Asymmetric go-around decision height in light twins

[Tee Emm]

Asymmetric go-around decision heights are not published in any manufacturer's POH. That is because there are too many variables involved. Individual flying instructors may teach a decision height during initial twin endorsement but this is usually because they were taught that height by whoever did their own twin endorsement. Whatever height is nominated is certainly not based on measured flight tests.

This brings into question the validity of a section of the CASA Part 61 Manual of Standards covering operate multi-engine aeroplanes.
AME.6: Manage engine failure and malfunction during approach and landing
Para 2.6 (B) states: Nominate decision height for landing.

Accepting that fact that aircraft manufacturers do not publish a minimum decision height for a single engine go-around in light twin engine aircraft, then requiring a candidate to nominate a decision height during a test when there is no POH figure published, would indicate this should not be an assessable item and the requirement to nominate such a figure is invalid.
............................................................ ............................................................ ............................................................ ...................................

In th past, Pprune has seen numerous discussions on pilot technique to be used if a wing should drop at the point of stall. The expression "pick up the wing with rudder" is frequently used in this context and there is little doubt many instructors teach students to skid the wings level before applying aileron. This is of course faulty technique and has the potential to cause an incipient spin in the direction to the dropped wing. Nevertheless the technique is almost universally taught at flying schools.

Having said that, it is interesting to note that Part 61 Manual of Standards at page 131 (Competency standards) paragraph 2.9 TR-SEA.9 - Operate aircraft in flight, states at sub-para (d) - (demonstrate approach to the stall and stall recovery) the following actions:

(I) recognises approaching stall symptoms;
(ii) reduce AOC at the stall;
(iii) prevents further yaw with rudder;
(iv) apply recommended power;
(v) when the wings are unstalled, level them using aileron control;
(vi) recover height loss

This would seem to put the kibosh on the popular teaching for a wing drop at the point of stall, that rudder should be used to pick up a dropped wing to level flight. The operative words are; (iii) prevents further yaw with rudder; In other words only sufficient rudder to prevent the wing from dropping further.

[ravan]

With regard to the second part of your post, that's the way I was taught and that's the way I have always taught it. It's nice to see someone in CASA has finally decided to put it into print.

[Tinstaafl]

Ditto, Ravan. I learnt over 30 years ago and was not taught to use rudder to force a roll, nor was it a technique during my instructor training in the late '80s. Always was what is stated above: Prevent yaw with rudder, roll after stall recovery.


W.r.t assy decision heights (somewhat tongue in cheek): If the student hits the ground during the missed - it's a fail (nominated too low an asym committal height). If the student attempts to go around instead of landing when below assy commital height but avoided the ground - it's a fail (ignored the commital height 'limitation'). If otherwise - a pass!

[Judd]

(ignored the commital height 'limitation').


But wasn't that the whole point by the OP? There is no officially published factual data in POH's on so called "committal height". You could come over the fence on one engine 15 knots above the VREF for a flapless and still go around safely. Even with a Seminole a single engine go-around at 200 ft in the normal landing configuration starting with 73 knots, can be done providing the flaps and landing gear are retracted promptly and the nose held down until 88 knots achieved. The problem is here pilots instinctively raise the nose as they apply full throttle on the live engine to the normal two engine climbing attitude like a go-around on two engines.


A single engine go-around commitment height is just fooling yourself. The situation changes second by second depending on airspeed, flap setting. That is why flap selection on one engine on final is best delayed in order to allow more options. But to set in stone (as blindly taught in many flying schools as a matter of policy), a generic committal height on one engine, is not very sensible

[scavenger]

Accepting that fact that aircraft manufacturers do not publish a minimum decision height for a single engine go-around in light twin engine aircraft, then requiring a candidate to nominate a decision height during a test when there is no POH figure published, would indicate this should not be an assessable item and the requirement to nominate such a figure is invalid.

No.

Most AFMs do not publish a minimum height loss for a stall, nor a method of increasing Vref to account for windshear.

Are the corresponding parts of the MOS that require assessment of these things similarly invalid?

You said it yourself:

Asymmetric go-around decision heights are not published in any manufacturer's POH. That is because there are too many variables involved.

It is a matter of pilot technique (company mandated or otherwise) and a good pilot will make a decision based on the circumstances, but not below the committal height. The actual height, as long as it is reasonable, is not important. What is important is that the pilot understands the risks associated with a SE go-around, and mitigates them appropriately. A committal height is just one countermeasure...

