Curtiss P-40 Tomahawk User manual

P-40 Tomahawk manual
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 Royal Air Force blocks from which the China-bound Tomahawks were
taken) tie it to the Tomahawk IIBs sent to Burma for the AVG. On the other
hand, there is also some internal evidence (i.e., references to French
instrumentation) that the text was not brought entirely up to date, and
that some paragraphs may apply to the Tomahawk I or IIA models.
I copied the manual in 1989 at the National Air & Space Museum, which in
turn had copied it and other material 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 by the webmaster; those beginning ES: are by Erik
Shilling, a pilot with the AVG, who read the manual with an eye to
comparing it with his memory of the AVG Tomahawks. 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. --
FOR OFFICIAL USE ONLY
AIR PUBLICATION 2013A
Pilot's Notes
PILOT'S NOTES
TOMAHAWK I
ALLISON V-1710-C15 ENGINE
INTRODUCTION
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 4x 4 Šeach 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. I earlier believed that this was a
mistaken carry-over from the I or IIA 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.
Updated:
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).

Pilot's manual for the Curtiss Tomahawk (cont'd)
Stuff in brackets [like this] has been added. Those beginning ES are by Erik
Shilling, a pilot with the
AVG 3rd Squadron.
SECTION 1
Pilot's Controls and Equipment
Introduction
This section gives the location and, where necessary, explains the
function of the controls and equipment in the pilot's cockpit.
NOTE: On aircraft Nos. A.H. 741 to A.H. 970 inclusive certain of the
electrical switches are "on" when in the "Up" position and care should be
taken to identify these. All switches are clearly marked "Off" and "On".
1. Cockpit - The cockpit is fully equipped and has the normal stick and
rudder pedal controls which are dealt with individually in the following
paragraphs. The sliding hood can be pushed right back from the cockpit and
is operated by a crank mounted on the upper right longeron. A pin on the
crank engages hole sin the drum and locks the cabin in the full back, full
forward and intermediate positions.
An emergency hood release is also fitted and is a lever painted red,
located at the top forward frame of the cabin roof. In case of an
emergency, while in flight, the entire enclosure may be released from the
fuselage by pulling on this lever. In the event of turnover on the ground,
pull the panel release handle and push open the emergency exit on the left
hand side of the cabin enclosure. This emergency exit may be operated from
the outside by means of a handle located on the lower rear left hand cabin
frame.
An emergency release which disengages the catches from the crank is
located at the top of the windshield and consists of a turnbuckle and wire
painted red. This eliminates winding the crank for rapid opening but the
enclosure must then be pushed back by hand.
A ventilator for the cockpit is operated by a push-pull control located
below the instrument board on the port side. When the control is pulled
out hot air is admitted to two vents,: one permitting hot air to enter
directly into the cockpit, the other deflects the hot air between the
windscreen and bulletproof safety glass, acting as a defroster, before
passing into the cockpit.
2. The seat is adjusted vertically by a lever on the starboard side of the
seat. The lever is moved upward and to the rear permitting the seat to be
raised manually. A release lever controlling the position of the pilot's
harness belt is provided at the port side of the seat. To operate, push
button on top of lever and move lever to rear locking position. This
permits free movement of the pilot in a fore and aft direction. A pilot's
relief tube is suspended from the bottom of the seat.
3. Control Column - The control column is of the conventional design. The
control column hand grip has two switches; the one on the top of the grip
is a push button and operates the landing gear; the other is a trigger
switch and operates the firing of the guns. [ES: Ours did not have the top
button. The hydraulic switch was a light weight switch just below the
pistol type control handle, and operated by the little finger.]
4. Rudder Pedals - The rudder pedals are of conventional design and they
are adjustable for leg reach by releasing a pin by means of the lever on
the inboard side of the pedal, and moving forward or aft as required.
5. Brakes - Brakes are operated by toe pedals and the parking brake lever

is located below the instrument board and may be engaged by being pulled
back when the pedals are depressed. It is automatically disengaged when
the pedals are depressed.
6. Trim Tabs - The adjustable trim tabs for the rudder and elevators [sic]
controls are located at the port side of the cockpit near the pilot's
seat, and work in the same plane as the controls concerned. The elevator
wheel has a crank handle for rapid adjustment. Dials at the hand wheels
indicate the positions of the tabs. [ES: the ailerons [also had] a cockpit
trim control which was located in front and just below the rudder trim
vertical to the rudder trim.]
7. Retractable Landing Gear - The retractable landing gear is operated
hydraulically by either the emergency hand pump or the electric pump. An
operating instructions plate is locate don the left hand side of the
cockpit. On aircraft Nos. A.H. 741 to A.H. 999 and A.K. 100 to A.K. 155
inclusive, a selector lever extends forward along the port side of the
cockpit and has a push button on the end which must be depressed to move
the handle from neutral. (The handle may be returned to neutral without
depressing the button.)
To retract the landing gear depress the button on the end of the handle,
and raise the handle to the "Up" position. Then operation the electrical
pump by pressing the switch button on the top of the control column. As a
precaution the gun selector switch should be "Off" in case the trigger
switch is squeezed by mistake. The switch must be held "On" during the
period required for the retraction of the landing gear. To lower landing
gear move handle to down position and operate switch button as before.
[DF: Note what Erik says above, that on the AVG Tomahawks the button on
top of the stick was replaced by a toggle below the pistol grip.]
NOTE: - On aircraft A.K. 156 and onwards the push button on the
undercarriage selector lever is replaced by a safety latch bolt which must
be pulled forward before the lever can be moved.
To ensure positive engagements [sic] of the locks, the switch should be
held on for a few seconds after the indicator and the warning horn show
that they are down. As a final check the pilot should try and move the
hand pump lever on the right hand side of the cockpit. If this lever
cannot be moved, except by a high load which brings the hydraulic bypass
valve into operation, the pilot can be sure that the landing gear is
locked down. The selector lever should then be raised to its neutral
position. This hydraulic valve control lever should be in neutral when
taking off or landing.
An indicator on the instrument board indicates the position of the landing
gear whenever the battery switch is turned "On." A warning klaxon which
operates when the throttle is closed with the wheels retracted, is only
connected to the locks and consequently will sound when the wheels are
down if the locks are not engaged.
This klaxon circuit is controlled through a toggle switch which is mounted
just ahead of the throttle quadrant and is actuated by a cam mounted on
the throttle rod. This came may be pulled out to turn the klaxon off
temporarily during a throttled dive with the wheels retracted. It engages
automatically when the throttle is opened to the stop.
Emergency operation: In the event of the electrical system failing, select
the required position for the undercarriage on the selector lever and
operate hand pump on right hand side of the cockpit.
Warning - Never operate pump with selector lever in "Up" position when
airplane is resting on its wheels.
[ES: In the event of electric failure the gear was dropped by operating
the emergency hydraulic hand pump. In the event of a hydraulic failure,
the handle was removed from its normal position, and placed on a second
position outboard of the normal position. In this position, would direct
pressure to the main gear and lower the mains, but it would not lower the

