Pilot Reports
Flying the SE5a
(Reprinted with permission from PROP-SWING, the journal of the Shuttleworth Veteran Aircraft Association)
It is summer. Someone has painted the sky a uniform light blue except where an unseen hand has blotted off the colour to form scattered cumulus clouds. The wind is blowing from the northeast at the canter. I am standing in the open doors of a blister hangar looking at a small olive-green biplane. In 2 days there is to be a big show; it is important that the machine be ready for it. Recent rectification requires that it must be air tested before the day. I am to fly the air test.
The engineers brief me on the repairs made and what to look out for and when. I try desperately to remember it all but know I shall forget something. The aircraft is pushed out of the hangar, rocking from side to side on its narrow track undercarriage. When it is arranged tastefully on the aerodrome, head to wind, the engineers busy themselves with last minute details. The chocks just so, the tanks all full and primed. I remove the pitot cover because I fear one day I will walk right past it and go flying with an unwanted extra streamer on the interplane strut. Now it is my turn to walk clockwise around the aircraft: I pretend to know what I am doing, waggling this and checking that. Are these ailerons differential? The radiator shutters are open (I must remember to check that the lever in the cockpit agrees and then close them for the warm-up). I double check that the pitot cover is off and having reached the tail check that the control surfaces are free to move.
It is time to mount the machine. Left foot in the kick-in’ stirrup just behind the wing trailing edge and then, with one hamstring straining, kick, swing the straight right leg over the fuselage and over the headrest before bending it at the knee to let the foot fall into the cockpit and onto the seat. The left leg joins the right inside and I fidget my feet down into the negative U hoops on the rudder bar as I settle down into the seat. The cockpit is small and there is no room for a parachute.
Like many pilots nowadays the first thing I want to do is to fasten my harness, but in this aircraft there is one job to do first. A small brass tap residing somewhere close to my left ankle must be set in line wit the adjacent pipe now, for once I am strapped in lightly it will be quite beyond my reach. Now, with the harness secure I am ready for the preliminaries to engine start. First I must pressurise the fuel tank to ensure a good feed to the engine. A mahogany-handled pump is used and always requires more pumps than I can comfortably provide without an aching left arm. Next, the confusing 5-position fuel selector is set to, let me see now, oh, yes, SERVICE TO CARB, and the air selector can go to FROM ENGINE AND HAND PUMPS.
I announce to the 2-man starting crew that I am ready to prime the engine. A typical start-up litany follows: “Switches Off Throttle Set, Sucking In.” As the propeller is turned one compression at a time, I operate another small pump adjacent to the first to squirt a mix of petrol and oil into the cylinders. I pump in 4 shots as the propeller is turned and then 2 more for luck. A voice from beyond the nose calls, “Ready for starting.”
Now we must all be careful as there is danger for the prop swinger if things are not done just so. I can set the prop swinger with one hand on the propeller which he has positioned ready for the start; his other arm is held slightly unnaturally behind his back to keep it clear of the prop when it starts. Another engineer is immediately to my right ready to turn the starter magneto crank, although as yet his hand remains well clear. I call “Contact” to let everyone know that the mags are now live; and then call “3 -2 – I – GO.” On the “GO” the propeller is swung; when it moves, and never before, the starter mag is cranked vigorously. Nothing happens.
“Switches Off” comes from the swinger. I select the mags off and report “Switches OFF.” The prop is repositioned and another call of “Ready for Starting” comes from up forward. The switches go on, “Contact” is announced, and then “3 – 2 – I – GO.” This time we are rewarded by a distinct “Chuff” We repeat the procedure twice more; we re-prime and try again. At last the motor fires and settles into a crackily fast idle, I adjust it to 1000rpm and check that the oil pressure is good and turn off the starter magneto.
There follows a longish wait for the coolant temperature to rise to the “opening up” value. Just before the radiator temperature reaches 60° C I open the rad shutters and once 60°C is reached I circle a finger vertically indicating my desire to test the motor. One of the engineers holds the tail down while I hold the stick fuilly back (all this to prevent the aircraft from nosing over and smashing its prop) and open the throttle slowly to 1640rpm. The rpm needle oscillates slightly, averaging the required value. Now holding full back stick with my right forearm while guarding the throttle with my right hand, I reach over with my left hand to select the magneto switch from left to right.
