoking, open flames, and other sources of heat.

A) 10 feet B) 25 feet C) 50 feet D) 75 feet

The answer is "B". Refer to paragraph 2-18.1 of NFPA 1127, 1998 edition.

A9a) Which of the following is a

requirement for high power certification:

A) The ability to understand written English instructions B) A minimum of 18 years of age C) A citizen of the United States of America D) No felony convictions


A10) Deleted A11) What is the maximum total impulse

permitted in a high power rocket per NFPA 1127?

A) 81920 Newton seconds B) 40960 Newton seconds C) 20480 Newton seconds D) There is no limit provided the FAA altitude waiver requirements are not exceeded.


A12) What is the maximum allowable weight

for a high power rocket permitted per NFPA 1127?

A) 30 pounds B) 60 pounds C) 120 pounds D) There is no limit provided the rocket weighs less than the rocket motor manufacturer's recommended liftoff weight for the rocket motor(s) used for flight.

The answer is "D". Refer to NFPA 1127, 1998 edition paragraph 2-8.1.

A13) What is the minimum age for user

certification?

A) 16 years old B) 18 years old C) 21 years old D) 25 years old

The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph 5-4.1.

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A14) Which of the following is not a

required feature of a rocket motor ignition system?

A) A removable interlock device is in series with the launch switch. B) The system is electrically operated. C) The launching switch will return to the "off" position when released. D) An audible or visual indicator shows continuity through the rocket motor ignitor.

The answer is "D". Refer to NFPA 1127, 1998 edition, paragraphs 2-12.1 and 2-12.2.

A15) Which of the following statements are

true concerning the definition of a High Power Rocket Motor?

A) Total impulse is more than 160 Newton seconds B) The motor uses a "composite" propellant C) Both A and B above D) The motor must use either fiberglass or metal case materials

The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph 1-3, for the definition of a high power rocket motor.

A16) Which of the following is (are) true of a

complex high power rocket per NFPA 1127?

A) The rocket is multi-staged or propelled by a cluster of rocket motors B) The rocket contains electrical or electronic devices intended for control of the rockets functions, e.g.

staging, recovery initiation C) The rocket uses other than parachute or streamer recovery, e.g. helicopter or glide recovery D) Both "A" and "B" above

The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph 1-3, Definitions.

A17) A launch site is defined as containing

areas for which of the following activities? A) Launching B) Recovery C) Parking D) All of the above

The answer is "D". Refer to NFPA 1127, 1998 edition, paragraph 1-3, for the definition of a launch site.

A18) A person shall fly a high power rocket

only in compliance with:

A) NFPA 1127 B) Federal Aviation Administration Regulations, Part 101 C) State, and local laws, rules, regulations, statutes, and ordinances D) All of the above

The answer is "D". Refer to NFPA 1127, 1998 edition, paragraph 2-2.

A19) Which of the following statements is

always true concerning the definition of a hybrid rocket motor?

A) The fuel component is composed of either paper or plastic. B) The fuel is in a different physical state (solid, liquid, or gaseous) than the oxidizer. C) The oxidizer component is nitrous oxide. D) Both "A" and "C" above"

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The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph 1-3, for the definition of a hybrid rocket motor.

A20) Per the ATF-Explosives Law and

Regulation (Orange Book) what kind of explosive material is Thermalite fuse:

A) High Explosive B) Low Explosive C) Blasting Agent D) Non-explosive

The answer is "B". Refer to section 55.202 (b) of the ATF-Explosives Law and Regulation, 6/90 revision.

A21) LEUP stands for:

A) Legal Entitity User Permit B) Liability Evaluation/Uniform Process C) Low Explosive User Permit D) Low Explosive Uniform Process

The answer is "C".

A22) The minimum age for an explosive

permits applications is:

A) 16 years or older B) 18 years or older C) 21 years or older D) 25 years or older

The answer is "C". Refer to ATF- Explosives Law and Regulation (Orange Book), Sections 843 (b) (1) and 842 (d) (1).

A23) Which of the following statements are

true concerning the definition of a High Power Rocket Motor?

A) Total impulse is less than 81920 Newton seconds B) The total impulse is more than 160 Newton-seconds C) Both A and B above D) The motor must use either fiberglass or metal case materials

The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph 1-3, for the definition of a high power rocket motor.

A24) Which of the following are

prohibited activities for participants prepping or launching high power rockets?

A) Consumption of alcohol B) Use of medication that could affect judgement, movement, or stability C) Both "A" and "B" above D) None of the above

The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph 6-1 "l".

A25) Which of the following are prohibited

activities for spectators in high power rocket prepping areas ?

A) Consumption of alcohol B) Use of medication that could affect judgement, movement, or stability C) Both "A" and "B" above D) None of the above

The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph 6-1 "l".

A26) An certified individual wants to

purchase a "L" motor reload kit at a launch in a state other than his residence. Which of the following is true?

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A) He must possess a Low Explosives User's Permit. B) He does not require a Low Explosives User's Permit. C) He must pay in advance for the motor purchase. D) He must use the reload kit on the same day as purchase.

The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph 5-2 "a".

A27) A certified individual wants to

purchase a "L" motor reloadable casing at a launch in a state other than his residence. Which of the following is true?

A) He must possess a Low Explosives User's Permit. B) He does not require a Low Explosives User's Permit. C) He must pay in advance for the motor purchase. D) He must use the reload kit on the same day as urchase.

The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph 5-2 "a". Note the difference from question A26 (casing versus reload kit).

Section B - Storage Requirements (2 questions) B1) What is the maximum net propellant

weight that may be stored in a indoor Type 3 or Type 4 magazine?

A) 10 pounds B) 25 pounds C) 50 pounds D) 100 pounds

The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph 2-18.2.

B2) Which type of storage magazine is

referred to as a "day-box"?

A) Type 1 B) Type 2 C) Type 3 D) Type 4

The answer is "C". A Type 3 magazine is a "day-box" or other portable magazine per page 51 of the ATF - Explosives Law and Regulations (6/90).

B3) Which of the following are

requirements for Type 3 magazine construction?