I can't believe the person who posted this rubbish:

You could come over the fence on one engine 15 knots above the VREF for a flapless and still go around safely.

and

Even with a Seminole a single engine go-around at 200 ft in the normal landing configuration starting with 73 knots, can be done providing the flaps and landing gear are retracted promptly and the nose held down until 88 knots achieved.

has the gall to question the sensibility of a committal height. Ever wondered why Piper don't produce an accelerate-go chart for a PA44?

If one has the skill to execute a go-around OEI from "over the fence" at Vref +15 with no flap, why would one be 15 knots too fast in the first place?

Teaching a 10 hr newly minted MEACR holder to go-around OEI from 200 FT, or from a fast approach close to the ground is misguided at the least, and criminally insane at worst. Start by reviewing VH CTT at YSBK a while back and go from there....

[Grogmonster]

I think you are all missing the point. The answer is that an OEI approach should not even commence unless the candidate is assured of getting visual off the approach. That is that the cloud base is well above the MDA or DH. If not stay at cruise altitude, if possible, and divert to the alternate. I won't go into what I think about teaching OEI missed approaches in light GA aircraft. Different story in Transport category aircraft.

Groggy

[thorn bird]

Interesting arguments.

A Navajo for example, on an ILS approach, with a minimum of 200 Ft AGL incurs an engine failure in IMC at 300 FT AGL. He arrives at 200 Ft AGL and is not visual...does he go round asymmetric?

Guess he could try, hate to predict the outcome.

[Oktas8]

Given the statement below from the PA44 POH, it seems to me that CASA's position is consistent with the overall intent of Piper's advice to pilots:

WARNING

Under some conditions of loading and density altitude a go-around may be impossible, and in any event the sudden application of power during one engine inoperative operation makes control of the airplane more difficult.

ONE ENGINE INOPERATIVE GO-AROUND

NOTE A one engine inoperative go-around should be avoided if at all possible.

[NIK320]

manufacturers do not publish a minimum decision height for a single engine go-around in light twin engine aircraft They do however publish an OEI rate of climb chart. You know theoretically what the plane can do, you know what CAsA or the terrain requires you to be able to do. Calculate the lowest you can go without infringing the limiting missed approach gradient and you get a minimum decision height for a single engine go-around.

[A37575]

Teaching a 10 hr newly minted MEACR holder to go-around OEI from 200 FT, or from a fast approach close to the ground is misguided at the least, and criminally insane at worst

The somewhat hysterical outburst above smacks of a tantrum. It has nothing to do with experience level. Either the pilot has been tested and certified as competent by a qualified authority to fly in command on the light twin in question - or he hasn't. He should not be certified to fly in command until he can demonstrate to at least a minimum safe standard the ability to conduct a single engine go-around in the circumstances under discussion.

[mudpig]

Haha. I'm finding this thread very amusing. So many posts here missing the obvious.
NIK320 is the only one that spotted it. You're supposed to work out your own minima if your ac can't meet the climb gradient required on one engine from the charts provided by the manufacturer.
Here is a practical example. We regularly fly into an airport that has an elevation of almost 5,500ft and from the ATIS we get the temp at the field. If the temp is above a set value we increase our minima so we can assure the a/c meets the climb gradient required to clear the surrounding terrain if we go OEI while on the approach.

[A37575]

If one has the skill to execute a go-around OEI from "over the fence" at Vref +15 with no flap, why would one be 15 knots too fast in the first place?

Easily happen when teaching students on their initial light twin. Gust factors, ham-fisted flying, you name it. After all, it is common knowledge (and this is from personal experience) to see airline aircraft at the flare 15 knots or more too fast beyond the published VREF.

However, back to the point made by the OP and that is the nomination of one arbitrary or generic 'committal" height during a single engine approach below which the pilot is supposed to, if necessary, commit himself to a forced landing or prang on the runway rather than risk a go-around. 400 feet seems to be a favoured figure used in initial twin training schools. IMC go-arounds from an instrument approach are a different matter altogether and responders are right in that a calculated MDA is a wise move in the pre-planning of the approach.

Instructors have a responsibility to teach their initial twin candidates a realistic altitude on short final below which a single engine go-around becomes a marginal manoeuvre. It is good instructional technique to start off by undertaking single engine go-around training at a safe initial height in a training area. Use 1000 feet above ground level as a simulated airfield level. A series of go-arounds can be practiced at various altitudes, to include demonstrations by the instructor. Repeat until the student is competent. That way, time is not wasted in the circuit area. The same technique should be taught "under the hood" until the student is confident, competent and knowledgeable of all the factors involved.