tail wheel which was left retracted.]
Before starting engine or taxiing, check landing gear lock by shifting
selector to "down" position and operating the hand pump until it is solid
to fore and aft movement. Return valve lever to neutral position.
8. Wing Flaps - The wing flaps are operated hydraulically by either the
hand pump or an electrically operated pump. The selector handle is located
on the port side of the cockpit beside the pilot's seat and moves fore and
after; - forward for "Down" and after for "Up" and neutral for "Off". The
hand operated hydraulic pump (see para. 7) may be worked back and forth to
raise or lower the flaps after the up or down position has been selected
on the handle. The flaps may be operated manually in order that partial
setting may be obtained more easily. With aid loads on the flaps they will
close automatically as soon as the selector switch is moved to the "Up"
position.
[ES: our flap control lever had a push button on the end which had to be
depressed in order to move the flap handle out of the neutral position.
When placed in the up position, the little finger was used to turn on the
electric hydraulic pump. The same switch was used to acctuate the
hydraulic pump both for the Flaps and Gear.]
NOTE: - Flap selector lever cannot be set to "Up" position until
undercarriage lever has been returned to neutral. [ES: We did not have
this type of flap control.]
9. Undercarriage and Flap Position Indicator - The position indicator is
located on the lower port side of the instrument board. The wheel and flap
images simulate the actual position of the landing wheels, tail wheel and
flaps. The images disappear from view when the electrical power is off,
thereby indicating failure of the instrument, or open battery or generator
circuit. The batter switch must be "On" to maintain operation of the
indicator. The battery switch should be "Off" before leaving the airplane.
Engine Controls
10. Throttle Quadrant - The throttle, automatic mixture and propeller
controls are located on the throttle quadrant. The mixture control locates
the automatic rich and automatic lean positions. Approximately the last
10° movement of the "lean" mixture on the quadrant is the engine "idle
cut-off" position. There is a spring stop included to prevent mixture
control from entering the "idle cut-off" position when normal pressure is
applied.
11. Airscrew Operating - This may be either "Automatic or "Manual
Selective". When on automatic control, a selected engine speed is held
constant by an engine driven governor. Speed selection is accomplished by
adjustment of the propeller control on the throttle quadrant, and the
toggle switch on the propeller control panel is in the "down" or "on"
position.
When on manual selective control, that is with switch in "Hand control"
position, the propeller acts as a controllable pitch propeller by the
operation of the "Increase R.P.M.", or "Decrease R.P.M." switch. Circuits
are independent of the governor so that if the governor fails the
propeller can be used as a multi-position controllable propeller.
Since the markings on the propeller control are for approximate settings,
the tachometer should be relied up to obtain the desired R.P.M.
General Operation: Automatic Control - Set toggle safety switch which is
of the circuit breaker type to "On" (Down) (automatic control) position at
all times that constant speed control by C.P. lever on throttle quadrant
is desired. (If the switch throws out it may be reset by turning to "Off"
then to "On". Successive throwing out will probably be an indication of
short circuit or overload and the switch should be left off, in this