On selecting L a small rpm drop is apparent but the engine note remains steady (that’ll be OK). I move the switch to R and the rpm falls 150 and there is no mistaking the resultant misfiring. I throttle back, we have a brief discussion and try once more with the same result. This won’t do. I will have to switch off. It is customary to open the throttle as the mags are switched off but this can be fraught with danger for the unwary. The ignition switches are not really on off switches in the same way a light switch is. To ensure the motor will continue to run even with a faulty circuit it has been so designed that when the switch is ON the circuit is broken and the engine can run. When the switch is turned OFF the circuit is made, earthing the magnetos and stopping the engine – but only if the circuit is complete. On one occasion I switched off and opened the throttle only to find the motor still running and the machine ready to nose over onto its prop. Not this time – with the stick held fully back, I switch off and when I hear the motor die I open the throttle. It stops cleanly.
Reluctantly I climb out and leave the machine with the engineers. Sometime later, after a plug set change and a clean-up of the suspect magneto, we are ready to try again. I have spent the time wandering among the other fighting machines here. There are scouts and 2-seaters in the various sheds, even a captured LVG.
We are getting old hands at stalling this engine by now, and freed of its earlier ailments, it decides to give us no more trouble and settles into a good idle. The mag check goes off without further incident and I wave the chocks away. The aircraft is fitted with a new tailskid ‘knife’ giving better braking on the rock-hard grass than I would expect with a flat skid shoe. Directional control is no problem in these wind conditions even when taxiing downwind. I do the usual before-takeoff vital actions plus the specials for this aircraft. Seeing no other traffic approaching to land I let the aircraft turn into wind and roll forward slightly to straighten the tailskid. At this stage I take a few moments to have a last check around the cockpit. The oil pressure is 50psi, the rad temperature is 80°C, and the fuel pressure is 2-1/2 psi.
I open the throttle steadily- a slam will cause a distinct falter and cannot be good for the engine. The aircraft accelerates briskly, and before I have fuilly opened the throttle I have levelled the machine with forward stick. Now, with the tail up, I can see ahead. The aircraft is light on its wheels, skipping from bump to hump; I know it will fly now although I have not referred to the airspeed indicator. I select a climbing attitude and, when clear of the trees, throttle back to 1800, the airspeed is 70mph; too fast; the best climb speed is 60, so I adjust the attitude and wait for the speed to scale. As this is a test flight I climb straight out at the best climb speed monitoring the fuel pressure, the oil pressure and the rad temperature until reaching 1000’.
All is well. I look for other aircraft but the sky, as usual, seems completely empty. I have started a stop-watch on takeoff and I will time the climb to 3000’- it will he a good indication of the power output from the motor. During the remainder of the climb I monitor the engine instruments, look out for aircraft, particularly from the southeast – into sun – and make a series of gentle left turns to keep the aerodrome in sight under the port trailing edge.
As height is gained I can relax a little, as height is like having savings in the bank, it provides a breathing space should things go wrong, in this case should the motor choose to stop. I can use height to try to diagnose the problem – Fuel? Ignition? Icing? I might attempt to restart if possible- or, if not, I can plan a leisurely glide landing back onto the aerodrome. The pilot that flies the machine next may not be able to climb as high as I can today, nor spend as much time studying the engine instruments. He may be flying in formation, with all his attention on his leader, or he may be maneouvring aggressively concentrating on the task in hand but, if the engineers have done their job well and I do mine then, with luck, he should have no unpleasant surprises.
The scattered cumulus cloud is at 3000’ and it has taken 4 minutes from the start of the takeoff roll to reach it. Now staying within about one mile of the airfield I throttle back gently to make sure that the motor continues to run at the minimum throttle setting. I slow down until the machine stalls at 4 mph and note that I can keep the wings level into the stall; and although there is no appreciable warning the stall, when it occurs, is a classic wings level nose-drop. After 2 more I am satisfied that the stall handling is as it should he, the airspeed indicator is telling something close to the truth and the motor will not stop if the throttle is closed at low speed.
The next pilot may have to dive to high speed and fly combat manoeuvres against an enemy aircraft and so I must make sure the aircraft and engine are ready. I dive to 120mph keeping the rpm under 2000 by throttling back. Then pull up briskly, keeping the wings level until the horizon is lost under the nose, then by looking left at the upper wingtip I keep the orientation of the loop correct with small rudder and aileron inputs before looking back for the inverted horizon. When this arrives it is clear that I have not kept the wings completely level; but there is adequate control to put matters right before completing the loop, watching the airspeed and the rpm in the recovery dive to keep them well within the limits.