A) Steel structure B) Wood lined C) Lockable D) All of the above

The answer is "D". A Type 3 magazine is constructed from steel, no thinner than 12 gauge, and lined with 1/2" thick plywood or hardboard. Provisions for 1 lock, no hood, are required.

B4) Which of the following is not a

requirement for an indoor magazine?

A) The magazine will be painted red. B) The magazine will bear the words "EXPLOSIVES-KEEP FIRE AWAY". C) The magazine will bear the words "EXPLOSIVES-50 POUND MAXIMUM" D) The words "EXPLOSIVES-..." are printed in white letters at least 3 inches high.

The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph 2-18.2.

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B5) In which of the following locations can a Type 3 or Type 4 magazine be properly located?

A) In the attached garage of a single family residence B) In the utility or laundry room of a multi-family residence C) In the bedroom closet for a non-smoker resident D) Anywhere inside the house at least 10 feet away from flame producing appliances (stove, water heater, etc.)

The answer is "A". Refer to NFPA 1127, 1998 edition, paragraph 2-18.2.3.

B6) In which of the following locations can

a Type 3 or Type 4 magazine be properly located?

A) In the utility or laundry room of a multi-family residence B) In the attached garage of a multi- family residence if the garage is surrounded on all sides by a 1 hour fire rated barrier C) In the bedroom closet for a non-smoker resident D) Anywhere inside the house at least 10 feet away from flame producing appliances (stove, water heater, etc.)

The answer is "B". Refer to NFPA 1127, 1998 edition, paragraph 2-18.2.4.

B7) In which of the following locations can

a Type 3 or Type 4 magazine be properly located?

A) In the bedroom closet for a non-smoker resident B) In the attached garage of a multi- family residence C) In a detached garage substantially removed or segregated from any residence.

D) Anywhere inside the house at least 10 feet away from flame producing appliances (stove, water heater, etc.)

The answer is "C". Refer to NFPA 1127, 1998 edition, paragraph 2-18.2.2.

Section C - Range and Safety Practices (15 questions) C1) What is the maximum launch angle,

measured from the vertical, for a high power rocket?

A) 10 degrees B) 20 degrees C) 30 degrees D) 40 degrees The answer is "B". Refer to section 15 of the NAR High Power Rocket Safety Code.

C2) What is the maximum wind velocity

allowable for launch operations? A) 20 miles per hour B) 25 miles per hour C) 15 miles per hour D) 30 miles per hour

The answer is "A". Refer to section 13 of the NAR High Power Rocket Safety Code.

C3) The minimum launch site dimension

for rockets having a maximum installed impulse of 320.00 Newton seconds is 1500 feet. What is the minimum distance between the launch site boundary and the launcher?

A) 150 feet B) 375 feet C) 750 feet

D) The launcher may be located anywhere on the launch site to

Section 8, Page 23

compensate for wind.

The answer is "C". A person shall not locate a launcher closer to the edge of the launch site than one half (1/2) the minimum launch site dimension. Refer to section 9 of the NAR High Power Rocket Safety Code (revision 7/95).

C4) The minimum launch site dimension

for rockets having a maximum installed impulse of 2560.00 Newton seconds is 5280 feet. Flights to 10500 feet are anticipated. What is the minimum distance between the launch site boundary and the launcher?

A) Approximately 660 feet B) Approximately 1320 feet C) Approximately 2600 feet D) The launcher may be located anywhere on the launch site to compensate for wind.

The answer is "C". A person shall not locate a launcher closer to the edge of the launch site than one half (1/2) the minimum launch site dimension. Refer to NFPA 1127, 1998 edition, paragraph 2-14.2 and section 9 of the NAR High Power Rocket Safety Code (revision 7/95). The anticipated altitude is important because the launch site dimensions may also be determined to be 1/2 of the maximum altitude expected (see NFPA paragraph 2-13.4). In this case 1/2 of 10500 feet is 5250 feet or about the same as specified in the safety code launch site table.

C5) The FAA has granted a waiver for high

power rocket flight to 18000 feet for your event. Flights up tothat altitude are expected. What are the minimum launch site dimensions?


The answer is "C". The size of the launch site may also be calculated as no less than one half (1/2) of the maximum altitude expected, calculated, simulated, or granted (by FAA waiver/authority having jurisdiction). Note that the minimum launch site dimensions may even beeven greater depending upon the total impulse flown. For example, "L" powered models require a minimum launch site dimension of 10560 feet. Refer to NFPA 1127, 1998 edition, para 2-13.2 and to section 9 of the NAR High Power Rocket Safety Code (revision 7/95).

C6) The FAA has granted a waiver for high

power rocket flight to 2500 feet for your event. What are the minimum launch site dimensions?


The answer is "D". The size of the

launch site may also be calculated as no less than one half (1/2) of the maximum altitude expected, calculated, simulated, or granted (by FAA waiver/authority having jurisdiction), however, in no case shall the minimum launch site dimension be less than 1500 feet. Note that the minimum launch site dimensions may even be even greater depending upon the total impulse flown. Refer to NFPA 1127, 1998 edition, paragraph 2-13.3 and to section 9 of the NAR High Power

Section 8, Page 24

Rocket Safety Code (revision 7/95). C7) In no case shall the minimum launch

site dimension be less than ______ the estimated altitude of the high power rocket or _______ .

A) 1/4, 1500 feet B) 1/2, 1500 feet C) 1/4, 2500 feet D) 1/2, 2500 feet

The answer is "B". Refer to NFPA 1127, 1998 edition, paragraphs 2-13.2 and 2-13.3.

C8) Your launch site borders on an

interstate freeway. What is the minimum distance allowable for location of a high power launch site from the interstate freeway?

A) 750 feet B) 1500 feet C) 3000 feet D) 5280 feet (1 mile)

The correct answer is "B". Refer to NFPA 1127, 1998 edition, paragraph 2-14.2.

C9) Your launch site's owner's house is

located in the middle of your site. What is the minimum distance allowable for location of a high power launch site from the owner's house?

A) 750 feet B) 1500 feet C) 3000 feet D) The launch site shall contain no occupied buildings; you cannot launch unless the house is empty. The answer is "D". Paragraph 2-14.2 of NFPA 1127, 1998 edition, states that

when occupied structures or busy roads border the launch site, a 1500 foot minimum separation is required between the launcher and the road or building.

