Small, fast, single-seat aeroplanes always hold a strong appeal to those who appreciate flying in the true sense of the word, so it is hardly necessary to mention that when I was granted an opportunity to fly a few hours in a Comper Swift I wasted no time before leaping into the air!
However, before harping on the merits of the type and the joys of flying it, perhaps a few details of its origin and layout will place the reader more truly in the picture, for the CLA 7 Swift is one of those pre-war designs that can claim no really direct connection with the major members of that aircraft industry; in fact, it is largely the result of a pilot’s dream, being based on the ideas of one who knew what he wanted to fly and therefore built it to his own personal ideals. How some of us wish that we could do the same today!
Responsible for the Swift’s conception was F/Lt. Nicholas Comper, an instructor at Cranwell, who was also behind the series of light aeroplanes that emerged from there as R.A.F. products. Unfortunately, he died just before the last war, as the result of an accident that was in no way connected with flying. Nevertheless, he lived long enough to prove to all those interested that his ideas of a sports-man’s mount were not far adrift from what others wanted — in appearance his little Gipsy-engined Streak left little to the imagination of an enthusiastic racing pilot, although in practice I believe it proved too vicious.
The Swift is a diminutive single-seat high-wing monoplane of just sufficient size to accommodate the pilot and with no room to spare; various power units have been used, but the standard equipment was the 75-h.p. Pobjoy “R” seven-cylinder radial fitted in an uncowled state, and one of the two surviving airworthy examples, G-ACTF, still retains this engine. This machine, until recently owned by Ron Clear, an Airspeed test-pilot, sports an attractive removable enclosed canopy as a very post-war mofification.
At one time, three Swifts existed with a far greater abundance of power than was available from the Pobjoys. Fitted initially with the Gipsy III, this “hotted” version was married eventually to the inevitable Gipsy Major, and one of these, G-ABWW, remains astray somewhere in this country despite fruitless efforts to trace its whereabouts.
G-ACTF’s only companion is G-ABUS, of 1932 origin and the fourth of the type to be built. Although most, of its life has been spent behind the standard “R” engine, in 1951 it was remotored to the tune of an additional 15-h.p. with the Pobjoy Niagara 3. and numerous other minor modifications have taken place front time to time.
G-ABUS, blessed with the name “Black Magic” and finished in a glossy black with white trimmings, has had a fairly notable career in post-war racing circles, firstly in the hands of A. L. Cole and more recently with Geoffrey Abington, a Fairey test-pilot and former owner of the late-lamented Miles Sparrowhawk G-ADNL., at the wheel. When permanent racing numbers were allocated for the 1951 season it was given “51,” which figure it still holds.
Within, ‘BUS boasts only the bare essentials for practical operation. There are neither brakes nor a trimmer, and the only instrument not usually found in so small an aeroplane is the cylinder-head temperature gauge, a rather essential item for a radial engine that is neither cowled nor baffled. It is interesting to note an increase of up to 100 deg. C. during a take-off and climb.
Starting can be something of a problem; the only person who seems to have the knack of swinging the propeller and obtaining the desired result each time is Douglas Bianchi, in whose capable technical hands “Black Magic” spent the past season. It is at this stage that the unwary pilot feels rather ill-at-ease, for with the engine idling the noise and vibration are nerve-racking, to put it mildly!
The reason for this shattering behaviour is the engine/propeller reduction gearing, and the sequence of events smooths itself only at settings in excess of 1,600 r.p.m. At this and all higher throttle openings the running is exceptionally sweet and quiet, and as the Niagara is a high-revving unit it is possible to remain at the higher end of the scale and so prevent the “sewing-machine” rattle.
Moving away needs a fair burst power to initiate the roll forward, as there is a tailskid attached direct to the fuselage stern-post and therefore unsteerable. Taxying, as a result, can present a very real problem and progress across wind is virtually impossible under certain conditions. With so few movable items to play with, the only possible vital action of relevance is to ensure that the fuel is on, as trimmer, mixture control, flags and hatches are completely absent.
Normal take-off procedure is not to be encouraged, as the propeller ground clearance is disturbingly small. As the aeroplane is light and the power available excessive, it is safe to hold the small wooden control column well behind neutral, open the throttle and wait; however, the delay is a short one, for into the gentlest of winds the Swift unsticks in under 100 yards and literally hangs in the air! At this stage the air speed indicator registers nothing and the rev-counter about 3,000.
The climb itself is fantastic and can be made at any angle to suit one’s feelings and ambitions. I have not measured the rate of ascent, but taking off from the south at White Waltham it is easy to attain 1,100 feet on crossing the northern boundary still with no l.A.S.
