Worldcrime Posted February 21, 2007 Report Share Posted February 21, 2007 check this out - What happened?Richard heli-safety.com Quote Link to comment Share on other sites More sharing options...
West Coaster Posted February 21, 2007 Report Share Posted February 21, 2007 At first I thought he was landing downwind, but the dust cloud shows he's facing the right way. Looks like he put himself into a vortex ring state, didn't realize it and so couldn't recover. Had he eased forward on the cyclic and checked down with collective just a hair he would have been able to fly out of it. Just a guess. Hope they were okay... my back hurts watching that. Quote Link to comment Share on other sites More sharing options...
500pilot Posted February 21, 2007 Report Share Posted February 21, 2007 This happened at Rucker a couple years back. Student was doing a 180 auto and just deceled a little to high and he ran aout of RPM, ideas and altitude right about the same time. He probably thought he was still in the TH-67. Quote Link to comment Share on other sites More sharing options...
permison Posted February 21, 2007 Report Share Posted February 21, 2007 This happened at Rucker a couple years back. Student was doing a 180 auto and just deceled a little to high and he ran aout of RPM, ideas and altitude right about the same time. He probably thought he was still in the TH-67. I thought that looked a little familiar. I spent a lot of time at lowe field. Though when I was there we did not have that dorky ball on top of the mast Quote Link to comment Share on other sites More sharing options...
joker Posted February 22, 2007 Report Share Posted February 22, 2007 Looks like he put himself into a vortex ring state Huh? How could this be possible with the rate of descent so low? I don't think so. It seems to me that in his attempt to make it so smooth, he left himself high and dry with no more collective/rpm for that last 2 feet. I'm quite amazed at how much inertia he had..from the termination of the flare to the drop is a good 10 seconds. The poor guy could have done with 12! Save for a broken helicopter and a broken ego, I think / hope they walked away in tact. Joker Quote Link to comment Share on other sites More sharing options...
Voluptuary5 Posted February 22, 2007 Report Share Posted February 22, 2007 Joker, I thought the exact same thing and is why I doubted they were doing autos in the first place. The camera (and audio) must have been next to another helicopter as you never hear the rpms change (but you can see the rotors slowing down after their on the the ground). It looks like initially he was going to come up short on the runway and tried to "walk it" back over. -V5 Quote Link to comment Share on other sites More sharing options...
Linc Posted February 22, 2007 Report Share Posted February 22, 2007 A. It was not an autorotationB. Both survive C. It is not Lowe AAF, but then, all of Lower Alabama looks the same!D. It wasn't me! (I wasn't even there.) E. It was not vortex ring state, either. Quote Link to comment Share on other sites More sharing options...
JDHelicopterPilot Posted February 22, 2007 Report Share Posted February 22, 2007 Then what was it Linc?? Quote Link to comment Share on other sites More sharing options...
West Coaster Posted February 22, 2007 Report Share Posted February 22, 2007 Huh? How could this be possible with the rate of descent so low? I don't think so. I'm confused. If you mean the rate of descent on impact I disagree. Were it a vortex ring state, it might not have had time to fully develop to the point where the bottom drops out from under the machine. If you meant the rate of descent wasn't enough to create a vortex ring state.... yikes. And since I was wrong with my guess anyways, you're thought about running out of collective sounds good too. That or he attempted some operational no-hover landing and was too aggressive and the gear split? I dunno. Quote Link to comment Share on other sites More sharing options...
Linc Posted February 22, 2007 Report Share Posted February 22, 2007 (edited) SEF at altitude. At the bottom, the aircraft seems to experience some sort of partial loss of power. Somehow there isn't enough engine torque to keep the rotor RPM high enough for the termination to a hover. He also doesn't have a high enough ROD in the aircraft for VRS. Note the weapons on the sides as the aircraft impacts. This is what they term a "heavy bird" and they only demo autos to the students, and straight-in autos at that. Auto training in the OH-58D is done in "slicks", aircraft without weapons systems mounted. They can, however, do SEFs with a "termination with power" to an improved landing surface (e.g. landing lane at a stage field) on heavy bird demo days. Techniques for entering the SEF include entering in the downwind or straight-in. Edited February 22, 2007 by Linc Quote Link to comment Share on other sites More sharing options...
klas Posted February 22, 2007 Report Share Posted February 22, 2007 SEF at altitude. At the bottom, the aircraft seems to experience some sort of partial loss of power. Somehow there isn't enough engine torque to keep the rotor RPM high enough for the termination to a hover. He also doesn't have a high enough ROD in the aircraft for VRS. Note the weapons on the sides as the aircraft impacts. This is what they term a "heavy bird" and they only demo autos to the students, and straight-in autos at that. Auto training in the OH-58D is done in "slicks", aircraft without weapons systems mounted. They can, however, do SEFs with a "termination with power" to an improved landing surface (e.g. landing lane at a stage field) on heavy bird demo days. Techniques for entering the SEF include entering in the downwind or straight-in. Okay, what is 'SEF'? Quote Link to comment Share on other sites More sharing options...
67november Posted February 22, 2007 Report Share Posted February 22, 2007 Okay, what is 'SEF'? Simulated engine failure? don't know for sure I was a military wrench, not a military pilot. Quote Link to comment Share on other sites More sharing options...
Linc Posted February 22, 2007 Report Share Posted February 22, 2007 Yes, SEF=simulated engine failure. It differs from an auto in the termination. The Instructor will designate either a "power recovery" where the throttle is rolled back on/open and flight is resumed, or "terminate with power", where the throttle is also opened back up but the autorotative profile is continued with the aircraft terminating at a hover. Quote Link to comment Share on other sites More sharing options...
Voluptuary5 Posted February 23, 2007 Report Share Posted February 23, 2007 Regardless, just another example of just how fast things can go wrong. -V5 Quote Link to comment Share on other sites More sharing options...
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