SA- None File No. 3-1541

AIRCRAFT ACCIDENT REPORT TAG AIRLINES, INC

DE HAVILLAND DOVE [DH-1041, N2300H IN LAKE ERIE

JANUARY 28,1970 Adopted: January 6, 1971

NATIONAL TRANSPORTATION SAFETY BOARD Washington, D. C. 20591

REPORT NUMBER: NTSB-AAR-71-5

1. 1.1 1.2 1.3 1.4

1.6 1.7 1.8 1.9 1 s o 1.11 1.12 1.13 1.14 1.15 1.16 2. 2.1 2.2

1.5

3.

TAG AIRLD!ES, INC. De Havilland Dove (DH-lob),

N23OOH, i n Lake Erie, January 28, 1970

TABLE OF CONTENTS

Synopsis Probable Cause Investigation History of the Flight In ju r ies t o the Persons Damage t o the Aircraft Other Damage

Aircraft Information Crew Information

Aids t o Navigation Meteorological Information

Aerodrome and GroUna Fac i l i t i e s Communications

Wreckage Flight Recorders

Fi re Swyival Aspects Tests and Research A i r c r a f t Modification and Applicable Airworthiness Directives Analysis and Conclusions Analysis Conclusions (a) Findings (b) Probable Cause

Appendix A Recommendations

Appendix B

Appendix C

Attachment 1

Investigation

Crew History

Aircraft History

Attachment 2 Photographs of Recovered Right Wing Components and Layout

1 1 2 2 2 3 3 3 3 3 4 4 4 4 4 6 6 6 6

8 8

11 11 12 12

Photograph of Fatigue Failed Wing F i t t i n g

r File No. 3-1541

NATIONAL TRANSPORTATION SAFETY BOAFC

AIRCRAFT ACCIDENT REPORT WASHINGTON, D. C. 20591

Adopted: January 6, 1971

TAG AIRLINES , INC . De Havilland dove (DH-lO4),

N23OOH, i n Lake Erie, January 28, 1970

*, SYNOFSIS

' A TAG Airlines, Inc., De Havilland Dove, N23300H, operating as Flight 730 of January 28, 1970, departed from Cleveland's Burke Lakefront Airport at 0738 e.s.t., f o r the Detroit City Airport with two crewmembers

disappeared from the Cleveland A i r Route Traffic Control Center's radar and seven passengers on board. The a i rcraf t ' s radar beacon target

at 0749. A t 0922, it was determined tha t the a i r c ra f t had crashed through the ice into Lake Erie, 26 miles north-northeast of the Cleveland VORTAC. The bodies of f ive passengers and two crewmembers were recovered and identified. Two passengers are missing and are presumed dead. The air- craf t was destroyed and portions of it sank i n 80 feet of water./

L The Board determines tha t the probable cause of t h i s accident was the _ ~ ~ _ in- f l ixht~ failure of the lower, right, main wing-to-fuselage root joint

attach f i t t i n g resulting from undetected-e cracks i n the wing portion of the f i t t ing . (The Board also finds tha t the Federal Aviation Administra- t i o n ' s requirement for the timely replacement of chromium plated root j o i n t f i t t i n g s was inadequate.)

On February 3, 1970, a f t e r consultation with the National Transportation Safety Board, the Federal Aviation Administration issued a precautionary telegraphic Airworthiness Directive pertaining to the engine mount framing and engine mount pickup f i t t ings . In essence, t h i s directive shortened the already existing b y e a r x-ray requirement t o a 2-year interval. The time between visual inspections of the engine mount framing and engine mount pickup was a lso reduced.

right main, wing-to-fuselage lower root joint f i t t i ng , the Board recomencled On May 27, 1970, after identification of the fatigue fa i lure i n the

to the Federal Aviation Administration tha t an expedited one-time inspection be made of all lower root joint f i t t i n g s t o determine the s tructural integri ty of the a i r c r d t . The recommended inspection w a s ordered. The Board also recommended tha t the existing Airworthiness Directives pertaining t o the wing f i t t i ngs and i n particular AD 61-18-3, dated September 1, 1969, be reviewed for be t te r c l a r i ty and purpose. AD 70-12-8 was issued on June 8, 1970, t o accomplish t h i s purpose.

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1. INVESTIGATION

1.1 History of the Flight

TAG Airlines Flight 730 of January 28, 1970, w a s a regularly scheduled passenger flight originating at the Burke Lakefront Airport (BKL) i n Cleveland, Ohio, and destined for Detroit City Airport i n Detroit, Michigan. The a i rc ra f t w a s a De Havilland Dove, N23OOH.

Flight 730 w a s cleared fo r takeoff from Burke Lakefront Airport at 0737:16 1/ and operated routinely t o the vicini ty of Crib Intersection 2/ over Lake Erie. -

A t 0745:23, when TAG 730 was 3 t o 4 miles north of Crib Intersection, ATC control was transferred t o the Cleveland Center and the flight was instructed t o contact the Center. This contact w a s made without delay and the flight reported at 4,000 fee t (the flight planned and clearance alt i tude.)

Detroit area altimeter set t ing of 29.83. This information was acknowledged by the copilot of TAG 730 at 0746:28. This was the last recorded r a d i o transmission from the f l ight .

