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VMC Rollover, ever done it?
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CarjCapt said:
a question.. why is a multi so much more difficult to deal with in stalls, spins? My instructor never let us get anywhere near a full stall or spin in our geronimo, but never really explained why a spin was so much more dangerous in twin..? Does retarding the throttles, level wings, and forward elevator not work as well for some reason? Or does it just take a lot more altitude?
PropsForward
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mayday1 said:
Don't see the problem with the full stall. But spins are prohibited in most twin engine aircraft.
You also need to realize that you are most likely learning how to fly a machine that your instructor can barely fly himself. Do you really want to test his VMC skills if an engine is lost during recovery from a full power off stall?
PropsForward
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I also like to teach VMC as an emergency, much like a stall. I found that most people I run into sees VMC as a checkride procedure to demonstrate loss of directional control and thats it.
So, I like to teach a simulated go-around at altitude with a pilot, get them near stall, then have them go around. I fail an engine and look for the VMC recovery. I do it on stall recovery as well.
So, I like to teach a simulated go-around at altitude with a pilot, get them near stall, then have them go around. I fail an engine and look for the VMC recovery. I do it on stall recovery as well.
Newton's Laws must be respected.
[font=helvetica,geneva,arial]I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.
[/font]One of the reasons a spin is more dangerous in a twin is because of the mass of the engines out on the wings make it much more difficult to stop the spin's rotation.
[font=helvetica,geneva,arial]I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.
[/font]One of the reasons a spin is more dangerous in a twin is because of the mass of the engines out on the wings make it much more difficult to stop the spin's rotation.
At our flight school we do not do full stalls in our Baron 55. (It may even be against our training regs.) I've talked to many MEIs and they say its too risky. However, if you retarted both throttles to idle, stalled the plane then recovered holding off on the power until above Safe Single Engine Speed I don't see the problem. I guess the biggest risk would be an ucoordianted stall.
I've talked to some NJA IPs who have to stall test their A/C after MS is done to the leading edge bleed air anti-ice system to reconfigure the stall warning system. And they have to do full stalls.
I'm going for my MEI right now so any comments would be helpful.
I've talked to some NJA IPs who have to stall test their A/C after MS is done to the leading edge bleed air anti-ice system to reconfigure the stall warning system. And they have to do full stalls.
I'm going for my MEI right now so any comments would be helpful.
CarjCapt
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Baron 55
About 30 years ago, while living in KMCI, there was a crash of a Baron 55 that was doing VMC demos with a student and a very experienced instructor.
The aircraft was found in a fully developed corn field and the corn wasn't disturbed in any direction around the aircraft. That, ladies and gentlemen, is the results of a VMC demo gone bad and the aircraft going into a flat spin.
It is valid to do VMC demos but the results of going any further than just a demo can take you into the experimental catagory.
About 30 years ago, while living in KMCI, there was a crash of a Baron 55 that was doing VMC demos with a student and a very experienced instructor.
The aircraft was found in a fully developed corn field and the corn wasn't disturbed in any direction around the aircraft. That, ladies and gentlemen, is the results of a VMC demo gone bad and the aircraft going into a flat spin.
It is valid to do VMC demos but the results of going any further than just a demo can take you into the experimental catagory.
Stalls in a multi engine airplane are a non-issue, so long as they are performed symmetrically. An assymetrical thrust situation in a stall can lead to trouble, and there is no good reason to perform it.
Why not perform loss of control demonstrations to a full loss of control? Isnt' that a little like asking why not try cocaine to learn why one shouldn't take it? Or getting shot in the leg to learn that firearms really can hurt you?
We teach kids to say no, to not try the coke. We teach range safety to preclude getting shot. That ought to do.
Years ago, multi engine training did include pushing Vmc and doing single engine stalls. A truism is that more people were getting killed doing training than in actual engine failure scenarios. Today, we rightly concentrate on taking the appropriate action at the first sign of a control loss, rather than waiting until it's out of control to do something.
