Why don’t you fly rotor wing?

Velocity173 said:
But what would be the negative transfer of learning in this case? An airplane doesn’t have a collective and if this was indeed a VRS accident, it would simply be the pilot on the controls pulling too much collective. If indeed it was the student on the controls, it’s incumbent on the CFI to keep the aircraft within safe parameters. That’s true of any student regardless of their background.

I will say this, when I instructed there was a tendency to let your guard down when you had a student with previous experience or they were solid performers. Then, they do something stupid that scares the **** out of ya when you least expect it.
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Well, the track I saw seemed to show slowing to 25-30 kts using this map: https://flighttracker.casper.aero/rbd/ around the time of the accident. They may have been coming to a hover, but it looked like it was some slow flying.

From the Helicopter Flying Handbook Chapter 11:
Pilots can avoid mast bumping accidents as follows: • Avoid abrupt forward cyclic inputs in two-bladed helicopters. Airplane pilots may find this a difficult habit to break because pushing the nose down is an accepted collision avoidance maneuver in an airplane. Helicopter pilots would accomplish the same rapid descent by lowering the collective, and airplane pilots should train to make this instinctual.
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RyanShort1 said:
Well, the track I saw seemed to show slowing to 25-30 kts using this map: https://flighttracker.casper.aero/rbd/ around the time of the accident. They may have been coming to a hover, but it looked like it was some slow flying.

From the Helicopter Flying Handbook Chapter 11:
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It were a 0 G mast bump then I’d agree, an airplane guy might very well push forward to avoid collision with another aircraft. However, once @Paul V mentioned this is possibly a VRS training area, then the over pitching with rotor stall made complete sense. In that case, an airplane background wouldn’t matter. It would be a case where the pilot on the controls tried to level the attitude with aft cyclic just as rotor flap back occurred. Any new student could make that error.

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Velocity173 said:
It were a 0 G mast bump then I’d agree, an airplane guy might very well push forward to avoid collision with another aircraft. However, once @Paul V mentioned this is possibly a VRS training area, then the over pitching with rotor stall made complete sense. In that case, an airplane background wouldn’t matter. It would be a case where the pilot on the controls tried to level the attitude with aft cyclic just as rotor flap back occurred. Any new student could make that error.

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I don't disagree, the main point is that some of us fixed wing drivers are used to being able to push the "stick" without serious consequence and that can be very negative in certain helicopter operations if you forget.
 
There have been enough accidents for Robinson to issue a safety notice and publish it in the POH.
 

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Paul V said:
There have been enough accidents for Robinson to issue a safety notice and publish it in the POH.
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The low rotor rpm comparison to a stall in an airplane makes sense. I wonder if they had low rotor during Vuichard recovery. Student aggressively goes with forward cyclic and up collective, CFI counters with aft cyclic but by that time it was a fully stalled rotor? I suppose we’ll never really know what happened during that evolution.

I agree with Juan and others on FB about new CFIs teaching new students. I remember my first 3 months teaching Black Hawks. It’s amazing I survived! I actually thought I got into VRS one night with a student. This was before Vuichard so the common train of thought was collective down and get airspeed. While you don’t have to worry about rotor stall in a Black Hawk, my attempt to fly out of it with forward cyclic was futile. My right arm was locked out fully forward and the nose just bobbed up and down. After a few occilations and around 800 ft straight down, she flew out of it. Scared the crap out of me. The old guys told me there’s a reason they removed VRS from the syllabus…they balled up too many aircraft trying to teach it.
 
Since the beginning of time, the solution for settling with power for a tandem rotor helicopter has been to apply lateral cyclic (stick input) and expose both rotors to clean air. It recovers quickly.

My only experience with VRS was when the landing site on a pinnacle was suddenly changed to a much lower pad directly under the helicopter. During the rapid decel and descent, the addition of power was not slowing the rate of descent. Uh oh! Thankfully, ground effect changed the flow enough to allow the non-stalled blades to stop the descent and we came to a low hover just in time to complete the landing without bouncing.

Climbing straight ahead would have been the proper thing to do, but seemed like a bad solution at the time because of the mountains surrounding the flight path...

My only time in a helicopter with a teetering rotor is in the UH-1 and that thing had the "rubber baby buggy bumpers" installed to give a warning when approaching mast bumping. I never had a good feel for that system since there was such a big lag between control inputs and blade changes.

