https://www.cbc.ca/news/canada/north/yt ... -1.5153434
There's a LOT of "if"s in order to make that statement correct. Especially when buying a used aircraft and ferrying it to it's new home.
N4512C, a privately owned Cessna 170B aircraft, was departing Whitehorse/Erik Nielsen Intl
(CYXY), YT for Anchorage/Ted Stevens Intl (PANC), AK with 1 pilot and 1 passenger on board.
Shortly after the takeoff from Runway 14R, the aircraft departed controlled flight and crashed into a
wooded ravine approximately 2000 feet south of the runway. A post impact fire consumed the
aircraft, and the 2 occupants received fatal injuries. An ELT signal was detected.
I really don't understand what these guys were doing. They were at max weight, possibly more and a fairly high density altitude in wind conditions that made it not a good day for flying. Then they decided to select flaps to 40 degrees after getting airborne, subsequently retracting them to either 30 or 20 degrees creating what must been massive drag during the process. There is a reason why the C170B flaps are known as Barn Door flaps and even 20 degrees creates a fair amount of drag.
Anyone have any theories on how all this flap might help in an expected windshear. Maybe 10 degrees.
I wonder if the application of full flap was an attempt to reject the takeoff, but it would cause them to balloon a bit which may cause them to reject rejecting the take-off and continue trying to fly. If this is the case, its a horrible string of bad decision making and hopefully others can learn from it.
They were also doing legs of around 200 miles all day, until this leg where they planned 437NM, and terrain does not allow for a direct flight. It would appear they may have taken on significantly more fuel than they had for previous legs.
I doubt it. The amount of flap lever travel between 20 and 40 is very apparent to the pilot. 10 to 20 can be mistaken, but 20 to 40 is pretty obvious. And, had the pilot made that error, it can be immediately corrected, the flaps move as fast as you can move the flap lever (which can actually be a problem!)Maybe he meant to apply 20 degrees of flap, but held the button in and it went to 40?
Pilots of manual flap Cessnas have been known to fool around with flap settings exceeding 20 on takeoff, particularly on floats. Some pilots might argue a very slight benefit in getting off the water with this trick, but it is hardly approved. Perhaps a land plane pilot might play around with this, but there is no point.
If you find yourself airborne in a Cessna with full flaps extended, fly the plane so as to remain in ground effect while you reposition the flaps where they should be. They will fly a balked landing with full flaps, but don't push your luck. Actually extending the flaps past 20 during takeoff... just don't do it, the risk far exceeds any very slight momentary benefit.
If you've had an engine failure after takeoff, you might get to the point in your immanent forced landing of extending full flaps, but that will be about the last thing you do as you flare. You very surely don't want any more flaps extended as you transition from departure climb to glide, you need every bit of momentum and clean plane you can retain to enter the glide.
From experience having done this, I agree 100 percent with this comment. We had flap motor fail in an old Cessna 172 during short field touch and go practice when the safety pilot retracted flaps on the ground from 40 degree landing position to 10 degrees takeoff position. Unnoticed by the two pilots, the flaps did not retract during the accelerating takeoff. As the speed increased, the aircraft ballooned into the air with Flaps 40 while horrendously out of trim catching everyone by surprise. There was not enough runway to recognize the problem, put the aircraft back onto the ground and stop safely. The pattern was flown just above the corn stalks while trying to re-trim and accelerate with two people on board with fuel fuel and no baggage. It would be quite some handful to try to finesse a heavily loaded C170 at a high density altitude in a gusty crosswind with Flaps 40.PilotDAR wrote: ↑Wed Dec 25, 2019 10:57 amIf you find yourself airborne in a Cessna with full flaps extended, fly the plane so as to remain in ground effect while you reposition the flaps where they should be. They will fly a balked landing with full flaps, but don't push your luck. Actually extending the flaps past 20 during takeoff... just don't do it, the risk far exceeds any very slight momentary benefit.