I apologise, I thought Walter 603 had finished. However I will continue.
On the Monday there was a strange atmosphere in the crew room. I was then summoned to the Sqn. Cdr.’s office and grilled about my instructor. He was a diving enthusiast and his car and his clothes had been found by a Welsh beach but there were no signs of him or his kit. “Was he behaving normally?” “I think so, I hardly knew him.” “Do you think he had suicidal tendencies?” “I don’t think so. I didn’t think my flying was that bad.” A few other questions and then I started again with another instructor.
Things, as always, get better as time went on and then, in preparation for your solo flying there comes Engine Off Landings.
EOLs are where one lands the aircraft without the benefit of power much in the same way as a glide approach and land in a fixed wing except that it is a lot more sudden.
When the power ceases to a rotor in flight it slows down; very rapidly. In a short time it will decay so much that it will cease to generate lift and it, plus everything attached to it, will go ballistic. However, at minimum, i.e. flat pitch, it will autorotate much in the same way as a sycamore leaf autorotates from a tree with a comparatively slow rate of descent. To enable this to happen if one has an engine failure in a helicopter the first and most important thing to do is lower the lever to the bottom to ensure that you maintain Rrpm. You will then descend at a reasonable rate of descent and the inertia in the rotor will give you sufficient energy to be able to raise the collective lever and cushion the landing to a gentle touchdown at the final stage. Practise EOLS are done on the airfield as if something goes wrong the fire engines and blood wagons are so much more convenient.
As you cross the airfield boundary one closes the throttle. Even though one is ready the Rrpm dies off somewhat but lowering the lever and flaring the aircraft back to 60 knots recovers it. As the descent starts the Rrpm will start to increase so two notches on the collective indicator will hold it nicely. It would be nice to think that one could then proceed with the practice and gently put it on the ground; but not with the Sycamore.
As I mentioned before raising the lever has a cam that opens the throttle. To allow this to happen would negate the whole practise because the engine would burst into life on the touchdown. It follows that the engine has to be shut down. Before this happens the engine must be run at 1,200 rpm to even the cylinder temperatures so this is done for a few seconds before the slow running cut-out is pulled. It is then very quiet; except for the swish of the rotor blades around you.
At about 100 feet one flares again and holds it until the forward speed is Zero and the rate of descent is minimal. It then descends vertically and as the ground starts to swallow you up one raises the lever to its full extent to cushion to a gentle touchdown. There is, however, one precaution to take.
The under carriage on the Sycamore is hinged laterally and there is no fore and aft movement. Should one land with no forward speed the wheels will splay outwards and at the best roll off the tyres. At worst only one leg will splay and the aircraft will lurch to one side with a decaying rotor with little or no control over it. Therefore it is essential to put a little bit of forward speed on just before touchdown.
I mentioned the performance with the droop stops before shutdown. With the engine shut down there are no getouts after an EOL so the first priority is to get the engine started again before the rotor gets anywhere near stopping. Once that is done one can relax.
I will now confess to a sin so that when I reach the Pearly Gates St. Peter can’t nail me for anything.
Solo engine offs on the Sycamore were not allowed to be undertaken by students so all the engine off landings were dual. It was a very critical manoeuvre and so the instructor would be closely monitoring it to the extent that his hands would be lightly touching the controls. I will admit that I never did an engine off landing in a Sycamore. The instructor was monitoring so closely that I would relax and let him do it for me and then he would congratulate me for doing a good one.
There; that’s off my chest.
There was a take off technique that I believe is unique to the Sycamore known as the Jump Take Off. This would be used when there was insufficient power for it to hover (anytime). The procedure was to sit on the ground and wind the Rrpm to max permissible. (260?) The lever would be raised and the throttle opened to maximum. This would cause the aircraft to ‘jump’ into the air but as there was insufficient power to hover the Rrpm would start to decay. When airborne one would ease the aircraft forward in such a way that transitional lift would kick in and then you could use the airspeed to keep the aircraft airborne whilst you recovered the engine and Rrpm.
Two weeks and eight hours dual later I was considered a suitable risk to be sent off by myself. The usual diet of circuits, navexs and practice autorotations. Then came the instrument flying stage.
The big difference between instrument flying in a fixed wing aircraft and a helicopter is that the former is inherently stable inasmuch as it will stay on a trimmed path through the void without too much divergence if you leave it by itself. Helicopters are the opposite. Without electronic stabilising the will very rapidly develop suicidal tendencies and send itself, and you, to oblivion. To avoid this it must be flown with a constant state of awareness and anticipation. When one flies straight and level every twitch from the ideal must be instantly corrected before it becomes untidy and progressively more difficult to correct. Just to make things even more difficult they are slower and so therefore have greater penalties of drift and groundspeed when flying procedures. With practice one can fly comfortably within Green Card limits but one has to work at it. The Sycamore had the old Blue/Amber instrument practice system. This is where the forward cockpit windows were screened with amber transparencies. The pilot practising wore blue goggles. Blue and amber make black so he could not see outside but could read the instruments whereas the safety pilot could see the rest of the World in amber.
One of the biggest differences is the Instrument Take Off.
On fixed wing it was a case of lining up, noting the runway heading, opening the throttle and maintaining that heading come what may until there was sufficient airspeed to get airborne. One would be blissfully ignorant of the mainwheels whizzing by the drainage gravel at the side of the runway by a few inches. The military helicopter, not the civil procedure, was to point the aircraft into wind and come to the hover. You would then raise the lever and climb vertically into the air. Your eyes would be fixed on the Artificial Horizon so as to ensure the aircraft climbs in the hover attitude with the heading being maintained with the pedals. When the altimeter starts moving the attitude is moved to 10 degrees nose down and one waits. There will be a pause with only the altimeter feebly struggling around the dial and then there will be the shake and rattle & roll of transitional lift. This is a good sign, things are going well. Almost immediately the ASI will start to indicate and in no time you are in a position to actually control what the aircraft is doing.
There was little IF on the Sycamore, just two forty minute trips both incorporating a GCA at Sleap. There was little point because any serious IF was to be flown on the Whirlwind Mk10.