These comparisons remain the same with the full fuel loads at present available (2 x 45 gall. long range tank Tempest, 1 x 90 gall. longe range tank Spitfire). Maximum Speed

25. From 0 - 10,000 feet the Tempest V is 20 mph. faster than the Spitfire XIV. There is then little to choose until 22,000 feet, when the Spitfire XIV becomes 30-40 mph. faster, the Tempest's operational ceiling being about 30,000 feet as opposed to the Spitfire XIV's 40,000 feet. Maximum Climb

26. The Tempest is not in the same class as the Spitfire XIV. The Tempest V however, has a considerably better zoom climb, holding a higher speed thoughout the manoeuvre. If the climb is prolonged until climbing speed is reached then, of course, the Spitfire XIV will begin to catch up and pull ahead. Dive

27. The Tempest V gains on the Spitfire XIV. Turning Circle

28. The Spitfire XIV easily out-turns the Tempest. Rate of Roll

29. The Spitfire XIV rolls faster at speeds below 300 mph., but definitely more slowly at speeds greater than 350 mph. Conclusions

30. The tactical attributes of the two aircraft being completely different, they require a separate handling techique in combat. For this reason Typhoon squadrons should convert to Tempests, and Spitfire squadrons to Spitfire XIVs, and definitely never vice-versa, or each aircraft's particular advantages would never be appreciated. Regarding performance, if correctly handled, the Tempest is the better below about 20,000 feet and the Spitfire XIV the better above that height. TACTICAL COMPARISON WITH MUSTANG III Radius of Action

31. Without a long range tank, the Spitfire XIV has no endurance. With a 90 gallon long-range tank it has about half the range of the Mustang III fitted with 2 x 62 1/2 gallon long range tanks. Maximum Speed

32. The maximum speed are practically identical. Maximum Climb

33. The Spitfire XIV is very much better. Dive

34. As for the Spitfire IX. The Mustang pulls away, but less markedly. Turning Circle

35. The Spitfire XIV is better. Rate of Roll

36. The advantage tends to be with the Spitfire XIV. Conclusion

37. With the exception of endurance no conclusions can be drawn, as these two aircraft should never be enemies. The choice is a matter of taste. COMBAT TRIAL AGAINST FW.190 (BMW.801D) Maximum Speeds

38. From 0 - 5,000 ft and 15,000 - 20,000 ft., the Spitfire XIV is only 20 m.p.h. faster; at all other heights it is up to 60 m.p.h. faster than the Fw 190 (BMW.801D). It is estimated to have about the same maximum speed as the new Fw 190 (DB.603) at all heights. Maximum Climb

39. The Spitfire XIV has a considerably greater rate of climb than the FW 190 (BMW.801D) or (estimated) the new Fw 190 (DB.603) at all heights. Dive

40. After the initial part of the dive, during which the FW 190 gains slightly, the Mk XIV has a slight advantage. Turning Circle

41. Spitfire XIV can easily turn inside the FW 190, though in the case of a right-hand turn, this difference is not so quite pronounced. Rate of Roll

42. The FW 190 is very much better. Conclusion

43. In defense, the Spitfire XIV should use its remarkable maximum climb and turning circle against any enemy aircraft. In the attack it can afford to "mix it" but should beware of the quick roll and dive. If this manoeuvre is used by the FW.190 and the Spitfire XIV follows, it will probably not be able to close the range until the FW.190 has pulled out of its dive. COMBAT TRIAL AGAINST Me. 109G Maximum speed

44. The Spitfire XIV is 40 m.p.h. faster at all heights except 16,000 ft. where it is only 10 mph faster. Maximum Climb

45. Same results. At 16,000 ft. indentical, otherwise the Spitfire XIV out-climbs the Me.109G. The zoom climb is practically identical when the climb is made without opening throttle. Climbing at full throttle, the Spitfire XIV draws away from the Me.109G quite easily. Dive

46. During the initial part of the dive, the Me.109G pulls away slightly, but when a speed of 380 m.p.h. is reached, the Spitfire XIV begins to gain on the Me.109G. Turning Circle

47. The Spitfire XIV easily out-turns the Me.109G in either direction. Rate of Roll

48. The Spitfire XIV rolls much more quickly. Conclusion

49. The Spitfire XIV is superior to the Me.109G in every respect. COMBAT PERFORMANCE WITH 90 GALLON LONG-RANGE TANKS 50. As the Spitfire XIV has a very short range it has been assumed that when a long-range tank is to be carried, it is most likely to be the 90 gallon tank rather than the 30 gallon or 45 gallon. Pending further instructions, no drops or trials have been carried out with the 30 gallon or 45 gallon tanks. The aircraft's performance with either can be estimated from the results given below of trials with the 90 gallon long-range tank. Drops

51. The aircraft was fitted with assistor springs as for the Spitfire IX. Two drops were made with empty tanks at 50 ft and 25,000 ft, A.S.I. 250 mph, with no trouble. Cine photographs were taken and show the tank dropping quite clear of the aircraft. Further trials would be necessary to check these results thoroughly. Speeds

52. About 20 m.p.h. is knocked off the maximum speed and correspondingly off the speed at intermediate throttle settings. The aircraft is still faster than the FW.190 (BMW.801D) and the Me.109G above 20,000 ft. Climb

53. Climb is most affected. With a half-full tank its maximum climb becomes identical with the Spitfire IX without the tank. Even with a full tank it can therefore climb as fast as the FW.190 or Me.109G. Its zoom climb is hardly affected. Dive

