landing configuration
2 Apr 2017 12:45:07 UTC
Topic 206580
(moderation:
In the SpaceX thread there has been some discussion regarding the condition of the paddles during the descent phase. Even the smallest of airborne creatures must consider the "paddle" reconfiguration to effect a save landing as caught by the camera on the front of the house. Note the feather configuration in two of the pictures. Quite amazing I think.
Flare!!!!
These are amazing photos !
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These are amazing photos ! :-)
I do love birds. We all want to fly like them. What a neat transition to stall in this sequence and mainly done by steepening the angle of attack as the speed decreases ie. 'flare'. However the stall speed itself lowers as the "flaps are set". Many modern aircraft have both trailing & leading edge ( typically Fowler type ) flaps. The A380 does a really good job at that, with quite a dramatic difference in wing curvature for landing say compared with cruising. Mind you, please don't try to flare an A380 ! But you can't beat birds for that shape change of the entire airfoil. Thanks for sharing.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Mike Hewson wrote:These are
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Thanks. Wish I could say I was that good with a camera but sometimes the most interesting images occur by chance as these did. When I looked at the video and framed through it I was amazed by the wing feather configuration when transitioning from flight to "short field landing".
robl wrote:Mike Hewson
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In my ( sadly long gone ) days of student flight tuition my instructor used to call them 'tactical approaches' : steep slope ingress, flaps right down, fast rate of descent, washing energy off left/right/centre, with a well timed flare. Airframe/wing drag consumes the gravitational potential energy being spent, so ideally there is little/no speed increase on the way down. Key point : trim carefully before entering the manoeuvre ie. you won't have the time during. Fun but not for the faint-hearted. If you yearn for even more excitement then try all of that with crossed controls - rudder kicked to yaw one way with ailerons to roll the other - as one might need to do in crosswinds etc. Or even better : simply go & learn in the New Guinea highlands. If you are alive after the first week then you pass ! :-)
I know an A380 chief pilot whose primary role is to take-off and land for the really long hauls eg. non-stop Melbourne to Los Angeles. Apart from that he clips the younger crew over the ear-hole if they need it. The trick, as it were, to landing well is very precise knowledge of the characteristics of the plane per configuration. Then one has a good approach setup, with the rest drawing on years of gentle but firm hands on the yoke.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Mike Hewson wrote:with the
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Yep, making sure the autopilot stays in autoland.
Gary Charpentier wrote:Mike
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Indeed ! ;-)
Real pilots anticipate in ways autopilots can't. Plus of course they fear death in a way that autopilots don't.
My 'per configuration' comment is to emphasize that modern planes can often change their 'type' dramatically, in ways not done earlier. Interestingly Mr Fowler invented his flap design - sliding extra wing segments down/out of slots to create curvature - in the mid 1920s ! Long before implementation. I'd bet he used to watch the birds too.
The best tactical approach flare ( aka well timed ) is to have some ground effect in play. You trap a volume of air b/w wing and ground. That air has an inertia such that it can't move quickly away from beneath ( over the time scale of the manouevre ). So the vertical velocity component is nulled in the manner of a cushion. It feels a tad weird through the controls if you do. I never managed to do that but my instructor could really get it right.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Nothing beats your first
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Nothing beats your first "auto rotation" as demonstrated by your instructor. Where did the air go? I used to watch a student at a local air field going for his instructor rating practice these by killing the engine and auto rotating to ground. For other students like me we could auto rotate with engine at idle and engage collective at ~3 feet.