PPRuNe Forums - View Single Post - "Why Robinson helicopters seem to have a bad habit of crashing"
Old 21st Apr 2019, 13:24
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Paul Cantrell
 
Join Date: Nov 2007
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Originally Posted by Ascend Charlie
If you treat a Robinson properly, and stay within its envelope, preferably as far from the edges as you can, it does its job superbly.

Get to the edges and it can slip over the side fairly rapidly, and that is where the low-timers and the doctors come unstuck.

I first encountered the R22 after 7000 turbine rotary hours, and after the first flight I was feeling a bit deflated, this little flimsicopter was a real challenge with its twitchiness and speedy responses to inputs. But I had a couple of refreshing fizzy drinks that night, and the next day I wrung its little neck and it behaved for me forever after that. Well, not really forever, I stopped flying them back in 08.
Well, against my better judgement I'll jump in on a month old thread, and with one of my typical longs posts...

I think first of if you're talking about the R22 I definitely agree with you. It's not at all a forgiving machine, and is tossable and agile to a fault. The 44 and 66 are much more forgiving, but of course there are still parts of the envelope you should probably not play with! When I first start teaching in the R22 in the mid 80s most of the FAA examiners were ex-Vietnam guys and I never met any of them that liked doing a checkride in the R22... Since these were almost exclusively CFI (instructor) rides, it invariably involved a touchdown auto as part of the test, and these guys were mostly Huey drivers. They really didn't like the R22 in the hands of a soon to be brand new instructor. They were afraid of hitting hard and injuring their back. And, I would say probably with good reason! The R22 is difficult to touchdown, especially if you don't want to slide 100 feet... The difference between a really sweet touchdown and a hard hit is measured in the difference of 1 or 2 feet of altitude. Compare that to a R44 or R66 which will do a 30 foot hovering auto at the end of a touchdown (with the RPM starting in the upper yellow).

Originally Posted by Triple Nickel 8 Ball
It's also the reason why an R22 went from the planned $40k - $50k USD or something for a new one that you threw away after 12 years (the plan), to the price they are at now. Because they were getting sued by people that used them for reasons they weren't designed for, or just weren't trained properly on....all of them getting killed or maimed and blaming the heli. That put the Robinson liability insurance premiums through the roof for the factory
Frank said multiple times that he would rather fight lawsuits than pay silly amounts for liability insurance (because the typical thing back then, and still today, was that people would sue for silly reasons and the insurance companies would just settle, inviting more lawsuits). He mentioned in my presence that if he had a couple really big settlements he would rather just close the doors than have to charge a lot for liability insurance. I believe at the time (when aircraft product liability was in the news) that 50% of the cost of a Cessna 172 was for the insurance. So, unless you have some information that I don't, I'm a little skeptical of your statement. When I first flew R22s they cost $85K. Using an inflation calculator that equates to $201K today. An R22 today is closer to $250K... But they have a lot more gear today... We didn't have attitude indicators (or any gyro gear), the engine was a little 150 hp O320, no GPS or Loran, no governor or rotor brake, no aux fuel tank, just a comm radio and some pitot static instruments. That more than explains a 25% increase in price over the years.

Originally Posted by ironbutt57
"for unknown reasons, the rotor diverged from its normal plane of rotation and struck the side of the helicopter"...far too frequently seen in Robinson accident reports..a former Army acquaintance of mine who was considering getting involved in a flight school flew a demo flight in one...this guy with several tours in "Nam, and more as an instructor at FT Rucker...his assessment..."thats probably the worst helicopter a beginner could get his hands on"
And I agree with him. It's a terrible machine for primary instruction. It's too agile, underpowered, not enough inertia, etc. etc. But... economics. We only teach in R44s but the extra $100/hr is simply too much for a lot of students... and they end up finding a school with R22s. I put myself through a flight school and I have to say I probably couldn't have afforded more than an R22 at the time...

Originally Posted by SASless
So Robinson has the inside scoop on Airplane Pilots do they?

Or....should Robinson have considered the training those Airplane Pilots are getting when being taught to be Helicopter Pilots?

I don't see a safety notice for Lawyers, Doctors, Dentists, and Wall Street Bankers being high risk when flying Heliicopters.

