RAF's 4 Squadron - how we learned to look after the Avro Rota autogyro

For an airman on No 4 Squadron, learning to look after the Avro Rota autogyro was not the most tantalising prospect — but it certainly made the summer of 1935 an interesting one

Early in 1935 I was called in to the flight sergeant’s office and told I was being flown to Old Sarum for an autogyro course with the flight commander, who was going for a flying course at the same time. I was not too sure about this as I only had a vague idea what an autogyro was. It was something quite new, and on occasions I would be landing in small fields to pick up army officers, who would be getting air experience for the coming manoeuvres. This was nothing unusual for us on No 4 Squadron, as being an army co-operation squadron, stationed at South Farnborough, we spent nearly all our time working with the army. In the summer months we were detached to various places, living under canvas, and were either artillery spotting, photographing the ‘enemy’, or carrying out reconnaissance during the army’s exercises.

Avro Rota K4232 was among an initial 10 licence-produced Cierva C30As delivered to the RAF between August 1934 and May 1935. It was delivered to the School of Army Co-operation at Old Sarum. The ‘bent’ rotor blade, of course, is a trick of the lens!
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I was more concerned with the thought that this would delay my air gunner’s course. Although I would have plenty of flying, I would not be getting the much-coveted ‘flying bullet’ that qualified gunners wore, and would miss out on the flying pay. I was not altogether keen on the prospect, but I had no choice, and as it was too late now to try and back out, I was committed.

We flew down to Old Sarum on the Monday, and I started my course which consisted of working with the permanent staff belonging to the Autogyro Flight of the School of Army Co-operation. As I entered the hangar I looked around to see this latest miracle of aeronautical science and my stomach nearly left my body when I saw it. It had no main planes and no rudder, although it did have a tail plane, which I learned afterwards was called a stabiliser. I swallowed hard and thought, “what the bloody hell have I let myself in for?”

“I swallowed hard and thought, ‘What have I let myself in for?’ ”

The course was excellent, the airmen working on the aircraft were very helpful, and the corporal in charge took me through first a daily inspection and then a 20-hour check. It was quite simple really, the only tricky part being to set the drag hinges. These allowed the rotor blades to move in a horizontal plane, relieving the stress on the blade roots caused by the varying speed of the blade as it rotated around its axis. After assembly to the blade, the hinges were checked by pulling the blade from the front stop to the rear stop by means of a strap, to which was attached a spring balance. If it was too low, they were tightened by adjusting the lock-nut that controlled the friction of the alternate fibre and steel plates which formed the drag hinge. If too high, the adjusting nut was slackened.

A trio of Rotas lined up alongside an Armstrong Whitworth Atlas army co-operation aircraft. Pilot training on the autogyro started at Old Sarum in September 1934, once operating and maintenance manuals had been compiled.

This was to cause me a lot of troubles in the weeks to come, because the Rota was to be kept out in the open, and the friction on the dampers varied with the humidity. Thus, if the ‘pull-off ’ was checked in the early morning when the dew was still about, it would have to be altered when the sun dried it out. This check was critical. If the blades were rotated at speed while unbalanced, the vibration was terrific, and if the speed was not reduced immediately it could even turn the Rota over. This vibration came to be known as ground resonance. When we came to operate in the field, I found it was more practical to carry out this check an hour before take-off.

The engine, an air-cooled Armstrong Siddeley Genet of 140hp, was no problem. It was very accessible, with a Fairey-Reed metal airscrew, and started by hand swinging. The only new item was a clutch, which engaged a metal shaft that rotated the rotor head. The airframe structure was metal covered with fabric, and the rotor blades had a nickel chrome steel spar with balsa wood to form an aerofoil section and covered with a fabric skin.

After a few days I was told I might as well start looking after my own aircraft and I first met K4231, which was to be my ‘baby’ for the next few months. I cannot thank the airmen enough for the help they gave me in learning the know-how of the handling and servicing of this new type of aeroplane, especially Cpl Josie Collins for nursing me through that early period when my knowledge was limited and my confidence low, particularly after an autogyro from the flight flew into Castle Rings, near Salisbury, and killed the pilot on his first solo. This incident caused some concern, and the aircraft were grounded while an investigation was carried out.

Running up the 140hp Armstrong Siddeley Genet radial engine on K4231.

