In the hangar, the SE5A looks just great. A squat biplane with ailerons on each wing, She’s Tiger Moth size with 200 HP up front and she’s still cleared for aerobatic flight. One can’t wait to get her into the air, but lifting the tail onto a trolley to get her out of the hangar rapidly brings the budding SE pilot down to earth – she is heavy! It’s no wonder there’s four ‘lift here’ points marked on the fuselage. Help must be summoned and the tail eventually coaxed onto the hand-steering rig. At last, the machine can be moved from the hangar to the airfield.
Shuttleworth pilots must learn how to operate old aeroplanes from the start of their careers at the Shuttleworth Collection. The best way to learn is by practice, so we start with pushing aircraft into and out of the Hangar. As with all aircraft of the same vintage, it’s easier to push the SE5A backwards. Further, the pilot soon learns that hand pressure must only be placed on the ends of struts, not in the middle, and only on a rib joint when pushing on the leading edge of the wing. Some aircraft, the Tomtit for example, require an extra man to prevent the tail from jumping out of the box of the hand-steering gear, but not so the SE5A….
Lets have a look at the layout of the machine: Starting at the sharp, or rather blunt end in the case of the Collection’s SE5A, we have a 200 HP Wolseley Viper, eight cylinder ‘V’, liquid cooled engine. The coolant system consists of a liquid filled (70/30 water/glycol) radiator at the front of the machine with pilot operated shutters to control the temperature between a nominal 75 to 85 degrees centigrade. The control lever is located on the port cockpit wall; it comes easily to hand and operates in the natural sense – forward opens the shutters and allows increased cooling airflow through the radiator. The system is replenished through the tap on the top of the radiator, it holds seven and a half imperial gallons. A small condenser and expansion reservoir is fitted to the right side of the upper wing centre section and an overflow pipe exits at the right trailing edge – more of this later.
The engine oil system is self-contained and, therefore, is of little interest to the pilot. However, some oil fumes emit from various parts of the engine in flight, the location of which must be noted and, of course, oil pressure must be monitored during all times that the engine is running. In some respects it is a relief (no pun intended) not to have to monitor oil flow by the amount of caster oil thrown back at the pilot in flight, as with the rotary.
Fuel is carried in two tanks, one of four imperial gallons capacity fed by gravity and located in the left part of the upper wing centre section. The other, of twenty eight imperial gallons capacity, is located in the forward fuselage and is fed to the carburettor by air pressure from an engine driven pump or pilot operated hand pump. The fuselage tank is referred to as the ‘service’ tank, and the centre-section tank as the ‘emergency’. As with the water system overflow, that of the emergency tank is at the trailing edge of the wing centre section, but this time, it is on the left.
With four gallons of fuel, the emergency tank will only keep the engine running for about 20 minutes at cruise power, therefore, as far as possible, it is kept full. Replenishment is carried out by pressurising the service tank and opening the line from the latter to the gravity tank by turning the fuel selector to the appropriate mark. The fuel selector is a rotary cock mounted on the left side of the instrument panel which either allows the fuel tanks to be isolated, or it opens taps to connect either the service tank to the emergency tank, or either both or separately, the service and emergency tanks to the carburettor. Replenishment is complete when the fuel overflows from the vent pipe.
Now, with two overflow pipes, both having the capability of dispensing scalding and/or noxious fluids, located just a few inches from the pilot’s head, the pilot must beware. In normal flight, should the fluids overflow, most of the liquid will be taken straight back in the slipstream. But taxiing out or in, with winds from all points of the compass, the direction of overflow can be anywhere. The desire to rid oneself of ones goggles immediately after landing must be put aside and the said items of protective clothing left firmly fixed in front of the eyes. It’s also prudent to select the emergency tank for taxiing in. It takes ‘the top’ off the fuel in the tank and thus, helps prevent some of the leakage.
