Light twin asymmetric decision heights

[Chuck Ellsworth]

Checkboard:

Our disagreement on the feathering thing is really not an issue, what is manditory is a professional approach to our flying and strict adherance to safety considerations.

We sometimes change our way of doing things based on our own experiences. I have decided many years ago not to full feather without a good reason due to two very bad experiences I had due to not being to unfeather during two training exercises.

There is nothing wrong with demonstrating full feathering of engines as long as you do everything to insure safety.

I just decided not to anymore.

So you and I do not have any real disagreement.

Cat Driver:

.....................
The hardest thing about flying is knowing when to say no.

[Turbine]

Multi Training

CAAP 5.23 recommends a number of things that could be considered 'dangerous' or questionable - and indeed they are in SOME aircraft.

It recommends a full feather drill at certain parts of the flight in flight F3, F4 & F6, including feathering in the circuit. The interpretation as to whether they suggest a fully feathered approach and landing can be made either way... and it doesn't matter. CAAPs are an Advisory publication. It gives a CASA preferred but not mandatory method of conducting training. The syllabus of training for your school should address these issues with an adequate explanation or reasoning for a particular methodology.

In the air exercise for Flight 4 it also recommends practice engine failure after tkof (EFATO) with a windmilling engine - which suggests an engine cut with mixture - although throttle can be used to achieve almost exactly the same effect.

A warning exists at the bottom of page 20 (flight F6).

Warning: Where a training power setting is used, the PIC should not hesitate to resume full power immediately should an actual emergency occur during training.

This CASA warning suggests that at times, they 'require' one engine to be feathered and thus inoperative.

Flight F8 also calls for Asymmetric circuits, go-arounds, landings and an EFATO at night. This is questionable. I have never personally being overly fond of asymmetrics at night. I am surprised that CASA even publish this requirement in an advisory since VH-NEJ (SA227) crashed in Tamworth conducting asymmetric training at night. Legislative deficiencies were identified; one was that insufficient CASA legislation existed to prevent such training.

Chuck Ellsworth said: The argument that a feathered engine gives you a more realistic flight demonstration is being intellectually dishonest.

Are you saying that having a prop turning is more realistic? Of course not. I don't think the argument has to do with the more realistic scenario but rather the safer situation. Sure you can pull power back to increase drag on the inoperative engine but once again, to use your phrase, you are being "intellectually dishonest" to think that anything other than the real thing makes an effective demonstration. Once again, the argument is whether that demo compromises safety to a point where it's not worth doing.

Checkboard said: I do, however agree that a full feather and unfeather in flight should be demonstrated. (I know that Cat Driver and I disagree on this.)

Absolutely right Checkboard. I have known freight drivers to run a tank dry of fuel and then have to restart an engine. I guess that is another thread altogether.

I personally wouldn't dare conduct twin training without having spent considerable time with a feathered prop in flight (initially with a good fuel load at altitude to simulate real one-engine performance.

I personally don't see a problem with a fully feathered approach and landing given the right precautions, suitable aircraft and student.

Another couple of questions, that could almost warrant their own thread:

1. Do you use Mixture of Throttle to cut the engine after TKOF?
2. Do you use a fixed Blue Line or reduce it for an increase in DH if the recommendation doesn't exist in the Flight Manual - even though you know that you will get better performance?
3. What speed is to be used as a decision speed on TKOF? Do you use Blue Line or manufacturers recommendations?
4. Do you do V1(or VR) cuts? (mainly in turboprops)
5. Do you use 'Flight Idle' in turboprops to simulate failures? Read vital report from ATSB .
6. What sort of climb profile do you use?
7. When do you retract gear and flap? When do you make your first reduction in power? When do you turn your fuel pumps off?

...etc. You could go on forever. No two people will ever use the same combination and as long as they both operate in accordance with their SOPs then they are really both correct!

Training simply has to be prepared with a particular aircraft in mind rather than the generic CAAP (CASA) ass-covering approach and then conducted in full compliance with your company Ops manual or Check & Training manual.

A good manual will always explain the methods used and how the company came to make various decisions and why they adopted certain SOPs, and it will discuss other options that could be flown - and why they are not.

OG3. Good thread. I agree with your approach to training. It has been many moons since I have had myself strapped into a Baron but I specifically remember the excess roll that cannot be countered with rudder in the event of a missed approach under certain conditions. Hope you're enjoying your multi training - and getting lots of it!

[weasil]

On a lighter note

Back when doing my initial Multi-Engine training my instructor had me doing an ILS with one engine failed (mixture cut) but still windmilling. After touchdown the failed engine immediately windmilled to a complete stop and we nearly lost directional control of the aircraft on the ground when adding power.

