MANUAL I > II > III FLYING > IV
Pilot's manual for the Curtiss Tomahawk (con'td)Stuff in brackets [like this] has been added. Comments beginning DF are by the webmaster; those beginning ES are by Erik Shilling, a pilot with the AVG 3rd Squadron.
HANDLING AND FLYING NOTES FOR PILOT
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".
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.]
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.
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.
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.
18. The aircraft can be side-slipped, although it is only just possible to hold the nose up and prevent the speed increasing unduly.
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.
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.
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.
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.
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.
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?]
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.
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|