[Pinky the pilot]

It is good instructional technique to start off by undertaking single engine go-around training at a safe initial height in a training area. Use 1000 feet above ground level as a simulated airfield level. A series of go-arounds can be practiced at various altitudes, to include demonstrations by the instructor. Repeat until the student is competent.

Which is precisely what a certain chain smoking Instructor made me (and others) do in his Seneca 1 all those years ago, when doing CPL and MEIFR training.:ok:

But he also had one hard and fast rule re assymetric go arounds; Once you had gear and full flap down, you were committed to land.:= A go around from that point was forbidden!

Some may disagree.:hmm:

[PA39]

There are many considerations, including the performance and capability of both plane and pilot.

[john_tullamarine]

There is no officially published factual data in POH's on so called "committal height"

FAR 23.1585(c)(2) (http://www.ecfr.gov/cgi-bin/text-idx?SID=66e1efb36cb95348f00a966f0aed5e46&node=se14.1.23_11585&rgn=div8) is pertinent to this aspect of the discussion.

There is nothing preventing the OEM from publishing OEI missed approach data although it is not difficult to see why most civil light certifications avoid it. For military certification processes, the OT&E process usually will be expected to address this aspect of operations.

[LeadSled]

Once you had gear and full flap down, you were committed to land.:= A go around from that point was forbidden!

Couldn't have put it better myself.

I have some great pics. of the remains of a Piper twin, where the hotshot instructor tried to go around with gear and flap out, they didn't come in quick enough (Ha Ha) because he had failed the engine with the only hydraulic pump. Luckily, both instructor and student got out with very minor injuries, but they went though the ridge of an old barn, you could see the aeroplane shape.

Please remember you are mostly flying FAR 23 aircraft, that says it all.

Tootle pip!!

[A37575]

Once you had gear and full flap down, you were committed to land. A go around from that point was forbidden!


Forbidden? Says who? Just another typical instructor's personal opinion and there is no shortage of those as we can see in this thread.

Many scenarios can be discussed if one had the time and inclination. A very high final with full flap and gear on one engine would be one example of a good reason to go-around. But that again depends on the length of the runway and surface conditions. In the case of a PA44 Seminole with mechanical flaps the pilot can dump the flaps to up in less than two seconds with no significant loss in lift but a very quick IAS increase. Select gear to up immediately the flaps are up giving more speed increase then raise the nose slightly and climb away at 88 knots. Nothing could be more simple to a competent pilot. Operative word being "competent"

Obviously techniques may vary for different aircraft types which is all the more reason why the generic 400 feet typical flying school teaching is flawed.

[Tankengine]

Perhaps one should review when to put down the gear and selection of landing flap!:hmm:
As there are not so many ILS's in uncontrolled airspace then checking visually there is somewhere to land is a good practice.:ok:

There are many variables of course. (Waiting for the "what if you are 50kts fast" etc etc.;))

[Metro man]

This is why the asymmetric approach and landing should be flown as closely as possible to the normal one. Carrying too much of a margin in height and speed is no use to you if it means you can't land because you are too high and/or too fast.

[LeadSled]

Forbidden? Says who? Just another typical instructor's personal opinion and there is no shortage of those as we can see in this thread. A37whatever,
It was also the view a mob called Qantas Airways Ltd., as expressed in the "opinion" of Qantas Airways Ltd Operations Manuals, but Hey!!! what would Qantas performance engineers know about operating aircraft.
In fact, in the aircraft used in Qantas cadet pilot training (mostly Aztec) and after a rigorous risk analysis, Qantas went further, and required that, once the gear was down and the flaps out to any setting, even on all engines a landing was required.
The basis of the risk analysis was quite simple, an all engines approach could turn into an engine out approach at any time.
As far as I am concerned, that is the way to go in any light twin that I have flown (or any B707 or 747 on two) and that includes DC-3/C-47, even though all DC-3/C-47 have dual hydraulic pumps.
That is also the point where you should forget "blue line speed" and fly a speed based on a Vref, with suitable but small increments wind condition and gusts.
FAR 23 light twins should be treated for what they are (and how they have been certified), a single engine aircraft, with twice the chance of engine failure, all the "second" engine does is extend the glide.
What amazes me these days is the loss of "aviation knowledge", go back 40 years (when small twins started to arrive), and what I have said above was common and accepted knowledge, there was no "debate" because the performance limitations were obvious fact, NOT "opinion".

