Why don’t you fly rotor wing?

Piperonca said:
Autogyros are in a continuous state of autorotation, which requires inflow based on airspeed. Never flew one, but understand that you don't descend vertically in them and have the flight end well.

Flare is a helicopter maneuver using the cyclic control to increase the angle of attack of the rotor disk, mainly to gain rotor rpm near the bottom of an autorotation and slow forward groundspeed.

Vertical descent, power off, in a helicopter gets very sporty as shown in a Height-Velocity diagram below. You control blade pitch with the collective lever and cushion descent by increasing blade pitch very low above the ground. This uses up kinetic energy from the rpm and inertia of rotor disk.

You do "hovering autorotations" just using cushion from available rotor kinetic energy, applied carefully with the collective. In that sense they're just power off landings from a hover.

For more information, see the FAA Helicopter Flying Handbook, Chapter 11: https://www.faa.gov/regulations_pol...helicopter_flying_handbook/media/hfh_ch11.pdf



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Well said. Note that the Height/velocity diagram that Piperonca included is for an aircraft certified under FAR pt 27 which is for smaller helicopters. That data is found in Section 4 (performance charts) of the RFM. Its a recommendation. Larger helos certified under Part 29 publish that chart in the RFM, section1 (limitations). The pilot then has to reference Sect 4 for the required landing and T.O. distances. Who said that helicopters have no published minimum take of distances.
 
Velocity173 said:
1800-2000 fpm at 60-80 kts isn’t exactly falling like a rock. In a mountainous situation, you aren’t going through the trees at that speed or FPM either. You decel to arrest the descent and slow the speed. Then a cushion with collective before tree contact. At contact, you should have zero airspeed and the collective in your armpit. That won’t be soft but survivable? Sure.
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An old, retired USAF pilot told me of two engine failure/crashes into Alaskan trees that he survived with zero injuries. In both crashes, he used the prevailing advice. Do a bodacious flare at the tree tops, then pull the nose up to the vertical and ride her down tail first. The entire airframe then absorbs the impact. Just think, you have thirty or forty feet of crushable structure. When I think of that huge Wright radial in the nose, now above you following you down, I shudder. I got this same advice when I was a student pilot but never had to use it.
 
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hindsight2020 said:
Video of Rowlett crash. Def a loss of tail rotor.
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Yeah, they are saying it was a student and instructor, which jives with the track of them doing patterns over in Rockwall. From the flight tracks, it looks like another helicopter I've flown in with them, an R-22, was only a mile or two away headed the same direction, and lower, so I'm wondering if they might have seen it or heard the radio transmission(s) if any.
 
Tarheelpilot said:
They cut the tail off. Unloaded the rotor disk.
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Could be mech failure but I’d agree. Most likely unloaded, forward cyclic followed by aft cyclic. Just like this vid only it’s not negative G but zero G and it doesn’t really show any aft cyclic.

 
Tarheelpilot said:
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They were still showing that vid in Army flight school back in 2000. Probably still showing it today…even though I’m pretty sure they don’t have any semi-rigid rotorcraft left in active inventory.
 
Velocity173 said:
They were still showing that vid in Army flight school back in 2000. Probably still showing it today…even though I’m pretty sure they don’t have any semi-rigid rotorcraft left in active inventory.
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I watched it in training too. One of my instructors was former army. Worked out for me considering almost all of my helicopter time after the commercial add on was in oh-58 and Huey’s.
 
Velocity173 said:
Could be mech failure but I’d agree.
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FYI: There are several accounts/reports the aircraft was stationary in a OGE hover just prior to the initial failure. A TRGB or TR drive failure could cause a similar structural failure as in Australia several years ago or could have induced a motion causing a MR strike on the tailboom. They recovered the aft tail section which should give some evidence of failure type.
 
Piperonca said:
Question: Does the autogyro you fly have stick shake? Saw a couple videos that showed the cyclic grip vibrating considerably. That normal?
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Mine is currently being manufactured, but they all seem to have a certain amount of stick shake. The one I did my training in had a small amount, maybe 1/4"? You tend to forget about it pretty quickly. I don't think I've ever seen one that had zero stick shake.
 