After establishing radar contact, the controller provided the current

radar target of TAG 730 had disappeared a t a point 5 t o 6 miles northwest of Crib Intersection over Lake Erie on the centerline of Airway Victor

radio but was unsuccessful. 42 East. A t 0749:53, he in i t i a ted attempts t o contact the flight by

Between 0749:25 and 0749:30, the Center controller noted that the beacon

About 0922, a hole through the ice i n the lake, with debris i n and around the hole, was located 26 miles on the 021" radial. of the Cleveland VORTAC. The debris was confirmed subsequently t o be a portion of the wreckage of TAG 730.

The accident occurred during daylight hours. The water at the accident s i t e was 80 feet deep and, a t the time, the area was covered by ice 12 t o 1 4 inches thick and extending 3 t o 5 miles i n all directions.

1.2 Injuries t o Persons

r- 1 .and,

i

- 3 -

1.3 Damage t o the Aircraft

The ai rcraf t was destroyed.

1.4 Other Damage

None.

1.5 Crew InPormation

The crew had the appropriate cert if icates, issued by the Federal Aviation Administration, for the operation involved. (For details , see Appendix B.)

1.6 Aircraft Information

There was no evidence of a departure from the prescribed maintenance procedures o r required inspections. (For de ta i l s of the a i rc ra f t ' s history see Appendix C.)

been refueled with aviation gasoline, grade 100/130. The a i r c r a f t ' s The fueling and load manifests were examined. The a i rc ra f t had

calculated gross weight for takeoff was 8,637 pounds a t a center of gravity reference of 4.27 inches aft of the datum reference. The maximum allowable gross weight f o r takeoff was 8,800 pounds.

Y' All Federal Aviation Administration Airworthiness Directives (AD), i n effect at tha t time, had been complied with i n the prescribed manner.

1.7 Meteorological Information

Surface weather observations taken by BKL Tower personnel on January 28, 1970, were i n part as follows:

0700 -J Estimated ceil ing 10,000 fee t broken clouds, v i s ib i l i t y 7 miles, wind 140", 25 knots.

0800 Scattered clouds 5,000 feet, estimated ceil ing 10,000 -, fee t overcast, v i s ib i l i t y 7 miles, wind 140°, 25 knots.

The data provided by BECL Tower personnel t o TAG 730 on the i n i t i a l radio contact were:

altimeter (sett ing) 29.96." "Wind variable 160 (degrees) e i ther side, 25 t o 30 knots,

The Weather Bureau, Cleveland, has cer t i f ied that no weather briefing ' , was furnished f o r the f l igh t of N2300H by personnel from that fac i l i ty .

.,,' a weather briefing was provided for N230OH (TAG 730) by personnel of that ' The records of the Cleveland Flight Service Station do not indicate that

,' f ac i l i t y . The accident occurred during daylight hours, with the sun \obscured due t o an overcast cloud condition.

- 4 -

1.8 Aids t o Navigation

accident.

1.9 Comunications

The navigation f a c i l i t i e s serving the area were not involved i n this

Normal communications between the a i r c r a f t ' s crew and the various control f a c i l i t i e s personnel were established a t 0733 and maintained u n t i l 0746:28. The copilot handled all communications from Flight 730.

1.10 Aerodrome and Ground Fac i l i t i es

Not involved.

1.11 Flight Recorders

None were insta l led or required by regulation.

1.12 Wreckage

a. Recovery

The a i rc ra f t crashed into the ice floe covering Lake Erie at la t i tude 41'42'36"N. and longitude 82401'12'"iJ. A major portion of the aircraft , including the two engines, broke through the 12 t o 1 4 inch thick ice i n two places and sank i n 80 feet of water. The two penetrations of the ice were approximately 120 fee t and 40 feet i n diameter, respectively, and were separated by approximately 60 feet . Concentric, circular cracks radiated outward from the larger hole for approximately 100 feet . These cracks encompassed the smaller hole.

surface of the ice. This wreckage was found spread i n a random pattern along a l ine for approximately +mile t o the north-northwest from the impact point on the ice floe. Included i n this portion of the wreckage was approximately 90 percent of the s t ructural components of the l e f t wing, which showed extreme damage, and the outboard 1 5 feet of the right wing, t o which re la t ively minor damage had been inf l ic ted The l e f t wing wreckage was on a magnetic bearing of 320°, 130 fee Y from the outer edge of the larger hole. The r i g h t wing section was located 330",

wreckage found +mile away from the impact hole was a f i l l e t section of approximately 300 feet from the larger hole i n the ice. The piece of

l igh t weight and re la t ively large, f l a t plate area.

T A re la t ively minor portion of the a i rcraf t structure remained on the

&Though the a i rc ra f t was destroyed by impact, approximately 95 t o 98 percent of the t o t a l wreckage, including the engines, was recovered. The right engine was recovered from the bottom of the lake, separated by

wreckage, exclusive of those portions recovered from the ice, was taken approximately 75 fee t from the r e s t of the wreckage. The r e s t of the

from an area i n the lake that was approximately 25 by 50 fee t i n size.

mounting frames, m d the right engine mounting frames.2 Included with t h i s major wreckage was the l e f t engine, including

b.

Re( detailel

of the m,

edge, a progess chisel- width c of the

#

l T on a Gj Dove a: mount,

TI three I

separa

A of r i b the bo

wing. resemb

1

remair same 1

blade from 1

scale p i c m recovc and a

separ There

~ The P 1 blade ~ sirnil

of t h four

defor f ram€ struc

i wing

I I

- 5 -

b. Examination

fled in t h i s

various ;ained until IO.

at la t i tude

k ice in i r c r a f t ,

of the ice

cracks t. These

LY, and

led on the

am the pattern

vreckage : l e f t ;he right l e f t ;he outer

:ce of : t ion of

9

'red. %e d by f the s taken size.