As well as for transfer to the emergency tank, air pressure is used to transfer fuel from the service tank to the carburettor and it is provided for by either, or both of, the engine driven and pilot operated hand pump. A second rotary controller fitted next to that for the fuel operates valves that either isolate the airflow, or open lines from either or both of the air pumps to the service tank. The cockpit hand pump has a further tap at its base that either isolates the pump, connects it to its air line, or allows air pressure to blow off to atmosphere. A pressure relief valve is fitted adjacent to the rotary switch that is reserved for ground crew adjustment of blow-off pressure. However, pilots with the relevant knowledge may use it to let off excess pressure in emergency by pulling up on the central valve spindle. A pressure gauge, red lined at two and a half pounds per square inch, also located on the pilot’s instrument panel, completes the air system.
Only the service fuel tank is gauged. But, as the gauge is fitted to the rear of the tank, it is almost completely out of the field of view of the pilot, being situated about two feet behind (in front of?) the main instrument panel.
To complete the description of the fuel system, a 1.8 pint priming fuel tank is fitted behind the engine firewall to allow priming of the engine via a ki-gass primer pump which is located low down on the port cockpit wall.
Walk around of the aircraft prior to flight follows the normal pattern. Special note must be taken of the security of the aileron control circuit as in the event of a wing drop during a previous take off or landing, the lower aileron horn would have contacted the ground first and if damaged, could lead to loss of aileron control on a future flight – close inspection of the Collection’s aircraft will show repairs in this area from previous mishaps.
Well meaning groundcrew always remind me to watch my head when mounting the aircraft, but at some stage in the entry/egress process, I always manage to ‘nut’ the Lewis gun in some way or other. Contemporary literature and pilot’s reports of the period all criticise the Lewis gun mounting. I can understand why, and not just from the ‘nutting’ viewpoint. With a Vickers gun mounted in the fuselage and arranged to fire through the propeller arc, why not mount another similar gun next to it. It would have provided a better concentration of bullets, a gun that didn’t require reloading in flight and a sight line close to both gun axes. In contrast, the Lewis mounting allows for a poor harmonisation of shot and therefore a low bullet density per unit area at the target and a large parallax between gun and sight. Further, and more importantly from a practical point of view, it requires reloading by pulling it towards the cockpit, and changing a drum of ammunition which is now flat plate to the slipstream. Also, the drum must have been stored in some way, and believe me, the cockpit is small. Then, after reloading, the pilot must push the gun back into position against its gross weight and also against the slipstream. How this could be achieved during combat manoeuvring beats me; it probably had them beat them too, and in more ways than one.
Anyway, we’re now seated in the cockpit and preparing for flight. Again, the groundcrew will often aid the pilot by pumping the service tank to pressure during their own pre-flight inspection. If not, about five minutes of slow pumping will be required to achieve the magic 2.5 psi tank pressure. Owing to the small pipe size, fast pumping will only serve to exercise the blow-off valve and increase the job time by a further five minutes – patience is required.
With the tank pressurised, one can now strap in – the tasks are impossible the other way round as the hand pump valve is located just outside the pilot’s reach when the pilot’s harness is fully secured. When settled, fuel is selected from service to carb, tank pressure is selected from hand and engine pump, and the groundcrew is informed that all is ready.
Consultation with the Crew-Chief provides the number of priming strokes required and the propeller is turned as the priming fuel is injected. The magneto switches, left, right and starter, all located on the starboard cockpit wall, are set to ‘ON’ and the throttle is checked closed.
Ignition for starting is by starter magneto, the handle of which is located on the outside of the starboard cockpit wall. For starting, it is turned rapidly by a third groundcrew member as two others pull the propeller over compression. Co-ordination is required as the magneto must not be turned until the propeller is moving, otherwise a kickback may result with it’s inherent dangers to the swinging crew. The normal method employed at Shuttleworth is for the pilot to shout: ‘Three – Two – One – GO!’, at which point the propeller crew pull the propeller and as soon as the third member notes the propeller’s movement, and not before, he rapidly turns the magneto handle. Normally, the engine starts at the first attempt, but the magneto must be kept turning even if the propeller apparently stops as a start can often be achieved even several seconds after the propeller has lost it’s momentum. As the engine fires up, the throttle is ‘cracked’ slightly to catch it, the engine, that is, and the oil pressure is checked. A rise to at least 50 psi must be noted within thirty seconds, but it is equally important that the maximum of 120 psi is not exceeded as this could lead to failure of the oil pump drive. RPM are kept below 1000 until smooth running is achieved, then revs are then set to 1000 for warm up. The 1000 figure must not be exceeded until the radiator temperature exceeds 60 degrees centigrade, but to prevent the coolant boiling due to temperature inertia, the radiator shutters are opened as the needle on the temperature gauge passes 50 degrees.
