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PFLs - preferred approach

I'm guessing we who instruct on singles all have strong opinions about the "best" way to teach and practice PFLS.

The various manuals I have describe various ways of flying the manoeuvre, and I've seen a number of variations: most survivable, a few perhaps not.

So, particularly given the ongoing and quite interesting "best field" thread in the student pilots page - what are the various instructors approaches to PFLs?

I'll offer mine, and happy to discuss why I do things in particular ways at leisure later..

(1) Aggressively pitch and trim to best glide

(2) Position for sensible fields

(3) IF time, height, and symptoms permit - attempt a restart

(4) Pick optimal field

(5) Try to position somewhere roughly between downwind and base for the selected field

(6) As time and height permit, brief pax, talk to ATC

(7) Fly a constant aspect continuous turn, checks / gear / flaps / re-trimming in the turn, occasional glances at airspeed, occasional blips of the throttle to protect the cylinder heads.

(8) Aim to roll out wings level on short finals at ~300ft.

(9) Go-around (verbalised as "go around, I say again, go around") once either the landing is clearly possible, or the landing is clearly not possible, or I instruct the student 'cos we're getting to close to a building and I'm worried about complaints.

(10) Full power/ fine pitch / carb heat in, pitch to climb, re-trim, flaps up in stages and only when a positive rate of climb is confirmed from at-least two sources at each point, flying field to field to ensure a safe landing if the engine really stops down there. Eventually normal climb from ~1000ft and turn en-route after that.

Stuff I regularly see and don't like (and worth mentioning that as a CRI, I don't fly with people who don't already hold some licence, so I don't teach ab-initio):-

  • Rectangular circuit PFLs
  • Complete failure to brief pax
  • Obsession with rule 5 (for non-Brits, that's the UK's "not closer than 500ft to person/vehicle/structure" rule), rather than leave that to the instructor and concentrate upon positioning the aeroplane for a safe landing.
  • Straight in approach from high, inevitably leading to misjudgement of flightpath and over or undershoot
  • Refusal to sideslip to lose height late in the PFL because some halfwitted instructor somewhere told them that sideslipping with full flaps is dangerous / prohibited.
  • Trying to raise flaps immediately they increase power, potentially stalling the aeroplane at low level.

G

Boffin at large
Various, southern UK.

I add (after your point 7), after being configured for landing:

Crack door open (C172), all switches off, fuel close.

The rest is exactly what I do. It is however hard to write down an exact procedure as circumstances vary, in particular altitude above ground, terrain characteristics, wind. For instance, if altitude is significant and wind is significant, I teach people to -as you say- agressively pitch and trim for best glide, but at the same time turn downwind immediately. Should give you more options for fields.

Private field, Mallorca, Spain

I teach the military high key - low key method which works brilliantly, allows adjustments and facilitates height judgement all the way round the pattern. If at about 1500' AGL or below, I teach to put nearest wingtip into wind on the DI, which puts you straight onto a base leg for an easy field selection and turn onto finals.

Points Id mention from your post -

engine warms should be a positive check that full power is available for a climb away, not a 'blip'

Some POHs do prohibit slide slip with full flap I think, although I agree most do not.

Types like PA28 with 40 flap ('drag flap') should have it removed straight after power application, then the others in stages.

I also always teach to use an Initial Aiming Point (IAP) a little way into the field, then when totally confident of making the IAP you use additional flap / slip to adjust to the Final Aiming Point. This gives a margin in case of an undershoot developing during the approach. it's also worth mentioning selection of a 7700 squawk if people have time.

FI - FE - FICI
Oxfordshire / Glocs

One thing that often gets glossed over in training is a properly and completely performed cause check, altitude/circumstances obviously permitting, which is the case for almost all real world engine failures.

For the C 172 I teach on this goes as follows and is done as a flow

Fuel................ Both and quantity check

Mixture ........... Rich

Carb heat..........On

Mags ...............Both, Left, Right, Both

Primer..............In and locked

As I mentioned earlier up to 80 % of all engine failures in certified aircraft with non turbocharged Lycoming/Continental engines, are caused by the pilot. Once you have established the glide attitude and pointed it at the field the priority should be to get the engine going again. The above check will cover all the things you can fix from inside the airplane and takes 5 to 8 seconds to perform if regularly practiced.

When I teach the PFL I terminate the exercise if the students doesn't do a good cause check and we try again. Too often in training the cause check is quickly verbalized so that you can get on to the "important" part of actually flying the procedure. The problem with this is it doesn't inculcate the importance of the cause check and so you see airplanes wrecked even though a few simple pilot actions could have restored power.

Engine failures are almost always taught as a binary exercise, engine runs, engine doesn't run. This type of failure is in fact the least likely to actually happen. Early indications of engine failure or only a partial failure are much more common.