It gave us both quite a shock cause I was new to the twin and he was new to teaching it... it was even hard to taxi clear of the runway cause the plane wouldn't turn the way we wanted when you added power. Haha.. it was funny afterwards.

Another couple of guys that I know came back from their last training flight where one of them was getting his ME Instructor's rating and told me that they fully feathered both engines at 5000 feet over an uncontrolled field (as if that made it safe).

Makes you wonder what people are doing with YOUR airplane doesn't it.

[Chuck Ellsworth]

Turbine:

It is interesting reading the various opinions regarding flying.

I have stated on several occasions that I do not feather unless there is a necessity to do so. ( piston engine airplanes )

You are of course entitled to your own preferences and opinions.

A little aside on the Throttle / Mixture cut on take off, there again pilot handling and technique can bring startling suprises.

In the mid sixties I was on my Captain check ride in a DC3 with the Chief pilot of an airline. He was one of the super great casual I can fly anything mind set. Just as I lifted off he snapped the right engine mixture to idle cut off. As I was frantically trying to keep the damn thing from killing us I noticed he was staring at the mixture control in his hand. It had snapped off in idle cut off and he was actually frozen in disbeliefe, anyhow I just punched the feather button and we staggered across the airport barely under control until the prop feathered and we got the gear retracted.

Lesson ?

Overconfidence and a casual attitude as shown by the chief pilot can truly screw up your day when murphys law comes into play.

And hey, I still say that the only difference between a feathered engine and one not feathered is in the eye of the beholder. Common sense dictates the flying characteristics can be simulated by power management.

During the past forty nine years I have had ample opportunity to marvel at feathered engines, but they were feathered for good reason.

Now you all have a safe day and take care.

Cat Driver

........................
The hardest thing about flying is knowing wher to say no.

[Slasher]

I remember about 24(?) years ago a Partenavia went in after TO at Essendon apparentley on a check or training flight where EFATO was simulated. Anyone know what came out of it? Heard the engine was cut via the mixture control.

[StallSpinCrashBurnDie]

In response to a couple of the questions raised here:

Lycoming actually recommend that an engine failure be simulated by moving the mixture into idle-cut-off. The basis of this is that leaving the throttle in the open position permits the engine to slow down due to a lack of fuel and allows the cylinders to fill up with air, resulting in normal compression forces that are sufficient to cushion the deceleration of the engine. Rapid movement of the throttle can also result in detuning of the counterweights on the crankshaft - particularly at high RPM/High MAP combinations.

That information came the Lycoming Flyer publication - an excellent one to have if you can get your hands on it.

With regard to decision heights, you will find that most piston twin aircraft will have some sort of remark like this one taken from the Duchess POH

Level flight may not be possible for certain combinations of weight, temperature and altitude. In any event, DO NOT attempt a one engine inoperative go-around after the flaps have been fully extended.

The Seminole handbook goes as far as to say:

SHOULD BE AVOIDED IF AT ALL POSSIBLE

[Achilles]

Getting back to flap, why not use partial flap instead??

Another can of worms, how many IFR twin drivers consider (and actually calculate) an alternative landing minima in the case of needing to execute a SE go around at the bottom (or more correctly, near the bootom)of an approach in IMC???

Be honest now..

[Blue Line]

I use the Mixture to simulate the Engine Failure, I think its better for training for the simple fact that if they are under the hood trying to maintain blue line, etc they have to work out which is actually the failed engine & cant cheat by lookin at the throttles - which i know some of them would do , is also good because lets them the Identify, verify , feather.

now a question, when you guys get the student to do a Engine Failure, when you get to Feather , do you get them to move it back 1/2 " or so or not touch it at all?

I've heard different reasons for both, I myself get them to move it, but have had to stop a few going all the way

[Icarus2001]

Blue Line

I brief them before hand for a touch drill and expect to see a finger on the pitch lever and a clear call "...feather left (or right)"

Amazing how many times the call doesn't agree with the finger.

[Disrep Air]

Hey there
I am in the process of doing my MEIR ... instructor has me pull the pitch about a knob length if the answer to 'are we terrain critical' is 'yes' ... then it's just a matter of trying not to overstress my "Live Leg", let alone the aircraft

[john_tullamarine]

A comment or two, if I may...

(a) please recall that if the aircraft is slow and you let it roll the wrong way, then the Vmca goes up rapidly and significantly .. and might bite you badly. At lower speeds (ie anywhere down near the published Vmca), don't let it roll into the dead engine... the subsequent Vmca departure will spoil your day in an upside down sort of way ..