Power checks are carried out on the chocks, with groundcrew holding the tail down. I’m not sure why we do this given the excess weight of the SE, but it’s probably because we do it to all other aircraft and it’s best not to change SOP’s (Standard Operating Procedures).
Full power must provide over 1700 rpm, but is not normally confirmed until take off. The magneto check is carried out at 1600 rpm and should provide a limiting single magneto drop of 100 rpm. Slow running should be between 600 and 750 rpm; a higher figure leads to overrun on landing, a lower figure increases the risk of an engine stop in flight.
Given the weight of the aircraft, the heavy steerable tailskid and an engine that can be controlled down to a useful idle, taxiing of the SE5A is a relative delight. It’s given, however, that the field of view forward is poor and there are no brakes fitted, so appropriate care must be taken. In anything other than light wind conditions, it’s also prudent to enlist wing-walkers for taxy.
Normal pre-take off checks work for the SE, and they commence with tail trim checked at neutral. Tail trim is achieved by an all-moving tailplane controlled by a wheel fixed to the port cockpit wall. The wheel moves in a number of detents, either thirteen or fifteen, I can’t remember exactly. However, as the tailplane actuator is part of the tail skid mechanism, the aircraft weight acts against movement of the wheel and setting the trim on the ground with any weight in the cockpit requires Herculean strength – perhaps the same strength as that required to reinstate the Lewis gun after reload? Thus, to limit the required trim wheel movement, suffice to say that, seven clicks nose down from full up puts the aircraft in trim at take off with my 15 stones in the cockpit.
The coolant temperature is confirmed within limits and the radiators set as appropriate – on an average UK summer day, they would normally be about 80 degrees and full open respectively.
Lined up, it is almost impossible to see directly forward, but there are adequate references on which to check the nose attitude for landing and the relative position of the horizon can be noted. The throttle is smoothly opened, 1700 plus is achieved and oil pressure is checked. Rudder is required to prevent the swing, but the main sensation is that of positive acceleration – the 200 HP really makes itself felt, even given the airframe weight. The tail is raised and within a few seconds a flying speed of around 50 to 55 mph is reached. The aircraft flies off the ground with a will and settles into a natural climb at about 60 to 65 mph.
Both control power and harmonisation are good. The SE is very similar to the Tiger moth but with higher roll rate and slightly heavier controls. There is also the absence of the inertia caused by the Tiger’s heavy centre section fuel tank. The climb is rapid and as briefed, slight oil mist/smoke is seen to emit from the radiator area and the starboard side of the engine cowl. After take off, the rpm are reduced to 1900 to reduce engine wear, and coolant temperature and radiator flaps are monitored and regulated respectively.
An appropriate height for stalling is soon reached and the slow end of the flight envelope can be essayed. First, engine management must be carried out and the radiator shutters are closed as the throttle is retarded. The latter must be done slowly as fast engine modulation brings unwanted stress on the engine and may lead to a damaging backfire. The stall break occurs at about 45 mph with more than adequate buffet as a warning and a wings level nose drop as an indicator. In flight, she’s a benign aeroplane, but as we’ll see later, the pilot-friendly stall does not carry over into ground effect. Further handling assessment shows a more than expected amount of adverse yaw, but no other significant anomalies. The adverse yaw leads to steady heading sideslip on aileron application alone, but with an appropriate amount of rudder deflection, balanced turns can easily be achieved.