event, the pitch should be changed only if absolutely necessary.)
The desired R.P.M. can then be obtained by moving the constant speed
control lever on the throttle quadrant.
Manual Control - Set switch from "on" (automatic control) to "Hand
Control". The throttle quadrant lever is then cut out and any change in
R.P.M. must be made by operating the manual switch over to "Increase" or
"Decrease" until the desired changed in engine revs has been made.
[ES: The propeller control was a four position toggle switch. Up was
automatic, down and left was manual decrease, down to the right was in
increase rpm, and center was off.]
12. The Fuel Cock is located on the port side of the cockpit below the
hand fuel pump and marked to show the tanks and capacities. [DF: See the
diagram above. Measurements are in Imperial gallons, the equivalent of
five U.S. quarts. In the manual this is Figure 4. All other figures
omitted because too difficult to read.]
13. Fuel Quantity Gauge for the auxiliary tank is located on the
instrument board and the front and rear main tanks on the floor of the
cockpit.
[ES: Fuel tanks were not as shown. The fuel selector had five positions.
1. Res. 2. Main. 3. Aux. 4. Fuse. 5. Off. The reserve and main tanks were
one and the same tank . The main tank was feed by a stand pipe in the main
tank and the reserve fed from the bottom of the same main tank. The
reserve was used for all take offs and landings. When reserve was
selected, fuel was taken from the bottom of the main tank and fed fuel to
the engine. In other words the stand pipe used all of the fuel in the main
tank, but when the main was selected, it used all, except I believe, a
positive amount of fuel giving 20 minutes at METO power. This was a
positive indication of exactly how much fuel remained, eliminating the
pilot having to rely upon a fuel gage which at best was an unreliable.]
14. Carburetor Air Heat Control - is located on the same bracket as the
rounds indicator on the starboard side. The carburetor air intake is a
scoop built into the top of the engine cowl. A butterfly valve, controlled
from the cockpit, is located immediately above the carburetor air screen
and permits either cold or warm air or a mixture of both to enter. Warm
air for the carburetor is taken from inside the engine compartment. The
carburetor air screen is installed to prevent the passage of any foreign
matter into the carburetor. The carburetor air control should always be in
the cold position when starting the engine.
15. The Engine Primer is located on the starboard side of the cockpit,
just below the instrument panel.
16. Starter - A foot operated electric inertia starter is provided. A foot
treadle on the cockpit floor is pushed back to operate a starter switch
which allows a direct flow of current from the battery to the starter
motor. When the starter has reached the desired speed, the foot treadle is
pushed forward actuating a starter meshing solenoid and a booster coil;
also by the same movement of the foot treadle the start switch contact is
broken. The first few impulses of the engine in starting will
automatically disengage the starter. On aircraft A.H. 971 and subsequent
the foot operated starter is replaced by a two way toggle switch located
on the switch panel on the port side of the cockpit. This is depressed to
energize the starter and raised to engage it, and the switch automatically
returns to the off position when released.
[ES: Starter had the foot treadle starter. DF: This strikes me as
particularly significant. All AVG aircraft were taken from blocks higher
than AH and therefore should have had the toggle switch. I don't see how
Erik could possibly be wrong on this, which leaves only two possibilities:

that the manual is in error, or that the planes diverted to China were not
equipped the same as those sent to North Africa for the RAF.]
In case of battery failure, the started may be cranked by hand with crank
and extension provided for this purpose, both being located in rear access
compartment. The starter is operated by turning the crank handle which is
inserted in the spiral slot provided in the end of the crank extension, on
right hand side of engine cowl. Turn the crank with gradually increasing
speed until a fairly good rate of speed is obtained. Remove the crank
handle and extension. The engagement of the started will then be
accomplished by a pull on the hand starter button located immediately
above the crank. Caution: Starter crank and extension must be removed
immediately after cranking and before actuating starter pull.
17. Oil Dilution Control is located on the switch panel on the port side
of the cockpit.
(a) Before stopping the engine when a cold weather start is anticipated,
hold the oil dilution control switch "On" for approximately four minutes
at 800 RPM and stop the engine with the ignition switch, continuing to
hold the dilution control switch "On" until the engine stops. Then turn
the standard fuel cock to the off position.
(b) In starting the engine a normal start should be made. After starting
the engine, if a heavy viscous oil is indicated by oil pressure that is
too high or by oil pressure that fluctuates or falls back when the engine
RPM is increased, the dilution valve should be held "On" to dilute the oil
and correct this condition. Over dilution will result in a steady low oil
pressure and should be avoided if possible.
(c) If the engine heat is excessive when operating the oil dilution
control, the heat may evaporate the fuel out of the oil and leave the
normal high viscosity oil in the engine. When this condition is
encountered, the engine should first be shut off and allowed to cool for
fifteen minutes, then re-started and the instructions outlined in
paragraph "a" followed in preparing the engine for cold weather starting.
(d) Take-off may be made four minutes after starting the engine if there
has been enough rise in oil temperature (40°c. minimum), if the engine
holds its oil pressure and if the engine runs smoothly, or, the take-off
may be made as soon after four minutes as these conditions are obtained.
18. Hand Fuel Pump Control is located on the port side of the cockpit
forward of the throttle quadrant.
19. Radiator Flap Control is located on the starboard side of the cockpit
near the floor. It consists of a long lever and a rack. The latter is
provided with a stop at each end and may be set for "full open" (handle
fully down), "Full closed" (handle fully up), or any intermediate
position.
NOTE: Filling points for:
Wing fuel tanks through left hand wing fillet.
Fuselage fuel tanks through rear vision glass, left hand side, forward.
Oil tanks through rear vision glass, left hand side, aft.
Coolant tank through inspection door, top of engine cowl.
Operational Equipment
20. Gun Firing Switch - See Section 1, paragraph 1 [DF: should be para. 3]
21. Switches and Rheostats are located on panel on the left, below the
throttle quadrant. Care must be taken to insure that all rheostats are in
the extreme "Off" position when not in use, as they are equipped with
integral switches.
22. Oxygen - Two oxygen bottles are carried in supports in the aft part of
the fuselage, and accessible through the fuselage access door. The oxygen
regulator and bayonet outlet are located on the starboard side of the

