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#11
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Jay Maynard wrote:
I did this on the first attempt in a Warrior with my CFI from 400 AGL. You're good! Did you know it was coming? A big part of this is the fast transition from climb attitude to power-off glide. |
#12
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Brian schrieb:
Your right in that many aircraft it is possible. But the problem is it isn't possible for many pilots when the engine quits. It is not a maneuver that is routinly practiced. Now this problem could be solved. |
#13
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On 2008-04-24, B A R R Y wrote:
Jay Maynard wrote: I did this on the first attempt in a Warrior with my CFI from 400 AGL. You're good! No, my CFI was. Did you know it was coming? A big part of this is the fast transition from climb attitude to power-off glide. This is why I succeeded: because I knew it was coming. It was intended as a demonstration, not as a test of my abilities. He talked me through it. Afterward, I set my personal decision height at 600 AGL. Below that, in that aircraft and under those conditions, I don't attempt it. Above that, it's possible. That's why I plan to do the same with the Zodiac: so I know where the line is, and have the decision already made before I take off. Too many lives are lost to indecision; I do not intend mine to be one of them. -- Jay Maynard, K5ZC http://www.conmicro.com http://jmaynard.livejournal.com http://www.tronguy.net Fairmont, MN (FRM) (Yes, that's me!) AMD Zodiac CH601XLi N55ZC (ordered 17 March, delivery 2 June) |
#14
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On Wed, 23 Apr 2008 22:26:44 -0700, Ron Wanttaja
wrote: On Wed, 23 Apr 2008 23:53:32 -0500, Big John wrote: AW&ST today had a small article that a Lancair piloted by Gerand Schkolnk crashed moments after takeoff during the Sun and Fun AirShow. He was director of Supersonic Technology Programs at Gulfstream. Anyone have any data on accident other than what AW&ST had? http://www.avweb.com/avwebflash/news..._197685-1.html Ron Wanttaja ******************************************** Tnx for info Ron. To comment about the 180 if engine out after take off. You cannot make a level turn, engine out, back to field. No way and better believe it. If you do not have enough altitude to make a diving 180 degree turn back to field, don't try it. If you are not comfortable to make a diving turn close to ground don't try it. If you believe in probabilities, then limit yourself to a max of 45 degree turn either right or left to miss any immovable object. NO MATTER WHAT HAPPENS AND WHAT YOU DO,FLY THE AIRCRAFT AND DO NOT STALL IT. Fly safe and survive. Big John |
#15
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On 2008-04-24, Brian wrote:
Depends on what you mean by "the impossible turn". If you mean turning back at 200 AGL, yeah, that one's pretty much impossible. If you mean 600 AGL, it's pretty much possible in the average aircraft. (Hell, that's pattern altitude at EFD!) The line lies somewhere in between. It is statements like this that get pilots killed. It's statements like 'never turn, always land straight ahead' that also gets pilots killed. There are plenty of airfields where going straight ahead is quite possibly the worst option, and the best survivability options are at least a 120 degree turn away from whatever point you're at when at 600' AGL. The only thing you can do is use the best judgement at the time. You get one chance - it may be wrong. Sometimes, trying to turn back might be wrong. Sometimes doing anything *other* than trying to turn back might be wrong. In gliders, every glider pilot is taught "the impossible turnback" from 200 feet (which, in the typical low performance training glider, is about equal to turning back at 600 feet in a C172). We actually train for it for real - there's no other way to do it - the instructor will eventually pull the bung on you at around 200ft. It's an essential skill because power failures (rope or cable breaks) are a lot more frequent than engines quitting on a single. Doing it off a simulated winch launch failure is quite exciting - we tend to do that at about 400 ft though because it's an extremely critical manoevre, since you're pitched up at 50 degrees or so and any delay equals a low altitude stall. The ground looks really, really close when you pitch down steeply to quickly regain your airspeed and can see nothing but green in front of you. The really important bit about this training though is you're not taught it as an absolute. The mantra is to first do what it takes to maintain airspeed, then quickly decide on a course of action. The course of action could be any of several possibilities - can you get down on the remaining runway? Can you turn back? Is what's in front of you landable? Land to the side? Which way is the wind going? (If there's a crosswind aloft, this affects the decision on which way you're going to turn: you should have already decided turn direction in the 'eventualities' part of the checklist before the slack is even taken up on the cable or tow rope). The answer is as always training, and having a plan. Think of the eventualities just as you line up - if you lose power at point X, what should you do. At point Y, what should you do? What about point Z? -- From the sunny Isle of Man. Yes, the Reply-To email address is valid. |
#16
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Jay Maynard wrote:
Afterward, I set my personal decision height at 600 AGL. Below that, in that aircraft and under those conditions, I don't attempt it. Above that, it's possible. I think personal decision height also depends on several other factors. - Departing from a 5500 (or longer) ft. runway vs. a 2500-3000. You'll be closer to the threshold as you glide back to a longer runway, because you were sill over it as you climbed. - What's at the end of the runway? A flat and open approach area beats big trees, power lines, factories, a river dike... Coming up short at one of my local fields puts you in a sewage pond, _if_ you clear the river dike, at another, a steel mill with large overhead cranes. In all probability, I'm going straight ahead, but there are individual circumstances that could sway that. The factors that might have me attempt the turn would have to be clear, obvious, and pre-planned. |