(b) in respect to landing with a feathered propeller, the only reason I can see for this is, with big prop engines (ie lots of HP), the exposure to unusual yawing moments during the flare as the operating engine is throttled. For small engines the effect will be minimal. In any case the consideration can be thrashed out in the briefing room without exposing both the aircraft and the crew to the elevated risk of a feathered approach and landing.

(c) the P68 at Essendon involved, as I recall, a simulated night failure during the takeoff. Implicated in the subsequent handling problems was a suspected trim runaway which led to an AD not long after on the system. The end result was that the aircraft collected the wires along Matthews Avenue, sort of tumbled across a row or two of houses and entered stern first into the final resting place. Tragically, as it passed through the roof of the Gull family's home, the fuel tank ruptured and an avgas-fuelled conflagration ensued in the house and a number of the family were killed. I drove past on the way from work very shortly after, with no knowledge of what had transpired.... the fire was quite horrific.

(d) as to raising the OEI minima for an instrument approach .. this is presumed to occur if the terrain and reduced climb capability so warrants. Given that the procedures planner works on a presumed climb capability substantially in excess of the capability of the OEI aircraft, it is trusting solely and completely in a higher presence not to make an appropriate allowance for most approaches and, for some runways .. the better decision is to go somewhere else.

[Centaurus]

As the author of the first post on asymmetric go-arounds I have found all the replies very informative and thoroughly interesting to read. Thanks for going to the trouble of replying.

The hundreds of instructors on light twins means many widely different different techniques are favoured. For instance, while the Lycoming advice on simulated engine failure technique is good gen, it should be remembered that once the mixture control is pulled back the engine is absolutely dead. In other words you have deliberately failed an engine. Any cock-up in immediate handling by the student at very low altitude (after lift-off) could be fatal. Instructors who indulge in this technique on take off would well be reminded to read the safety tips at the back of the Seminole Information Manual POH and which is good for any light twin. It reads:

"Experience has shown that the training advantage gained by pulling a mixture control or turning off the fuel to simulate engine failure at low altitude is not worth the risk assumed. Therefore it is recommended that instead of using either of these procedures to simulate loss of power at low altitude, the throttle be retarded slowly to idle."

If a handling cock-up happened during an engine cut by mixture after take off, I would not like to be in the instructor's shoes if he survives. The lawyers would have his guts for garters - and rightly so.

Also in mid 1976, the NTSB issued an urgent warning to all pilots simulating an engine-out condition on multi-engine aircraft, to eliminate actual engine shutdown and substituteinstead reduction of power at low altitudes such as in the traffic pattern. The recommendation resulted from the NTSB investigation of the fatal crash of a light twin in which a flight instructor and a student were killed. The Board's investigation revealed that some instructors do use the mixture control to shut down an engine to test a student. The NTSB observed that use of such procedures at traffic pattern altitude may not permit instructors enough time to overcome possible errors on the part of the applicant.

The recommendation by the NTSB means that all simulated engine-out operation at the lower altitudes will have to be accomplished by retarding the throttle - and unless this can be executed slowly and carefully - engine failure can result.

So there you have it from a reliable and authoritive source. And by the way, the NTSB warning on simulated engine-out manoeuvres is repeated on that authoritive publication The Lycoming Flyer on page 52.

With regard to the touch drills used by some instructors to indicate which lever is simulated, be careful that the student does not touch then pull. I have seen this happen. For the same reason the risk factor increases if the instructor requires the student to actually pull the feather (pitch control) lever back a bit as part of the touch drill. This really is a gimmick which is inadvisable. You could even call it bad airmanship.

Lastly, while I don't dispute the advice by Lycoming that a mixture control cut is better engine handling, you need to look at the timing involved.
Within a second or two of the instructor cutting the mixture the student identifies and simulates feather drill. The instructor immediately closes the "dead" engine throttle (already done by student as part of confirmation process) and puts the mixture lever back to rich. He then should immediately set zero thrust.
Therefore the total time that the mixture is cut with the throttle wide open is probably less than five seconds. After that the throttle is closed as part of the ID process which in turn seems to nullify the Lycoming advice on the advantage of the mixture cut in terms of engine handling!

Stick to throttle closure every time. It is safer.

[dragchute]

Turbine,

Re your query "...flight idle in turboprops to simulate zero thrust..." I have some observations relating to asymmetric training in the B350.

Large diameter, four bladed props create enormous drag at flight idle and control problems particularly with high power on the live engine. In fact the POH advises the setting of 1700 RPM and 5% TQE to simulate zero thrust and warns that "...intentional in-flight engine cuts should be conducted by retarding the power lever to zero thrust at or above the Vsse speed of 110 knots..."

In normal circumstances an EFATO would result in operation of the auto-feather system (provided it was armed and the power lever left at TO setting). Therefore zero thrust should be set and not flight idle.

