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I WAS SORTING through one thing and another when I came upon the British Air Ministry’s 1943 Air Publication 1565K, Spitfire F XII Pilot’s Notes.
The Supermarine Spitfire single-seat fighter was produced in greater numbers than any other British aircraft of its era. A total of 20,351 of these aircraft were built between 1938 and 1948. Twenty-four different Marks were produced, the XII being the first powered by the Rolls-Royce Griffon engine, as opposed to earlier versions, most of which had Rolls-Royce Merlins.
Regardless of the Spitfire Mark, its pilot had plenty of gizmos to identify in the cockpit. For example, Nos. 60 and 61 on the starboard side were the master switch and pushbuttons for Identification Friend or Foe. IFF was a byproduct of radar and gave automated interrogation and response of friendly aircraft. Failure to respond implied it might be, albeit not necessarily, a foe.
Starting the engine. Like other engines of the era, the Spitfire’s Griffon used a cartridge starter in lieu of an electric system. The impulse of firing a shotgun-like cartridge forced one of the engine’s 12 pistons downward, initiating engine rotation. The Pilot’s Notes specify different cartridge types depending upon ambient temperatures, above or below 10 degrees Celsius/50 degrees Fahrenheit.
Take-off. The Spitfire F Mark XII’s “aircraft controls, including the undercarriage [Brit for landing gear], flaps and brakes, are identical with those of earlier Marks.”
A critical difference is noted, however: The Mark XII check list for take-off includes setting the rudder trimming tab to ”Fully left.” Also, on take-off, “Open the throttle slowly up to +7 lb./sq. in. boost only. This is important, as otherwise there is a strong tendency to swing right in the initial state (note that the swing is opposite to that of Merlin marks).”
Though not explicitly stated in the Pilot’s Notes,, this reaction seemed likely related to the direction of prop rotation being opposite for the two engines. There’s a long discussion of this at Griffon vs Merlin rotation. An interesting tidbit there suggests propeller vortex, not a reaction to engine torque, is responsible for this behavior.
General flying. “Rudder control is heavy, and changes of power and speed cause changes in directional trim which require frequent adjustment of the rudder trimming tab. Aileron control is very light.”
Item No. 44 on the cockpit’s port side is that oft-employed rudder trimming tab handwheel. No. 26, a crowbar, is part of the emergency equipment.
“Pending readjustment of the carburettor, engine cutting may occur in tight turns at high boost and low r.p.m. At + 4 lb./sq. in. boost at least 2,400 r.p.m. should be used to overcome this.”
As with many other carb-equipped World War II aircraft (only some German World War II planes had fuel injection), this sensitivity of fuel delivery had its effect on aerial maneuvering. Initiating a dive with a wingover was one way to avoid this momentary fuel anomaly.
Spinning. “Spinning is permitted and recovery is normal, but the loss of height involved in recovery may be very great and the following limits are to be observed: (a) Spins are not to be started below 10,000 feet. (b) Recovery is to be initiated before two turns are completed.”
“Spinning is not permitted when fitted with a drop tank or when carrying a bomb.” In truth, hitherto I thought a spin was an aircraft’s perverse reaction; I didn’t realize it was considered a pilot’s voluntary maneuver, except for acrobatic fun.
Flying limitations. And, sure enough, the Pilot’s Notes reemphasized, “When fitted with a drop tank or bomb, spinning is not permitted and violent manœuvres must be avoided. The angle of dive, when carrying a bomb, must not exceed 40 º.”
These Pilot’s Notes for Spitfire F XII certainly add to my admiration of the brave young men who flew these machines. Deadly combat isn’t even given a mention. ds
© Dennis Simanaitis, SimanaitisSays.com, 2016