Bell206 said:
FYI: There are several accounts/reports the aircraft was stationary in a OGE hover just prior to the initial failure. A TRGB or TR drive failure could cause a similar structural failure as in Australia several years ago or could have induced a motion causing a MR strike on the tailboom. They recovered the aft tail section which should give some evidence of failure type.
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There is some discussion that it may have been error in the recovery of vortex ring state (gripping throttle / over pitching) which could have led to low rotor rpm and possibly rotor stall. In this state the rotor can blow back and cut off the tail.

They were operating in an area typically used the operator for VRS training and the ADSB flight track seems to align with VRS training.
 
That’s one thing that I don’t like about the Vuichard technique; apply full collective or full take off power. You wrench that collective up while coming straight down in VRS and you’re gonna droop the rotor, especially in something underpowered. Just pull enough collective that would normally sustain cruise flight and slide out of the dirty air (cyclic / pedal).
 
Paul V said:
There is some discussion that it may have been error in the recovery of vortex ring state (gripping throttle / over pitching) which could have led to low rotor rpm and possibly rotor stall. In this state the rotor can blow back and cut off the tail.

They were operating in an area typically used the operator for VRS training and the ADSB flight track seems to align with VRS training.
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At an aerial photography seminar a few years back we had an extended discussion about that since the photographer doesn't want to push a helicopter pilot into getting into that kind of position.
 
Velocity173 said:
That’s one thing that I don’t like about the Vuichard technique; apply full collective or full take off power. You wrench that collective up while coming straight down in VRS and you’re gonna droop the rotor, especially in something underpowered. Just pull enough collective that would normally sustain cruise flight and slide out of the dirty air (cyclic / pedal).
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I completely agree. I’ve seen first hand how quickly the rotor rpm can droop in the R44 when performing the Vuichard technique. The crazy thing is you don’t really know the collective is too high until the rotor gets into clean air and I can see how that can very quickly cause things to deteriorate if the immediate reflex isn’t to get the lever down.

Robinson has been very heavily promoting the Vuichard technique at the factory safety course the last few years.
 
Velocity173 said:
That’s one thing that I don’t like about the Vuichard technique; apply full collective or full take off power. You wrench that collective up while coming straight down in VRS and you’re gonna droop the rotor, especially in something underpowered. Just pull enough collective that would normally sustain cruise flight and slide out of the dirty air (cyclic / pedal).
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The other question I often have when I read about accidents is what was the first helicopter in the training program. If it was an aircraft that was fully governed and did not require any manual throttle input I have always suspected there may be some lack of awareness by the pilot of how much power demand is being put on the aircraft with control inputs. something like pulling pitch, power pedal and slide of to the side can quickly droop rpm if done with to much vigor. I know the transition from the r-22 to the 269C to finish my training made me much more aware of how my control inputs ate into power reserve. Just a passing thought...
 
Paul V said:
There is some discussion that it may have been error in the recovery of vortex ring state (gripping throttle / over pitching) which could have led to low rotor rpm and possibly rotor stall.
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FYI: There's also been some discussions on a students extreme pedal inputs during this OGE maneuver could cause an upset and possibly catch an instructor off guard. This is outside my skill set but it seems to have happened in the past.
 
Tarheelpilot said:
The other question I often have when I read about accidents is what was the first helicopter in the training program. If it was an aircraft that was fully governed and did not require any manual throttle input I have always suspected there may be some lack of awareness by the pilot of how much power demand is being put on the aircraft with control inputs. something like pulling pitch, power pedal and slide of to the side can quickly droop rpm if done with to much vigor. I know the transition from the r-22 to the 269C to finish my training made me much more aware of how my control inputs ate into power reserve. Just a passing thought...
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Yeah definitely something to consider. We don’t demo VRS in the 407 but I’ve done it at the sim. I’ve done the Vuichard as described I over torqued and drooped the crap out of the rotor. I modified it with just a healthy amount of collective and it worked out much better. Unlike the R44, there’s little chance of the blades flapping and hitting the tail in a 407. Although that has happened before though but different type of situation.
 