The majority of my experience is with fully-articulated rotor heads and they are not as susceptible to excessive flapping under low-G conditions. In fact, the CH-47 has "droop stops" that will make loud bumping noises and feeling when the blades get to their lowest flap angle during ground and slope operations. That signals the pilot to stop doing whatever he is doing. Those stops bolt on and are replaceable. Sikorsky uses a similar system on some of their four and five bladed rotor systems.

Settling with power demonstrations in the S-269/300 are easily recovered with forward cyclic, but there is considerable altitude loss.
 
IK04 said:
Since the beginning of time, the solution for settling with power for a tandem rotor helicopter has been to apply lateral cyclic (stick input) and expose both rotors to clean air. It recovers quickly.

My only experience with VRS was when the landing site on a pinnacle was suddenly changed to a much lower pad directly under the helicopter. During the rapid decel and descent, the addition of power was not slowing the rate of descent. Uh oh! Thankfully, ground effect changed the flow enough to allow the non-stalled blades to stop the descent and we came to a low hover just in time to complete the landing without bouncing.

Climbing straight ahead would have been the proper thing to do, but seemed like a bad solution at the time because of the mountains surrounding the flight path...

My only time in a helicopter with a teetering rotor is in the UH-1 and that thing had the "rubber baby buggy bumpers" installed to give a warning when approaching mast bumping. I never had a good feel for that system since there was such a big lag between control inputs and blade changes.

The majority of my experience is with fully-articulated rotor heads and they are not as susceptible to excessive flapping under low-G conditions. In fact, the CH-47 has "droop stops" that will make loud bumping noises and feeling when the blades get to their lowest flap angle during ground and slope operations. That signals the pilot to stop doing whatever he is doing. Those stops bolt on and are replaceable. Sikorsky uses a similar system on some of their four and five bladed rotor systems.

Settling with power demonstrations in the S-269/300 are easily recovered with forward cyclic, but there is considerable altitude loss.
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We used to preach in VRS, get air speed. Forward, sideward, rearward. Anything to get out of the dirty air.

One of the old IPs asked if I knew why it took so long to recover with forward cyclic. I really didn’t and he explained for a couple of reasons. First, the CG on a UH-60 is generally several inches aft of the rotor mast and I’ve got the fulcrum effect of trying to raise a tail with so much mass aft of the turning point (mast). Second, the rotor system is producing a fraction of the thrust it normally does during VRS. Best CoA is to go lateral. Years later had an XP tell me that most likely I didn’t get into VRS. Said I’d have to pretty much be in a vertical auto (2,500 fpm) to get into it in a Hawk. Read reports from well known Sikorsky test pilot Nick Lappos who stated the same thing.

O g isn’t an issue in UH-60s either. I have seen people do it so aggressively that it brings on the oil pressure light though. Have the problem of floating FOD in the cockpit as well. :(
 
Forward stick in a tandem rotor is the worst possible response to a low speed, high rate of descent condition. Because there is no cyclic input with fore and aft stick input and pitch attitude change is made with differential pitch change, adding forward stick increases the pitch on the aft blades and reduces pitch on the forward blades. This could lead to aft rotor blade stall and really make thing worse!

The lateral stick inputs are pure cyclic and will allow the helicopter to rapidly fly out of a settling condition. Both rotors are immediately presented with clean air and the drag of the fuselage helps slow the rate of descent.

This is very different from helicopters with antitorque rotors and must be learned.

I have experienced blade stall and it was at a high altitude, heavy and hot temp scenario during the recovery from a decel during an approach. Having half your rotor system stop producing the needed lift is a real eye opener and requires immediate application of neutral stick and lower thrust rod (collective).
 
I think y'all are scaring off some prospective helicopter pilots.

What used to tickle me is when I would go get a fixed wing checkout somewhere, like a flying club, the CFI would go on about how stalls were these big scary things. I would smile and go "pffft" mentally.
 
IK04 said:
Helicopter pilots are different. Much more suspicious for things to go wrong.
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Indeed. The Hook has (5) transmissions and multiple hydraulic lines and servos, all of which are intolerant of fluid loss. Then there's the drive shaft connecting the two rotor systems which viewed in slow motion (with the covers off) wiggles like a Python on meth. How those rotors stay synchronized is a mystery to me. Ironic it has maybe the best safety rep of all Army rotorcraft. All gauges good, it's no big deal to fly in turbulence, weather, etc.

