As a pilot one of the things we are faced with is an engine failure immediately after take-off. What do we do? Do we execute "the impossible turn?" For those not familiar with the phrase, the impossible turn refers to turning back to the runway behind you in the event of an engine failure. The concept is simple, unless you have sufficient altitude, your rate of descent is too great for your rate of turn, and simple math will tell you that you’ll hit the ground before completing the turn. Thus the term the impossible turn.
The Impossible Turn RevisitedIn an interesting article in the EAA online publication the "EAA Experimenter" we found an article titled "The Impossible Turn Revisited". The author had this to offer:
Why Am I So Interested in This Subject? Several years ago while training for my instrument ticket, I was left seat, under the hood on the missed approach. I had a highly competent CFII (certificated flight instructor – instrument flight rules) in the right seat who is perhaps the most safety-minded individual I’ve ever met. Certainly a credit to his rating. He had recently attended an Aircraft Owners and Pilots Association (AOPA) convention and sat through a seminar on the subject of steep bank angles during the 180-degree turn back to the runway. Sometime earlier, he even presented this information to our EAA chapter. At about 750 feet AGL, on the left crosswind leg of our departure from the pattern, the Cherokee we were flying suffered a broken crankshaft: 100 percent loss of power. I tossed the hood in the back seat while my training kicked in. I knew we had enough altitude to make it back safely to the runway, so while pitching for airspeed, I entered a standard rate, 180-degree turn back toward the airport. No sooner had I established best glide and a 2-minute turn did my instructor grab the yoke and announce aggressively that we needed to speed up the turn if we were going to make it back. The 1963 Cherokee we were flying had only a stall warning light on my side (which was illuminated at the moment), out of sight of the instructor who was looking outside the windscreen anyhow. As I told him we were getting close to stall (the ASI was indicating well over 90 knots – best glide is 69), he rolled out of the turn. We were now on what would be considered a close right base, with the runway rising in the windscreen. We weren’t going to make it. Looking at the instruments, I saw that we were still doing over 90. I told my instructor that we could trade this speed for altitude, and he relaxed his grip on the yoke. The plane was still trimmed for 70. It then became apparent that we would most definitely make it back with no problems, so I asked the instructor if I could take the controls back. We had enough energy left to taxi halfway back to the tie-down area. Long story short, although my instructor had the best intentions and the appropriate head-knowledge, his choice to execute a maneuver which he never practiced in this plane (as opposed to just doing as he was trained, has practiced, and has even trained others to do) could have led to a disaster.