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The word from the folks on the ground who witnessed the whole thing is that they were demonstrating/practicing settling with power per their syllabus in the area designated for that maneuver.

That narrows the cause of the tail boom chop to the more obvious choices.
 
While Juan did a decent job of explaining mast bumping above but this is better. Doesn’t go into the VRS low Nr situation but those unfamiliar with this type of event can at least understand how the rotor teeters about the mast.

 
To answer the question "why don't you got rotor wing?".... this is why. The line between doing something dumb and getting into an unrecoverable situation is so much thinner.

Today I found out that a helicopter can chop its own tail off if you operate it wrong enough.... this does not help the case.

And money.
 
So how does a helicopter like an R22 handle moderate to severe turb? Do the moments of unloading, low, no, or negative G, cause issues?
 
Bill said:
So how does a helicopter like an R22 handle moderate to severe turb? Do the moments of unloading, low, no, or negative G, cause issues?
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It doesn't handle very well. And even though such flight is prohibited for certain pilots as shown below, turbulence induced mast bump kills high time pilots as well every year. Its this "feature" that led me not to work on Robbies anymore.
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Jim K said:
The line between doing something dumb and getting into an unrecoverable situation is so much thinner.
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Not really. Any aircraft, both rotor and fixed wing, will take advantage of a pilot's short-comings. Unfortunately some models provide a more direct path to that advantage with a Robbie being one of them.
Salty said:
It can also chop off your head…. https://www.wfla.com/news/local-news/man-decapitated-in-helicopter-accident-at-brooksville-airport/
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FYI: Unfortunately in this case, the pilot exited the running helicopter which led to the M/R blade hitting him and the EPU. Thankfully it doesn't happen as much as walking into a running airplane prop which can be just as bad.
 
Accidents like these create an unfounded fear of helicopters. The R22/R44 series have limitations that must be adhered to. That’s why SFAR 73 exists. I’m not a fan of Robbies but a competent pilot should have no problems operating them.

The B206 was operated at Ft Rucker for 35 years without a single inflight breakup. Same type (semi-rigid under sling) of rotor as a Robbie. No telling how many millions of hours during that time and all through various flight conditions.

What’s the rate of inflight breakups of helicopters vs airplanes? There’s a crapload of PA28s and PA32s that have come apart more often than Robbies…yes I realize they out number them as well. What’s the safety record of helicopters vs airplanes?

https://www.afar.com/magazine/how-safe-are-helicopters
 
It is true that helicopters in many ways have a lower margin for error. Some helicopters more so than others. As long as the limitations are respected and the pilot operates the helicopter with strict adherence to the approved operating envelope, they can be as safe as any other comparable aircraft in their class. This is no different than the limitations and associated hazards in the fixed wing world for certain types (e.g. multi-engine VMC roll over).

The training environment creates a unique degree of risk as the student by definition will not be as skilled or proficient as a rated and experienced pilot yet the maneuvers being practiced in training are often the maneuvers that carry the greatest degree of risk (autorotation, VRS, etc..). The instructor must be extra vigilant to avoid allowing the helicopter to get into a situation where it can become unrecoverable.
 
Paul V said:
It is true that helicopters in many ways have a lower margin for error. Some helicopters more so than others. As long as the limitations are respected and the pilot operates the helicopter with strict adherence to the approved operating envelope, they can be as safe as any other comparable aircraft in their class. This is no different than the limitations and associated hazards in the fixed wing world for certain types (e.g. multi-engine VMC roll over).