54. So long as the tank is more than 1/3 full, the dive acceleration is similar. Turning Circle

55. The Spitfire XIV now has a definitely wider turning circle than before, but is still within those of the FW.190 (BMW.801D) and Me.109G. Rate of Roll

56. Similar. Conclusions

57. Even with the 90 gallon tank, the Spitfire XIV can equal or outclass the FW.190 (BMW.801D) and the Me.109G in every respect. Its main advantages remain the tight turn and maximum climb. TECHNICAL Gun Harmonisation

58. As for the Spitfire IX. Gun Firing

59. Trials were carried out without any troubles or difficulties. Re-arming

60. As for the Spitfire XI. Cine-gun installation and harmonisation

61. There is no difference in installation, but in the Spitfire XIV the camera is fitted on the port side. Radio

62. One V.H.F. set is fitted as in the Spitfire IX. Oxygen

63. Normal Bristish type oxygen system, as in all Spitfires. Engine Temperatures

64. The glycol shutters are automatically controlled. There was no overheating at any time, except during sustained climbs at maximum boost and r.p.m. when the glycol temperature once exceeded 105 deg C. STARTING HINTS 65. The aircraft is generally more difficult to start than the Spitfire IX. Care should be taken not to over-dope it and one third of a pump full is usually quite sufficient when the engine is warm. SERVICING HINTS 66. Careful watch should be maintained on the Rolls-Royce Auxilary Gear Box oil contents level. The aircraft under test (RB.179) suffered with a bad oil leakage, all oil being consumed or lost in a 30 minute flight. This was cured by a careful check and tightening of all connections and plugs, when the consumption was decreased to approximately 1/2 pint per hour. 67. Touble has also been experienced with the Coffman Starter Breech sticking. A daily shot with a grease gun on the grease nipple provided helped to eliminate this stickiness. Normal Spitfire equipment was used throughout the trials. GENERAL CONCLUSIONS 68. The Spitfire XIV is superior to the Spitfire IX in all respects. 69. It has the best all-round performance of any present-day fighter, apart from range. 70. Modification to the compass bracket, to enable the pilot to obtain an unresticted view of the compass, should be incorporated.

AFDU Wittering July 1943 Spitfire XIV JF317 SHORT TACTICAL TRIALS OF EXPERIMENTAL SPITFIRE XIV INTRODUCTION On instructions from Headquarters, Fighter Command, an experimental Spitfire XIV JF317 (Griffon 61) was made available by A&AEE for three days for short tactical trials. The trials took the form of a direct comparison with a Spitfire VIII (Merlin 63) JF664, and flying took place from 27 to 29 July 1943. BRIEF DESCPRIPTION The aircraft used is a conversion of the Spitfire VIII. The larger engine involves a much longer engine cowling and the extra weight forward has been balanced by ballast in the tail. The fin has been increased in area to help directional stability and a large rudder is fitted. This aircraft had the normal span wings of the Spitfire VIII with small span ailerons, but the extended wing tips had been replaced by the standard wing tips as on the MK IX. The engine is not representative of production as the FS gear is higher and the MS lower. A five blade propeller is fitted. The engine had a Bendix injection carberator and boost for combat is limited to plus 15 lbs. The Spitfire VIII weighed 7,760 lb, the XIV 8,376. Performance - Speeds near the ground are identical, at 10,000 and 15,000 feet the Spitfire VIII is faster, at 20/25,000 ft. similar, at 30,000 ft. and over the Spitfire XIV accelerated faster and was the superior aircraft. Climb - Zero to 30,000 feet the Spitfire VIII is the better aircraft, at 30,000 ft. and over the Spitfire XIV is by far the better. Manoeuvrablility - The elevator control of the Spitfire XIV was found to be much heavier than that of the Spitfire VIII, unpleasantlly so, and the other controls felt to be slightly heavier than on previous Spitfire Mks. In spite of heavier controls the Spitfire XIV is more manoeuvrable than the Spitfire VIII in turns at all heights. Spins were carried out in the Spitfire XIV at 25,000 feet. The aircraft did not spin voluntarily but had to be put into and held in the spin. Instead of spinning in the normal nose down attitude, the nose of the aircraft oscillated from an almost verticle position downwards to a position with the nose well above the horizon, so that the aircraft was tail down. It spent most of its time in this flat position from which, after four turns, recovery was fast by the normal method or slower if the controls were released. It never appears to become uncontrollable. Search view - Pilots view is superior on the Spitfire Mk XIV due to the lower engine cowling. Range and Endurance - Both aircraft carry the same amount of fuel (96 gallons in the main tank and 27 gallons in two wing tanks.) Refueling checks made to compare consumption showed than when the two aircraft stayed together throughtout the trials, the Griffon engine was using approximately 10-15 gallons more fuel per hour than the Merlin. Conclusions - Of the two aircraft the Spitfire VIII is preferable at all heights up to about 25,000 feet except for its turning capabilites. It is much lighter on the elevators and easier for the average pilot to fly. Its performance and fuel consumption are better. The Spitfire XIV is superior above 25,000 and with its better turning characteristics it is more than a match for the Spitfire VIII. The difficulties of trimming will probably be reduced as pilots gain familiarity.



Stall: Flaps up 87, Flaps down 75

Engines: Griffon 65 2,035 hp @ 7,000 feet, Griffon 85 2,750 hp @ 8,250 feet, Griffon 61 1,785 hp @ Take off (2,750 rpm)

Range: 460 normal, 860 max

Endurance: 1.9 hr

Service Ceiling: 43,000 feet

