![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#16
|
|||
|
|||
![]()
At 05:54 30 October 2011, Bruce Hoult wrote:
On Oct 29, 12:22=A0pm, Martin Gregorie wrote: Both show what we are exhaustively trained against: assuming that you're OK once you've pushed over to a normal gliding attitude. You're not of course, because you'll be too slow and, unless you reacted IMMEDIATELY and got the stick far enough forward for a zero G push-over you'll be below stall speed, from where any turn will spin immediately. The rule of thumb[*] is to push over until your dive attitude is as steep as you were going up and then hold the attitude without attempting to turn until you've reached the landing approach speed you'd chosen for the day. Then, and only then you decide whether you've space to land ahead or whether you need to turn. Yes, I agree with this, except there's no need to push. Simply keeping the stick roughly in the middle will allow the nose to fall through as the speed drops, without any danger of stalling, and with the wing operating at an efficient (low drag) angle of attack. That is incorrect and sounds positively dangerous - the speed will drop off to well below the stall speed before the nose comes down sufficiently for the airspeed to increase due to gravity. You are, in effect, doing a steep stall, which is means that the aircraft goes through a phase of not being positively controlled! Easing the stick forward enough to get zero G is OK too, but unnecessary. Negative G is likely to be counterproductive and actually cause more drag and therefore bleed off more energy than a small amount of positive G. While there may be slightly less drag with neutral control rather than with the elevator pointing down, this is a moot point. you may save a little potential energy, but this will be at the expense of airspeed and it will take longer to regain it than if you push the stick over. The idea is to rectify the "unusual" undesirable attitude before it becomes an issue. Near the ground, airspeed is everything. [*] unless, of course, its a low break where you'd become a lawn dart if you used the above technique. Off a winch you'll always have plenty of specs ahead, so a shallower recovery attitude is OK once you're comfortable above stall speed and anyway you won't need to turn. I don't agree. Assuming you maintain a low drag angle of attack, you'll arrive back at the release height with the same speed you had on the way up. We know you made the pull up into the climb from just above ground level, with an adequate safely margin from stalling, and with lower speed than you had in the climb. There's no reason at all that you can't safely pull out of the dive, starting from the cable break height, even if the cable broke just as you were entering full climb. Again, I'd rather have the positive control that pushing the stick forwards (obviously without being a lawn-dart) gives than wallowing about at less that 100' agl. I'm totally with Martin and the BGA (and all of the winch qualified instructors!) on this. If I demonstrated this laissez-faire attitude to winch launch failures (in the UK at least), I would not be allowed to fly solo! This explains it in much more detail (and with greater authority) than I can he http://www.gliding.co.uk/bgainfo/saf...ts/safewinchbr ochure-0210.pdf |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Final NTSB report on Fossett crash | danlj | Soaring | 0 | July 10th 09 06:32 AM |
NTSB Factual Walton Crash | ChuckSlusarczyk | Home Built | 29 | September 5th 06 06:59 PM |
NTSB Preliminary report on HPN crash | Peter R. | Instrument Flight Rules | 83 | May 10th 05 08:37 PM |
Hendricks Crash- NTSB Prelim | C Kingsbury | Instrument Flight Rules | 10 | November 14th 04 02:18 AM |
NTSB: Co-pilot error caused AA 587 crash | Bertie the Bunyip | Piloting | 4 | November 3rd 04 04:30 AM |