I wing-over to the right to stay close to the field, and from the wing-over I start a barrel roll to the left getting the nose very high to make sure that the second half is not over steep. From the hand roll I pull up for a stall turn to the left. In a classic stall turn the aircraft is pulled into vertical flight and as it stops rudder is used to yaw the aircraft through 180 degrees so that it is pointing vertically down; recovery to level flight is thereafter straightforward. It is a good way of reversing direction. But at the point of yawing the airspeed is near zero; and as the effectiveness of the flying controls is proportional to the square of the airspeed (and the square of zero is very small!) it is quite easy to put the aircraft into a position from which the pilot cannot prevent a tailslide or flop-over which could damage the aircraft or its engine. It is not my job today to see if I can break the machine, so I cheat on the stall turn by starting the yaw with airspeed to spare. With some opposite aileron to overcome the dihedral effect the machine rotates through the first 90 degrees under control; the next 90 is considerably aided by gravity acting on the motor and this pulls the nose down cleanly. I try one the opposite way; the only difference seems to be less aileron control required to stay in the plane of the manoeuvre hut this is due to the effect of the propeller.
Confident now that the machine can climb and manoeuvre, I dive to the maximum speed checking the engine rpm, temperatures and pressures – everything is fine and the motor sounds smooth and untroubled. I carry out a series of simulated strafing runs, tracking a point with the gun sight, and once again the aircraft responds normally. A few low-level evasion manoeuvres between the trees complete the test, and now I pull up and position for the landing. The fuel pressure and oil pressure are both good and the rad temperature is 85. I slow the aircraft on the downwind leg to 70 mph and when abeam my landing point turn in, throttling hack and easing the speed to 65. As the speed reduces, with little slipstream from the prop over the fin and rudder the machine feels very loose directionally: it is quite happy to yaw this way and that, and my attempts to control its head accurately meet with only limited success.
Now, lined up into wind I bring the speed back to 60 and wind the tail trim fully nose up for the landing. As I get closer to the ground I flatten out, surprised initially with the sensitive pitch control; but this is a scout after all. I memorised the 3-point attitude before takeoff- it is when the lower edge of the windscreen mount is on the horizon. I start a scan between the attitude and the height as judged by looking at the grass just forward of the port wing. The ideal landing will he achieved if I put the aircraft in the 3-point attitude as the height reaches zero – the wheels and the tail skid will all touch at the same moment. So much for the theory.
The aircraft touches down slightly before reaching the 3-point attitude – this aircraft exhibits little float once the throttle is closed and with the speed below 55 it stops flying pretty quickly. This is what has happened, and it has caught me by surprise – the aircraft has dropped the last foot onto its main wheels – I should know better by now but I must be a slow learner. The aircraft responds out of all proportion to the magnitude of my misdemeanour. It buckets from wheels to skid and back again 4 or 5 times but never more than a foot or so from the ground.
When things settle down I add power smoothly to take off again. I fly a tight circuit, not above 400’, a more or less continuous 360 degree turn until I am flattening out again 3 or 4’ above the grass. This time I am ready, and steeling myself not to overcontrol, I hold off a little longer and this time things work well and the machine sets down.
Without drama on 3 points, it starts to swing gently to the left, but this is easily corrected and I am reminded once again to pay attention to directional control right down to walking pace. I turn to the left through 90 degrees and fully open the rad shutters. A leisurely taxi back to the sheds allows the heart to slow down and subside gratefully to its proper resting pace. Now it is possible to wear a confident smile and assume the appropriate aviator air.
I am met by the engineers who are eager to know if the machine needs more work. At their request I repeat the magneto check and then I allow the engine to idle for a while noting that the oil pressure is now down at 30psi. The idle rpm is lower than the book figure and really should be adjusted up but there was no tendency for the motor to stop, and if set too high it makes for over-long landings.
After allowing the motor to idle for a couple of minutes I switch off and climb out of the cockpit answering the engineers questions as I go. We agree that the machine is ready for service. I walk towards the flight offices with a certain lightness of step because it is always a pleasure to fly a Scout Experimental No 5.
Where did this test flight take place and when? The depot at St Omer in August 1918 just before the big push at Biaches? No, at Old Warden Aerodrome, August 1999.
