contactflying wrote:Both of these accidents, one poorly filmed and one filmed well, involve inside the Practical Test Standards box thinking that is taught throughout the country. That thinking, and the teaching that resulted, was that climbing out of ground effect at Vx was the one and only way to deal with short field over an obstacle.
Rather than look at the way crop dusters do it or any other way of doing it, the FAA solution to this problem they have created is to find fault with the operator, pilot, or mechanic, to teach avoidance of all situations except the easy ones, to explain and reexplain the aerodynamics of only the one solution, and to damage control the accident investigation. These accidents cry out that there may be another way or even other ways to take off safely over obstacles.
There are at least two other ways. One is to make a wings level rudder turns to lengthen the time we may stay in low ground effect before encountering obstacles. The other is to at least stay in low ground effect as long as possible before pitching up to Vx or Vy as appropriate.
Given the training both of these pilots probably did not get in maneuvering flight operations, they both did an excellent, life saving, job of flying the airplane all the way to the crash.
Of course we need to use common sense in our decisions about where and when to go, how much to load, multiple loads, etc. That is no excuse for not teaching better ways to do things. Teaching better techniques and using better techniques on a regular basis far better prepares us for those times when conditions, situations, and just our own screw ups, try to kill us.
Without admitting any error on their part, the FAA in 2013 changed the normal, short, and soft field PTS to require acceleration in ground effect until Vx or Vy as appropriate. It will probably take another fifty years and many more takeoff accidents until they again change the PTS to require acceleration in LOW ground effect until near the obstruction and pitching up only to that pitch attitude that will cause a zoom climb just over the obstruction.
You know I just tested something along these lines with my own plane yesterday.
My home strip is fairly short (maybe 1700ft usable - 6600ft field elevation) I have obstructions on both ends. Normally, in my plane I take off by grabbing 2 notches of flaps as I rotate, and just enter straight into a Vx climb (about 55mph). The plane climbs great, and I always check my altitude (bad elf pro) over the top of the obstruction at the far end. I'm usually in the 6900ft area with just me onboard (I'm 6'4" and prob 250 with clothes etc.) - 2/3s fuel, warm out like it was yesterday.
I was just sure I was getting the most altitude by instantly leaving the ground and climbing with flaps, then raising them before making a turn out. I thought I'll try something more along the lines of what your talking about... So i powered down the runway, grabbed some flaps, and this time stayed in ground effect long enough to get rid of the flaps and pick up some speed. It only takes a couple seconds, but it feels like you are eating up precious runway.. but when I pulled it into a steep Vx climb, I was in the range of 70-100ft higher over the same obstruction every time (7000ft +).
Now this might have something to do with climbing without flaps... I need to also test building speed in ground effect, and still climbing with 2 notches to compare directly to my original technique.. But the bottom line is that even though I'm using up more runway, and leaving myself less distance to climb.. building energy in ground effect and then trading it for a strong climb netted more altitude. Just as you mentioned. Somehow I already knew this to be true, but had convinced myself I had found the best technique with the way I was doing it.
I haven't owned my plane very long, and have spent a lot of time modifying it, and probably only have 25-30 hrs in it. But it still goes to show there is always room to improve and learn new techniques. That's what I love this site.. I have been religiously practicing the slightly nose up, power off STOL approach outlined here, and it has cut down my landing distance by probably half! (because I do have to descend over power lines and couldn't help but pick up some speed and float- even with a big slip... as my plane has the "speed wing" and the flaps are not real impressive).