Well, from a simple question that was correctly answered in post 2 this thread has really gone off the rails.
Originally Posted by
Pilot DAR
Understand that generally, Vx is somewhat slower than the glide airspeed you'd like to have when you go to pull to flare. 50 to 100 feet is not enough altitude to push over, accelerate to glide speed, and still have altitude to spare to flare with. In my opinion, it is a serious omission that flight manuals do not contain this warning. Rather, they usually say words like: "lower the nose and accelerate to Vy when the obstacle is cleared". So, if there's no obstacle, don't be flying at Vx in the first place.
Nobody is saying to climb at Vx if you don't need to. But Vx is a safe speed to flare from. There is no need to accelerate to best glide, let alone Vy, for a safe flare. The 50 foot speed in a max performance take-off will be equal or less than Vx and yet it is certified “safe under all reasonably expected conditions including complete engine failure” and “not requiring undue skill”. References below.
Vx is somewhat slower than the glide airspeed you'd like to have when you go to pull to flare
I don't know where you are getting this idea that it is better to flare from best glide speed, whether that be an EFATO or any other forced landing. The best glide speed gives you best glide range.
It does not follow that best glide speed = best flare speed. If you have an engine failure at 50' it is hardly likely that you will need to prioritise range over minimum landing distance. Best glide is unnecessarily fast for a flare when you are in danger of running out of space to get the aircraft stopped. The glide speed I "would like to have" is the one recommended for engine failure, so here are some POH figures:
C-172: glide 65kts; landing without engine power
60kts. (Vx = 59)
PA-28: glide 73kts; “when the field can be easily reached slow to
63 knots for the shortest landing”. (Vx = 63)
M20K: glide 90kts; EFATO
75kts flaps down. (Vx = 79)
...high wing, low wing, and high performance, so fairly representative of the pisotn single fleet. Recommended power-off landing speeds less in each case than best glide. All certified and approved by authorities worldwide. NB the following certification requirements and guidance regarding the 50 foot speeds:
shall be an airspeed not less than 1.2 VS1 or VS1 plus 10 knots, whichever is the greater, at which adequate control is available in the event of sudden complete engine failure during the climb following take-off ....Take-off techniques should produce consistent results and not require undue skill or strength on the part of the pilot. [CASA Part 21 FTG]
speed and height sufficient to ensure capability of performing all maneuvers that may become necessary for safe completion of the takeoff and for safe landing if necessitated by power failure. An airspeed margin above stall in conjunction with a height of 50 feet is presumed to assure the desired maneuvering capability.....The procedures used for determining takeoff and landing distances must be executable consistently by pilots of average skill [FAA CFR 23 and AC23-8]
A speed that is shown to be safe under all reasonably expected conditions, including turbulence and complete engine failure [EASA CS23]
A single engined GA plane probably cannot glide back to a safe landing after an engine failure at 50 feet and VX
Based on the recommended speeds and regulations I have referenced here, your opinion is definitely not shared by the company test pilots and certification authorities worldwide.
“The takeoff speed investigation should include a demonstration that controllability and maneuverability following engine failure at any time between lift-off and the 50-foot point are adequate for safe landing.”
...so, evidently, all certified single engine planes have demonstrably achieved what you think probably can't be done. Of course it requires the pilot “without undue skill” to act promptly and get the nose down but that is why we train and licence the pilots too.
So, to practice safely (before you assert that I'm wrong), try the following: Establish a safe hard deck for yourself, a few thousand feet up in the practice area. Do your HASEL check ('cause you're probably going to need it!) Slow the airplane at cruise power to Vx at exactly that altitude. Apply takeoff power, and climb from that altitude while maintaining Vx. At 50 to 100 feet, close the throttle. Now you're going to have to push the nose down fairly promptly to enter a glide, But, because you were actually expecting this, delay one second before you push to make it more realistic. Now establish the POH glide speed, and then, while referring to the altimeter, and leaving the throttle closed, momentarily arrest your descent at your hard deck altitude, just long enough to see the altimeter pointer pause there. If you can pause the altimeter there long enough to see that you did, you succeeded in a simulated flare and landing. If the plane just stalled, and kept on down through your hard deck, you crashed.
You may as well argue you can teach a pilot to land by establishing a glide and then giving them a target altitude to stall at. Your little exercise in aircraft control is seriously unrepresentative of an engine failure at 50', or any round-out for that matter, where you are controlling the plane primarily according to the ground references. If nothing else, you have totally overlooked ground effect. The certification basis for the safety of the take-off performance is to demonstrate an actual landing on an actual runway and does not include trying to accelerate from Vx up to the best glide speed that you seem to have fixated on.