Tootle pip!!

[Metro man]

A landing with the gear down and full flaps, even if not on the runway will usually have a better outcome than a stall/spin.:hmm:

BTW On airline jets, once reverse thrust is selected on touchdown you are committed to the landing. During Ansett's mishap with the B747 landing with the nose gear retracted, the Captain was considering aborting the landing but was prevented from doing so by the F/E as the reverses had deployed.

[Adsie]

I am with thorn bird !!

If you have completed all checks and alternatives and you end up with the only option but to conduct an approach down to the minima with one engine out - continue with the approach - go below minima and land the bloody thing, there is no real long future in single engine go arounds.

The pilot is already about peaked in the stress level department - adding a go around into the mix may not be a good idea.

In my opinion, there is no option for single engine go arounds.

I was taught in my multi engine training that if you were below 400 ft AGL with one engine inop you WILL land the aircraft. Regardless

[Mach E Avelli]

Also to consider is we do all our training at light weight - typically one student with an instructor.
Load up some light twins with a commercial payload, and an engine inoperative missed approach is not an option, no matter what altitude.

[CharlieLimaX-Ray]

Google VH-CLY and see what happens in a transport category aircraft with an assymetric go-around, interesting read.

[waren9]

In fact, in the aircraft used in Qantas cadet pilot training (mostly Aztec) and after a rigorous risk analysis, Qantas went further, and required that, once the gear was down and the flaps out to any setting, even on all engines a landing was required.

might be fair enough in a training environment but would be very restrictive in a commercial operation.

oei g/a's are ok with sufficient talent and a bit of height. part of my training were a few go arounds noting the height loss before climbing again.

and its very rare you have to land with full flap.

[Oktas8]

I don't think it's a good idea in any operation Waren9. To be clear, I'm talking about disallowing a go-around when normally configured, just in case an engine failure might happen at a future point.

No go-arounds allowed with gear & flap extended means that every approach must be a flapless approach until short final - just in case a go around might be needed. This either requires exclusively flapless landings, or a requirement to configure flap on short final. And all for the remote possibility of an event requiring a simultaneous go-around and engine failure.

There is no support for this concept in any POH or AFM I've read.

CAO 20.7.1 does not require me to guarantee performance in this eventuality - an engine failure coincident with a go-around - even in my RPT turboprop.

Let's get back to the discussion of go-around decision making with an engine already failed & secured.

[waren9]

we're on the same page. i think.

if it'll climb oei, it can go round oei. may be just not from the charted mda

[Mach E Avelli]

The decision making process needs to consider so many variables:

1 Aircraft type and loading - e.g. Baron versus Apache versus Chieftain/C402 etc. A 285 hp Baron with four on board is not too bad a performer, and in the right hands could probably execute a single engine missed approach from the ILS minima. But see 3. below for the caveat. A 150 hp Apache is committed to a landing at the time the engine fails, no matter what skill level you have. Certain laws of physics can not be denied. 150 h.p. in a draggy airframe such as an Apache can only propel it forwards and downwards - albeit fairly slowly. A Chieftain or C402 with every seat occupied probably lies somewhere between these two.
2 Temperature. Under extreme summer conditions turbocharged twins will suffer overheating if the remaining engine is flogged at the low speeds required to avoid obstacles when climbing. Normally aspirated engines won't be developing rated horsepower on a hot day. Plus of course density altitude affects all aircraft.
3 Pilot familiarity with the type and overall proficiency. A five hour endorsement won't prepare most pilots adequately for such a critical event as a OEI missed approach from the minima in a fully loaded twin. And now that formal endorsements are not required on each type, pilot familiarity and overall proficiency will be even more pertinent to such decision making. How the Examiner will adequately assess this on a flight test will be interesting to watch - safely from the ground, thank you.

Re the reference to the VH CLY accident. If that was the Heron, it was not caused by an engine-inoperative lack of performance. An engine out in a Heron is almost a non event. In fact we could and did take off on three engines sometimes, though not with passengers. The cause of that prang was as in 3 above. If you dump the flaps from the landing setting back to the takeoff setting on a Heron, in a split second they go from about 60 degrees to about 20 degrees - with predictable consequences.

[MakeItHappenCaptain]

In the past, PPRuNe has seen numerous discussions on pilot technique to be used if a wing should drop at the point of stall. The expression "pick up the wing with rudder" is frequently used in this context and there is little doubt many instructors teach students to skid the wings level before applying aileron. This is of course faulty technique and has the potential to cause an incipient spin in the direction to the dropped wing. Nevertheless the technique is almost universally taught at flying schools.