95 to 98

detailed examination were made. 'Wreakage was taken t o a warehouse &ere a layout and a

B ~ " e w t b o a s d section of the right wing, recovered from the surface of t W " & C & ; : . H a d separated between r i b stations 9 and LO a t the leading edge, and the fracture continued inboard toward r i b section No. 8 as it progessed aft. The surface of the separation contained sawing/cutting,

width of the wing. W.aS@#.rr&lOn C o m a e ~ & ~ , ~ ~ ~ ~ ~ ~ lnches t o the right chisel- like marks from the bottom skin surface upward across the ent i re

of the outboard engine mount.

The radius of an arc that would be described by a propeller mounted on a Gipsy Queen Model 70 Mark 2 engine ins ta l la t ion of a De Havilland Dove ai rcraf t , i f that engine were rotated about %BtllBo%M%a.rd engine mount, $W@+WS f"'ln~heac /+ three slash marks between r i b stations 12 and 14. The f l ap was separated from the wing.

The leading edge of the outboard f l ap of the right wing contained

A section of wing from rib s ta t ion 5 outboard t o the inboard side of r i b s ta t ion No. 10 w a s recovered. Upward cuts were observed along the bottom outboard surface of t h i s inboard section of right wing which resembled those discussed previously on the outboard section of the right wing.

jepgiqe was recovered from the bottom of the lake i n the same locale as the fuselage and empennage. The propeller assembly remained attached t o the l e f t engine. Blades Nos. 1 and 2 separated

blade torque shims, index ring, blade gear segment, and the degree from the assembly. There was damage t o all the blade packing plates,

pickup f i t t i n g attachments, and all four of the mounting pads were scale on the blade shank. The l e f t engine mount framing, the two upper

recovered attached t o the engine. The bottom inboard pickup f i t t i n g and attachment had separated but were recovered.

%tgW:errgfhe.mas recovered from the lake. This engine was from the other wreckage on the lake bottom by about 75 feet .

There were no other s t ructural components recovered near the right engine. The propeller assembly remained attached t o the right engine but the No. 1 blade was missing from the assembly. The damage i n t h i s assembly was

of the right engine mount framing, pickup f i t t ings , attachments and three of similar t o that described for the l e f t engine's propeller assembly. All

wing and fuselage. The right engine mounting frames were symmetrically four mounting pads were recovered with the inboard sections of the right

deformed down and t o the r ight . (See Attachment 1.) The inboard frame's tfibing was found flattened and compressed into the f i r e w a l l structure.

- 6 -

Two sections of bottom wing skin, the forward and aft fuel tank panels between Rib Stations Nos. 1 and 4, were recovered. Attached t o +&e aft panel was a section of the bott@qrMh rsot.,&tnZrhP$Ctfng. This f i t t i n g was broken through the 718-inch diameter bol t hole aWthe inboard e* 0% the part of the f i t t i n g that had been attached t o the wine.

Washington, D. C., where photographs and hqm$wers .tests -nere-.peH?ormad, A visual examination was also completed. T Q . E i & D ~ . ~ & & e n . t a b s n t o Hawker-SiWf&ey Wiekion ZIimited., Matgaild~..He~fordshire,.Eflglaod, #'

where, a t the request of the Board, a detailed examination was conducted. This exmination was conducted by Hawker-Siddeley personnel under the auspices of the A i r Registration Board and was observed by NTSB and Federal Aviation Administration off ic ia ls .

3DXIPMbaatiori of t h i s f i t t i n g was first conducted by the Board i n

1.13 E=! 4

No evidence of f i r e was found.

1.14 SuruiVavb.&ap&q

This w a s a nonsurvivable accident.

1.15 Tests and Research

Following the accident, samples were dram from the fue l truck used t o service N2300H. These samples, from the "sump" and the fuel nozzle, were taken by the Safety Board t o Wright-Patterson AFB where an analysis of the fuel was made. The t e s t s confirmed that the t ions f o r . . , . a v i a t ~ . C i Q e (100/130 octane) and no could contribute -to. the cause of t h i s accident were found.

r ight wing panel, the deicer s t r i p from the right wing, and sections of

Washington, D. C., where it was established that the paint smears found engine cowling. These samples were taken t o the FBI laboratory i n

on the right wing were from the engine nacelles.

Ssmples of paint markings were taken from the upper surfaces of the

Santplesof a bYaEk, rubberlike substance a lso found on the deicer

propeller deicer boot were tested and determined t o have been of the same s t r i p from the right wing, and samples of the material used t o make the

material.