This business of having no measurement of forward speed is not quite so terrifying as it may sound, for it does not necessarily mean that the true figure is a very low one. Although the A.S.I. is graduated upwards from 40 m.p.h., the absurd position of the pilot and static heads between the front and rear wing-struts causes a blanketing effect and it is a wonder that the instrument reads at all! However, it jumps into action at between 65 and 70, and appears to be quite normally accurate throughout the remainder of the scale.
As soon as one is airborne in the Swift and, in fact, to a smaller extent even when on the ground, there is a very satisfying sensation of being aloft in a home-made toy, yet at the same time having an almost fighter-like reserve of power that creates an uncanny unreality. I like very small aeroplanes with an abundance of horses, so I was more than happy with it right from the start.
I have mentioned already that there is no fore-and-aft trimmer and whilst climbing this is particularly noticeable, for ‘BUS is nose heavy and it is necessary to maintain a steady back pressure on the stick at all times. With no recommended figures available I coined my own, to find 80 I.A.S. and 3,000 r.p.m. a comfortable combination.
Stalling is a game always to be tried with a strange type and as one may not know the idiosyncrasies of the individual machine, I took the Swift to 3,500 feet and had a go. Owing to the ineffective pilot it is impossible to measure the speed at which it actually falls out of one’s hands, but with power off there is an increasing degree of all-round slop at speeds below 70, and at a guess I should imagine the stall to be around the 50 mark, but it is a tame enough sequence with no inherent flicking tendency, although the starboard wing will play foul if provoked.
The Swift appears considerably faster than it is in reality, a delusion caused, of course by its size. At a cruise setting of 2,800 r.p.m., the needle settles at between 105 and 110 m.p.h. and at this speed the controls are pleasantly responsive. They are, in fact, about as light as one would like them to be, although there is an unfortunate sensation of a hunting instability.
At full-throttle the A.S.I. winds round to 136, whilst the revs, do the same to nearly 3,600 under very favourable weather conditions. I mention this as on those days when neither humans nor machines seem to have any power, the Pobjoy refuses to give more than 3,400 r.p.m. The gearing gives a very genuine step-down in revs, from engine to propeller, and it is momentarily worrying to look at the gauge and then glance at the large coarse-pitch blades, which appear to be windmilling — all of which creates the erroneous impression of an engine failure!
Being a small aeroplane with plenty of urge, there is more change in foot-load between full throttle and the glide then is normal with light types. Actually, at 3,200 r.p.m. with feet off the rudder and holding-off bank with port aileron, the nose swings starboard round the horizon through ninety degrees in sixteen seconds!
In pre-war days Swifts were aerobated with some élan, but the increased weight of the Niagara over the Pobjoy “R” has resulted in G-ABUS being granted a C. of A. only in the Special Category. This is a pity, for I should imagine that successive loops could be maintained with a gradual increase in height between each.
Lack of view is perhaps one of the Swift’s most apparent shortcomings. In flight there is a complete blind spot forward, so it is necessary to poke one’s head outside either to port or starboard and look ahead under the wing. However, this shortcoming is not very upsetting, for in normal circumstances there is no need to be able to see what is going on in front; it is merely a luxury to which we have been accustomed and the Swift’s blindness is no worse than some piston-engined fighters, while the racing Percival Mew Gull G-AEXF after the Henshaw/Cross modifications (see Motor Sport for April 1952) was considerably worse. It is merely a penalty for performance.
Returning to the circuit it is especially important to keep one’s eyes wide open and perhaps raise the odd wing from time to time to ensure that all is clear; with no flaps, the glide is rather flat and there is a marked tendency for the air speed to build up on the way in, but a curved fighter approach should be made, aiming to cross the boundary at from 75 to 80 m.p.h. I.A.S.
The actual landing is straightforward, but must be made on three points owing to the small propeller clearance. Fortunately it is quite safe to hold off rather high and drop in from a few feet, rather than risk touching without having the tail right down; however, towards the end of the run if slightly out of wind there is a tendency to weathercock and this cannot always be checked, for the rudder is the only medium for directional control and when this becomes ineffective at low speed there is nothing left. The moral, of course, is to land exactly into wind, but this is not always possible.
During last summer I flew about fifteen hours in C-ABUS and became very attached to it. It is an aeroplane that serves no practical purpose — there is no room even for personal luggage, as everything has been faired over — but an ideal mount for personal entertainment of a rather spirited nature. If I finish by saying that I would like a Swift of my own, preferably Gipsy-powered, I consider further comment unnecessary.—D. F. Ogilvy.