cockpit. (Aircraft Nos. A.H. 741 to A.H. 990 have one bottle only) [ES: We
did not have the oxygen as shown since it was a high pressure system, not
the low pressure demand system.]
23. Aircraft Flares - Two M-8 type flares are carried in the flush type
built-in wing flare racks. Flare release handles are located on the
starboard side of the pilot's seat.
24. Recognition Device - A bracket for mounting the damped rate control is
provided on the starboard side of the cockpit which actuates the
recognition device mounted on brackets near the top of fuselage accessible
through fuselage access door.
25. Landing Lamp - A landing light is fitted to the underside of the port
wing and is operated by a switch on the main switch box.
26. Formation Lights - for lighting the upper surface of the wing are
located in the fuselage aft of the cockpit. These are controlled through a
rheostat on the port side electrical boxes. (Aircraft A.H. 971 onwards)
27. Identification Lights - Provisions are made in top of the fuselage aft
of cockpit enclosure and starboard rear wing fillet for upward and
downward identification lights. The identification light switch box is
locate don starboard side of cockpit.
28. Wireless Controls - [DF: This section omitted. The AVG Tomahawks had
after-market radios designed for civilian use.]
Miscellaneous Equipment
29. Dalton Computer - Provision is made for the Dalton computer to be
inserted in a stowage on the port side of the cockpit. [ES: no Dalton
computer.]
30. Shield - An instrument light shield is provided to prevent reflections
on the windshield.
31. Fire Extinguisher - is located in brackets on port side of cockpit
floor.
32. Map Case - is fastened to the starboard side of the cockpit.
33. Life Preserver - The back cushion of the pilot's seat may be used as a
life preserver. [ES: no life preserver.]

SECTION 2
HANDLING AND FLYING NOTES FOR PILOT
INTRODUCTORY NOTES
Note: - These notes should be read in conjunction with the Flying Training
Manual, Part 1, Chapter III, which sets forth in detail the technique
which is only outlined here.
1. Full details of the equipment of the aircraft are given in Section 1,
and pilots should be acquainted with these details, which are only
mentioned hereafter when there is some particular point to which attention
should be drawn.
(i) Hydraulic system:- The hydraulic system operates the undercarriage,
tail wheel and flaps, and a diagram of the complete system is given at the
end of Section 1 [DF: diagram omitted].
(ii) Undercarriage:- See Section 1.
(iii) Flaps:- The operation of the flaps is deal with in Section 1. In the
event of flaps being required for take-off, it is advisable to operate
them manually in order to obtain more easily the partial setting required.
This setting should be 20°. When flaps are down, caution should be
exercised not to re-set the selector to the "up" position when there is
any possibility that the resultant loss of lift might prove dangerous.
Flaps should not be lowered at over 140 m.p.h. and should be raised for
taxiing.
(iv) Wheel brakes:- These are toe-operated. They are satisfactory in
operation and may be applied reasonably hard to restrict the landing run,
but the good taxiing qualities of the aircraft do not necessitate their
use under normal taxiing conditions.
(v) Gun firing system:- As the guns are fired electrically through a
trigger switch on the stick, great care must be taken that this is not
depressed accidentally or when operating the undercarriage and flap
switch.
(vi) Trimming tabs:- The elevator trimming tab is efficient and not unduly
powerful for small movements of the trimmer wheel. The rudder trim is
powerful and must be used at all times whenever speed of the aircraft is
varied, particularly when the cockpit hood is open.
(vii) Air screw:- See Section 1, para. 11, for main operating
instructions. When it is necessary to check the engine revs on the magneto
switches, the propeller switch must first be put to the "Hand Control"
position, when any fluctuations of revs will show on the rev counter. Care
must be taken to see that the switch is returned to the "On" position,
i.e., automatic position, so that C.P. lever on the throttle quadrant is
again in operation, before taking off.
(viii) Cockpit hood emergency release: - See Section 1, para. 1.
(ix) Fuel, Oil and cooling systems:- Diagrams of these are given at the
end of Section 1 [DF: omitted except for fuel; see Erik Shilling's
comments on fuel sytem].
Note:- On aircraft Nos. A.H. 741 to A.H. 970 inclusive, certain of the
electrical switches are "On" when in the "Up" position and care should
be taken to identify these. All switches are clearly marked "Off" and
"On".
FITNESS OF AIRCRAFT FOR FLIGHT
2. Ensure that the total weight and distribution of the load are in

accordance with the weight sheet summary and ascertain that the aeroplane
is in all other respects fit for flight.
PRELIMINARIES
3. Before starting the engine, check the following:
(i) That the ignition switches are OFF;
(ii) That undercarriage, tail wheel, and flap selectors are in NEUTRAL;
(iii) That constant speed toggle switch on control panel is ON; i.e., in
"Automatic Control".
(iv) That wheel brakes are ON
(v) Switch on main battery switch and check undercarriage, tail wheel and
flap indicator
(vi) Turn on fuel and check fuel tanks for contents
(vii) Check controls for free movement.
STARTING ENGINE AND WARMING UP
Note: For main engine details see Handbooks and paragraph 27 of these
Notes.
4. (i) If engine has been standing, turn over by hand.
(ii) Turn carburetor air to "COLD", radiator shutters to "SHUT".
(iii) C.P. control to 2800 r.p.m.
(iv) Throttle to give approximately 800 r.p.m.
(v) Mixture control to idle cut-off. (See note)
(vi) Wobble pump to 4 lbs. pressure.
(vii) Prime engine with two to four strokes
(viii) Mixture control to FULL RICH
(ix) Switch ON
(x) Push heel on starter pedal to energize starter.
(xi) When starter has reached sufficient speed, push down toe of starter
pedal to engage.
Note:- Do not increase fuel pressure above 4 lbs. with the mixture control
out of the idle cut-out position. If necessary, prime the engine to keep
it from stalling, as pumping the throttle does not prime the engine.
TESTING ENGINE AND INSTALLATION
5. (i) Warm up at 800 to 1000 r.p.m.
(ii) Minimum oil temperature before running up over 40°C. - Maximum 85°C.
(iii) Oil pressure - 60 to 80 lbs.
(iv) Radiator temperature for running up - 80°C.
(v) Whilst warming up the engine, check the operation of the flaps.
(vi) Set propeller switch to "manual selective".
(vii) Check the functioning of the engine and magnetos at 2200 r.p.m. and