However, I would not enjoy flying in a Robinson after reading the Safety Notice. "If something bad hasn't happened, it is about to."
 
I suppose if I had learned in a Robinson and knew them well, I would have no issues flying one. I just never had the urge to do it after being spoiled by the Schweitzer.
 
It's easy to pre-flight a helicopter. If there's no oil on the ground, something's wrong.
And helicopters don't really fly. They're so ugly, they repel the Earth.
 
The Robbies aren’t too bad. The R44 and R66 fly similarly to a 206. They just have small margins for error and are not tolerant of sloppy handling. All designs are a compromise and the Robinsons are reasonably fast and have pretty decent utility for their class.

sure it would be nice to fly a 407 but dollar for dollar the 44 and 66 are tough to beat and are the only viable options for most private owners. The lower cost, however, means that they will be operated by less experienced pilots and unfortunately, some pilots that probably shouldn’t be operating any helicopter.
 
Paul V said:
All designs are a compromise
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Agree. But when the design is centered around a price point vs a performance point it make for some very small error margins especially as an entry level aircraft. Then again aviation has always been about economics. Having followed the Robbie story since the 80s, its amazing how those economics continue to trump such an unforgiving track record in the rotorcraft world regardless of pilot experience or governmental interaction. As the rotor turns they say....
 
NoHeat said:
Now that’s scary.
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Maybe but I’m not sure the specific type is to blame here. The reality is that the instinctual reflexes required in a helicopter in a power loss event regardless of manufacturer/ type are opposite of what is required in an airplane. You won’t get away with ramming the cyclic forward and keeping the collective up in a jetranger or an a-star either.
 
Paul V said:
Maybe but I’m not sure the specific type is to blame here.
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Paul V said:
in a jetranger or an a-star either.
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Unfortunately the existing data puts this type of occurrence at a much higher rate for Robbies than all other types combined. Its also the reason there are no SFARs on those types. For example, even though an AS350 MR system is considered a "light inertia system" it doesn't hold a candle to R44 MR design which can stall within a second per Robinson and cause the excessive flap of the blade. Throw in pedal inputs and it closes the tailboom/blade gap even more. In 206/350 world, you'll find that a pilot transitioning to light-blade 350s from heavy-blade 206s, will ride his low rotor horn down and break his tailboom off at ground level vs at altitude. As stated by many CFIs, the R series has little to no leeway when training new pilots, with the experienced fixed wing guys the ones who put Robbie CFIs in a jam more than a brand new pilot with zero experience.
 
The higher accident rates probably have a lot to do with the fact they are overwhelmingly used for training. I agree that Robbies aren’t ideal for training. There’s also no question that a 206 or a 350 are a much nicer place to be and both give a much higher margin for error. My point is that there are things that will get you killed in a helicopter regardless of what type is flown.

Regarding transitioning pilots, there really aren’t a lot of options. The cabri g2 seemed promising with its higher inertia fully articulated rotor system but so far it hasn’t really done too well in the US. There just aren’t enough of them in service.
 
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Paul V said:
The higher accident rates probably have a lot to do with the fact they are overwhelmingly used for training.
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These are not general accident rates but global in-flight break-up rates. There is no close 2nd to the Robbie line regardless of ops or pilot experience. Some governmental agencies/companies have even prohibited the use of Robbies for certain operations due to this data on an international scale.
Paul V said:
My point is that there are things that will get you killed in a helicopter regardless of what type is flown.
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True. But what other OEM releases a safety notice with this wording? As you mentioned earlier those other models have a much higher margin for error which is the big difference between these models. As stated its the blade stall that actually kills people which is directly related to Frank's design. I've always been surprised he didn't fix its short-comings especially after all the bad press/FAA review/ SFAR issuance in the early 90s. Fix the rotor and it becomes bullet-proof... but at a higher price tag.;)
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https://robinsonheli.com/wp-content/uploads/2015/12/rhc_sn24.pdf
Paul V said:
The cabri g2 seemed promising with its higher inertia fully articulated rotor system but so far it hasn’t really done too well in the US. There just aren’t enough of them in service.
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It still is promising. But since its only been certified in the US since 2015 its sales have been increasing every year. While it doesn’t compete with an R22 on all levels it definitely is making inroads to the domestic training market. Throw in Schweizer RSG has restarted the 300 production and Enstrom has new US owners I think the rotorcraft training market is fixing to diversify away from Robbies.