When I was doing structure fire, we were put twice a year through what was called a Swede Prop, also called a Flashover simulator. A flashover occurs when the ambient temperature in a structure or environment reaches a point at which everything begins to burn simultaneously. Usually at a minimum of about eleven hundred degrees F. The atmosphere around you burns, the fuels ignite, everything burns. It's beautiful to watch, but deadly, and unsurvivable.
In the swede prop. we were put in an environment in which it got really hot. Our helmets were too hot to touch for some time after we exited the container. The air in our SCBA tanks was very hot; it sometimes hurt to breathe. I saw masks melted, and nomex burned off of people's faces with some mild second degree burning beneath. To say it was realistic and intense might be an understatement. It was also a thing of beauty. The air around us caught fire in what were referred to as "snake flames;" the atmosphere merely began burning, and soon everything around us was burning. We felt thermal expansion of water in the heat, the steam burning, watched the effects of upsetting the thermal balance, and even watched a firehose contribute to and ignite the fire...and as the water left the hose and turned to oxygen and hydrogen, we saw water appear to burn.
We didn't go in there to practice surviving a flashover. We went in there for one reason,and one reason only. To recognize the signs of rollover, heat, thermal balance, and other things that are encountered in a hot environment leading up to a flashover. We learned to turn our heads and feel the burning in our ears as a sign of what was coming. We learned the sights, the sounds, the circumstances the contributing factors. We sat through hours of class before and after, watched filsm of burned firefighters who died in flashovers, listed to the testimonies of their buddies on the line.
Our sole reason for being there was to recognize the flashover before it happened, and to get out. That was it. Hours of training and intensity burned down to one thing; recognize it and get out.
Training for Vmc is the same way. Vmc can kill you, even in training. You have one mission in life for the period of time in which you train in that one, important maneuver. Recognize the signs and stop it before it starts. No need to burn in, no need to roll over, no need to lose control. You have one reason for drawing breath and for living when you teach that to a student; to teach the student to recognize the situation reduce power on the good engine(s), and to reduce the angle of attack. Your one purpose for drawing breath and for living when you teach this exercise is to provide the student the resources to recognize Vmc and to have the privilege of drawing breath himself or herself after the fact.
Why not perform loss of control demonstrations to a full loss of control? Isnt' that a little like asking why not try cocaine to learn why one shouldn't take it? Or getting shot in the leg to learn that firearms really can hurt you?
We teach kids to say no, to not try the coke. We teach range safety to preclude getting shot. That ought to do.
Years ago, multi engine training did include pushing Vmc and doing single engine stalls. A truism is that more people were getting killed doing training than in actual engine failure scenarios. Today, we rightly concentrate on taking the appropriate action at the first sign of a control loss, rather than waiting until it's out of control to do something.
When I was doing structure fire, we were put twice a year through what was called a Swede Prop, also called a Flashover simulator. A flashover occurs when the ambient temperature in a structure or environment reaches a point at which everything begins to burn simultaneously. Usually at a minimum of about eleven hundred degrees F. The atmosphere around you burns, the fuels ignite, everything burns. It's beautiful to watch, but deadly, and unsurvivable.
In the swede prop. we were put in an environment in which it got really hot. Our helmets were too hot to touch for some time after we exited the container. The air in our SCBA tanks was very hot; it sometimes hurt to breathe. I saw masks melted, and nomex burned off of people's faces with some mild second degree burning beneath. To say it was realistic and intense might be an understatement. It was also a thing of beauty. The air around us caught fire in what were referred to as "snake flames;" the atmosphere merely began burning, and soon everything around us was burning. We felt thermal expansion of water in the heat, the steam burning, watched the effects of upsetting the thermal balance, and even watched a firehose contribute to and ignite the fire...and as the water left the hose and turned to oxygen and hydrogen, we saw water appear to burn.
We didn't go in there to practice surviving a flashover. We went in there for one reason,and one reason only. To recognize the signs of rollover, heat, thermal balance, and other things that are encountered in a hot environment leading up to a flashover. We learned to turn our heads and feel the burning in our ears as a sign of what was coming. We learned the sights, the sounds, the circumstances the contributing factors. We sat through hours of class before and after, watched filsm of burned firefighters who died in flashovers, listed to the testimonies of their buddies on the line.