26 in. Hg. (65 Cm.Hg.)
Note:- Care must be taken to see that the tail does not lift when 1800
r.p.m. is exceeded, and it is advisable to have somebody holding this down
whilst running up.
(viii) Reset propeller switch to "automatic" position and check C.P.
controls.
TAXIING
6. Owing to the steerable tail wheel, brakes are not necessary in normal
circumstances. The view ahead is average and the machine is readily
controllable.
If the engine is kept ticking over for any period of time, it should be
cleared by being run up against the brakes prior to take-off.
ACTIONS PRIOR TO TAKE-OFF
7. Prior to actual take-off, check the following points by means of some
suitable reminder, such as "T" - "M" - "P" "FLAPS" - "RADIATOR"
(i) "T" - trimming tab controls for rudder and elevator should both be in
neutral as shown by the marks on the indicators.
(ii) "M" - mixture control should be at full rich.
Note:- It should be at auto-rich if aeroplane is above 3500 feet.
(iii) "P" - constant speed control should be set to give 3000 revs, and
check that toggle switch is in the UP (automatic) position.
(iv) "FLAPS" - may be used up to 20° for take-off if required, although
the advantage of so doing is very small. See paragraph 1 (iii).
(v) "RADIATOR" - position for this will be dependent on the outside air
temperature.
TAKE-OFF
8. The aircraft is very easy to take-off and shows scarcely any
inclination to swing, although a little right rudder may be needed. As the
Allison engine has a particularly quick pick-up, the opening of the
throttle must be done slowly and care must be taken to ensure that the
specified maximum manifold pressure of 41 in. Hg (104 Cm.Hg. on French
instruments) is not exceeded. See para. 27 for full engine take-off
limitations.
ACTIONS AFTER TAKE-OFF
9. (i) Once clear of the ground, raise the undercarriage and tail wheel by
pressing the release knob on the end of the undercarriage selector lever,
bringing the lever up to the undercarriage "UP" position, and pressing the
thumb operating switch on the top of the control column. [DF: Erik says
that on the AVG Tomahawks the button on top of the stick was replaced by a
toggle below the pistol grip.] This operation is rather slow and whilst
the undercarriage is going up -
(ii) reduce the boost pressure to 35 in. Hg. and reduce revs to 2600, and
(iii) maintain a flying speed of approximately 140 m.p.h.
(iv) When the indicator shows that the undercarriage and tail wheel are
finally up, check that they are locked into position by operating the
emergency hand pump, and if it is solid then the undercarriage and tail
wheel are full retracted. Return undercarriage selector lever to neutral
position, and
(v) If lowered, raise the flaps by selecting the "Up" position on the flap
selector lever, and press the thumb operating switch on the control

column. When the flaps are up return the lever to neutral.
(vi) Set mixture control to automatic rich.
ENGINE FAILURE DURING TAKE-OFF
10. If the engine should fail during take-off, put the nose of the machine
down and maintain flying speed. See that the undercarriage has commenced
to come up and, if possible, select the "DOWN" position on the flap lever
and give any possible assistance with the hand pump.
(i) Switch off and land straight ahead.
CLIMBING
11. Whilst climbing away, check cockpit instruments systematically.
(i) Best climbing speed up to 14,000 feet is approximately 150 m.p.h.
(ii) R.P.M. and boost as given in para. 27.
(iii) Mixture in automatic rich.
(iv) Radiator control adjusted to keep coolant temperature between 85°C
minimum and 12585°C maximum.
CRUISING
12. For high speed cruising the r.p.m. may be 2600, with manifold pressure
at 35 in. Hg. and mixture control in automatic rich.
For normal cruising the r.p.m. should be 2280 with manifold pressure at
27.9 in. Hg. and mixture control in Automatic Rich.
For most economical cruising, set revolutions to 2190 and manifold
pressure to 25.2 in. Hg. Switch propeller control from Automatic to Manual
and weaken mixture on mixture control until engine shows a drop in revs of
40 to 50 r.p.m. Switch propeller control back to Automatic. Provided no
change is made altitude or cruising conditions this will be most
economical condition.
GENERAL FLYING
13. Whilst this aircraft has a good view and is very maneuvreable, it is
directionally unstable, and this instability most pronounced with the
cockpit hood in the fully open position. It is necessary to use the rudder
on all turns and it is also necessary to readjust the rudder bias for all
changes of speed. As speed is increased the aircraft tends to yaw to the
right, and left rudder bias must be applied. (See para. 14)
The controls themselves are powerful at all speeds. It is possible to
obtain high acceleration loadings by coarse use of the elevators. Trimmer
tabs are effective.
INSTRUMENT FLYING
14. Owing to the directional instability of this aircraft with the hood
open, it is essential that the hood be shut before any blind flying is
attempted. It will be necessary to fly with the feet on the rudder bar,
and particular care must be taken to avoid yaw. It would be advisable to
lower the seat in order to obtain a better view of the instruments, which
are somewhat masked by the reflector sight bracket. [DF: The AVG Tomahawks
used a jury-rigged optical sight, and some had none at all.]
STALLING
15. The stalling characteristics of this aircraft are good. At minimum
speed the stall is gentle and there is some buffeting and pitching before
the wing, generally the right, drops gently, followed by the nose.
At high speed the machine can be stalled as a result of the coarse use of
the elevators producing high acceleration loadings, but due warning is
received, particularly on the high speed turn, by a shuddering of the