#17
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On Thu, 24 Apr 2008 12:46:29 GMT, Jay Maynard
wrote in : On 2008-04-24, WingFlaps wrote: When will pilots learn to stop trying to do the impossible turn... and go for a straight ahead landing on soemthing horizontal? Depends on what you mean by "the impossible turn". If you mean turning back at 200 AGL, yeah, that one's pretty much impossible. If you mean 600 AGL, it's pretty much possible in the average aircraft. (Hell, that's pattern altitude at EFD!) The line lies somewhere in between. This subject has been discussed in detail with the assistance of erudite professor Lowry's input: http://groups.google.com/group/rec.a...1d80a2e846a88b John T. Lowry Best turnaround bank angle phi (least altitude loss per angle turned through) for a gliding airplane is given by: cos(phi) = (sqrt(2)/2)*sqrt(1-k^2) where k = CD0/CLmax + CLmax/(pi*e*A) where CD0 is the parasite drag coefficient, CLmax is the maximum lift coefficient for the airplane's flaps configuration, e is the airplane efficiency factor, and A is the wing aspect ratio. I know most ng readers hate those darned formulas, but that's the way the world works. For GA propeller-driven airplanes, k is a small number (0.116 for a Cessna 172, flaps up) and so the best turnaround bank angle is very closely the 45 degrees cited by Rogers and, much earlier, by Langewiesche (Stick and Rudder, p. 358). For the above Cessna, for instance, it's 45.4 degrees. For a flamed-out jet fighter, however, things are considerably different. The formulas above, along with formulas for the banked stall speed, for banked gliding flight path angle, and for the minimum altitude loss in a 180-degree turn, can all be found in my recent book Performance of Light Aircraft, pp. 294-296. The following seven pages then treat the return-to-airport maneuver, from start of the takeoff roll to contact with the runway or terrain, in excruciating detail. Including wind effects, the typical four-second hesitation when the engine stops, etc. John. -- John T. Lowry, PhD Flight Physics; Box 20919; Billings MT 59104 Voice: 406-248-2606 Nov 1 1999, 1:00 am Newsgroups: rec.aviation.piloting, rec.aviation.student From: "John T. Lowry" Date: 1999/11/01 Subject: Turn Back Maneuver Best turnaround bank angle phi (least altitude loss per angle turned through) for a gliding airplane is given by: cos(phi) = (sqrt(2)/2)*sqrt(1-k^2) where k = CD0/CLmax + CLmax/(pi*e*A) where CD0 is the parasite drag coefficient, CLmax is the maximum lift coefficient for the airplane's flaps configuration, e is the airplane efficiency factor, and A is the wing aspect ratio. I know most ng readers hate those darned formulas, but that's the way the world works. For GA propeller-driven airplanes, k is a small number (0.116 for a Cessna 172, flaps up) and so the best turnaround bank angle is very closely the 45 degrees cited by Rogers and, much earlier, by Langewiesche (Stick and Rudder, p. 358). For the above Cessna, for instance, it's 45.4 degrees. For a flamed-out jet fighter, however, things are considerably different. The formulas above, along with formulas for the banked stall speed, for banked gliding flight path angle, and for the minimum altitude loss in a 180-degree turn, can all be found in my recent book Performance of Light Aircraft, pp. 294-296. The following seven pages then treat the return-to-airport maneuver, from start of the takeoff roll to contact with the runway or terrain, in excruciating detail. Including wind effects, the typical four-second hesitation when the engine stops, etc. John. -- John T. Lowry, PhD Flight Physics; Box 20919; Billings MT 59104 Voice: 406-248-2606 Mo http://groups.google.com/group/rec.a...4829291b24775f http://groups.google.com/group/rec.a...c37fab40401aba http://groups.google.com/group/rec.a...73917967e58181 http://groups.google.com/group/rec.a...b42a74fe660741 http://groups.google.com/group/rec.a...73917967e58181 http://groups.google.com/groups/sear...X-Y_&filter=0& http://groups.google.com/group/rec.a...095b7459a04b3a |
#18
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On Thu, 24 Apr 2008 17:05:06 +0200, Stefan sayeth:
Brian schrieb: Your right in that many aircraft it is possible. But the problem is it isn't possible for many pilots when the engine quits. It is not a maneuver that is routinly practiced. Now this problem could be solved. You're suggesting instructors practice engine failures with their students on takeoff? Oh boy, better hope Dudly doesn't see this... |
#19
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Buttman schrieb:
You're suggesting instructors practice engine failures with their students on takeoff? Oh boy, better hope Dudly doesn't see this... Glider pilots do it routinely. |
#20
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Hi,
In article , wrote: On Thu, 24 Apr 2008 17:05:06 +0200, Stefan sayeth: Brian schrieb: Your right in that many aircraft it is possible. But the problem is it isn't possible for many pilots when the engine quits. It is not a maneuver that is routinly practiced. Now this problem could be solved. You're suggesting instructors practice engine failures with their students on takeoff? Oh boy, better hope Dudly doesn't see this... EFATO practice is normal during the PPL in the UK (simulated, obviously). The instructor chops the throttle and you pick a landing sight and get set up for it in much the same way as you would a PFL. You do have a bit of warning when he announces 'fanstop' over the radio though! Andy |
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