C10) What is the minimum safe distance

from a high power rocket containing a single "I" motor?


The answer is "B". Refer to Table 2-15 .3 of NFPA 1127, 1998 edition, and the safe distance table in the NAR High Power Rocket safety code (revised 7/95).


from a high power rocket containing two "H" motors?


The answer is "A". Refer to Table 2- 5.3 of NFPA 1127, 1998 edition, and the safe distance table in the NAR High Power Rocket safety code (revised 7/95).


from a high power rocket containing two "K" motors?


The answer is "D". Refer to the NAR High Power Rocket Safety Code and Table 2-

Section 8, Page 25

15.3 of NFPA 1127, 1998 edition. C13) Which of the following igniters may be

ignited by the continuity test of some launch controllers?

A) Nichrome wire B) Flashbulbs C) Electric match D) Both "b" and "c" above The answer is "D". Refer to the "Handbook of \Model Rocketry" by G. Harry Stine, 6th edition, Chapter 6 on "Ignition and Ignition Systems". Look at page 94.

C14) In the event of a misfire how long

should you wait before approaching the launch pad?

A) 15 seconds B) 60 seconds C) 5 minutes D) No wait is required

The answer is "B". Refer to paragraph 12 of the NAR High Power Rocket Safety Code.

C15) Which of the following is most likely to

cause catastrophic failure of a black powder rocket motor?

A) Temperature cycling B) Electromagnetic fields C) Vibration D) High altitude

The answer is "A". Temperature cycling is the primary cause of black powder rocket motor catastrophic failure. Temperature cycling cause expansion and contraction of the black powder grain and motor casing causing delaminations between the case and propellant grain and cracks within the

grain. These delaminations and cracks expose additional burning surface that increases combustion pressures. The result is a motor failure. Note that shock or vibration can also damage a black powder rocket motor, however thermal cycling is the most likely cause of failure. Refer to the May and June 1992 issue of American Spacemodeling magazine, page 10, the article "A Theoretical Analysis of Why Black Powder Model Rocket Motors Fail".

C16) Igniters for clustered rocket motors

should be wired together in: A) Series B) Parallel C) Short Circuit D) Open Circuit

The answer is "B". If the igniters are wired in series the first igniter to burn out opens the circuit preventing any other igniters from receiving electrical power. Parallel connections allow all of the igniters to independently receive electrical power.

C17) When should igniters installed in

rocket motors be checked for continuity?

A) Any time B) Only in an enclosed shelter C) Only on the launch pad when ready for launch D) Igniters should never be checked for continuity while installed in a rocket motor.

The answer is "C". Continuity is typically checked by the launch controller when the rocket is placed on the launch pad. This is considered safe practice because the number of personnel around the model is at a minimum and the model is pointed

Section 8, Page 26

skyward which minimizes the hazard in the event of inadvertent ignition.

C18) Which of the following is the preferred

method for attaching fins to a high power rocket?

A) Tube surface mounting B) "Wedge" mount C) "Though the wall" mounting D) All fin mounting methods are all equally strong; it does not matter.

The answer is "C". Through the wall mounting is stronger because the model is supported and attached to the rocket at two locations. The fins are attached to the motor tube and the body tube. In cases where through the wall mounting is not usable "wedge" mounting may be possible. Wedge mounting places the fin at the junction of two tubes; this mounting is typically used in cluster models. Surface mounting, like that used in most model rocket kits, is not recommended for high power rockets.

C19) Which of the following adhesives

should not be used on rubber (or elastic) shock cord components?

A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C) Aliphatic resin based glues D) White "Elmer's" glue

The answer is "B". Cyanoacrylate glues will chemically attack rubber or elastic shock cord components allowing them to break when stretched.

C20) Which of the following adhesives is

most likely to be weakened under humid or wet weather conditions?

A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C) Aliphatic resin based glues D) White "Elmer's" glue

The answer is "D". White glues are weakened under high humidity conditions. Use aliphatic base (wood or carpenter's) glues instead of white glue.

C21) Which of the following adhesives is the

best choice for engine mount construction?

A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C) Aliphatic resin based glues D) "Hot melt" adhesives

The answer is "A". Epoxies can be used to easily form fillets at the bond joints which provides an increase in strength. Epoxies also bridge gaps in loose fitting parts to improve bond strength. One caution when using epoxies is that they are relatively heavy; they can reduce model stability by making the model tail heavy. Cyanoacrylate glues are not recommended for engine mount construction because they tend to soak into paper/cardboard body tube materials and are poor gap fillers. Hot melt adhesives should never be used for engine mount applications because they weaken with heat.

C22) The centering rings provided with your

high power kit are a loose fit around the motor tube. Which of the following adhesives is the best choice for a strong joint?

A) Epoxy adhesives B) Cyanoacrylate glues (super glue) C) Aliphatic resin based glues D) "Hot melt" adhesives

Section 8, Page 27

The answer is "A". Epoxies can be used to easily form fillets at the bond joints which provides an increase in strength. Epoxies also bridge gaps in loose fitting parts to improve bond strength. One caution when using epoxies is that they are relatively heavy; they can reduce model stability by making the model tail heavy. Cyanoacrylate glues are not recommended for engine mount construction because they tend to soak into paper/cardboard body tube materials and are poor gap fillers. Hot melt adhesives should never be used for engine mount applications because they weaken with heat.

C23) A small hole is typically recommended

near the top, but below the nosecone or payload section shoulder, of a high power rocket's booster section. Why?

A) This hole allows excessive ejection charge pressures to vent to reduce shock cord stress. B) The hole is used to give air pressure readings for on board altimeters. C) The hole vents internal air pressure as the rocket gains altitude to prevent internal air pressure from prematurely separating the model. D) The hole allows easy verification that a parachute is installed.

The answer is "C". Air pressure external to the rocket decreases as the rocket ascends. Trapped pressure within the model can prematurely separate the model. The hole vents this internal air pressure to prevent separation. Note that the hole size is dependent on model size; larger models require larger holes. Use caution in locating the hole such that the nosecone (or stage coupler) does not block the hole. Also, position the hole such that ejection

charge pressure is not vented before ejecting the recovery system from the body tube.