As there was no obvious mechanical failure, one theory put forward was that the pilot may have accidentally locked the control arm, which operated the rotor head, and positioned the rotor disc in the desired ‘tilt’ for the required direction of flight. On the autogyro there was no provision for a cyclic pitch change like modern helicopters, but the complete head was moved to control the direction of flight. The purpose of this lock was to keep the rotor head steady when the aircraft was parked. It was released by pressing a button on the control panel, and locked automatically when the control arm was pushed fully forward and a spigot entered a spring-loaded lock. Listening to the discussion I heard the station commander say he would — very courageously, in my opinion — fly the aircraft solo, and lock and unlock the control arm in the air. Whether this dangerous operation was ever carried out or not I never discovered, but that afternoon the Rotas were allowed to fly again.

“The rotor blades turning faster produced a horrifying howl

Later on, Flt Lt Wills-Sandford, a former pilot with No 4 Squadron who was now a flight commander in the School of Army Co-Operation, asked me if I would like a flight to Farnborough with him. As I would have to do a lot of flying in the Rota in the near future, I apprehensively said yes. I borrowed some flying gear and walked out to the aircraft, and was helped into my seat under the pylon which supported the rotor head. The aircraft were dual-controlled and so the huge control arm hung down in front of me. The pilot climbed into the rear cockpit — the Rota was always flown from the rear seat, except in the case of dual instruction. The mechanic commenced the starting procedure by asking the pilot the standard phrase, “switches off, petrol on, suck in”, which the pilot repeated. The mechanic turned the prop over several times and said “contact”, the pilot switched on and repeated “contact”, the mechanic swung the prop and the engine fired, hesitated for a second and then picked up before starting to run evenly. The pilot waved the chocks away and taxied out onto the airfield, turned into the wind which was almost gale-force, and put the brakes on. He ran the engine up and checked the magnetos, oil pressure, temperature and rpm, prior to throttling back. Then started what was the most terrifying experience of my life.

The pilot engaged the clutch, and as he slowly opened the engine the rotor began to turn slowly at first, and then faster and faster. The engine was straining like mad to pull the aircraft forward, which was held by the brakes. The rotor blades turning faster produced a horrifying howl and, to make things worse, the aircraft began to vibrate violently so that my whole body was shaking from head to foot. When the rotor blades reached the required speed, the pilot operated a red-knobbed lever, which released the brakes and clutch simultaneously. The Rota leapt forward like a greyhound freed from a leash, started hopping up and down like a pregnant grasshopper and, after an extra large jump, became airborne.

Washing off the red distemper on completion of the 1935 manoeuvres on Salisbury Plain. The Rotas were kept outside for the duration, which accounts for the dilapidated appearance.

After climbing to around 300ft, the pilot set course for Farnborough, which was very simple — it just meant following the railway line from Salisbury to London which passed through South Farnborough, about a mile from the airfield. As I became more at ease, I began to look around and make a calmer assessment of the situation. Flying so low gave the impression of great speed, but a glance at the air speed indicator showed only 95mph and, as I knew before take-off, there was a fairly high headwind, so our ground speed must have been very low. This was confirmed when a train on its way to London caught up and passed us, with passengers leaning out of the windows, waving to us. Once I got used to the vibration, I really began to enjoy it. Flying alongside the railway tracks at such a low altitude was quite exhilarating, heading over the fields with farmers looking up, passing small villages and watching the traffic moving along the roads.

Eventually we landed at the Royal Aircraft Establishment side of the airfield and taxied onto the concrete apron near the control tower, stopped the engine and climbed out. Wills-Sandford told me he was going to a conference regarding the Rota the RAE was testing with a larger engine (K4775) and told me to be ready to fly back at about half past two.

Since it was a long walk up to the RAF camp, I decided to have a ploughman’s in the Swan Hotel, just outside the RAE main gate. As I sat and had my lunch, I started to think of the morning’s events, and came to the conclusion that looking after the Rota when we started working with the army on exercise — like we used to do every summer, sleeping under canvas away from parade grounds and station WOs — promised to be quite interesting. I wondered if we would get one with the larger engine, like the example at the RAE. I also thought of the one at Felixstowe which was on test there fitted with floats for sea patrols, and decided that, after our leaping take-off that morning, I did not fancy doing the same thing on water. I later met the young ex-apprentice like myself who was looking after the Felixstowe Rota, Duff Cooper by name, and we compared performances. Theirs did not take off any quicker, and often flew solo with some light ballast weights fitted, which on one occasion fell off and landed on a laundry.

This red distemper scheme was applied for the summer 1935 exercises, the Rotas being assigned to the ‘Red’ forces.