aircraft, and loads of over 5g. can be applied to 180 to 200 m.p.h.
without the aircraft stalling.
The stalling speeds of the aircraft at normal operational loads, were as
follows:
Undercarriage up and flaps up - 80 I.A.S.
Undercarriage down, flaps up - 82 I.A.S.
Undercarriage up, flaps down - 73 I.A.S.
Undercarriage down, flaps down - 75 I.A.S.
SPINNING
16. This aircraft has been spun up to 5 turns and recovery was normal. The
commencement of the spin is erratic and the aircraft tends to come out
unless held in the spin. As soon as the standard actions for recovery are
taken the spin ceases.
GLIDING
17. This machine handles quite normally on the glide both with flaps up
and flaps down.
(i) The glide with flaps up is flat and the view ahead is restricted.
(ii) With flaps and undercarriage down, the glide is steep and a good view
is obtainable ahead. The lowering of the flaps makes the aircraft slightly
nose heavy. Gliding turns with flaps and undercarriage down should be done
at 105 to 110 m.p.h. at normal loadings.
(iii) The engine assisted glide is considerably flatter and should be done
at 100 m.p.h., but the view forward is rather restricted by the high angle
of the nose.
SIDE-SLIPPING
18. The aircraft can be side-slipped, although it is only just possible to
hold the nose up and prevent the speed increasing unduly.
DIVING
19. The maximum permissible diving speed is 470 m.p.h. indicated. [ES: An
indicated speed of 470 mph at 20,000 feet was a true airspeed of 658 mph
... or well into compressibility. A speed at which the controls became
useless, and the plane could not recover from the dive.... This is what
happened to Pete Atkinson over Toungoo.]
(i) Before commencing a dive propeller should be put into coarse pitch to
prevent over revving and the throttle should be left slightly open.
(ii) Flaps must never be used in an attempt to reduce diving speed.
(iii) As speed increase the aircraft tends to yaw to the right, this must
be counteracted by the application of left rudder tab. With the hood open
this tendency to yaw to the right is considerably worse than when the hood
is shut.
(iv) As speed increases there is a tendency for the aircraft to become
left wing low and roll to the left, which must be counteracted by the
ailerons.
(v) Rate of descent is extremely rapid and speed is picked up very
quickly.
(vi) Recovery is normal but elevators are powerful and considerable
acceleration loads will result if too much force is used during recovery.
AEROBATICS
20. Subject to any current restrictions, normal aerobatics may be carried

out on this aircraft. Due to the controls being powerful and moderately
light the aerobatic qualities are good, but great care must be exercised
to see that all aerobatics are carried out at sufficient height to enable
the pilot to recover from a dive without exerting excessive loads on the
aircraft. Care should also be taken to ensure that speed is maintained
during aerobatics in the looping plane.
APPROACH AND LANDING (GENERAL)
21. This aircraft is very easy to land, but the following features should
be noted:
(i) Landing must always be made with flaps down.
(ii) The angle of descent with flaps and wheels down and engine off is
steep.
(iii) If an engine assisted approach is made with too much engine, the
view ahead is apt to be restricted owing to the high position of the nose
relative to the horizon.
(iv) When in the tail-down landing position this aircraft is at a
considerable angle of attack so that if a 3-point landing is desired, some
excess speed must be held in order to give sufficient elevator control to
change the attitude of the machine from the steep gliding angle to the
landing attitude, and to overcome any tendency to stall when making this
change.
PRELIMINARY APPROACH
22. Reduce speed during the initial circuit of the aerodrome and -
(i) Open hood,
(ii) Ensure mixture control is in full rich,
(iii) Carry out the following vital actions in good time prior to the
final approach, as the undercarriage takes some time to come down,
(iv) "U" - undercarriage and tail wheel down; depress button on the
undercarriage selector lever and select "Down" position and press the
operating switch on the top of the control column. [DF: toggle switch on
the AVG Tomahawks?] Check that the undercarriage and tail wheel are locked
down by operating the emergency hand pump. Undercarriage and tail wheel
are fully down when this is solid. When down, return selector lever to
neutral.
Note:- Do not lower undercarriage above 175 m.p.h.
(v) "P" - pitch. Set constant speed control to give 3000 r.p.m., and check
that the toggle switch on control panel is "ON" (in the down position).
(vi) "F" - flaps. When in the correct position for the final approach,
select "flaps down" on the flap selector lever (lever forward), and press
the thumb switch [DF: toggle switch on the AVG Tomahawks?] on the control
column until flaps are fully down. Do not lower flaps at over 140 m.p.h.
Note:- In the even of failure of the electric motor, undercarriage and
tail wheel and flaps may be operated by selecting the required position on
the selector levers and operating the emergency hand pump.
(vii) Radiator closed as necessary.
FINAL APPROACH
23. The final approach should be done at the following speeds under normal
load conditions:

(i) For the engine off approach, a speed of 95 to 100 m.p.h. should be
maintained. This will give a steep angle of glide and a good view will be
obtained of the landing area. Control at these speeds is good.
(ii) An engine assisted approach should be carried out at approximately 90
to 95 m.p.h. For this, very little engine is required and if too much
engine is used, whilst serving to reduce the approach speed slightly, the
angle of approach is too flat for the pilot to obtain a satisfactory view
of the landing area.
LANDING
24. (i) The landing itself is easy, but if a 3-point landing is made, the
angle of attack as the aircraft settles on to the ground is high, and if
the flattening out process has been commenced too soon it might be
possible to stall the aircraft and drop a wing, and this point should be
watched.
(ii) Normally there is no tendency for this aircraft either to drop a wing
or to swing after landing.
(iii) Brakes may be applied to reduce the landing run.
(iv) Flaps should be raised as soon as the run is finished and before
taxiing in, but care must be exercised to see that the undercarriage and
tail wheel selector lever is not moved instead of the flap lever.
Note:- If this mistake is made, the tail wheel will retract first before
the undercarriage, so that the pilot should have warning that he has made
a mistake and should cease to press the thumb operating switch
immediately. [DF: toggle switch on the AVG Tomahawks?]
FORCED LANDING
25. In the event of a forced landing, the pilot must decide whether or not
it is advisable to lower the undercarriage or whether the landing should
be carried out with the undercarriage retracted.
(i) If in doubt, decide to land with the undercarriage up;
(ii) Turn off the petrol and switch off engine; open hood.
(iii) Lower the flaps to reduce forward speed.
(iv) In the event of a forced landing on water, undercarriage, tail wheel
and flaps should be UP. Hood must be open and harness done up.
NOTE:- FOR FURTHER DETAILS OF THE LATEST TECHNIQUE IN CONNECTION WITH ALL
THE FOREGOING NOTES, PILOTS SHOULD REFER TO FLYING TRAINING MANUAL, PART
1, CHAPTER III.
POSITION ERROR TABLE
26. The corrections for position error are as follows:
At 60 mph I.A.S. reading subtract 2.5 mph
80 mph I.A.S. reading subtract 2.5 mph
100 mph I.A.S. reading subtract 0.5 mph
120 mph I.A.S. reading add 1.0 mph
140 mph I.A.S. reading add 3.5 mph
160 mph I.A.S. reading add 5.0 mph
180 mph I.A.S. reading add 6.0 mph
200 mph I.A.S. reading add 8.0 mph
220 mph I.A.S. reading add 8.5 mph
240 mph I.A.S. reading add 9.0 mph
260 mph I.A.S. reading add 10.5 mph
Next: notes on the Allison V-1710-C15 Engine

NOTES ON THE ALLISON V-1710-C15 ENGINE
(Using 100 Octane Fuel)
27. The following should be carefully noted:
(i) Limited operational conditions
Take-off * Maximum r.p.m. 3000
Maximum boost at S.L. 41.0 in.Hg.
Maximum boost above 2600 ft. 38.9 in.Hg.
Mixture control below 3500 ft. "Full-rich"
Mixture control above 3500 ft. "Auto-rich"
Climb* Maximum r.p.m. 2600
Maximum boost 35.0 in.Hg.
* Note: - For take-off and climbs of short duration (not exceeding 5 min.)
from sea level, the throttle should be adjusted to give 41 in.Hg. and left
in this position until the boost falls to 38.9 in.Hg. This boost should
then be maintained by adjustment of the throttle. For climbs of longer
duration the boost should be adjusted to 35 in.Hg.
Maximum cruising
(mixture control
"Auto-rich") Maximum r.p.m.
Maximum boost 2600
35 in.Hg.
Maximum cruising
(mixture control
"Auto-rich" or
weakened.) Maximum r.p.m.
Maximum boost 2280
29.2. in.Hg.
Maximum level
(5 minute limit) Maximum r.p.m.
Maximum boost 3000
38.9 in.Hg.
Maximum dive Maximum r.p.m.
Maximum boost 3120
38.9 in.Hg.
(ii) Oil Pressure
Normal 60-65 lb./sq.in
Minimum 50 lb./sq.in
(iii) Oil inlet temperatures
Minimum for take-off 40°C
Normal 70-80°C
Maximum 85°C
(iv) Coolant temperature
Maximum 125°C
Minimum for take-off or flight 85°C
FUEL CAPACITY AND CONSUMPTIONS
28. Note the following:
(i) Fuel capacity (in Imperial gallons)
Main tank 50 gallons [62.5 gal U.S]
Fuselage tank 47 gallons [58.75 U.S.]