C24) When clustering combinations of black

powder and composite motors, which type of rocket motor should be ignited first?

A) Composite rocket motors should be ignited first B) Black powder rocket motors should be ignited first C) It does not matter which motors are ignited first D) Clusters should never mix composite and black powder motors The answer is "A". Composite rocket motors are harder to ignite than black powder motors. The concern is that the model will leave the launch pad before the composite motor has ignited.

C25) Why should composite motors be

ignited first in a mixed composite and black powder cluster?

A) Composite motors are more difficult and take longer to ignite. B) Composite motors are more likely to "cato" than black powder motors C) The exhaust products from black powder motors prevent composite motor ignition. D) Composite rocket motors are more powerful than black powder motors

The answer is "A". Composite rocket motors are harder to ignite than black powder motors. The concern is that the model will leave the launch pad before the composite motor has ignited.

C26) If individual igniters are used for

igniting a clustered model's motors which of the following statements is

Section 8, Page 28

typically true:

A) The launch control must have an audible as well as visual indication of igniter continuity. B) The launch control must provide additional current to ignite the additional igniters. C) The launch control must provide higher voltage to ignite the additional igniters. D) The launch control must use a car battery as a power source

The answer is "B". Parallel wiring used in cluster ignition models "shares" the current among all the igniters. If the ignition circuit is marginal those igniters which are slightly more sensitive will ignite before their mates. The model may leave the launcher prior to full ignition of the cluster. Common practice is to use a battery which can deliver higher currents than dry cells; automotive, motorcycle, and "gell cell" batteries are common. Increased voltage will not significantly improve cluster ignition reliability. House voltage, 110 volts AC, should never be used for ignition systems.

C27) What is (are) the advantages of using a

"relay" type launch control?

A) It is cheaper than a non-relay launch control B) The relay allows a better indication of igniter continuity C) It can deliver more power to the rocket motor igniters D) Both "B" and "C" above

The answer is "C". A relay launch system uses a relay to switch the power needed for rocket motor ignition. The battery is usually placed adjacent to the launch pad which allows for shorter

power wires. The shorter power wires minimize the normal loss of power that occurs over long wire lengths (remember that several hundred feet of wire may be required to reach a high power launch pad). The wires going to the launch officer only carry the power required to operate the relay; this power is typically much less than that required by an igniter.

C28) Petroleum based lubricants should not

be used with the oxygen or nitrous oxide systems used in hybrids. Why?

A) They thicken when exposed to oxygen or nitrous oxide. B) They lose their lubricating properties when exposed to oxygen or nitrous oxide. C) There is a risk of spontaneous ignition or explosion. D) The lubricant can promote corrosion of the metal components in the presence oxygen or nitrous oxide.

The answer is "C". Petroleum lubricants are a fuel. Oxygen rich environments are more likely t o promote combustion.

C29) Which of the following safety hazards

may be associated with hybrid rocket motors?

A) High pressure gas, low temperatures (frostbite) B) Low temperatures (frostbite) C) Corrosive materials D) High pressure gas

The answer is "A". The pressure within a nitrous oxide cylinder used with hybrid rocket motors is approximately 750 psi. When filling or venting the nitrous oxide cylinder individuals need to use caution to avoid having high

Section 8, Page 29

pressure gas or liquid impinge on skin or eyes. Oxidizer cylinders need to be inspected after crashes for damage that may compromise their structural integrity. Nitrous oxide boils at -127 o F. Partially filling and allowing the liquid to drain (boil-off) from a nitrous oxide cylinder is a technique used to pre-chill the nitrous oxide cylinder in some motor applications (called shock chilling). The low temperatures achievable through this method may present a hazard to exposed skin.

C30) The range safety officer says that your

model is unsafe to fly. Who has the authority to overturn this ruling:

A) The Launch Control Officer (LCO) B) The individual who "checked-in" the model C) Three certified high power fliers who agree the model is safe D) The safety monitor's (RSO) decision cannot be overturned by anybody

The answer is "D". The range safety officer's decision is final. If the flier can produce additional information which shows the safety of the model, e.g. simulations, previous flight data, then the flier should present the information to the range safety officer.

C31) Parachute ejection systems that sense

barometric pressure for activation need a outside hole in their compartment because:

A) This hole allows excessive ejection charge pressures to vent B) The hole is used to give outside air pressure readings C) The hole vents internal air pressure as the rocket gains altitude to prevent internal air pressure from prematurely separating the model.

D) The hole allows easy verification that the battery is installed

The answer is "B". Air pressure external to the rocket decreases as the rocket ascends. Most barometric ejection systems trigger after detecting a minimal change in the outside barometric pressure (which happens near apogee). The hole allows the sensor to "see" the outside pressure. Use caution in locating the hole such that the nosecone (or stage coupler) does not block the hole.

C32) Which of the following individuals has

the final authority in permitting a high power rocket to fly?

A) The launch control officer (LCO) B) The range safety officer (RSO) C) The check-in officer D) The rocket owner

The answer is "B". The range safety officer's decision is final.

C33) Which of the following individuals has

the ultimate responsibility to ensure that the rocket was built in a safe manner?

A) The launch control officer (LCO) B) The safety monitor (range safety officer or RSO) C) The rocket owner/builder D) All of the above

The answer is "C". Range personnel can do inspections to catch lapses in construction quality or rocket design errors but the owner/builder bears all responsibility for the "goodness" and safety of the model.

C34) Parachute ejection systems that sense

barometric pressure can malfunction

Section 8, Page 30

during supersonic flight because:

A) Aerodynamic heating changes the values of electronic components B) The outside pressure distribution is not continuous around the model C) Static discharges will "zap" sensitive electronic components D) Both answers "A" and "B" are correct

The answer is "B". During supersonic flight shock waves are generated off various model features. The pressure distribution across the shock wave is not continuous. The pressure change across the shock wave may fool the ejection system logic causing a premature ejection.