Pig's Arse. Not at my school. If this practice is so prevalent, why aren't CFI's and FE's picking it up in S&P's or renewals? Please remember a vocal minority of ill advised PPrune contributors are not the practical majority.

[dhavillandpilot]

I agree with Mach E Avelli, I'd never dump flaps. Having had 4 engine failures, 2 of which have been on take off, it is a recipe for disaster.

My first twin was a L12A and the last thing you would want to do is dump the Fowler flaps.

Every endorsement I've ever done has been identify, feather, gear up and control. But most of all CONTROL.

Better to have a prang at the end of the runway with wings level than cartwheeling because you let the wing drop.

As for decision height, I can testify. ALL non transport category twins have a decision height of around 400 feet.

Picture this scenario, Pa39, 8inches of left prop broken, engine feathered but canted 10 degrees off centre, night landing. This is what I faced in 1984, flew the aircraft 10 knots above approach speed and made the decision height 500 feet. Result here to tell the tale.

If I was to repeat my career And needed to do an initial twin, I'd seek out an older instructor with experience. People such as Bill Whitworth at Bankstown or his equivalent in Moorabbin or Archerfield would be money well spent

[Metro man]

Can anyone remember a light twin with only one hydraulic pump ? If the engine failed on that side you needed to hand pump the gear and flaps, not ideal during a go around.

[Oktas8]

Aztec, I think. Reason #671 to scrap it and buy something younger than the chief pilot.

ALL non transport category twins have a decision height of around 400 feet.

Most non transport category twins have no decision height specified - see post #15 above by JT in particular. (But I agree with everything else you said!)

[Judd]

universally taught at flying schools. Pig's Arse. Not at my school. If this practice is so prevalent, why aren't CFI's and FE's picking it up in S&P's or renewals? Please remember a vocal minority of ill advised PPRuNe contributors are not the practical majority
So beautifully articulated. :yuk: Definitely qualifies for a seat in the Senate.

[LeadSled]

might be fair enough in a training environment but would be very restrictive in a commercial operation.

Waren9,
As I understand your comment, asymmetric approaches must be a common situation in "commercial operations", and, therefor, a higher risk ( less safe) operation is justified on the basis of a commercial operation.

I trust you are only a FlightSim pilot, it is an absolute nono to make decisions based on commercial considerations in a non-normal situation. Strangely enough, "the law" suggests precisely this.

The FAA figures are sobering, there is a greater probability of a fatal crash in the case of an engine failure in a light twin than in a single.

I suggest you

[LeadSled]

Pig's Arse. Not at my school.Make It Happen,
A rather public announcement of your non-compliance with the Part 61 MOS, Competency Standards for a stall recovery.
Seriously, this MOS will kill people.
Tootle pip!!

[waren9]

mr leadsled go back and have another read

[UnderneathTheRadar]

Can anyone remember a light twin with only one hydraulic pump ? If the engine failed on that side you needed to hand pump the gear and flaps, not ideal during a go around.

Aerostars came like the from the factory originally - and there was no pump option available. Lose a right engine was a very bad thing.

Now fitted with an AUX backup

[Stationair8]

Early model Piper Aztecs only had one hydraulic pump as standard, the later F models all came with two pumps factory fitted.

When I did my Navajoo endorsement, the checkie doing it was also endorsing another company pilot Captain Ace Four Bars Baron expert.
Captain Ace Four Bars had a number of asymmetric go arounds because he would persist in leaving the gear up until late on the base leg, consequently final the gear would not be locked down and around we would go!

[LeadSled]

Folks,
I would suggest that what you are doing, in risk management terms, on every IMC approach on a light twin (unless certified to the "commuter" amendment to FAR 23) are betting on an engine not failing --- and statistically it is a pretty good bet, except in the case of fuel starvation, a common cause of "engine failure".

It is a nonsense to suggest that you have to stay clean until short final --- predicated on a simultaneous engine failure and a missed approach.

Flying an unstable approach is a greater risk (less safe if you insist on the use of the "safe" word) probability of causing an accident and accident, than a probability of an engine failure and a missed approach on the same approach.

For the same reason, the teaching of maintaining the "blue line" speed to short final is seriously flawed teaching, but very common, and apparently "encouraged" by CASA.