The training environment creates a unique degree of risk as the student by definition will not be as skilled or proficient as a rated and experienced pilot yet the maneuvers being practiced in training are often the maneuvers that carry the greatest degree of risk (autorotation, VRS, etc..). The instructor must be extra vigilant to avoid allowing the helicopter to get into a situation where it can become unrecoverable.
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I was reading on FB from people who knew the CFI and said she had an add on student. They expressed concern about airplane students looking for an add on might have contributed to the accident. Not really sure what they were getting at. A student is a student and you monitor their actions closely regardless of their background. I was fixed wing prior to Rucker and my IP immediately knew I was ahead of the crowd. That is until I hovered and realized I sucked at flying helicopters just as bad as everyone else. ;)
 
Velocity173 said:
A student is a student and you monitor their actions closely regardless of their background.
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FYI: Several people are saying that when practicing those OGE hover maneuvers in a Robbie it is important for the CFI to guard the pedals to prevent the student from mashing a pedal when the collective is lowered. Seems a hard pedal input induces an attitude that lowers the M/R tip clearance to t/boom which a subsequent cyclic input could cause contact. Perhaps that is what some could be inferring to?
 
Bell206 said:
FYI: Several people are saying that when practicing those OGE hover maneuvers in a Robbie it is important for the CFI to guard the pedals to prevent the student from mashing a pedal when the collective is lowered. Seems a hard pedal input induces an attitude that lowers the M/R tip clearance to t/boom which a subsequent cyclic input could cause contact. Perhaps that is what some could be inferring to?
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I suppose that’s possible. I had a tendency to add way too much pedal in turns from my airplane days but never hovering. In fact my feet weren’t nearly active enough at a hover. Also called adding pedal “rudder” which drove my IP nuts. :(
 
Velocity173 said:
I was reading on FB from people who knew the CFI and said she had an add on student. They expressed concern about airplane students looking for an add on might have contributed to the accident. Not really sure what they were getting at. A student is a student and you monitor their actions closely regardless of their background. I was fixed wing prior to Rucker and my IP immediately knew I was ahead of the crowd. That is until I hovered and realized I sucked at flying helicopters just as bad as everyone else. ;)
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It's called negative transfer of learning, from the Fundamentals of Instruction, and may also involve an element of primacy. You might not know that an airplane student might manipulate the controls in a manner out of habit in a plane until it's too late. During the few months I worked as a helper at a helicopter school with Robinsons down in the San Antonio area while I was working on my fixed wing ratings I saw that possibility. I got to do one flight with them and they gave me the whole Robinson special training endorsement in the logbook. There were serious cautions about if I pitched like I might in an airplane that we could have this problem.
I think there are similarities in tailwheel training, where sometimes it's easier to teach someone from scratch than to undo poor previous training.
I still think this is what happened in my accident, rather than what the NTSB decided. The student mashed hard and stayed on the left rudder and I believe he momentarily reverted to thinking it was a brake from his years of driving a car, even though we had literally just briefed brakes and rudder pedals again, and there was no effective fighting it fast enough in the spot we were in. I've seen some other negative transfers that weren't as scary, but they can come out of nowhere, even if you think you are prepared.
 
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RyanShort1 said:
It's called negative transfer of learning, from the Fundamentals of Instruction, and may also involve an element of primacy. You might not know that an airplane student might manipulate the controls in a manner out of habit in a plane until it's too late. During the few months I worked as a helper at a helicopter school with Robinsons down in the San Antonio area while I was working on my fixed wing ratings I saw that possibility. I got to do one flight with them and they gave me the whole Robinson special training endorsement in the logbook. There were serious cautions about if I pitched like I might in an airplane that we could have this problem.
I think there are similarities in tailwheel training, where sometimes it's easier to teach someone from scratch than to undo poor previous training.
I still think this is what happened in my accident, rather than what the NTSB decided. The student mashed hard and stayed on the left rudder and I believe he momentarily reverted to thinking it was a brake from his years of driving a car, even though we had literally just briefed brakes and rudder pedals again, and there was no effective fighting it fast enough in the spot we were in. I've seen some other negative transfers that weren't as scary, but they can come out of nowhere, even if you think you are prepared.
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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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