E ~ ' ~ ~ . ~ ~ i ~ . m a t " e r i ' a l ' t a k e n from the lower surface of the ri&t r analysis were determined t o be %+&ma frmX*.W@-Z&.finob.

p . 1 6 Aircraft Modification and Pertinent Airworthiness Directives

r - . /%e manufacturer and the FAA have, a t various times, issued docken ! T ~ l a t m g t o the inspection and maintenance of the wing main lower root

Joint f i t t i n g , the wing lower spar boom, and the fuselage center'seEtion lower spar boom. The manufacturer's documents were en t i t l ed Technical News Sheets (TNS) and were recornendations or information items, rather

~. ~.

than r were t

were I

I

scribl t o thl lower Life , c ra f t

which jo in t chrom bore,

This

- 7 -

than mandatory changes to be accomplished, i n as far as U.S. operators

were mandatory md frequently based on the related TNS.' were concerned. The Airworthiness Directives (AD), on the other hand,

~ ~ ~ ~ : ~ " , ~ i 5 ~ ~ , ~ 61-u-3 on Juns WpT91) which pre- scribed the accomplishment of the manufacturer's recommended modification t o the W U I ~ &mer spar boom (Mod. 780) m d the fuselage center section lower spar boom (Mod. 799) i n order t o inE*swe @pactive;hy-.W@ -861?rPce IWMF the wing\ In order t o accomplish t h i s 'An, the wings of the a i r - craft would have to be removed from the airframe.

which prescribed a method of inspecting and t es t ing of tkxs,wlng XmeF reow

bore, the following action was directed: chromium plated. If the b o l t hole was found t o have a chromium plated

The manufacturer issued TNS 178, issue 1, -&ve.imly+@y:lgBl, .i

't.tt;bdefermine whether o r not the bore of the bolt hole had been

"7. RFCTIFICATION AND RE-ASSEMBLY

7.1 When the resul ts of the t e s t prove that chrome plating is present, the wing lower root joint f i t t i n g P a r t No. hW.271 must be changed as follows:

(a ) Fi t t ings with l e s s then 10,000 flying hours. A t next wing removal or at 10,000 flying hours whichever i s the sooner.

(b) .x-mC"

This AD was based on TNS 178 and directed, i n part: On September 1, 1961, AD 61-18-3, issued by the FAA, became effective.

"* parts were f i t t e d t o the a i rc ra f t o r supplied as

to-fuselage attachment bolt chromium plated. Tests spare items with the bore of the hole fo r the main wing-

have shown tha t hard chrome plating reduces the fatique l i f e of the part. Therefore, the following inspection shall be accomplished:

(a) Wing lower root joint f i t t ings , P/N 4W.2nJ with 9.970 or l e s s hours' time i n service must be inspected at o r prior t o accumulating 10,000 hours' time i n service. Remove the lower main wing-to-fuselage attachment bolt and inspect the bore of the bolt hole f o r chromium plating i n

Sheet C t (104) No. 178 issue 1. Fi t t ings showing accordance with De Havilland Technical News

prior t o accumulating 10,000 hours' time i n service. evidence of chrome plating must be replaced

(b) Fi t t ings exceeding M."

- 8 -

The manufacturer, on September 21, 1964, issued a revised TNS 168, il

$ssue 3, which discussed an inspection.for corrosion and f r e t t i ng of $4

the main lower root joint f i t t i ng . This TNS also prescribed the actions.) 'to be taken t o minimize these problems. Based on th i s TNS, the FAA 'issued AD 67-32-3, effective December 18, 1967. The intent of t h i s AD : was t o prevent fatigue fa i lu re of the main wing lower root joint fitting.'" The AD established an inspection interval of 6 years o r 5,400 flying hours, whichever occurred f i r s t .

I n 1965, TAG Airlines sent N2300H t o an FAA Authorized Repair Station t o have major maintenance performed on the structure. A Major Repair and Alteration Form (FAA Form 337) was issued by the repair agency as a part of th i s maintenance procedure. Specifically l i s t ed on t h i s form were the following entries: 1 "Installed de Havilland modifications No. 779 and 780."

"Complied with de Havilland Technical News Sheet CT(104), No. 168 Issue 3, dated 21-9-64."

* + + * x *

"Total a i rcraf t hours t h i s date: 4998:50"

A handwritten notation jus t below the above-typed entr ies was:

"Comprising AD Notes 61-11-3 & 61-18-3 DC"

were entered, the following notation, i n part was: In the block on the a i rc ra f t logsheet where corrective actions taken

"Kt-10-65 Complied with Mods 779 & 780, Complying also with TN-No.

AD 61-18-3. I n s t l of Mods 779 & 780 Comply's with AD 168 iss. 3 New pins were insta l led which complys with

61-11-3. * * P The entr ies on the a i rc ra f t logsheet, the FAA Form 337 and the

handwritten notation were signed or in i t i a led by the same individual.

2. ANALXSIS AND CONCLUSIONS

structural separation had occurred. Evidence of a w a s apparent from the in i t i a t ion of t h i s accident investigation

panel; the heavily damaged l e f t wing; two holes through the ice; and the s t ructural fa i lu re included: the re la t ively undamaged outer right wing

sawing/cutting, chisel- like marks across the butt of the separated outer right wing panel. These cutt ing marks were a t the point where the right propeller would have struck the wing if the engine, with the propeller assemble attached, had pivoted around the outboard engine mount attack$ f i t t i ng . Additionally, the paint samples taken from the outer r ight wing surface and the wing's deicers t r ip were found t o be the same as the paint

US' r e as Th f o i n

WE 0 1 ir tl

E! hr

s1 f

f a#

W

e d

t E

i 1 I

- 9 - used on the a i rcraf t ' s engine nacelles, and the sample of black rubber residue from the wing's deicer s t r i p was identified as the same material

These indications strongly suggested the possibi l i ty that the causal area as the rubber deicer boots mounted on the shank of each propeller blade.

fo r the in-flight structural separation was the fa i lu re of the right, inboard engine mount attach f i t t i ng .

wever, upon resumption of the recovery of the wreckage, evidence d that the fa i lure had not been i n the engine mount attach f i t t i n g gine mounting frames.,,#The almost identical bending of both the

the attach f i t t i ngs had maintained s t ructural i n t e g i t y until the engine inboard and outboard engine mounting frames was a clear indication that

had. rotated almost 90" t o the right. \The frame tubing would not have

mount was the

against the firewall. It is apparent that if the engine mount attach flattening of the inboard engine mounting frame tubing as it was crushed

would not have been deflected t o the r ight a t the time o f impact. f i t t ings had failed, the framing would have gone with the engine and

if it had not been anchored t o the wlng structure. antiating evi-e 01 t m g r l t y VI

- explosion, or i n - f l i g h t fa i lure . All fractures were typical of fa i lures due t o overloads.

