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A recent article from the Robinson Helicopter Company 3 March 1999 Click here to view original memo The following is an Urgent memorandum issued by the Robinson Helicopter Company (as the copy faxed to us was a little 'smudged' we have re-typed it here for clarity):-
Date: Januay 20 1999 To: All R22 & R44 Pilots 
Some sprags in overrunning clutches have been found cracked in service. All
R44 clutches and those R22 clutches manufactured or overhauled after 1 January 1997
may be affected. A broken sprag could conceivably prevent the clutch from
overrunning when entering autorotation. The sprag clutch manufacturer is currently
investigating the problem. Until this discrepancy is resolved, do not enter practice
autoroations by rapidly closing or “chopping” the throttle. “Chopping” the throttle
could result in a sudden loss of rotor RPM if the clutch failed to overrun.
Enter autorotation by first lowering collective and then rolling off just enough
throttle to produce a small visible split between the rotor and engine tachometer
needles. If the clutch fails to overrun, immediately complete a power recovery.
Perform hovering autos only after checking the function of the overrunning clutch prior
to lift-off, then smoothly rolling off the throttle from a low hover with the skids no
more than two feet above the ground.
What we want to know is - what happens if you are unfortunate enough to suffer an engine failure in an aircraft that has one of these 'doggy' sprag clutch's ? The importance of knowing your aircraft 21 Feb 1999 Being one of a few small outposts based away from the main flying school, our helicopters are often swapped around especially when services and/or maintenance is needed. This does have advantages in that when checking the aircraft, because you have others to compare things with, you get to know what feels and sounds right. i.e. how much play ‘this’ should have, what sound ‘that’ should make etc. One of the R22’s at our flying school had developed the familiar oil leek on the tail rotor gearbox. Because the leak was not too bad it was decided to leave it until the next scheduled service, at which stage the aircraft also needed to undergo an air test for renewal of its COA. Following the service a CAA authorized examiner air tested the aircraft. Then, before being returned to us the aircraft was taken to another flying school where it was used by a couple of instructors and their students and logged a further 6 hours flying. On its return I was due to be the first one to fly the aircraft, as usual when ever an aircraft comes back from maintenance I give it a through ‘A’ check. During this check I found that the movement of the long 'tail rotor pitch change' link, that runs the length of the tail boom, (from the bell crank by the upper clutch pulley to the tail rotor gearbox bell crank), was extremely stiff. - Much stiffer than normal, and certainly a lot stiffer than before the aircraft had gone for maintenance. Also the normal ‘rubbing’ noise associated with its movement sounded more like a ‘graunching’ than the usual rubbing. I investigated further, and although it is hard to see up through the tail boom, it seemed to me that the pitch linkage rod in question had not been ‘threaded’ correctly. Instead of running through its guides it appeared to be running over the top of them. Being unhappy with this situation I rang the pilot who had previously flown the aircraft. (I have to say there that the previous pilot is very experienced, has logged several thousand hours in helicopters, and as well as being a TRE was, was also the man in charge of our flying schools). Having discussed the matter he said that he had not noticed anything unusual and that the linkage in question always made a noise. Still being unhappy with the situation I rang the engineering facility who had undergone the maintenance on the helicopter. I was informed by them that although the linkage in question had been removed whilst the tail rotor gearbox seal was replaced it was impossible to put it back the wrong way. I was again told that the linkage is always noisy and that I had no need to worry. Foolishly I flew the aircraft for an hour with a student of mine. On return I again checked the linkage. Still not being happy I removed the inspection holes in the tail boom and tried to investigate further. Although I could still not see properly into the tail boom I still thought that it did not look right. I again rang engineering and was told exactly the same thing - it was impossible to thread the pitch change rod incorrectly. I was still not convinced and so decided to do what I should have done in the first place - ground the aircraft until it had been inspected again by an engineer. The next day an engineer arrived and found that sure enough the long pitch link in question had been threaded incorrectly, instead of running through its guide it had been threaded over the top. Where it had been rubbing backwards and forwards against the edge of the guide inside the tail boom the metal of the hollow pitch linkage had been worn quite severely. If it had been allowed to continue I would suggest that the linkage would have eventually jammed on the edge of the guide thereby locking the pedals and causing loss of tail rotor control. I honestly believe that having had knowledge of the aircraft both before and after the maintenance, and my familiarity with several other R22’s avoided what could have been a potentially fatal incident. Interesting to note that the maintenance/engineering organization, a CAA test pilot and a chief pilot all failed to notice the problem and that the aircraft had flown over six hours following the original maintenance before the problem was finally rectified. QHI