C35) Your rocket was returned from its flight

with "zipper" damage where the shock cord tore through the model. What is the possible cause:

A) Parachute ejection occurred too soon after motor burnout B) Parachute ejection occurred too late after apogee C) Parachute ejection occurred at apogee D) Both "A" and "B"

The answer is "D". "Zippers" are caused when the model is moving too quickly during parachute deployment. Ejection too soon after burnout does not allow the model to slow down. Ejection too late after apogee allows the model to gain velocity. Ejection at apogee is best because the model velocity is lowest.

C36) Your payload section, with heavy

payload, separated from your model immediately after motor burnout. What might be the cause?

A) The center of pressure at burnout

was behind the center of gravity for the model B) The payload shoulder was too loose in the body tube C) The rocket motor had a failure of its delay system D) Both "B" and "C" are correct.

The answer is "D". Delay train failures do happen and can cause this problem. More often, though, "drag separation" causes this problem and is mistaken for a motor failure. Drag separation is caused by the drag on the aft section of the model being higher than the drag of the forward section. The difference in drag causes the aft section to be pulled away from the forward section. This problem is more pronounced with heavier forward sections because the momentum of the forward section tends to carry it away. Preflight inspection should confirm that the forward section cannot separate under its own weight. More sophisticated models will use some form of positive retention, e.g. shear pins, to prevent premature separation.

C37) What is the distance around a launcher

with a "J" powered model that must be cleared of easy to burn material?


The answer is "C". Refer to paragraph 2- 4.1 of NFPA 1127, 1998 edition.

C38) What is the distance around a launcher

with a 2 "J" engine cluster powered model that must be cleared of easy to burn material? A) 10 feet B) 30 feet

Section 8, Page 31

C) 50 feet D) 75 feet

The answer is "D". Refer to paragraph 2- 4.1 of NFPA 1127, 1998 edition.

Section D - Rocket Stability (3 questions) D1a) For a rocket to be stable which of the

following statements is true?

A) The center of pressure (CP) must be behind the center of gravity (CG). B) The center of pressure (CP) must be in front of the center of gravity (CG). C) The rocket must have fins. D) The length of the body tube must be at least 5 times the model diameter.

The answer is "A". Refer to the "Handbook of Model Rocketry" by G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note references on pages 137 and 138.

D2) An unstable rocket can be made stable

by:

A) Adding weight to the nosecone B) Removing weight from the nosecone C) Moving the fins forward towards the nosecone D) Making the rocket shorter

The answer is "A". To make the rocket stable the center of gravity (C.G.) must be moved forward of t he center of pressure (C.P.). Adding weight to the nosecone moves the C.G. forward. Removing weight from the nosecone moves the C.G. aft which is incorrect. Moving the fins forward towards the nosecone moves the C.P. forward which is also incorrect. Finally, making

the rocket shorter reduces the correcting moments produced by the aerodynamic forces at the C.P.; the reduced moment makes the rocket less stable.

D3) Rocket stability can be estimated by:

A) Center of pressure "Barrowman" equations B) "Cardboard cutout" method C) Determining the relative positions of the center of pressure and center of gravity D) Stability cannot be estimated before a test flight.

The answer is "C". Refer to the "Handbook of Model Rocketry" by G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note Figure 9-6 on page 138. Center of pressure equations and the cardboard cutout method only allow you to determine the center of pressure of the model; the center of gravity location must also be known to determine stability.

D4) A high power rocket's center of

pressure can be estimated by: A) The "Barrowman" method

B) Finding the point where the model balances C) Center of pressure equations D) Both "A" and "C" above

The answer is "D". The "Barrowman" method is a set of equations developed by J. Barrowman for estimating modell rocket stability. More sophisticated methods are available to cover conditions not covered by the Barrowman method, e.g. supersonic flight. Refer to the "Handbook of Model Rocketry" by G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note

Section 8, Page 32

references on pages 140 and 14, Appendix II, and Appendix IV.

D5) An unstable rocket can usually be made

more stable by:

A) Using a shorter nosecone B) Increasing the size of the aft fins C) Using a larger, heavier rocket motor D) Increasing the rocket diameter

The answer is "B". To make the rocket stable the center of pressure (C.P.) must be moved aft of t he center of gravity (C.G.). Adding larger fins on the aft portion of the model moves the center of pressure aft. A shorter nosecone removes weight from the nose moving the C.G. aft which is incorrect. A larger, heavier rocket motor has the same affect of moving the C.G. aft. Finally, increasing the rocket diameter has essentially no effect on its stability.

D6) During boost a rocket powered by a

solid rocket motor tends to become:

A) Less stable in flight B) More stable in flight C) No change in stability D) Unstable

The answer is "B". During powered flight the solid rocket motor consumes its fuel causing the aft end of the rocket to become lighter. This moves the C.G. forward and enhances stability. This can be seen in instances where a unstable rocket becomes stable partway during the rocket motor burn; this is also particularly dangerous because the now stable rocket may be pointed in any direction.

D7) Which of the following is true of an

unstable rocket?

A) The center of pressure (CP) is behind the center of gravity (CG). B) The center of pressure (CP) is in front of the center of gravity (CG). C) The rocket has more than 6 fins. D) The length of the body tube is less than 5 times the model diameter.

The answer is "B". Refer to the "Handbook of Model Rocketry" by G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note references on pages 137 and 138.

D8) As a rule of thumb, how far should the

center of pressure be from the center of gravity?

A) The center of pressure should be at the same location as the center of gravity. B) The center of pressure should be at least 1.0 body tube diameters behind the center of gravity. C) The center of pressure should be at least 1.0 body tube diameters ahead of the center of gravity. D) The center of pressure should be 1.0 body tube diameters ahead of the fin leading edge; the center of gravity does not matter.

The answer is "B". Refer to the "Handbook of Model Rocketry" by G. Harry Stine, 6th edition, Chapter 9 on "Stability". Note references on pages 141 through 146.

Section E - Rocket Motor Designations (2 questions) E1) What does the "H" in the motor

designation H100-5 stand for?

A) It is the first letter in the manufacturer's name.

Section 8, Page 33

B) It indicates the total power range or impulse range of the rocket motor. C) It indicates the total thrust of the rocket motor. D) It indicates that the motor uses black powder as a propellant.