The examination of the fuselage structure revealed no evidence of f i r e ,

the wing was attached t o the fuselage a t impact and that the fl ightpath angle a t impact was 60" or greater.

The deflection and bending of the l e f t wing structure indicated tha t

There w a s no evidence of f i r e , in ternal d i s t ress or other operational distress i n e i ther engine. Blade angles of the propellers were determined t o be approximately 28'. Examination of the recovered engine mount components showed no evidence of in- fl ight separation due t o material failure or s t ructural weakness. -

hbviously, since the evidence established that the r ight outer wing was severed from the a i rc ra f t by the right propeller prior t o impact with the ice, the single component o r combination of components that would induce such a fa i lu re mode had t o be found. These conditions were

of recovery operations, of the fa i led right wing lower root joint at tach satisfied with the recovery from the lake, during the last scheduled day

fitting.1

" h e lower root joint attach f i t t i n g carried the ent i re load which is smitted from the fuselage t o the wing i n the ver t ica l lift/weight e. The fa i lure of t h i s f i t t i n g resulted i n the r ight wing folding

upward along a hinge l i ne at the fuselage.

eM'ine, when the right wing fai led upwards, caused the engine t o separate &om i ts mounting i n an apparent down and t o the r igh t movement. The

.dThe combination of i ne r t i a l and gyroscopic loading on the right

gine then passed across the bottom surface of the wing with the propeller t t ing through the structure, precipitating a complete wing fa i lu re at

&at point.,

- 10 -

f i t t i n g established it had fa i led through the 'f78-kri&&-ar b a t bole a t the inboard end of the part of the f i t t i n g that had been attached t o the wing. (See Attachment 1.) -%e-; .tbirr,, pa-&

all of the fracture surface OD, ane sic& ~~~~~~. .aaaal-.wma 50

break on the l a t t e r fracture was typical of t ens i le overl2ad. (See p e r c a t of the.arsa on the other side of the hole. The remainder of the

Attachment 2.) The tens i le overload evidence was present in' approximately 25 percent of the t o t a l cross sectional area of the fa i lu re face.

The metallurgical examination of the failed,lower root joint at tach

contSiparl:*lT~&~f-iagd.. s&MW-,f&tigue fa i lure across nearly

A metallurgical examination conducted on the failed root joint f i t t i n g confirmed that the f i n a l fracture o f the component was from tensi le over- load. This overload resulted from the s t ructural weakening of the component by the fatigue crack.

ejchibited a pattern of crazing cracks and nperous larger cracks which had penetrated through the chromium layer but had not entered the parent metal. The fatigue fa i lu re originated at the periphery of the hole i n a~ area where the chromium plate was chipped and irregular. (See Attachment

The bore of the bolt hole had been chromium plated and the plating

2.)

root joint f i t t i ng . There was no evidence of material defects i n the structure of the

chromium plating process and had reduced the "safe l i f e" of t h i s f i t t i n g t o 10,000 flying hours i n July 1961 (TNS 178). A t t h i s time, it was recommended that an inspection for the chromium plating of the root jo in t attach f i t t i n g be carried out at the next convenient opportunity and, i n

recommended that any f i t t i n g found t o have the chromium plating be any case, prior t o the accumulation of 10,000 flying hours. It w a s

changed at the next removal of the wing or before 10,000 hours, whichever came first. The above recommendation had the approval and concurrence of

mandatory f o r a i rc ra f t registered i n the United Kingdom but not for the United Kingdom's A i r Registration Board. These requirements became

those registered in the United States.

The manufacturer had long been aware of the problem caused by the

Aviation Administration issued Airworthiness Directive 61-18-3, effective Based upon th is recommendation by the manufacturer, the Federal

September 1, 1961. This directive repeated the opening preamble of the TNS 178 but adopted only the requirement t o inspect the f i t t i n g f o r chromium plating and t o replace it, if so plated, prior t o the accumulation of 10,000 flying hours. The recommendation t o replace any chromium plated f i t t i ngs at the next wing removal was not made a part of the requirement by the FAA on the U. S. registered ai rcraf t .

incorporation of modifications 779 and 780. An entry was made on the Repair and Alteration Form (337) and on the a i rc ra f t logsheet tha t AD 61-18-3 had been complied with. The logsheet entry stated erroneously that the incorporation of "new pins" complied w i t h "AD 61-18-3." It is

