Best Of The Web: Impossible Turn Misconceptions

Brian – 54:24 – “you are not supposed to use a 45 degree bank in the pattern – something in the regs on that”. What is that about?

Yeah, that caught me by surprise too.

Sorry Brian. Nothing in the regs about 45º bank in the pattern. The Overhead Approach Maneuver (AIM 5-4-27) expects a 60º bank on the break (upwind to downwind turn) and this is completely normal.

Also, this maneuver is NORMAL and a REQUIRED DEMONSTRATION for glider pilots. It is what you do after passing 200′ and you have a rope-break. I learned it in a glider and when I went out to practice it in a powered aircraft (I have done it in several) it was not at all difficult.

I could go on but you are right, there is a lot of misunderstanding out there when it comes to the [not so] impossible turn.

So, years ago, when I was an Instructor, and our airport wasn’t as busy as it is now, I took a 152 up to see what it would be like to lose an engine at 400 feet. (This is when patterns where typically 800′ AGL.)

We had (and have) parallel runways, albeit a little close together. And not as long as they are today. (KDVT.)

IIRC, I either went up to the Tower or called by landline, explaining what I wanted to do. I was given clearance for take off, “cleared to land any runway.” I did about five.

What I found was: IF you lose an engine at 400 feet, and IF you act right away, and IF you roll into a 45 degree bank in the descent, and IF the winds aren’t too strong (blowing you back toward the runway), then you can make it safely to the parallel runway – in a 152.

IIRC, I wasn’t able to make a teardrop back to the departure runway. Only a 180 degree turn to the parallel.

In real life, I dunno. I had the airport to myself when I did this. If someone were doing T’n’G’s on the parallel runway, that would eliminate returning to the parallel rwy. (Maybe land on a taxi way?) And I doubt, in real life, that I would be able to tell the Tower what my plan was after declaring an Emergency. (Assuming that I could get a word in edgewise on a busy Saturday. And it is dual frequency Tower, so the poor guy on the parallel won’t know of my Emergency, even if the two Tower Controllers could coordinate in a split second.) Nor does this take into account oil on the windshield, smoke in the cockpit, or some other distraction like that.

Of course, in a non-parallel runway situation, this option is totally out.

While I taught “land straight ahead,” that option is not as palatable today as it was then, given all the new development the airport. Still, I suppose the old adage, “Hit the softest, cheapest thing as slowly as possible” still has merit.

Let’s talk about airspeed for a second. Maybe I missed it, but it the only mention I heard was “best glide airspeed”. Ugh.

Best glide airspeed gets you the best distance for foot of altitude lost (the inverse of Vx)… but while I’m turning around, I want least altitude lost per second (the inverse of Vy). The minimum sink airspeed (which glider pilots know well) is a little slower than best glide. A 45-deg bank at min-sink will result in a surprisingly tight turn.

Second, best glide varies with wind. When you turn back, you’ll probably have a tailwind, so your best glide airspeed will be slower.

Most importantly, this was an hour long video with no real math. It left us with an understanding of how complex the decision is (and I love the idea of pre-briefing) and an awareness of the factors that go into finding a solution. But it didn’t include a workable process for applying that understanding. I’d love to see a practical video on how to determine if you can make that runway so your decision is fact based.

Watched the nice graphics at the beginning of the video then turned it off. I can’t suffer another hour long analysis of the “impossibe turn”. In one of Paul Bertoreli’s excellent articles he suggested a 20 degree deviation to the right on lift off will keep the runway in sight and create a scenario in which one can likely make it back. I’ve worked that concept at every flight since reading the article and I’m confident I can get back to the runway on engine out. I fly 20 degrees right and climb directly to pattern before initiating the cross wind leg and take headwinds into consideration. At my home airport my “straight out” decision below 1000 ft will put me in a nice open field full of tall grass and crickets. OTW I’m going to land safely. I sleep better now. Thanks PB. Problem solved.