When I teach the forced approach exercise I try to mix it up so that I will give the student a low oil pressure, high oil temp scenario and then see what decision making occurs and then a few minutes later fail the engine. I also do at least one PFL where I restore partial engine power after the cause check.

Wine, Women, and Airplanes = Happy
Canada

What you describe PBF is more or less what I both do and teach now. (The less is that for any cockpit-forward apparent fault, I now teach and practice a simple right to left across the cockpit of "is this control likely to do anything, if so use it, if not, move on". By and large the same as you're doing, mine is a little slower and a little more general-purpose.)

But I was also taught the engine running / engine failed approach with no grey areas - straight into the PFL every time, and took that with me in my head for far too long. It's become clear now as a CRI that I was far from alone in that, as the majority of pilots I fly with have the same approach and no concept of trying to find and correct faults.

G

Boffin at large
Various, southern UK.

Some POHs do prohibit slide slip with full flap I think, although I agree most do not.

There are a few which advise against it, but don't prohibit it (the C172 is I think one such), but I can't recall ever seeing a prohibition in a manufacturer's POH.

G

Last Edited by David at 15 Nov 09:59
Boffin at large
Various, southern UK.

In my Bonanza, there is so much drag available, a slip is never needed. With gear and flaps down, the rate of descent will be 2500 FPM and if I am high, lowering the nose will burn altitude at a rapid rate with only grudging airspeed increase that is easily bled away when excess altitude is lost.

In the full emergency descent maneuver, with just the gear down and descending at maximum gear speed, the descent rate is between 6000 and 7000 FPM. I was once on a base leg into Charlotte and the controller had kept me high at 4000 feet. He cleared me for a relatively close in landing if I thought I could get down in time. My remark to him was: A Bonanza is never too high. I made it with ease.

On the other hand, the Bonanza is a great glider if it is kept in the clean configuration. It has a glide ratio just above 10 to 1. As a result, with an engine failure, if the airplane is clean, one does not add the gear or flaps until the field is made. This has to be practiced as lowering the gear makes for a very steep approach. My visual guide is when the landing point is just still visible over the nose, lower the gear.

If the Bonanza has oil pressure, the position of the prop control makes for a large difference in glide ratio. For example, if the prop is set anywhere other than at the full rear stop, the engine speed will wind mill at around 1800 RPM with a rate of descent near 1400 FPM. If the prop is at the full rear stop, the RPM will windmill at around 1000 to 1200 RPM and the descent rate will drop dramatically to 800 to 1000 FPM.

KUZA

So, with those provisos, how does that affect how you teach PFLs Yankee? Doesn't sound to me that there's anything there I'd regard as more than "type knowledge", and I'd still fly a forced landing in basically the same way.

G

Boffin at large
Various, southern UK.

Fuel................ Both and quantity check

Mixture ........... Rich

Carb heat..........On

Mags ...............Both, Left, Right, Both

Primer..............In and locked

And don't forget Throttle.......Full

They can back out if the friction is not tight, or get bumped...done it myself!

I use FCMIT: Fuel, Carb heat, Mixture, Ignition and Throttle.... And then FISH when committed to power off landing: Fuel, Ignition, Switches (master - when gear and flaps no longer required), Hatches/Harness

EGPD / OMDW / YPJT, United Kingdom

Anthoy Q

I strongly disagree with flight school one size fits all mnemonic checks. The check should IMO be airplane model specific and regularly practiced as touch drills (a great exercise when you are droning along in cruise and getting bored).

In my post I was insufficiently clear because the check I posted is for C 172's powered by the 4 cylinder carburated Lycoming engine. There is different touch drills for the fuel injected R and S model 172's.

For example taking your FCMIT check and starting with "fuel" what you actually do is quite different depending on the aircraft.

In a Pa 28 it is boost pump on, fuel quantity check , fuel on fullest tank in that order..

In the C172 (carburated) it is fuel selector to both, fuel quantity check in that order.

In a C172 (fuel injected) it is Fuel shut off valve On (push full in), Fuel selector valve both, Fuel Quantity check, fuel boost pump on in that order

Differences between airplane models apply to the other parts of you mnemonic and I don't think do a good enough job of helping the pilot when the adrenaline is pumping.

I feel quite strongly that the average PPL will not get it right unless a full cause check ** specifically for the model of the aircraft**, is regularly practiced with touch drills. Unfortunately many accident reports where aircraft were force landed despite the fact that a correctly applied cause check would have restored power.

Your comment about the throttle also IMO feeds the full power/no power flight school dynamic. There can certainly be uncommanded power loss with a throttle creeping back, but that IMO should be treated as a partial power loss.

That is why I have a separate "Loss of Power/Rough Running" engine check that deals with everything short of a sudden total loss of power, starts with verifying throttle position and its existence reinforces to the student that if you have an engine failure it will probably involve those symptoms not a sudden total unexpected loss of all power the only scenario generally taught at flight schools.

Wine, Women, and Airplanes = Happy
Canada
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