In November 1965, the wings of t h i s a i rc ra f t were removed for the

apparel interpl replacl s ta t io ] replac1 no exp

T at a t:

hours crack

limit since

inspec E?.% , w 3

platel J

re@ reaso: neces por t i these In or at 80 chang consi Dent man& f i t t i

impii r igh and "go> s i ze gram e i th or o eliu

2.2

rch lole .O

Y

he

tely

tting 3 1 -

< I t

'hment

5

3 t 1

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'e

Nmium

I

- 11 - apparent, from th i s entry, that the repah- s ta t ion personnel had m i s - interpreted the AD as requiring replacement of the pin as well as the replacement of any chromium plated f i t t ings . Persopnel of the repair station stated, during an interview, tha t they knew the f i t t i n g had t o be

no explanation fo r the incorporation of new pins? lb) replaced prior t o 10,000 hours, however, upon re-reailing the AD, they had

e r root joint attach f i t t i n g hail occurred I hours and the inception of the fatigue e point occurred within the last 4,386:51

hours af ter it was inspected. Both the t o t a l time on the part and the time since it was inspected for a crack are below the 10,000 hours "safe l i f e " limit (AD 61-18-3) and the 5,400 hour time period established for the i r inspection (AD 67-32-3). fl OW ;B iBw&hi t s established fo r the

yealisticdl,

As was noted ear l ier , the recomendation t o replace any chromium plated f i t t ings a t the next wing removal was no t made a part of the requirements of AD 61-18-3. It has not been possible t o document the reasons for noninclusion of th is requirement i n the AD. It is, of necessity, the prerogative of the regulatory agency t o accept all or portions of recommendations of a maufacturer and the decisions made in these cases can only be as good as the data supplied by the manufacturer. In order t o insure the maximum protection, it would seem, however, tha t a t any time the recommendations of the manufacturer are going t o be changed or modified, the more stringent of two alternatives should be considered as preferable. In t h i s particular instance, i f the require- ment t o change chromium pla tedf i t t ings at the next wing removal had been mandatory, it can be adduced that the fa i lu re of the fatigue-weakened f i t t i n g would, i n all probability, not have occurred.

'/ '

impinged on the bottom rear surface and f l ap of the re la t ively undamaged right wing outer panel. This matter was examined by the FBI laboratory and found t o be feathers from a Spinus Tristis, commonly referred t o as a "gold finch.'' This bird is resident of Eastern North America. The b i rd ' s size and weight, approximately 5 inches i n length and weighing 10 t o 1 5 grams, is not considered sufficient t o have damaged the a i rc ra f t structure,

or other remains or evidence of damage that could be related t o birds, either singly or i n small groups. The lack of any great number of feathers

eliminates t h i s possibi l i ty from the causal area.

During the early stage of the investigation, foreign matter was found

2.2 Conclusions

(a) Findings

1. The crewmembers were cer t i f icated for the duties they were performing.

2. The a i r c r a f t was cer t i f icated and the a i rc ra f t records indicated the a i rc ra f t had been maintained i n accordance with the exist ing company and Federal Aviation Administration regulations.

3.

4.

5.

6.

7.

8.

9.

10.

ll.

12 a

13 0

- 12 - The performance of the crew was not a factor i n this accident.

The weather was not a factor i n t h i s wcident.

The ATC handling and control of the flight were not factors i n t h i s accident.

A l l of the effective Airworthiness Directives issued by the Federal Aviation Administration had been accomplished.

Airworthiness Directive 61-18-3 required that chromium- plated wing joint f i t t i n g s were t o be replaced prior t o accumulating 10,000 hours but omitted the requirement t o change the f i t t i n g s at the "next wing removal" as had been recommended by the manufacturer.

During ai rcraf t modification i n 1965, the repair s ta t ion erroneously stated that the replacement of the pins had complied with AD 61-18-3.

The right, lower main wing-to-fuselage root attach joint f i t t i n g had a chromium-plated bore of the bolt hole.

The right, lower main wing-to-fuselage root attach joint fa i led i n f l igh t .

The wing portion of the wing t o fuselage root jo in t at tach f i t t i n g had a fatigue crack across 75 percent cf the fracture face.

The f i t t i n g had been i n use f o r approximately 9,384 flying hours e

The f i t t i n g had been i n use for approximately 4,387' f lying hours since it had been inspected for cracks.

(b) Probable Cause

the in- fl ight fa i lure of the lower, right, main wing-to-fuselage root j o i n t attach f i t t i n g result ing from undetected fatigue cracks i n the wing portion of the f i t t ing . The Board also finds that the Federal Aviation Administration's requirement for the timely replacement of chromium-plated' root joint f i t t i n g s was inadequate.

The Board determines that the probable cause of t h i s accident was

3 . RECOMMENDATIONS

Safety Board personnel during the i n i t i a l f i e l d phase of the investigation, the Federal Aviation Administration issued a precautionary telegraphic Airworthiness Directive pertaining t o the engine mount framing and engine momt pickup f i t t ings . This Airworthiness Directive superseded AD 55-20-1 and AD 65-20-2 which pertained t o the aforementioned components.

On February 3, 1970, and a f te r discussions with National Transportation

I ment f time 1: mount of the withir inter1 correc

I the r' Board fitti: in teg

/ for ' c hours ChrOII

p t e l e f nonck h i s E

Admix until in i t : dinal Regit airc: flow mot1 furt!

bore remu

Past

crac the 25 f

or 3

!