So why....pick on our Fixed Wing Brethren?
Because that was in context of discussing low gee pushovers... and the idea was that lots of fixed wing pilots, when encountering a bird or other object in flight, might try to push the nose down to avoid a collision and end up inadvertent low gee. I was always skeptical that briefing people not to do something that is basically instinctive could help, but I was training a guy in Tennessee with 14,000 hours in jets and we had a very close encounter with a very large bird, and he told me afterward that he remembered not to do a cyclic push to avoid hitting the bird, so apparently there is some benefit to briefing airplane drivers on the risk of a cyclic pushover.

Originally Posted by CGameProgrammerr
Mast bumping only occurs as a result of two things, both of which must happen: First you must enter low G, typically by being stupid and shoving the cyclic forward very suddenly, although it can also happen when flying fast through severe turbulence. When in low G, the nose will drop and the helicopter will roll to the right (with a counter-clockwise rotor). If, and only if, you respond to the roll with left cyclic while still in low G, then mast bumping may occur in which case you die.

However that only happens if you apply left cyclic while in low G. If you either avoid low G (the correct thing to do) or you apply gentle aft cyclic to recover from low G without trying to correct the roll first, then everything will be fine. But keep in mind that when the uncommanded roll to the right occurs, the nose will be down, because if it is not then you won't roll at all.
This is not correct. While adding left cyclic will make the situation worse, you can still bump the mast if you do not add left cyclic. When I first started going to the safety course Frank would actually teach some of the course himself. He mentioned at one point that the tail rotor on an R22 helicopter can induce a roll rate in excess of 100° per second. The R22 only has 12° of flapping clearance. It will happily bump the mast all by itself if you unload the head. I've probably done 1,000 cyclic pushes on R22s to get the right roll (because when SFAR 73 came out it was required, but we were teaching low gee avoidance and recovery well before SFAR 73)... Sometimes it rolls slow, sometimes it can snap on you. It depends on your forward speed, power setting, attitude, and amount of cyclic push. As for your statement that the nose has to be down to get the roll, this is a disagreement that Tim Tucker and I have had over the years. Certainly I've been able to make it roll to the right in a level attitude (by starting in a climb attitude and giving it a good push to a level attitude). While it's certainly easier to get the right roll coming over the top and pointing the nose down, in my experience it's not required. (it's an airspeed thing - it's hard to fly the necessary low gee profile at low speed because it's such a sharp curve, and when the nose is up an R22 (which isn't that fast to start with) it bleeds speed rapidly, requiring quite a push to get the roll.

Originally Posted by aa777888
Do you really think that is the case? More than a few times folks here have pointed out the rather extraordinary safety bulletins that form part of the POH. Not to mention the rather blunt, no excuses stuff they teach at the factory Robinson Safety Course. And their total support of SFAR 73.
It's an interesting course. In many ways it's a two function course. One is indoctrination (pistons can be as safe as turbines if you treat them right) and the other was "please stop crashing our helicopters". The indoctrination part shrunk in my opinion partly due to their success as a company (like, back when they were producing more aircraft than the rest of the aviation industry combined) and also probably partly because they now ship a turbine helicopter. There's no question in my mind that the the "please stop crashing our helicopters" part is useful. But it's a very different course than Bell Helicopters Training Academy, for instance. It's also a very good value (less than $1,000 compared to $10,000 for Bell School). When I go to Bell, I come away basically knowing what every nut and bolt on the aircraft does etc. etc. It's clearly intended for professional pilots. Unlike the early days of the Robinson Safety Course when you had to be an instructor to go, currently their student mix seems to be quite a few student/private pilots with their instructor, which is fine, just a very different mix and not surprisingly the course is tailored somewhat towards that level of experience pilot versus the almost all professional mix I tend to encounter at Bell.

Originally Posted by Bell_ringer
They are a victim of their own success, becoming popular with people and operations that will be more prone to accidents.
That's certainly a part of the problem, and is of no surprise to anyone. The typical R22/R44 owner may have gotten his rating with between 60-100 hours. Most of them only fly 50 hours or less a year, and a fairly large percentage that I encounter don't fly with an instructor regularly so by the time they need a Flight Review they can be very rusty indeed. To some degree it's actually a testament to the reliability of the helicopter because a fair number of them won't even get the collective down for an engine failure, let alone dealing with something scary like a tail rotor failure. There are exceptions of course, I have a few guys that fly with me every few weeks to stay current, but I would say that's the minority of the private owners. So, they're low time and stay that way, with very little recurrent training, which is fine as long as nothing goes wrong.
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