Lets keep some distance between us and mother earth 16 Feb 1999 I have been instructing in Robinson R22 Helicopters now for over 4 years. I enjoy flying the R22 and have the utmost respect for the aircraft. The problem was however that the more familiar I became with the aircraft and the more comfortable I felt with its characteristics the more complacent I became in relation to some of the procedures and safety aspects needed not only for instructional discipline but also for handling in general. In the summer of 1997 I was training an experienced PPL(A) student in the Robinson 22. To date the course had been going well and on this particular day we were going to undertake Exercise 15 - the incipient stages of vortex ring. Having covered the ground briefing we took to the air, heading west into an area of uncontrolled air space. Conditions were ideal, good visibility, little or no wind and not a cloud in sight. We climbed to around 2500feet AGL and I demonstrated to the student the incipient stages of vortex ring, pointing out the usual buffeting, wallowing, sloppy controls etc. Following recovery I gave control to the student and we continued to practice entry and recovery from Vortex. As any instructor will know with exercises like vortex ring, PFL’s, basic autos etc a lot of the lesson time is taken climbing back up to a sensible height before another practice can be undertaken. This is where my complacency started to creep in, instead of climbing back up to a safe height from which to undertake the exercise I was telling the student to level out at lower and lower altitudes. Everything had been going well and I decided to demonstrate to the student how easy it was to enter vortex ring if the aircraft was allowed to sink into its own down-wash following a quick stop. We were 1500ft AGL at this time, which I thought, would be plenty for what I wanted to demonstrate. So with an IAS of about 50kts I gently flared the aircraft allowing it to climb slightly, as the air speed approached zero I held a slight ‘nose up’ attitude. The aircraft started to sink and with little or no warning fell straight into vortex ring. I was actually quite surprised, this time, at how quickly and smoothly the aircraft had dropped into vortex. Anyway having proved my point, I eased the cyclic forward in order to gain some forward air speed. As I did so the aircraft yawed quite violently to the right. I immediately applied left pedal but found that the pedals had jammed solid…. I do not know exactly, how long it was before I realized what was wrong, but certainly a number of seconds. Sometime during the demonstration my student had moved his feet and now the welk of his right shoe (Dr Martins by the way) was jammed between the two pedals. He was completely unaware of this and I had to tell him, in no uncertain terms, to get his feet out of the way. This he tried to do but was unable to do due to the fact that I was still applying a lot of pressure to the pedals in my attempt to regain control of the aircraft. Whether I released my pressure on the pedals or my student literally managed to yank his foot from between the pedals I cannot really remember, but either way his shoe came out and control was eventually gained of the aircraft by which time we were a mere 300ft agl. So what lessons can be learnt? Well obviously several. Hindsight is a wonderful thing and looking back I can think of several things I should have done, if I had kept the nose forward, the helicopter would have picked up air speed, and weather cocked itself straight quite happily. If I had released my pressure on the pedals straight away control would have been gained earlier. Had I pointed out to my student that thick welked Dr Martin shoes were not the ideal footwear to fly Robinson R22’s in (I do now). If I had… etc etc. The fact of the matter is, that in suddenly finding yourself in an unplanned and potentially fatal situation i.e. jammed pedals, it takes time (as in this case several seconds) firstly to realise what has happened, what has caused it, and what you are able/going to do about it. Even having realised the cause of this situation my initial instinct was to apply more force to the pedals in order to try and resolve it, in this situation the wrong thing and again more valuable time lost. You will always get out of vortex ring provided you have the height and you take the correct action. We cannot always be prepared for every unexpected situation but we can always ensure we have a safe altitude - it really did not take long to lose that 1200 feet. QHI, ATPL(H), PPL(A) Something Controversial 10 Feb 1999 OK - lets start with something a little controversial - which appears to undermine one of the main priorities in aviation - Safety... The following has been sent to by a disgruntled QHI who writes as follows:- Attached is an article from a local area paper, I think the opening heading says it all - "MAD, BAD, DANGEROUS PILOT" - Is this the image we want in the Helicopter World - I think not. The article is actually trying to advertise trial lessons at the local airfield not scare people away - anyway worth a read. we have purposely removed the name of the pilot from the article  Interesting to note that this pilot has managed to maintain not so much his MAD and BAD image but certainly his DANGEROUS one. In the past year he has managed to catch the stinger of a Squirrel helicopter in the ground at Ascot. This was whilst trying to stop having been hover taxing too quickly. He has also managed to cause serious damage to two Bell 206 helicopters whilst trying to land the one he was flying too close to one which was on the ground warming up. Signed Anonymous So... good article to start the News & Views section. 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