- 13 - In essence, the telegraphic AD shortened the previous X-ray require-

ment for the engine mount framing from a byea r t o a 2-year interval. The time between visual inspections of the engine mount framing and engine mount pickup f i t t i n g was also reduced. I n addition, a visual inspection

within 25 hours of service. If, during t h i s inspection, indications of of the engbe mount framing and engine mount pickup f i t t i n g was required

internal corrosion, cracks, or s t ructural defects were found, immediate corrective action w a s required before further flight. 4

On May 27, 1970, af te r identification of the fatigue fa i lu re i n the right wing lower root jo in t f i t t i n g of the crashed aircraft , the Board recommended t o the FAA that an inspection of all lower root joint f i t t ings be made on an expedited basis t o determine the s t ructural integrity of the a i rcraf t and t o review the adequacy of AD 61-18-3.

/The Administrator issued a telegraphic AD ordering an inspection

hours of flight, but did not specify a check for and removal of the for corrosion, frett ing, or cracking of the f i t t i n g within the next 25

chromium-plated f i t t ings .

POn June 6, 1970, as a resu l t of the inspection required by the

nonchromim.plated f i t t i ng . On the basis of t h i s finding, he grounded telegraphic AD, an operator reported that a crack had been found i n a

his aircraft . Based on t h i s report, the Safety Board recommended t o the Administrator that he consider a similar action f o r all DH-104 aircraf t until an inspection of the f i t t i ngs could be made. The Safety Board also init iated action t o acquire the suspect f i t t i n g for examination. Coor- dination between the Safety Board, the FAA, and the United Kingdom A i r Registration Board resulted i n the suspect part being removed from the aircraft, delivered t o the Safety Board representative i n New York, and flown to England f o r exmination. In the interim, the Administrator issued another telegraphic AD requiring the inspection of the f i t t i n g prior t o further f l ight. This telegraphic AD, included the inspection for, and removal of, the lower wing root attach f i t t i n g s that had chromium-plated bores of the b o l t holes, or any f i t t i n g found t o be f r e t t ed or corroded past acceptable limits. k7

/

crack i n the nonchromium-plated f i t t ing , and the time requirements f o r The examination of the suspect part established that there was no

the inspection of this part were relaxed so as t o be accomplished within 25 flying hours. A repeat inspection cycle time of 2,500 flying hours or 3 years was also established.

BY THE NATIONAL TRANSPORTATION SAFETY BOARD:

/ s / JOHN H. REED Chairman

/s / OSCAR M. LAUREL Member

/ s f FRANCIS H. McADAMS Member

/ s / LOUIS M. THAYER Member

/ s f ISABEL A. BURGESS Member

-January 6, 1971. \

APPENDIX A

INVESTIGATION il. Investigation

The Board received not i f ica t ion af the missing TAG flight at approxi- mately 0840 e.s.t . on January 28, 1970, and confirmation of the accident at 0947. The decision t o dispatch a Washington-based invest igat ive team was made at 1045. The team departed Washington National Airport at 1330 and arrived at Cleveland's Burke Lakefront A i r p o r t at 1515.

surveyed the hole in the i c e pr ior t o establishing working groups. The Ut i l iz ing U. S. Coast Guard helicopters, the Board's invest igators

working groups were: Operations/Hman Factors, A i r Traff ic Control, Stmctures/Systems, Powerplants, and Aircraft Maintenance. A weather study was i n i t i a t ed i n Washington, D. C.

tion, TAG Airlines, and the A i r Line P i l o t s Association. Hawker-Siddeley

limited basis. (De Havillaad) was invi ted t o par t ic ipate and sent a representative on a

Par t ies t o the investigation included the Federal Aviation Administra-

-... and the moving i c e on Lake Erie. As a resul t , the on-scene investigation The recovery of wreckage was interrupted by exis t ing weather conditions,

\ ,

'&ad wreckage recovery were not completed u n t i l May 28, 1970.

2. public Hearing

There was no public hearing held i n t h i s case.

3. Preliminary Report

A preliminary report of the available f a c t s and conditions was adopted by the Board on March 18, 1970, and released t o the public on March 30, 1970

Flightcrew History

a. Captain Jake Feldman

Date of Birth: October 20, 1925 Height Weight

: 68 inches : 170 pounds

Captain Feldman held Airl ine Transport P i lo t Cert i f icate No. 1004985, airplane multiengine land, commercial privileges, and airplane single- engine land ratings. He also held a Class I medical ce r t i f i ca t e issued January 10, 1969, without l imita t ions or waivers. He had no s ignif icant i l lnesses or hospitalization i n the last 8 years. Captain Feldman's l a t e s t electrocardiogram reading was reviewed by the Aeromedical Cert i f icat ion Branch i n Oklahoma City with negative resu l t s .

Captain Feldman was employed by TAG Airl ines i n May 1965. He was previously employed by Boone County Aviation i n Cincinnati, Ohio, and by Zantop/Capitd Airways/Aaxico. His t o t d f ly ing time was approximately 10,200 hours, of which 2,000 hours were i n the DH-104 a i r c r a f t . He had flown 272:17 hours during the last 90 days (October t o December) and 60:49 hours since January 1, 1970. During the past 24-hour period, he had flown 2 hours and 9 minutes. Captain Feldman's crew r e s t period was 18 hours and 30 minutes. His most recent proficiency check on the DH-104 was passed on November 26, 1969. He was also route qualif ied on November 26, 1969. Both checks were given by Captain John A. Lyszczyk, an FAA-designated company check p i lo t .