The answer is "B". In a rocket motor designation the alphabetic character indicates the total impulse (or total power) for the rocket motor. High power rocket motors are rated as follows: "H" 160.01 to 320.00 Newton-seconds "I" 320.01 to 640.00 Newton-seconds "J" 640.01 to 1280.00 Newton-seconds "K" 1280.01 to 2560.00 Newton-seconds "L" 2560.01 to 5120.00 Newton-seconds "M" 5120.01 to 10240.00 Newton- seconds "N" 10240.01 to 20480.00 Newton-seconds "O" 20480.01 to 40960.00 Newton-seconds. Note that the total allowable impulse doubles with each letter class.

E2) What does the "100" in the motor


A) It is the peak thrust in pounds of the rocket motor. B) It is the rocket motor burn time in seconds. C) It is the average thrust in Newtons of the rocket motor. D) It is the manufacturer's retail price code.

The answer is "C". In a rocket motor designation the number before the dash is the average thrust in Newtons of the rocket motor. Divide this number by 4.45 for the average thrust in pounds.

E3) What does the "5" in the motor


A) It is the rocket motor burn time.

B) It is the peak thrust (in kilograms) of the rocket motor. C) It is the average thrust of the rocket motor. D) It is the ejection charge delay time.

The answer is "D". In the standard designation system for rocket motors the number after the dash indicates the delay in seconds between rocket motor burnout and ejection charge operation. Note that a "0" (zero) delay indicates a booster rocket motor; the propellant grain is exposed and no delay or ejection charge is used. A "P" may also be used; this indicates that the end of the motor where the ejection charge and delay train normally reside is plugged.

E4) What are the units of measurement for

the "100" in the motor designation H100-5?

A) Newtons per second B) Newtons C) Newton-seconds D) feet per second

The answer is "B". In a rocket motor designation the number before the dash is the average thrust in Newtons of the rocket motor. Divide this number by 4.45 for the average thrust in pounds.

E5) What is the maximum total impulse for

a "J" rocket motor?

A) 320.00 Newton-seconds B) 640.00 Newton-seconds C) 1280.00 Newton-seconds D) 2560.00 Newton-seconds

The answer is "C". In a rocket motor designation the alphabetic character indicates the total impulse (or total

Section 8, Page 34

power) for the rocket motor. High power rocket motors are rated as follows:

"H" 160.01 to 320.00 Newton-seconds "I" 320.01 to 640.00 Newton-seconds "J" 640.01 to 1280.00 Newton-seconds "K" 1280.01 to 2560.00 Newton-seconds "L" 2560.01 to 5120.00 Newton-seconds

"M" 5120.01 to 10240.00 Newton-seconds "N" 10240.01 to 20480.00 Newton-seconds "O" 20480.01 to 40960.00 Newton-seconds

E6) Assuming that each motor has the full

allowable impulse, how many "H" motors have the same total impulse as a single "J" motor?

A) 3 B) 1 C) 2 D) 4

The answer is "D". An "H" motor has a maximum allowable total impulse of 320.00 Newton-seconds and a "J" motor has a maximum total impulse of 1280.00 Newton- seconds thus it takes 4 "H's" to equal 1 "J".

E7) The Department of Transportation

explosives classification "EXPLOSIVES B" indicates what type of hazard?

A) Mass detonating type explosive B) Mass fire and hot gas production

C) Shrapnel or projectiles resulting from detonation D) Limited fire, hot gas production

The answer is "B". Classification "EXPLOSIVES A" indicates a mass detonation hazard; this class has n o use in high power rocketry. Classification "EXPLOSIVES B" indicates the production of large

amounts of fire and hot gas; this is the classification typically given to high power expendable rocket motors and large (54mm or greater) reloadable motors. Classification "EXPLOSIVES C" indicates the production of limited amounts of fire or hot gas; Class "C" devices typically contain limited amounts of Class "A" or Class "B" materials. Model rocket motors are sometimes classified as Class "C" devices.

E8) What classification in the United

Nations (UN) system is similar to t he Department of Transportation classification "EXPLOSIVES B"?

A) UN Division 1.1 B) UN Division 1.2 C) UN Division 1.3 D) UN Division 1.4

The answer is "C". UN Division 1.1 is similar to the DOT "EXPLOSIVES A" classification. UN Division 1.4 is similar to the DOT "EXPLOSIVES C" classification. UN Division 1.3 is similar to the DOT "EXPLOSIVES B" classification. (As a note UN Division 1.2 is shrapnel producing; Division 1.1 usually is applied instead.)

E9) You have an H64-8 rocket motor which

has been certified to have a total impulse of 320.00 Newton seconds. What is the approximate burn time for this motor?

A) 3 seconds B) 5 seconds C) 8 seconds D) 10 seconds

The answer is "B". Divide the total impulse by the average thrust to determine the motor burn time. 320

Section 8, Page 35

(Newton-seconds) = 5 (seconds) 64 (Newtons)

E10) The manufacturer's test data shows a total impulse of 680 Newton-seconds for your motor. What impulse class does your motor represent?

A) "H" B) "I" C) "J" D) "K"

The answer is "C". Refer to the answer for question E5 above

E11) The manufacturer's test data shows an

average thrust of 100 Newtons for 6 seconds for your motor. What impulse class does your motor represent?

A) "H" B) "I" C) "J" D) "K"

The answer is "B". The total impulse is calculated by multiplying the average thrust by time. In this case the total impulse is 600 Newton seconds. Refer to question E5 above for the letter versus total impulse class table.

