This manual probably accompanied the AVG Tomahawks to Rangoon. It was published by the British Air Ministry, and the title page says Tomahawk I. However, internal evidence (the engine designation and references to the RAF blocks from which the China-bound Tomahawks were taken) tie it to the Tomahawk IIBs sent to Burma for the AVG. There is also some internal evidence (including references to French instrumentation) that the text was not brought entirely up to date.
I copied it in 1989 at the National Air & Space Museum, which in turn had copied it from Larry Pistole's large collection of AVG memorabilia. Pistole's collection was later acquired by the Flying Tigers Association, and NASM's copies somehow went missing, so this is the only version known to be accessible.
I follow the original as exactly as possible, including spelling and typography. Words in brackets [like this] have been added. Comments beginning DF: are mine; those beginning ES: are by Erik Shilling, a pilot with the AVG. Erik's comments (with other information) seem to suggest that the planes sent to China may have had components of older aircraft installed, possibly so Curtiss could use up its inventory of parts, and that the planes were actually closer to IIA models than the IIBs shown in Curtiss records. -- Dan Ford
FOR OFFICIAL USE ONLY
AIR PUBLICATION 2013A
ALLISON V-1710-C15 ENGINE
1. The Tomahawk I is a single-seater, low wing, monoplane with retractable landing gear and enclosed cockpit, powered with an Allison V-1710-C15 engine, which drives a Curtiss multi-position, constant speed, electrically operated, tractor propeller. The following are the main dimensions:
Span 37 ft., 3 1/2 in., Overall length 31 ft. 8-9/16 in.
Overall height with tail down 9 ft., 7 in.
2. The cockpit is totally enclosed. The windscreen is in three sections of laminated glass and behind the windscreen there is a section of 1-1/2 inch glass for protection from gunfire. The transparent cabin cover slides fore and after for entry and exit purposes. An emergency release is provided by which the entire sliding section has an emergency exit on the port side, for us in event of turnover. The structure behind the pilot is of sufficient strength to withstand a turnover landing. Three pieces of armor plate are provided; one piece 7 mm. thick ahead of the pilot from the windscreen line down to the top of the engine, a piece 7 mm. thick behind the pilot's back, and 9 mm. thick behind his head.
3. The main plane is a cantilever multi-spar, skin stressed type built in two pieces and joined at the centerline of the airplane. The wing tips are detachable. The joint where the two wing sections are connected will serve as a skid in case of an emergency landing with the wheels retracted.
The ailerons are both dynamically and aerodynamically balanced. They are operated by the conventional stick control. A fix type trimming tab, adjustable in the ground is provided on each aileron. The ailerons have a stressed metal skin leading edge and are fabric covered.
The flaps are of the split trailing edge type, extending from the aileron to near the centerline of the airplane and are operated hydraulically by an electrically driven pump or by an emergency hand pump. An indicator on the instrument boards shows the position of the flaps at all times when the battery switch is on.
4. Cooling system - Air passing through prestone radiators and oil cooler and exhausting into a common exit duct. Airflow through this duct is controlled by cowl flaps operated by a lever on the starboard side of the cockpit with a locking device incorporated.
5. Wing Guns - Two rifle caliber guns may be carried in each panel. Wing gun charging handles are located on the centerline of the airplane beneath the instrument panel. Ammunition boxes hold 500 rounds per gun. The trigger switch is located on the stick.
6. Fuel Tanks - The fuel is carried in three tanks two in the center of the wing and one in the fuselage aft of the pilot. The total capacity of the three tanks is 132.6 imperial gallons. (See fuel system diagram.) All fuel tanks have "Superflexit" covering. [DF: See Erik's comments in Part II about fuel tanks. The reference to Superflexit suggests that the Tomahawk IIB had an exterior membranes. At first I believed that this was a carry-over from an earlier version of the manual, but it tracks with Erik's recollection.]
Oil Tank - Oil is carried in a 12.7 imperial gallon tank in the fuselage behind and above the fuselage fuel tank. Climbs up to 60° and dives up to 90° should be performed only with not less than 1/3 of the maximum oil capacity. The tank should be refilled to 9.6 imperial gallons maximum service capacity at all times.
Coolant Tank - The coolant expansion tank is forward of the firewall and has a capacity of two imperial gallons.
7. The fuselage is of semi-monocoque, skin stressed construction, and has a motor mount of welded steel tube and steel forged links. The fuselage access door is on the port side of the fuselage near the tail.
8. Fuselage Guns - Two synchronized guns may be carried just ahead of the pilot. These are .50 caliber Colt guns, and are charged directly through an opening on each side of the instrument panel. Electrically operated rounds indicator are mounted near the instrument board on the upper longeron. The gun triggers are electrically operated by a selector switch located above the port longeron, and the trigger switch is located on the stick. Ammunition boxes hold 380 rounds per gun.
9. Battery - a 34 ampere hours capacity, 24 volt battery is carried in the airplane and is accessible through the fuselage access door.
10. Landing Gear - The landing gear is equipped with oleo-pneumatic shock struts which are hydraulically retracted to rotating backward about a trunion at the top of the strut. During retraction the strut is rotated 90° about its longitudinal axis by gears, so that the wheel lies flush in the wing. The gear is locked in both the up and down positions by hydraulically operated mechanical locks. The upper half of the strut has members attached to take side and drag loads and is attached to the lower half of strut through a scissors to take torque. The landing gear is equipped with 30 inch diameter smooth contour tires and wheels with 12 x 2 1/4 inch hydraulic brakes. An indicator on the instrument panel shows the position of the landing gear at all times when main battery switch is turned on.
11. Tail Wheel - The tail wheel assembly consists of a standard steerable knuckle unit and a 12 1/2 inch heel with earth conducting tire. The steering mechanism disengages at approximately 35° deflection from the longitudinal axis and when disengaged will swivel through 360°. The tail wheel is fully retractable and operates "clam shell" doors which enclose it completely after retraction. An indicator on the instrument board shows the position of the tail wheel at all times when the battery switch is turned on.
12. Fixed Tail Surface - The tail plane and fin are of all metal constructions attached in fixed alignment to the fuselage.
13. Control surfaces - The rudder and elevators are aluminum alloy construction, fabric covered. They are dynamically balanced and are equipped with trim tabs controlled from the cockpit. Rudder and elevators are controlled by the conventional pedals and stick.
14. Additional Equipment - In addition to the armament, the airplane is equipped with parachute flares, landing light, recognition device, oxygen, life preserver, radio, map case, engine and cockpit covers, navigation, formation, identification and cockpit lights. (See Section 1.)
15. Tie Down Rings are located inboard of the wing tips on the underside of the wing and marked "Tie Down".
16. Tool Box - A tool box for carrying the airplane and engine tool kit as an overload is provided in the fuselage and is accessible through the fuselage access door.
17. First Aid Kit - is located on the port side of fuselage being accessible through fuselage service door.
18. Propeller - The propeller is a Curtiss multi-position and/or constant speed type. The propeller is operated electrically from the airplane electrical supply thru brushes mounted in a housing, attached on the engine section, to slip rings mounted on the rear boss of the propeller hub, and thence to the pitch changing motor.
Automatic electric cutout switches limit the pitch range for ordinary operation and give high and low pitch settings.
Two types of control, manual selective and automatic, are
available for selection by the pilot. The change from one to the
other is made by a toggle switch located on the propeller control
panel. (See Section 1, para. 11).
Next: Pilot's Controls and Equipment