April 26, 1969. His l a t e s t FAA administered f l i g h t check was f irst Captain Feldman's annual recurrent ground school was completed on

taken January 4, 1968, i n a Piper Aztec and retaken on January 8, 1968 because of inadequate techniques on autopilot , f l i g h t maneuvers and other procedures.

b. F i r s t Officer Robert Grant Arthur

Date of Birth: August 13, 1943 Height Weight

: 72 inches : 190 pounds

~r . Arthur held Commercial P i lo t Cer t i f ica te No. 1708036 with ra t ings ASm, Flight Inst ructor - Airplane and Instruments. He also held a Class I medical ce r t i f i ca t e issued April 8, 1969, without waivers o r l imitations. No s ignif icant i l lnesses o r hospitalization were recorded i n h i s medical records.

previous employment had been with Beaver Aviation, Beaver Falls , Pennsylvania, as a f l i g h t instructor, and as a high school teacher i n Rochester, Pennsylvania. His t o t a l f lying time was approximately 1,475

Mr. Arthur had been employed by TAG Airl ines since April 1969. His

- 2 -

hours, of which approximately 700 hours were i n the DH-104. His recent f ly ing experience was essental ly the same as t h a t of Captain Feldman: 268:3 hours during t h e last 90 days, 46:47 hours since January 1, 1970,

was 18 hours and 30 minutes. and 2:O9 hours during the last 24 hours. Crew rest prior t o t h e accident

He was given a competency check on June 19, 1969, i n the DH-104 by Captain Robert D. Bellenbarn, company chief p i lo t . Annual recurrent ground school was occomplished on May 6, 1969. Mr. Arthur was checked out as a copilot on the DH-104 on April 3, 1969, by Captain L. Gossen, company check p i lo t .

Mr. Arthur received monthly proficiency ra t ings by Captain Feldman.

:nt

70, ident

l a n . tptain ichool j i lo t t i lo t .

APmNbIx c

Aircraft History

a. Aircraft

The aircraft, a De Havilland Dove Model DH-104-6A, s e r i a l No. 04444 w a s manufactured by De Havilland Aircraft Company-, Ltd., i n 1953. It w&s placed in to " l ine service" by TAG Airlines, Inc., on December 5, 1963. The "II" number was changed from 1588V t o 230OH, and the a i r c r a f t model changed from a DH-104-6A t o a DH-104-5A. These changes were signed off as completed on May 28, 1 9 4 .

An FAA Operating Cer t i f ica te No. 5-CE-30 for A i r Taxi Commercial Operators was issued on August 23, 1968, t o TAG Airlines, Inc. The

135 and w a s maintained i n accordance with FAR Part 43, using a 100- a i rc ra f i was operated under Federal Aviation Regulation (FAR) Part

hour and annual inspection system.

hours. The last postf l ight inspection had been performed on January 27, 1970, at an a i r c r a f t time of 9,383:41 hours. The last 100-hour inspection was performed on January 15, 1970, at an a i r c r a f t time of 9,347:52 hours. The last annual inspection was completed on May 23, 1969, at an a i r c r a f t time of 8,677~34 hours. The last weight and balance calculation was accomplished on January 15, 1970, with an empty weight of 6,207.5 pounds, a 6.47 inch center of gravity, and a maximum gross weight limit

The t o t a l aircraft time, at the time of the accident, was 9,383:52

of 8,800 pounds.

completeness in the relat ionship of work accomplished and signoff by Federal Aviation Administration licensed maintenance personnel. A i r - worthiness Directive compliance w a s found t o be within the prescribed time limits, as were the 100-hour and annual inspection.

The company maintenance records ref lec ted a general continuity and

b. Engines

was ins ta l l ed i n the No. 1 posit ion and s e r i a l No. 66822 was ins ta l l ed The De Havilland Gipsy Queen Model 70 MK2 engine s e r i a l No. 66182

i n the No. 2 position on September 18, 1969, at a t o t a l a i r c r a f t time of 8,998:02 hours. Both engines had a zero time since overhaul (TSO) at the time they were ins ta l l ed and had accumulated 435:50 hours since ins ta l la t ion.

e. Propellers

The propellers were De Havilland Model No. PD 143-312-7. Propeller hub s e r i a l No. A12055 with blade s e r i a l Nos. BA-515, BA-520, and BA-525, with TSO's of l,27O:52 hours, was i n s t d l e d i n the No. 1 position.

a-264, with TSO's of 1,026~52 hours was, ins ta l l ed i n the No. 2 postion. Propeller hub serial No. 12216 with blade s e r i a l Nos. BB-120, BA-217, and.

Both propellers were ins ta l l ed on September 18, 1969, at a t o t a l a i r c r a f t time of 8,947:02 hours.

Attachment 1

Right Outer Wing Section as recovered from Ice floe.

View of r igh t i nne r wing section lay out from r ib station No. 1 outboard to the area between r i b stations Nos. 9 and 10.

1. Engine mount framings. 2. Section of top wing skin with fuel tank cap assembly attached. 3. Bottom main spar to fuselage attach fitting. 4. Area of wing separation. 5. Crushed leading edge of wing outboard of engine. 6. Right engine nose cowl panel.

ATllACHMENT 2

,Fractures

FAILED WING ATTACHMENT FITTING FROM TAG AIRLINES DOVE, N2300H

SURFACES OF THE FRACTUMS IN THE FAILED FITTING

"0" - Points where the fatigue

"F" - Fatigue fracture areas. "I" -

fractures originated.

Instantaneous overload fractures.

7lOM

I