Section 8, Page 36

NAR SAFETY OFFICER TRAINING PROGRAM Introduction: Model rocketry was created in the late 1950's as a means by which non-professional individuals could build and fly their own rocket powered models. The hobby was structured to safely pursue an activity that has a potential for personal injury and property damage. The use of manufactured motors to minimize the mixing and handling of propellants was a major factor in model rocketry's safety success. Safety procedures for the construction and operation of the models, based on aerospace industry practices, were another factor in this excellent safety record. Hobby maturity and technology advancements permitted the use of more powerful motors and more sophisticated models. High power rocketry describes the step beyond model rocketry. Safety procedures for high power rocketry evolved from model rocketry. This document augments those safety procedures with practical guidance for individuals experienced in model rocketry and familiar with high power rocketry. The intent of this guidance is to assist individuals in performing safety officer functions on a high power rocket range. This guidance is based on experience, regulatory documents (e.g. FAA FAR Part 101), and codified practices (e.g. NFPA 1127). Note that regulatory or codified practices shall supercede guidance in this document if conflicts occur. The primary safety officers are the Range Safety Officer (RSO) and the safety check-in officer. The RSO is responsible for safe operation of the rocketry range. The RSO shall have the final authority to approve or disapprove the launch of a vehicle. The safety check-in officer is responsible for verification of the vehicle flight worthiness. He will inspect the vehicles for structural integrity, systems condition (e.g. recovery system, motor restraint), motor certification, and dynamic properties (e.g. center of gravity, center of pressure). Participants in this program will be required to complete tasks relevant to range safety. Individuals will share safety critical range positions with a mentor. Individuals performing mentored RSO or safety check-in functions must possess a high power certification (Levels 1, 2, or 3). Mentors will be individuals who are both generally acknowledged to be competent in the safety critical roles and are currently certified to NAR level 2 or 3 (Proof of Tripoli certification is not adequate; Tripoli members must have a NAR Membership License showing their certification level). Mentors will observe and advise the participants while they apply suggested guidelines to real world situations. The objective of this program is to educate NAR members by exposing them, with guidelines and mentors, to “real world” situations. These members, when acting as safety officers and instructing other NAR members, will increase the level of safety awareness at our launches to continue our legacy of safety in the rocketry hobby. Requirements: 1.0 Specific Safety Check-in Officer Tasks Description A) 20 check-ins required (Level 1 or 2) B) A minimum of 6 models must be Level 2 C) 2 cluster model check-ins D) 1 “staged” high power model check-in E) 4 models w/ electronic recovery deployment systems check-ins F) 3 post flight failure analyses

Section 8, Page 37

Requirements called out in C, D, and E above can be met at the same time as requirements in A and B.

2.0 Range Safety Officer Tasks Description A) 15 launches required (Level 1 or 2) B) A minimum of 6 models must be Level 2 launches C) 1 cluster model launch D) 1 “staged” high power model launch E) 2 model launches using electronic recovery deployment systems F) 1 launch site evaluation required

Requirements called out in C, D, and E above can be met at the same time as requirements in A and B.

Safety Check-in Officer Guidelines: The items below offer guidance for the acceptance and rejection of models presented for inspection. In addition to the inspection, question the modeler about his model. Ask him if he has any worry areas and what, if anything, he has done to minimize that worry. Other questions may be directed towards specific features of the model. Ask if he has flown the model before with the installed motor and recovery system. If, for example, electronic recovery or staging are being attempted for the first time ask the modeler how he tested their operation prior to flight. If a lack of knowledge or skills is evident from the conversation then consider performing a more extensive inspection of the model. Items A1 through A3 provide administrative guidance. Items A1 and A2 are necessary to assure compliance with Consumer Product Safety Commission (CPSC) and NFPA 1127 user requirements. Item A3 guidance is intended to assure compliance with the Federal Aviation Administration (FAA) Part 101 requirements. A1) Is the modeler over 18? If not, the modeler cannot legally use high power motors, reloadable

motors of any power class, or "G" motors. "G" motors and reloadable motors may be used if the individual is accompanied by a parent or legal guardian.

A2) Is the modeler certified to the power level being flown? Ask to see his membership card to

verify the certification level. Make sure that the membership card is current. Note that some events will verify the certification level at registration. In that case, the person will have event identification showing the certification level. Individuals flying models meeting the following criteria will require high power certification:

a) Launches models containing multiple motors with a total installed impulse of 320.01

Newton-seconds or more, or

b) Launches models containing a single motor with a total installed impulse of 160.01 Newton-seconds or more, or

c) Launches rockets that weigh more than 53 ounces (1500 grams), or

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d) Launches models powered by rocket motors not classified as model rocket motors per NFPA 1122, e.g.:

• Average thrust in excess of 80.0 Newtons • Contains in excess of 2.2 ounces (62.5 grams) of propellant • Hybrids Note that some “F” and “G” motors fall into this category. A3) Does the model fall within the FAA limitations? Models with less than 4 ounces of propellant

and weighing less than 1 pound at launch do not require any additional interface with the FAA. Models with 4 to 4.4 ounces of propellant or which weigh 1.0 to 3.3 pounds at launch require a notification to have been previously submitted to the FAA. Verify with the event director or RSO that the notification has been submitted prior to accepting these models. Models should be weighed prior to flight to verify that they fall within the weight limit. Motor data, typically available on certification lists, must be consulted to verify compliance with propellant limits.

Models containing in excess of 4.4 ounces of propellant or weighing over 3.3 pounds can only be flown with a FAA waiver. The waiver will specify a maximum altitude for flights. Verify with the event director or RSO that a waiver has been approved prior to accepting these models. Models must be weighed and motor propellant weight determined to verify that the model needs a waiver for legal flight. The performance of the model must be evaluated to determine compliance with the waiver altitude limit. Tables listing the motor type and model diameter may be available to indicate a minimum weight for the model. Models under the minimum weight must add ballast or reduce power to stay within waiver limits. Computer software may also be available on the field to estimate performance.

When estimating performance be conservative by using a lower value for the drag coefficient (CD ). Most airframes will have a CD between 0.65 and 0.75. Use a CD value between 0.45 and 0.50 for a conservative estimate of airframe performance.

Cluster combinations will not be addressed on most performance tables. A computer simulation will provide the best estimate of model performance. If a simulation prediction is not available then total the impulse of all motors and the average thrust of all motors. Use this number to identify a similar single motor model for comparison. If the model performance is within 15% of the waiver altitude limit do not permit it to fly without a higher fidelity prediction. Staged models have a similar issue. Since staged models will typically have less drag and higher performance than clustered models the method described above is less reliable. Use the method suggested for evaluating clusters but allow a larger margin for error; if the model is within 25% of the waiver altitude limit do not permit it to fly without a higher fidelity prediction.