Reserve tank 33 gallons [41.25 U.S.]
Total 130 gallons [162.5 U.S.]
(ii) Fuel consumptions (in Imperial gallons per hour):
Approximate consumptions at 12,000 feet are as follows:
Climbing ----- at 2600 r.p.m. and 35 in.Hg. boost 84 [105 U.S.]
Cruising ----- at 2600 r.p.m. and 35 in.Hg. boost 84 [105 U.S.]
-- (mixture at 2280 r.p.m. and 29.2 in.Hg. boost 52 [65 U.S.]
-- control at 2280 r.p.m. and 27.9 in.Hg. boost 50 [62.5 U.S.]
-- "Auto-rich" at 2190 r.p.m. and 25.2 in.Hg. boost 42 [52.5 U.S.]
Note: It is possible to improve on the last cruising consumption by
weakening the mixture as described in para. 12.
Tye Lett's additional notes on the Allison
[Like the Tomahawk manual, the following notes came from the copies of the
Pistole Collection at the NASM Archives. The repetition between part 1 and
part 2 is in the original. "sic" indicates a typo in the original.]
ALLISON ENGINE
FIELD SERVICE MEMORANDUM
FAR EAST NO.2
RANGOON, BURMA
September 26, 1941
To: Col. C. T. Chien.
From: Tye. M. Lett, Jr.
SUBJECT; STARTING PROCEDURE, ALLISON MODEL V 1710 C 15 ENGINES
1. The Starting procedure described below is the latest as recommended by
Allison for the V 1710 C 15 Engine.
2. It is observed that several methods of starting subject engine are in
use at various points.
3. To provide specific instructions regarding procedure it is suggested
that this information be relayed to all pilots and ground personnel
concerned with the operation of Allison Engines.
1. PROPER STARTING PROCEDURE
The priming system on all Allison engines is independent of the
carburetor, and pumping the carburetor throttle will not discharge fuel
into the engine, as all fuel is injected by the fuel discharge nozzle to
the supercharger inlet, where it is mixed with the air passed through the
carburetor throttle openings.
(a) Set propellor [sic] to manual low pitch.
(b) Carburetor Heat Control should be in the OFF position.
(c) Set throttle at position corresponding to 1000-1200 R.P.M.
(d) Set carburetor manual mixture control in IDLE-CUT-OFF POSITION, and
operate the wobble pump to maintain a fuel pressure of 4 lbs./sq in.
(e) Energize starter.
(f) Prime a COLD engine with not over two strokes for a large size primer,
or four for a small size primer. For a WARM engine, one stroke with large
primer; or two with a small size primer is sufficient.
(g) Turn on ignition switch and engage starter. When propellor turns,
maintain fuel pressure by wobbling; and as engine starts firing, move the

carburetor manual mixture control to Automatic-Rich position.
Should engine stop, return the manual mixture control to IDLE-CUT-OFF
position to avoid flooding the engine with fuel, as the fuel pressure will
build up to normal operating pressure (12-14 lbs./sq in.) when engine
starts firing. Another start can be made using the same procedure, and
using priming charge only if necessary, and the engine is not over-primed.
(h) IF OIL PRESSURE is not established within 15 seconds after starting,
stop engine by setting manual mixture control in IDLE-CUT-OFF and
investigate oil pressure failure. If oil pressure is established at start,
continue to warm engine up at 900-1000 R.P.M. as too low idling and
warm-up speeds will result in oil and fuel load fouling of the spark
plugs.
Warm-up speed can be increased up to 1400 R.P.M. as oil and coolant
temperatures rise, and oil pressure is stabilized.
2. STARTING
(a) With Ignition Switch "OFF" pull engine through several revolutions,
turning propellor by hand, with throttle open.
(b) Carburetor Heat in "OFF" or "COLD" position.
(c) Radiator flap position as required.
(d) Throttle 1/10 open, or 1000-1200 R.P.M.
(e) Mixture control in "IDLE-CUT-OFF".
(f) Electric and Propellor switches "ON".
(g) Propellor in Manual "Low Pitch".
(h) Fuel tank selector on "Reserve".
(i) Pump up, and maintain 4 lb fuel pressure.
(j) Start energizing starter.
(k) Prime "COLD" engine 3 strokes - "WARM", 1 stroke--close and lock
primer.
(l) Turn ignition switch to "BOTH ON" position.
(m) Engage starter, and when engine starts firing, move mixture control to
Automatic-Rich position.
(n) After engine starts, IDLE at 600 R.P.M. and if oil pressure is not
established within 15 seconds, stop engine and investigate oil pressure
failure.
(o) Start warming-up by operating the engine at 900-1000 R.P.M. gradually
increasing to 1400 R.P.M. as the temperatures rise, and oil pressure
stabilizes.
With throttle closed the Klaxon horn will be silent, if landing gear is
locked down.
2. UNDERPRIMING AND OVERPRIMING
(a) Underpriming is sometimes caused by leaking primer lines and
connections, or defective primer pump packing. The fuel supply to the
primer, wobble or electric fuel supply pump, if so equipped, should be
checked.

(b) Overpriming is first indicated by very weak combustion, followed by
black smoke discharge from the exhaust. Excessive priming is evidence by
wet spark plugs and fuel appearing at the exhaust stacks.
(c) As the prime fuel is injected directly into the intake manifolds of
each cylinder, excess fuel will not be carried off by the supercharge
scroll drain which relieves the scroll housing of excess fuel delivered
only by the discharge nozzle which has opened, either by too high fuel
pressure being wobbled with carburetor manual mixture control out of
IDLE-CUT-OFF position, or by leakage of the discharge nozzle. Check nozzle
for leakage, or holding open due to dirt or foreign material.
(d) Overprining [sic] constitutes a dangerous fire hazard, as well as a
detriment to the oil film lubrication of the pistons, rings, and cylinder
walls of the engine.
(e) Extreme CAUTION should be taken to aboid [sic] overpriming on either a
HOT or COLD engine.
(f) To relieve overpriming, crank engine several revolutions, with switch
in OFF position, throttle wide-open, and carburetor manual mixture control
in IDLE-CUT-OFF position. This can also be accomplished by turning
propellor by hand in direction of rotation.
(g) Loss of compression (check by rotating propellor by hand in direction
of rotation) due to over priming may require lubrication of pistons,
rings, and cylinder walls with oil through the valve ports or spark plug
holes.
NOTE: IT IS RECOMMENDED THAT ALL PERSONNEL BECOME FAMILIAR WITH THE
SUGGESTIONS ON "GROUND TEST" AND "GROUND CHECK" AS DESCRIBED IN ALLISON
TROUBLE SHOOTING AND MAINTENANCE MANUAL RECENTLY RELEASED.
/s/ TYE. M. LETT, JR.