Upon finishing my lunch, I walked back to the aircraft and checked it over, and when I was satisfied I put on my flying gear and sat down by the undercarriage. As it was a fairly warm day, I dozed off to sleep. Some time later I was awakened by approaching voices and footsteps and stood up to meet the pilot, who was ready to fly back. After he had finished talking to the officers who had come out to see the Rota, we prepared to start the engine, the pilot in the cockpit and me swinging the airscrew. We went through the normal procedure, but swinging as much as I tried, it just would not start. After a while I was sweating profusely and just had to stop for a rest. The pilot thought he would try, so he set the controls, climbed out of the cockpit and started swinging the airscrew himself. I was standing on the step, waiting to open the throttle if it fired. He swung the prop several times with no success and then suddenly peered into the front cockpit. “Look, you clot”, he said to me, and belted me round the ear. I had forgotten to switch ‘on’ in the front cockpit. He climbed back into the aircraft and, after turning the engine backwards a few times, I shouted ‘contact’ and swung the prop. It started on the first swing. I put on my ’chute, climbed into the aircraft and we taxied out, went through the pre-take-off checks and flew back to base. I was a somewhat chastised but wiser young airman.

I finished the course without further incident, and Capt Hannay asked me how I had got on with my written exam. I told him I had got 95 per cent. “Good God!”, he said. “I only got 70 per cent on mine”. I refrained from telling him that the sergeant in charge of the course had given me the paper to look over the night before. On the Friday we flew back to Farnborough to rejoin No 4 Squadron, and from then on the Rota was mine for the rest of the summer. We did a few local flights, giving army officers air experience, and to give Capt Hannay and Lt Wheldon — who had also been on a Rota course — some extra flying practice on the type.

“The squaddies thought the engine drove the blades all the time

One thing I really hated was forced landing training. This was always carried out on what we called the ‘Speedway’, on the farthest side of the airfield from our hangars, ending by the road from Cove to Aldershot. It meant turning into wind and then slowly closing the throttle until the aircraft was almost hovering, and sometimes stopping the engine. The control arm was immediately pushed right forward, the blades speeding up. As there was no engine noise, they made a horrible ‘whacking’ sound. We descended rapidly and flared out just before landing. The snag with this operation was that when the engine was warm it was a devil to start again, and after a long spell of swinging the prop we frequently had to push it back to the hangar with the help of the crash crew, who always stood by on their truck when this type of training was carried out. I had often pushed an unserviceable motorbike along, but pushing an aircraft home always struck me as ridiculous, not to mention the caustic remarks from the airmen pushing it.

That summer we were to be attached to the ‘Red’ army, so I had to paint my Rota with red distemper which deteriorated as the time passed, especially as it was picketed out in the open. Our first campsite was at Ford, near Littlehampton. This was before they built the Fleet Air Arm station, and the only other occupant of the field was Alan Cobham’s flying circus which had a small hangar on the far side. The squadron’s Audaxes were parked away from the road, but my Rota was picketed quite near it, and sheltered by the canteen tent as much as possible.

Army co-operation was seen as an ideal role for the autogyro, not least given its ability to operate from locations close to ground forces.

Older members of the squadron were not too keen on these detachments, which meant leaving their married quarters and their wives and families, but the younger ones loved them and took full advantage. In the evenings we were free to ride out on our motorcycles and drive our old bangers to explore the district, sample the local brews and attend village dances. With petrol at 5p a gallon, cigarettes at 20 for 5p, and beer 2p a pint, we had a wonderful time. Such minor inconveniences as sleeping under canvas, early morning patrols, crude cooking and bathing facilities were accepted without dissent.

We flew many senior army officers, some of whom were to become famous in the war that, in our ignorance, was only four years away. The Rota was kept busy, and most of the generals seemed very keen to experience the potential of the autogyro. One who was particularly so was Gen Wavell, later Field Marshal Lord Wavell of Western Desert fame. I remember one interesting experience which concerned him. I was told to fetch some clean overalls and to get the Rota ready to fly off to a small field about 20 miles away. Lt Wheldon was the pilot on that occasion, and when we landed we covered the Rota with small branches and sat and had a smoke until the general arrived. He eventually arrived in a large, luxurious staff car, accompanied by his aide-decamp dressed in highland uniform. We started the Rota, and I helped the general into my ’chute. It took him some time to climb into the front seat under the pylon, and I hoped that if the occasion arose it wouldn’t take him as long to bail out, as the Rota usually flew at a very low altitude. It suddenly struck me that this possibility also applied to me, and I immediately lost a lot of enthusiasm for flying in the Rota.