I looked at the Entrom TH180 with the new Lycoming 390 several years ago and believe it will be at a performance/price point close enough to a Robbie to make it viable. I think once there is a comparable alternative in sufficient numbers to challenge the R series you’ll see other entities like insurance companies start to apply a higher premium to train with Robbies vs one of these more conventional models. Interesting times ahead from my vantage point.
 
So not only is this thread confirming that I don't want to try flying a helicopter, it's reinforcing my general caution of the damn things.
 
The accident statistics can be analyzed different ways to tell different stories.

I think it’s incumbent upon anyone considering flying helicopters to research the statistics themselves and make their own determination as to risk / reward. The USHST does a great job of keeping track of statistics and trends. Their reports are freely available.

In any case, at a bare minimum pilots should demand the best training, the best maintenance, and fly in a methodical and conservative manner.

as a side note, John Zimmerman wrote a piece a few years back that provides an interesting perspective on helicopter safety and R44s in particular.

https://airfactsjournal.com/2019/01/whats-wrong-with-robinson-r44-pilots/
 
Albany Tom said:
So not only is this thread confirming that I don't want to try flying a helicopter, it's reinforcing my general caution of the damn things.
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And I think you would be making a mistake to make such an assumption. What you witness here are several people with a lot of helicopter experience discussing specific items within that side of the industry that few fixed wing people know or understand. There are more equally relevant discussions made daily on the fixed wing side. Statically speaking, you should be more cautious in flying around in your Uncle Bobs 172 that he flies only 50 hours a year.;)
 
IK04 said:
Since the beginning of time, the solution for settling with power for a tandem rotor helicopter has been to apply lateral cyclic (stick input) and expose both rotors to clean air. It recovers quickly.
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I'm alive because of this technique. It was the most scared I've ever been in my life to this day.

Do you happen to have that video of the sync shafts? I've always heard about it, but never seen it.
 
I’m a fixed wing guy that gets to ride in helicopters occasionally who if he had the money to burn would love to fly rotors, but I’d hope to be doubly cautious due to the knowledge that’s been shared with me of negative transfers. That need not scare other fixed wing people, instead it is the best way to try and prevent tragedies, by awareness.
 
Bell206 said:
And I think you would be making a mistake to make such an assumption. What you witness here are several people with a lot of helicopter experience discussing specific items within that side of the industry that few fixed wing people know or understand. There are more equally relevant discussions made daily on the fixed wing side. Statically speaking, you should be more cautious in flying around in your Uncle Bobs 172 that he flies only 50 hours a year.;)
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:) If I had any uncles left, they'd be in their 90s. So yep, I'd be a bit cautious there.

But joking aside, I'm not making any assumptions. I'm not saying that any particular helicopter flight is more dangerous than some particular airplane flight. But... There are way more things to go wrong with rotary wing than fixed. There are many more failure modes for rotary wing than fixed, and from what I can tell they are less intuitive and in many cases require a faster response to fix. Can better maintenance, training, and procedures make helicopters safer than airplanes, under some circumstances, especially if the aircraft process is deficient in one or more of those areas? Sure. But that isn't a simple process. Evaluating the risk isn't a simple process, either. It can't be, the systems are more complicated. Anyone that doesn't approach rotary wing flight with more caution than fixed wing is, in my view, kidding themselves.
 
I think there’s a misconception that just because parts are attached to a spinning object they’re most likely to fail. Stress is stress and you’ll find static parts (spars) on airplanes failing just as often.

Numbers don’t lie. You’re still statistically safer flying in non commercial GA helicopters vs airplanes. In 2019 20 % mechanical airplane vs 5 % for helicopter (but a higher fatal) Even pilot error rates are more for airplane vs helicopter. So yeah, I approach flying a helicopter with the same level of caution as flying an airplane.

https://www.aopa.org/training-and-s.../joseph-t-nall-report/nall-report-figure-view
 
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Years ago, I did a one hour lesson at FCM just to try it out.

A year later, I had gone through Private RH, Commercial RH, CFI RH. :D

They are great fun. But expensive and not that practical.
 
Very expensive to learn and then very costly to rent after you get your ticket. Tried it twice ,very busy at all times.
 
Helos have way higher maintenance costs. You can repair a wing skin, but many helos have critical 'no damage zones' where the only option is new, and many parts are life limted.
 
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