S E C R E T

 

111 (Fighter) Squadron, R.A.F. Northolt,
 
Station, Headquaters, Northolt.
 
(Copy to F/Lt. BULMAN for information. Delivered by hand).
 
14th January 1938.
 
1113/93/Air.
 
Subject:- Tests to be made to determine the Operational Characteristics of Hurricane Aircraft.
 
              In reply to your letter N3/12/4/E dated 16th December 1937 on the characteristics of the Hurricane Aircraft, this Unit has now been equipped with Hurricanes for four weeks, and forwards herewith a preliminary report on the flying characteristics of this aircraft.
 
2.       FLYING CHARACTERISTICS.

 (i) The Hurricane is completely manoeuvrable throughout its whole range, though at slow speeds between 65 m.p.h. and 200 m.p.h. controls feel a bit slack.
 
 Owing to its weight and speed some time is taken in coming out of a dive and at high speed the turning circle is large.
 
 On the ground the Hurricane is as manoeuvrable as is possible and has the additional advantage of feeling secure across wind or a strong wind owing to its high wing loading.
 
 (ii)Cross wind landings are particularly easy in the Hurricane. Simplicity in cross wind landings is a characteristic of aircraft with high wing loading.
 

 (iii)VIEW:-
  (a)Taxying with the seat full up and the hood back is exceptionally good all round, better in front and above than in fighter aircraft before in the service, and just as good in all other directions.
 
  (b)Taking off.   The View is considerably better than the Gauntlet and better than the Demon, both individually and in formation.
 
  (c)Landing.   The View is considerably better than the Gauntlet and better than the Demon both individually and in formation.
 
  (d)Flying in formation   The view is better than the Gauntlet or Demon with the hood open or closed, though at present no experience is available of flying in formation, in bad rain or damp cloud when it is thought the hood may fog or ice up.
 
  (e)The View is better than the Gauntlet or Demon.

 (iv)Formation flying at height at speeds in excess of 200 mph is very simple. It is thought the reason being that the air resistance at this speed is considerable and that the power used by the engine at this speed the pilot can slow his aeroplane up or accelerate it very quickly indeed.
At slow speeds in the neighbourhood of 100mph when only a small proportion of the engine power is in use and the resistance to the air of this clean aeroplane is comparatively small, some difficulty is found in decelerating the aircraft though no difficulty is found accelerating.
 
 Landing in formation is similar to landing in formation in any other type of aircraft.
 
 Taking off in formation is simple, but immediately after leaving the ground when pilots retract their undercarriages and flaps aircraft cannot keep good formation as undercarriage and flaps retract at different speeds in each aircraft. It is recommended therefore, that takeoff should be done individually in succession.
 
 (v)The Hurricane is a simple aeroplane to fly at night. There is no glare in the cockpit, either open or closed, from the cockpit lamps or luminous instruments.
 
 The steady steep glide at slow speed which is a characteristic of this type makes landing extremely simple.
 
 The takeoff run being longer than has been experienced in the past, it is recommended that the landing light should be at least 600 yards away from the beginning of he run instead of the normal 250 yards on ordinary flare paths.
 
 Opportunity has not arisen to test the landing lamp installed in this type, but experience is available to this unit of a smaller lamp installed experimentally in Hart aircraft when no difficulty was experienced in landing without any lights on the ground and it is anticipated that this will be the same with the Hurricane.
 
 (vi)The minimum size of aerodrome from which the Hurricane can be operated in still air in England must depend upon the obstructions surrounding the aerodrome. With good approaches and inexperienced pilots the Hurricane could be operated from an aerodrome 800 by 800 yards and with experience could probably be reduced to 600 yards.
 
 (vii)The Hurricane without its engine running has a very steep glide and to the pilot inexperienced on this type judging the flattening out may be difficult. Therefore it is recommended for initial training that pilots should come in with their engines running. After they have become accustomed to an aeroplane of high wing loading and steep glide they should be able to land efficiently off the glide in the Hurricane as in any other aircraft. It follows that landing with an engine lengthens the period of holding off, making landing easier, and in the event of flattening out to high gives the pilot time to stop the aeroplane falling heavily on the ground as speed falls off.
 
 (viii)The cockpit is large and comfortable and there is room for the largest man inside with the hood shut and by using the adaptable seat the smallest man can see everything comfortably.
 
 It is thought that from an operational point of view that the system of having a selector box and a lever which each must be operated to move either the undercarriage or the flaps is unsatisfactory and furthermore it occupies for a period of perhaps half a minute the right hand of the pilot whist he flies with his left and neglects his throttle. Should it be essential to take off in formation as in conditions of bad visibility the difficulties of the system are obvious, and it is recommended that two simple controls, one which moves the flaps to full up and full down position and the other which would move the undercarriage from full own to full up and vice versa could well be substituted.
 
 All other controls are easily accessible and efficient and the instrument lay out is good and not complicated.

3.       OPERATIONAL CHARACTERISTICS

 With more experience on this type of aeroplane further figures will be submitted, but as far as can been seen at present the indicated airspeed at 2,000 feet is 270 m.p.h. at 10,000ft indicated airspeed 260 m.p.h. and at 15,000 feet indicated airspeed 240 m.p.h.
 
 The petrol consumption at 15,000 feet and economical cruising speed of 160 m.p.h. indicated correcting to 200 m.p.h. is 25.08 gallons per hour. Plus 2 boost the maximum permissible cruising speed-petrol consumption approaches 60 gallons per hour.
 
 At 2,000 feet an indicated air speed of 200 m.p.h. petrol consumption is 30 gallons per hour at an indicated boost of plus one.
 
 The remaining operational characteristics have yet to be investigated, but as yet the windscreen has shown no sign of oiling up and the cockpit is weather proof as far as can be seen at present.

 J.W.Gillan.
Squadron Leader, Commanding,
111 (F) Squadron, R.A.F.
NORTHOLT.

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