Items A4 through A7 concern the rocket motor(s). The NAR safety code requires the use of certified rocket motors. Item A4 addresses this requirement. Items A5 and A6 are intended to verify the correctness of the motor choice and to identify potential safety hazards associated with the igniter. Item A7 addresses a potential hazard with some reloadable designs. A4) Is the motor certified? Certification lists are available on the Internet or in publications from

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the certifying organizations. Verify the motor certification status by consulting the certification lists. Note that certification status may not extend to all delays within a motor type.

A5) Is the motor or motors adequate to safely fly the model? If available, consult the

manufacturer's recommended liftoff weight. Model drag and weather conditions should be considered. High drag models (caused by basic model design, poor finish) will not go as high as streamlined models. Low average thrust motors in windy conditions allow more weathercocking of the model. The altitude may be limited due to weathercocking and the delay may be too long. Remember that motors with longer delays have lower recommended liftoff weights than the same motor with a shorter delay. If still in doubt, ask the modeler for his performance predictions and the prediction method for the model.

A6) Is the igniter a low current type? Flash bulbs and electric match current requirements are low

enough that some launch systems my set them off with continuity power. Verify with the RSO or LCO whether the launch system is "flash bulb safe". Annotate flight cards if required to show the presence of a low current igniter.

A7) Ask the modeler if he is using the motor ejection charge. If he is, verify that he installed the

black powder. Also, some motors rely on a tape disk to retain the powder in its cavity. Disks with dry adhesive or lubricant contamination on the forward face of the cavity may reduce the paper disk adhesion. Deceleration forces may cause the paper disk to come free and disperse the black powder. This will cause an ejection failure. It is suggested that the modeler backup the paper disk with masking tape around the edge to prevent it from coming free.

Items B1 through B8 cover the inspection of the basic model structure and recovery system. The check-in officer will need to handle the model during this phase of the inspection. Ask the model builder if there are any safety hazards, e.g. electronic systems, which may be activated while handling the model. The check-in officer needs to use his judgement when pulling and pushing on model parts; the effort needs to be sufficient to find marginal installations or construction but not so great as to damage a properly built model. B1) Examine all "slip-fits", e.g. nosecone or payload shoulder, which are intended to separate in

flight.

Turn the model nose down. It is unacceptable if the nosecone (or payload) can separate under their own weight. If it does, the nosecone (or payload) may "drag separate" just after motor burnout. Drag separation typically occurs at the highest velocity; the effect is often recovery system failure from excessive loads. A loose nose cone (or payload) can be tightened by the addition of tape to the shoulder.

Does the nosecone (or payload) slide free without excessive effort? A tight nosecone (or payload) can be caused by several problems. Paint overspray in the tube or on the shoulder may cause stickiness in the sliding area. A light sanding or a dusting with talcum powder can reduce the stickiness or remove the overspray. A burr may also form at the edge of the body tube. Again, a light sanding can correct the problem.

Check that the nosecone, if used as part of a payload section, is firmly installed. The object is

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to prevent loss of the nosecone and the payload contents in flight.

Consider the comment "it's flown before" with caution. Temperature and humidity affect the fit of airframe parts (parts swell or contract, finishes may soften in the heat). A smooth fit in an Arizona winter may become a test of muscle and patience in an Alabama summer.

B2) Examine the launch lugs. Are the launch lugs firmly attached to the model without evidence of

cracking in the joints? Are the lugs adequately sized for the model?

Suggestions are 1/4" minimum for models up to 3.3 pounds; 3/8" to 1/2" lugs for models up to 20 pounds, 3/4' or larger lugs for models over 20 pounds. Single launch lugs should be at least 6 inches long and mounted at the model's CG. 2 lugs, each spaced a minimum of 2 body tube diameters from the CG are preferred. The separated lugs are preferred because they better resist rotation (from winds) of the model on the launch rod. Rotation of the model on the launch rod may cause binding during launch.

Check the lugs for paint buildup or burrs inside the lug(s). Paint or burrs may cause binding on the launch rod. A rolled sheet of sandpaper can be used to remove burrs or paint.

B3) Examine the fins. Are the fins mounted parallel to the roll axis of the model? Attempt to

wiggle the fins at their tips. There should be no movement and minimal deflection. If the fins deflect is the fin material appropriate for the model? Models powered by H, I, or J motors should use 1/8" plywood or fiberglass at a minimum. Higher powered models and high aspect ratio fins (large fin span versus fin chord) require additional strength to resist launch loads and possible flutter problems. Laminated or built-up fins should be checked for delaminations. Bubbles mayindicate delaminations. Tapping the fin with a heavy coin (e.g. half-dollar) will give a "dead" thud if a delamination is present. Examine the fin roots for cracks; minor "hairline" cracks may be acceptable if the fins are not loose or if the fins are mounted using "through the wall" construction. Check the fins for warpage; their should be little, if any, warpage.

B4) Examine the engine installation. Verify, if possible, that the engine is what the flight card

indicates. If in doubt, ask that the engine be removed from the model. Pull on the motor to make sure it is firmly restrained in the model. If the motor is friction fitted then it should not move when strongly pulled. A positive means of engine retention, e.g. motor clip, bolted washers, is preferred. Verify that the motor cannot deflect the retention device and then eject. A wrap of tape around motor clip(s) to restrain the them against the motor is suggested.

B5) Can the motor "fly through" the model? Push on the nozzle end of the motor. The motor

should not move forward in its mount nor should the mount move within the model. Try to determine the type and quantity of adhesive used in construction. Any evidence of "hot melt" adhesives should make the model suspect. Motor mounts should typically be mounted with epoxy adhesives with a sufficient quantity to form fillets at the centering ring to body tube joints.

B6) Is the model stable? Find the CG (center of gravity) of the flight ready model (motors installed,

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recovery system packed) by finding the model balance point. Where is the CG relative to the leading edge of the fins? On a single staged model with only a rear set of fins the CG should typically be forward of the forward root edge of the fins.

Canards, wings, forward swept fins, and strakes will require the CG to be further forward. Multi-staged models must be evaluated for each stage. Ask the modeler to show the CP (center of pressure) location on the model (and less each stage for a staged model). Request to see the calculations if in doubt. The CG must be a least one body tube diameter forward of the CP in each flight phase. Note that a subscale model may, in most cases, al

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