Once they had taken off, I got into the staff car and was driven off to a nearby army camp, where the ADC gave me sixpence for my lunch. In the army canteen tent, I purchased a hot pie and chips, a cup of tea, and a packet of five Players Weights cigarettes. I sat in the tent eating my lunch, watched with curiosity by the squaddies. When they did eventually start speaking to me, I was surprised at their ignorance of the RAF and aircraft generally. I was amazed that they had no aircraft recognition lectures, no idea of the armament of aircraft, relative speeds of various types, or the different roles they performed. Then I realised I had no idea of the various types of tanks, or the size of artillery weapons, and I remember thinking that army co-operation was a very limited expression. This failure of the authorities to familiarise the different services with each other’s functions and general principles was to have serious effects in the war that was soon to erupt.

As far as the Rota was concerned, they didn’t know how it flew. They thought the engine drove the blades round all the time. I explained to them how the engine only gave the initial start to the rotor blades, and thereafter — being an aerofoil shape — they kept rotating by aerodynamic forces, providing sufficient forward speed was maintained by the engine. In the event of an engine failure, the nose had to be placed downwards, and in fact the blades would speed up. They were confused how the blades produced lift, so I explained briefly the forces acting on an aerofoil in flight with the aid of sketches on the table-top, telling them the blades were just like main planes on an ordinary aircraft except that they had a much larger aspect ratio.

Two periods with the School of Army Co-operation for Rota K4232 were interrupted by assignments to No 2 Squadron and the A&AEE. Today it is preserved in the RAF Museum London. Here it overflies the surviving foundations of the Norman cathedral at Old Sarum.

The impromptu lecture suddenly ended when a sergeant came into the tent, with a very large, waxed moustache and a much larger voice, and chased them out, threatening all sorts of terrible things if they were ever late on parade again. I started to tell him it was really my fault, but he winked and said, “That’s alright, mate. Just keeping them on their toes”. He put his cane under his arm and followed them out with many loud, uncomplimentary remarks. Later in the afternoon the ADC arrived with the car and picked me up. We drove off with the ADC in the back and me sat in front with the driver. We went to a small field some miles away and waited for the Rota. It came at last, ‘hedge-hopping’ over the fences and landed as near to the car as possible. Gen Wavell climbed out and, after a short discussion with the pilot, got into the car and drove off. I clambered into the Rota and we flew back to our base.

During that summer we had several flight detachments under canvas. Finally, as always, we ended up on Salisbury Plain, joining up with the rest of the squadron which at that time was commanded by Sqn Ldr Freddie West VC. I was told he was the last surviving air VC of the First World War. In addition to our normal army co-op duties we were working very closely with the Royal Tank Corps, which was training to operate as an independent force. Our wireless tenders were attached to the tank units, and we were using a new type of RT set. Our wireless operators were flying on almost every flight. Ominously the callsign was Tiger, a name we would come to fear a few years later when Hitler’s Panzers rolled almost unopposed across France, and No 4 Squadron, by then equipped with Westland Lysanders, was forced to return to England.

“We were either very brave or very ignorant. I was in the latter category

Another operation I can remember was the photographing of the armies’ progress from their starting-point to Salisbury Plain. The photographs were laid out side-by-side, and gave an accurate picture of the exact position of the advancing forces. From time to time, when they were in a location that was suitable for attack from the air, the whole squadron of Audaxes would take off and fly very low in line-astern, and then at ground level carried out a simulated low-level machine gun and bombing attack on the surprised ‘enemy’. I can remember vividly their upturned faces, and a good many, either on instruction or through instinctive self-preservation, dived into the roadside ditches.

Eventually the manoeuvres came to an end, and we flew bank to Farnborough. My Rota returned to Old Sarum, and I resumed my normal duties, looking after Audax K2018. However, I was not allowed to forget the Rota as by now the RAE was flying its example frequently, sometimes accompanied by a Westland Pterodactyl. They were usually flown by Sqn Ldrs Richard Atcherley and George Stainforth of Schneider Trophy fame, who were RAE test pilots. On one occasion I really thought I was seeing things. As I walked out of the hangar, in the sky were several large balloons shaped like animals. There were pink elephants, blue pigs and other coloured things all over the place, and flying round them were the Rota and Pterodactyl, the pilots trying to shoot them down with Very pistols. We were told they were practising for the Hendon air display, and very entertaining it was. Whoever was flying the Pterodactyl was scoring the most hits, as it was noticeably the more manoeuvrable. It confirmed the pilots’ most consistent criticism of the Rota: that a rudder would have improved its performance immeasurably.

Looking back to the Rota in these days of modern helicopters, the comparison is ludicrous. However, none of the later innovations were known in my autogyro days, and we flew happily around knowing little of the aerodynamic forces which kept us airborne. We were either very brave or very ignorant, and from my later experiences on helicopters I have come to the conclusion I was in the latter category.