The cockpit field of view is poor forward and down, but good in other respects. The upper wing gives some restriction to the view, but it is not excessive. Cockpit noise is high and as the engine is effectively silenced by the long exhaust pipes, it is difficult to separate engine noise from that of the slipstream. As called for in the Pilot’s Notes, specific attention must be given to ‘feeling’ the engine’s operation as a misfire is difficult to perceive by ear alone.
Currently, the maximum airspeed is limited to 150 mph although, anecdotal evidence suggests that the machine was dived to in excess of 300 mph in combat. Aerobatics can be performed with ease at 120 to 130 mph, so the 150 mph never exceed is all that is required. Aerobatically, the machine handles like an overpowered Tiger Moth – aerobatic speeds can, after all, be achieved in level flight. However, engine rpm must be constantly monitored as an over speed cannot be supported – sever engine damage would result and as we have only one SE5A engine on the books at the moment……….. Further, one eye must never be far from the coolant temperature gauge and the radiator shutters must be modulated as appropriate. In practice, a radiator setting of open for take off, half for display, closed for approach and open after landing meets most of the requirements of an average Collection flight.
Aerobatic manoeuvres flown are now limited to loops and barrel rolls only. The machine is more than capable of a crisp stall turn and a precision slow roll, but both manoeuvres reduce oil pressure to zero and as a mark of respect for the longevity of the engine they are no longer flown.
So, we find ourselves in a delightfully powerful, manoeuvrable and easily flown machine. The only vice so far seen is an excess of adverse aileron yaw, but it’s easily controlled with judicious use of rudder. Surely the SE must have some vices…… After every flight must come a landing.
With no brakes and only a steerable tailskid for ground control the SE must always be landed into wind. Those who have tried otherwise have suffered the inevitable ground loop with attendant wing drop and associated destruction of the lower aileron horn. Also, it’s worth noting that following any wing drop on landing it is imperative that the machine is not flown again until the ailerons have been checked – thus, a go-around is not an option on a particularly bad landing.
The approach is set up into wind at about 60 to 65 mph aiming to over fly the airfield boundary at about 55 mph. A normal round out is attempted and then the fun starts. The stall in ground effect can lead to a nasty wing drop – beware aileron control – or if the stall is not coincident with touchdown and the machine comes down on the main wheels first a rather unnerving bucketing motion occurs. The machine rocks aggressively between the main wheels and tailskid giving the pilot the most uncomfortable ride. SE folklore has it that a go-around from this condition would only lead to a damaged propeller, so the best course of action is to hold the stick fully back and hope for the best. The only consolation is that it feels and looks far worse from within the cockpit than it does from outside.
Landing over, the pilot must first resist the temptation to raise his goggles to wipe his sweating brow and instead, to give himself the best chance of avoiding a petrol eyewash, turn the fuel cock to: ‘FROM GRAVITY TO CARB’. Oh!, nearly forgot, and also open the radiator shutters.
After flight, the engine is allowed to temperature stabilise at fast idle for about 3 to 5 minutes, then it is shut down from slow idle by turning off the magnetos in turn. The fuel and air are then isolated and tank air pressure is blown off using the hand pump tap. All that remains is the traditional ‘nutting’ of the Lewis gun as the cockpit is vacated.
It’s so easy to criticise an aircraft of the 1914 – 18 era when compared to modern specifications written nearly a century later. But in the case of the SE, I believe we have an exceptional aircraft. True, the systems require more than normal monitoring, but they do provide several methods of getting fuel to the engine in the event of failure or battle damage. The coolant system also requires time and effort, but otherwise the operation of the machine is simple. In any event, the systems are easily learned and understood. Any pilot who is competent on the Tiger Moth would have no difficulty converting to the aircraft in very few hours indeed. As a combat aircraft it was, and under the same circumstances, still would be, an effective machine. Perhaps the only let down is the characteristic Lewis gun over the top wing, but it just wouldn’t look the same without it, would it?
ã A J Sephton
ANDY SEPHTON