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PFLs - preferred approach

I agree totally, but I also don't think you should assume that the "best" glide characteristics in a real engine failure will be what you got with a serviceable aeroplane. So technique needs to be flexible enough to compensate for those uncertainties.

G

Boffin at large
Various, southern UK.

Balliol, I realize was not being specific. The dilemma of whether to move or just touch the fuel selector arises when training for simulated engine failure, not in normal operation.

We don't use touch drills, partly for the reason I mentioned with the pilot expecting the engine to spring to life when just touching the fuel lever, resulting in an actual emergency landing. Well, I admit we don't actually shut down the aircraft; so that last bit is done using touch-and-say-aloud.

One more point for clarification: on older PA-28's the fuel selector can rotate freely all the way round, including to the OFF position.

huv
EKRK, Denmark

Have to agree with Genghis, the constant aspect approach works the best. Balliol, I stand corrected, but according to my last visit the the Senior Instructor's Forum at Cranwell in 2010 the "High Key - Low Key" has been superseded by the CA method. Maybe because it works!

High Key is only a reference for judging Low Key which is itself a reference for being able to glide to the aiming point on the field. If you use one or both of these markers you are using a Constant Angle method. Somewhere that will pass through the mythical 1000 ft Point which is only another “guessed” reference poiint to acheive the same result. Ideally you are attempting to get yourself onto a curved path towards the Aiming Point how you acheive it is probably of little consequence but the one thing they should all have in common is a constant angle from the aircraft to the aiming point, or a line of constant nearing. Simple geometry really.

Also from my side, a few more thoughts re PFL training. I am not instructing much at the moment, but plan to get back to doing more in the future.

  • I totally agree with GTE on his “two-phase approach” regarding the choice of landing field (i.e. first steer towards the generally most suitable area, late, then select the exact landing site; in the meantime, try restart, pax brief and mayday call). Unfortunately, most instructors merely teach a plain “select field” approach.
  • However, in most cases, a suitable field is right below. Therefore, assuming the exercise is started at 1500 or 2000 feet AGL, there is enough time to fly a complete (left hand!) “circuit” around that field. It is important to fly that circuit rather tight…many times, I have seen students “lose” their field when on “downwind” or “base”. For the reason stated above (i.e. suitable fileds usually being right below one’s wings) I think we shoudn’t become too anal about maintaining best glide speed – it’s just not necessary to maximize the glide distance in these cases. Instead, the student should merely establish a safe airpspeed and concentrate on other things.
  • in most aircraft, it is not sufficient just to open the doors; once opened, one also needs to “lock” them. Otherwise, the door will probably “swing shut” again upon landing. Locking is particularly important in aircraft like 150 and 152 with their “slam” door mechanisms.
  • “blips” of throttle will do absolutely nothing significant to CHTs
  • in Germany, unfortunately, one can only go below 500 feet AGL a) during official PPL (or CPL) training b) during check-flights with an examiner on board. This means that, for example, during the biennual revalidation flight (now called “traning flight”), or during any other refresher training, type conversion training, etc., we cannot really pratice any PFLs too well (have to abort at 500 feet). I wonder what the situation will be in the UK after december 2014, when the strict 500-feet minimum rule will come into effect..
  • unless there is really enough time, I teach students not to worry too much about setting squawk 7700. A positive radio call to ATC is much more useful if time is a factor. Know those nasty new TRIG transponders? If a student tries to set 7700 in a genuine emergency, he will probably crash before he’s done setting it… there should really be an “emergency button” on every certified transponder, but there isn’t.
  • in a PA28, I insist on only simulating the change of tanks, as the switch is too hard to see for the instructor. Obviously I will stress that in a real emergency, the switch will indeed have to be actuated.
Mainz (EDFZ), Germany

Somewhat agnostic between constant aspect and aiming for a 1,000’ point, although CA is more elegant, the aim is to ensure PPLs are able to maintain control at best glide speed and position for a controlled forced landing. Statistically with modern engines this event should have longer odds than a 1 in 5,000 hour event.

Only comments on GtE’s procedure is to brief for increasing best glide speed if there is a strong headwind to improve glide ratio – moving out along the flat bottom of the drag curve to improve ground speed. I would also spend some more time on ensuring harnesses are secure, not comfortably loose, and briefing for brace position.

We seem to ensure good practice of PFLs in exams, re validations, when in fact more emphasis on precautionary landings with power would actually save more lives – fatalities linked to VMC into IMC still represent around 40%+ of PPL fatalities. A real tragedy when the main types are well built, simple FG aircraft which can easily operate out of a field if circumstances dictate.

Oxford (EGTK)

when in fact more emphasis on precautionary landings with power would actually save more lives

What evidence is there to support this? Close the throttle and you are back to the datum you have practiced. I was always taught not to rely on partial power, it may not last the course!

fatalities linked to VMC into IMC still represent around 40%+ of PPL fatalities.

A very good argument for retaining the IMC rating where the statistics are quite different!

I think we shoudn’t become too anal about maintaining best glide speed – it’s just not necessary to maximize the glide distance in these cases

I thought it would be necessary to maximise the glide distance. Can you elaborate on this? I accept 5 knots either side wont make much difference really, but in my mind its good to have a number drilled into your mind so at least airspeed, and danger of stalling or losing height unnecessarily is just one thing less you don’t have to worry about.

I thought it would be necessary to maximise the glide distance.

Why do you need to maximise glide distance? You only need enough to get to a field. If you consciously try to maximise the glide range you will probably finish up stretching the glide. Keep energy in hand and dump it when you no longer need it.

Why do you need to maximise glide distance?

I guess it’s not so much as maximising glide distance as such, but giving more time in a safe configuration to make sure the field you choose is the best one maximising your chance to select what looks like the best possible landing area. Or even trying using the NRST function to find out the nearest airfield (though I wouldn’t be doing that at 1000’).

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