Our sole reason for being there was to recognize the flashover before it happened, and to get out. That was it. Hours of training and intensity burned down to one thing; recognize it and get out.
Training for Vmc is the same way. Vmc can kill you, even in training. You have one mission in life for the period of time in which you train in that one, important maneuver. Recognize the signs and stop it before it starts. No need to burn in, no need to roll over, no need to lose control. You have one reason for drawing breath and for living when you teach that to a student; to teach the student to recognize the situation reduce power on the good engine(s), and to reduce the angle of attack. Your one purpose for drawing breath and for living when you teach this exercise is to provide the student the resources to recognize Vmc and to have the privilege of drawing breath himself or herself after the fact.
I don't know of any particular videos detailing flashovers, but I'm sure they're out there. There was one particular training film that was regularly shown, and I'm sure is available from the industry, though I don't have it. It detailed a several alarm fire that put four firefighters inside a wearhouse, fighting a fire in an office at the rear. They knocked it down, thought they had the fire, and were exiting the building when it flashed. One made it to a doorway, all four died where they stood, and the clothing, including all their heavy turnout fire resistant gear, was vaporized off their bodies. their SCBA packs fell on the ground, the straps holding them in place simply gone. The most striking picture fo the entire presentation was what was left of their uniforms and gear arranged just as they'd have worn it, one alongside the other, on the ground. They were fried.
Somoeone sitting alongside me asks "what's the deal with the vaporized uniforms...how can they be arranged on the ground if they're vaporized?"
Rather than come back to explain that, I'll do so now. The packs fell off their bodies, and their turnout gear was destroyed, right down to melted and burned helmets. The straps holding on their gear were completely burned up, and the tattered remains of those four firefighters were arranged in the same position on the ground for the film that they would have been had the entire corpse been there, still wearing the gear...except no corpse. The bodies weren't vaporized, but what was left of them had been trucked away...the scene was still very sobering.
Someone else loaned me a video, though I'm sure it's not on the web, detailing the use of nomex in aircraft flash fires. I found it very convincing. It's an older army video detailing an incident that took place during the vietnam conflict. The person who loaned it to me noted a certain distain I had for full personal protective equipment in a hot cockpit, and wanted to see if the video might encourage me to wear everything...it did. I do.
I know that Bob Hoover did his routine in the Shrike Commander with both engines, then one shut down, and finally both shut down. I've seen other piston acts at airshows over the years in piston twins. There is no good reason why an aerobatic act can't be done in a piston twin, any more than a piston single, but certainly greater care must be taken, and greater potential for rapid change is there in the event of an engine failure. I've seen it done in a cri-cri, and other novelty acts, as well as certificated aircraft. I even saw a man with no legs perform an airshow act in a Cessna 337 mixmaster.
Somoeone sitting alongside me asks "what's the deal with the vaporized uniforms...how can they be arranged on the ground if they're vaporized?"
Rather than come back to explain that, I'll do so now. The packs fell off their bodies, and their turnout gear was destroyed, right down to melted and burned helmets. The straps holding on their gear were completely burned up, and the tattered remains of those four firefighters were arranged in the same position on the ground for the film that they would have been had the entire corpse been there, still wearing the gear...except no corpse. The bodies weren't vaporized, but what was left of them had been trucked away...the scene was still very sobering.
Someone else loaned me a video, though I'm sure it's not on the web, detailing the use of nomex in aircraft flash fires. I found it very convincing. It's an older army video detailing an incident that took place during the vietnam conflict. The person who loaned it to me noted a certain distain I had for full personal protective equipment in a hot cockpit, and wanted to see if the video might encourage me to wear everything...it did. I do.
I know that Bob Hoover did his routine in the Shrike Commander with both engines, then one shut down, and finally both shut down. I've seen other piston acts at airshows over the years in piston twins. There is no good reason why an aerobatic act can't be done in a piston twin, any more than a piston single, but certainly greater care must be taken, and greater potential for rapid change is there in the event of an engine failure. I've seen it done in a cri-cri, and other novelty acts, as well as certificated aircraft. I even saw a man with no legs perform an airshow act in a Cessna 337 mixmaster.
KeroseneSnorter
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