Blenheim IV
Cliffs of Dover
History
The Blenheim during the Battle of Britain
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The Blenheim units operated throughout the battle, often taking heavy casualties.
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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;
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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.
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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.
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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.
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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 Data
Maximum takeoff power to 1000ft, 3 minutes limit:
with 100 octane fuel (outer tanks):
+9 boost
2750 RPM
with 87 octane fuel (inner tanks only):
+5 boost
2650 RPM
Max. climb power, 30 minute limit:
regardless of fuel octane rating
+5 boost
2650 RPM
cylinder head temps (CHT) at 210C
oil temps at 80C
Max. continuous power (no time limit) for rich mixture:
regardless of fuel octane rating
+3.5 boost, 2400 RPM
CHT at 190C
oil temps at 70CMax. continuous power (no time limit) for
weak (lean) mixture:
regardless of fuel octane rating
+1.5 boost
2400 RPM
CHT at 190C
oil temps at 70C
Max. all out limit (war emergency power):
with 100 octane fuel:
+9 boost, 2750 RPM
CHT at 235C, oil temps at 90C
30 minutes time limit
Indicated Airspeed (IAS) restrictions:
Diving 325 mph
Gear down 140 mph
Flaps down 125 mph
Diving Restrictions:
maximum boost +5
maximum RPM 3120
exceeding 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 degrees
Climb 40 degrees
Bank 10 degrees
Exceeding these during a bomb drop probably means
that your bombs will bounce around inside your own
aircraft.
with 87 octane fuel:
+5 boost, 2750 RPM
5 minutes time limit
This is my first flight in a twin engine plane. What extra controls do I
need to operate the Blenheim IV?
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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
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Open starboard and port fuel cocks
– One click, outer tank
– Two-clicks, inner tank
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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
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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.