It is a very conspicuous example of the very poor risk management approach all too common in Australian aviation, that the "maintain blue line speed" demands that a final approach is unstable, ie: that 1:1 normal approaches are of increased risk, to cover an approximately 1: 10-4 risk.

As to the various claims of heroic pilots, and extraordinarily able pilots who have all sorts of examples of "what they did" --- what they mean is "this is the situation I found myself in, and didn't die, so what I did must be OK for all operations.

Tootle pip!!

[Oktas8]

Leadsled - yes!

Every ops-normal approach should be flown the same way, using speeds & configuration recommended for the type. There is nothing wrong with a go-around from the flare or even later, should it be necessary. You'll be well below Vyse of course, which is irrelevant to an AEO go around.

If an approach is commenced when already OEI - then a decision height is useful for VFR, an adjusted MDA is often necessary for IFR, and you might not configure quite so early on the approach (especially in IMC.)

If you lose an engine on approach or during a go around, you get to earn your pay that day. It's possible that 100% power on the live engine might briefly be needed even to continue the approach! But most pilots don't conduct every ops-normal approach based on the very low risk of that circumstance, nor does CASA require it at any level of the industry.

When did this become controversial?

[LeadSled]

Oktas8,
In my region, CASA "require" blue line speed to the mythical "commit point", allegedly somewhere on short final.

In something like a little Partenavia P-68, for example, there is quite a gap between "blue line" speed, and a sensible approach Vref, resulting in a very unstable short final.

What I see, sitting watching having lunch, all to often, is 'orrible, with an aircraft floating 1500 ft or more, trying to wash of the excessive speed.
Unsurprisingly, these very poor (euphemism bloody dangerous) "techniques" carry through, resulting in speeds "over the fence" in aircraft like Metro anything up to 20kt above Vref.

Most of us can remember a Metro, engine out, going off the end and being badly damaged at Mckay, simply because the speed over the fence was no where near an appropriate Vref under the circumstances.

I can think of a number of cases of Metro off the end, all the same cause, and plenty of cooked brakes.

Tootle pip!!

[Mach E Avelli]

The controversy seems to be the insistence of some Examiners that blue line speed must be maintained all the way down final approach when OEI. Further compounded by some who want blue line even with all engines operative on the basis that an engine 'might' fail.

The three speeds which will kill you if not absolutely respected are: Vs, Vmca and Vmcl.

There comes a time on every approach in most light twins (there are a couple of low performance exceptions) when blue line speed needs to be thrown away in favour of a stabilised approach speed which could be considerably less. An extreme example of this is the MU-2 which has a split between blue line and Vref of about 60 knots.

As long as you are headed down the slope, going below blue line on one engine is unlikely to kill you. BUT, if you go below Vmcl you can not safely apply power if you get too low. Vmcl is a little understood speed. It will probably be less than blue line and may or may not be below Vref. If Vmcl is above Vref, then Vmcl would be a wise speed to respect when OEI. If engines are performing as advertised, reasonable risk management means Vref is more relevant. Vref plus 5 knots is a good target and one I normally use unless it is very gusty, when plus 10 is a nice number. Considering that Vref is already either 1.25 or 1.3 Vs, then Vref plus 15 is too fast!

If Vmcl is below Vref, lucky you - you are probably in a nice forgiving twin. Not that I am very familiar with it, but I think the BN 2 Islander is in that category, i.e. Vmca and Vmcl are less than recommended approach speeds. The problem is, Vmcl is not a speed that is published in every light aircraft POH. Also, published Vref or recommended Vapp may not have any correlation to it in this class of aircraft. In bugsmasher-land you are sometimes left to establish these things for yourself.

Whether stabilisation is three miles/900 feet (e.g. my choice for the aforementioned MU-2), two miles/600 feet (quite appropriate for most, including most turboprops) or one mile/300 feet (OK for Aztecs etc where there is not much of a split between the various speeds) really is what should be emphasised in training.

[LeadSled]

Further compounded by some who want blue line even with all engines operative on the basis that an engine 'might' fail.That's what CASA want to see in my region!! Despite all the publications, spelling out in fine detail, why stable approaches are the norm.

Guaranteed 100% unstable approaches for 100% of operations, to cover a 10-4 or less occurrence.

Risk management from the Campaign Against Safe Aviation.

It's years ago, now, but it took us a while, in an airline training environment, to figure out why so many new intake pilots had such problems with a stable approach --- until we realised that in their GA years, CASA had dictated unstable approaches.

Tootle pip!!