Blenheim IV

Cliffs of Dover

HistoryThe Blenheim during the Battle of Britain

• The Blenheim units operated throughout the battle, often taking heavy casualties.

• The Blenheim units raided German occupied airfields throughout July to December 1940, both during

daylight hours and at night. Although most of these raids were unproductive there were some successes;

– on 1 August five out of 12 Blenheims sent to attack Haamstede and Evere (Brussels) were able to

bomb; destroying or heavily damaging three bf 109s of II./JG 27. Two other bf109s were claimed by

Blenheim gunners.

– Another successful raid on Haamstede was made by a single Blenheim on 7 August which destroyed

one bf109 of 4./JG 54, heavily damaged another and caused lighter damage to four more.

• There were also some missions which produced an almost 100% casualty rate amongst the Blenheims; one

such operation was mounted on 13 August 1940 against a Luftwaffe airfield near Aalborg in north-eastern

Denmark by 12 aircraft of 82 Squadron. One Blenheim returned early (the pilot was later charged and due

to appear before a court martial but was killed on another operation), the other 11, which reached

Denmark, were shot down, five by flak and six by bf 109s.

• As well as the bombing operations, Blenheim-equipped units had been formed to carry out long-range

strategic reconnaissance missions over Germany and German-occupied territories. In this role, the

Blenheims once again proved to be too slow and vulnerable against Luftwaffe fighters and they took

constant casualties.

Introduction to crew positions

Press C to move between positions

Introduction to Crew Positions

Bombardier

Turret Gunner

Alt-F to move to firing position

Cockpit Controls

Pilot view to lower left

Throttle Quadrant

Pilot view over right shoulder

Pilot view to lower right

Pilot view to upper left

Pilot view to lower left

Carburettor Heat

Carburettor heat use:

Set to on:

a. For all flying at less than +3.5 boost, unless the ambient air temperature is above +15C. When it is higher than +15C, turn it off regardless of boost settings. (Magpie note: Suggest above 2,500ft. Dover average summer daylight temperature 20C, temp reduces by 13C per 6500ft, 1C per 500ft) .

b. For all flying (irrespective of boost and atmospheric temperature) in conditions of high humidity, in or just below clouds, in rain, snow or sleet. It can also be used to help warming up the engines in very cold weather.

Set to off for all other conditions including:

a. Engine start at all times.

b. Take off.

c. Landing, except in the high humidity conditions.

Technical DataMaximum takeoff power to 1000ft, 3 minutes limit:with 100 octane fuel (outer tanks):+9 boost2750 RPMwith 87 octane fuel (inner tanks only):+5 boost2650 RPM

Max. climb power, 30 minute limit:regardless of fuel octane rating+5 boost2650 RPMcylinder head temps (CHT) at 210Coil temps at 80C

Max. continuous power (no time limit) for rich mixture:regardless of fuel octane rating+3.5 boost, 2400 RPMCHT at 190Coil temps at 70CMax. continuous power (no time limit) for weak (lean) mixture:regardless of fuel octane rating+1.5 boost2400 RPMCHT at 190Coil temps at 70C

Max. all out limit (war emergency power):with 100 octane fuel:+9 boost, 2750 RPMCHT at 235C, oil temps at 90C30 minutes time limit

with 87 octane fuel:+5 boost, 2750 RPM5 minutes time limit

Indicated Airspeed (IAS) restrictions:Diving 325 mphGear down 140 mphFlaps down 125 mphDiving Restrictions:maximum boost +5maximum RPM 3120exceeding 2750 RPM permitted only for 20 seconds with the throttle not less than 1/3rd of the way open

Clearance for bomb drop with 500lb bombs (no idea about the 250lb ones):Dive 55 degreesClimb 40 degreesBank 10 degreesExceeding these during a bomb drop probably means that your bombs will bounce around inside your own aircraft.

This is my first flight in a twin engine plane. What extra controls do I need to operate the Blenheim IV?

• Select engine 1, 2 and all• Open/Close Bomb Bay Doors• Drop Bombs• Carburettor Heat On/Off• Suggest assign keys to awkward to click controls. Personal

preference here, but I would suggest the following:– Radiator Open/Close

– Propeller Pitch Increase/Decrease

– Slow-running Cut-Out

What controls need to be keyed?

Start-up Procedure

• Open starboard and port fuel cocks– One click, outer tank– Two-clicks, inner tank

• Open Radiator 100%

• Turn magnetos on (four)

• Check fuel mix is at normal (52%)

• Check fuel gauges

• Set propeller pitch to 100%

• Throttle to 10%

• Select engine one, prime engine, ignition (i)

• Select engine two, prime engine, ignition (i)

• Select both engines.

• During warm-up period set compass and directional gyro.

Take-Off Procedure

• When engines have warmed to 100C, apply full left rudder, advance throttle carefully and taxi towards airstrip.

• Always be aware of engine temperature.

• Continue to apply full left rudder once commencing take-off roll.

• Rotation at 90mph

• Landing gear up immediately airborne.

• Reduce RPM via throttle or propeller pitch to prevent over-heating

• Fly level until airspeed builds up

• At 130mph adjust propeller trim to 0%

• Reduce radiator cowling as temperature cools, cruise between 190-210C.

• Trim rudder and elevators so a cruise of 220mph is attained.