At lower power settings, such as used during descent the auto-feather system would not feather the propeller because of the power lever position (below 88% N1). In such circumstances flight idle simulates the failure until manually feathered (simulated or otherwise). Zero thrust should then be restored.

Feathering is also an option during training bearing in mind that the gas generator is still operating. However some delay and controlability problems will be experienced as the prop comes out of feather and before the power lever is moved forward of the flight idle detent. This action should be done at reduced power on the live engine.

Centaurus,

Closing of the throttle may be fine on light piston engine types but may lead to serious damage on more sophisticated piston engines such as the GTSIO's. As stated by a previous poster the closing of the throttle reduces induction of air into the cylinders and removes the cushioning effect that it provides. The piston is then stopped at the top of its travel by the crankshaft, con-rod and gudgeon pin. The damage may manifest itself in some later flight when least expected, by a pilot and passengers with the element of surprise and without the guidance of an instructor or safety pilot!

[Centaurus]

Drag Chute. I think you are right re larger engines. I recall a fatal accident at Essendon years ago when C402 crashed after engine failure just after lift off. Six dead. Turns out that the pilot had never done simulated engine failures on the 402 due perceived possible damage to engines and instead had done all his prof checks and instrument rating engine cuts on a C310 which had entirely different engine failure characteristics.
I am not entirely sure if that story is dead accurate but I do know the fact was brought up by the investigators.

[RHLMcG]

The 402 prang at Essendon ?

As I remember, the pilot was the owner of the operation and "encouraged" his own version of reduced thrust takeoffs ?

I think that there was a similar in house thrust consideration with the Advance Airlines KingAir prang in Sydney some years ago as well ?

[I Fly]

Chuck Ellsworth, I pray to god that it will never happen. BUT. Would you prefer that your pilots 'practise' feathered landings when the engine failure is real and he/she has a load of passengers on board? I'd rather have them 'practise' with me on board and I make certain that all the parameters are there to bring it to a safe conclusion. I would agree that handling or performance wise there is not a lot of difference in many light twins. However there is a lot of difference in the mind of the pilot.
Icarus2001, your statement "Amazing how many times the call doesn't agree with the finger" indicates to me that retarding the pitch leaver a little might solve any ensuing arguments. It also gets the message across that in a real engine failure situation the pilot has to do a little more than just to point at it and say "feather". It will not listen to him/her.

Yes the CAAPs are advisory. We can argue until we are blue in the face on how to do a certain thing. However CASA is quite clever. They get us to write in our Ops. Manual on how we are going to do it. What is written in the Ops. Manual becomes mandatory unless it is written in a way that allows some leeway. When my twin flies on my AOC and Ops. Manual, certain things are mandatory. When it flies on another AOC, the same things might be prohibited, or visa versa. All I can do is not to hire it to certain operators or pilots. My insurance reads "..........pilots as approved by (me)". If someone bingles I will have to justify to the insurance as to why or how I "approved".

[john_tullamarine]

Apart from the mental comfort of the pilot, which is a valid consideration, the main question still remains ... what technical skill benefit do we gain from shooting a feathered landing ? .. and does the value of whatever we gain outweigh the significantly increased training risk associated with gaining it ?

There will never be consensus on this but, like everything else we do, the risk management considerations should be paramount.

[MICHEAL STIPE]

Just Ask the GURU himself.........

"Billy Whitworth"
He's been at it for years ...
Go Straight to the Source!

AAAAAAAHHHHHHHHHHH OOOOOOOOOHHHHHHHHHHHh ,HEY HEY ,HEY ,HEY ,HEY AAAAAAAHHHHHHHHHH NNNNNNOOOOOO, NOOOOOOO OOOOOHHHHHHHHHAAAAAAAAAAAA ,NO , NO ,NO ,NO NO, OK ,OK, OK,OK, OK,OK,OK, AND AND AND AND AND OHH NOOO NO NO AHHH OFF TO KAMBA HEY HEY HEY HEY HEY AND AND AND ETI OK OK OK TEN MINUTES OK OK OK AND PRACTISE ILS AT RICHMOND OK OK OK OK THEN THEN THEN OFFF TO TO TO TO TO AH MUDGEEE HEY HEY HEY THEN BATHURST FOR A NDB OK OK OK OK AND BACK VIA WATLE ARRIVAL OK OK OK OK ,,,,,,OH HANG ON GOTTA GO GET SOME TYRES OK ,,,HEY ILL BE OUT SOON OKOKOK!!!!!!

Those who can understand this will know what I mean......

[t303]

My .02c
I have always used mixture c/o for reasons of mechanical sympathy, i.e. not going from full song to fully choked in a microfurk. The engine is not absolutely dead, it has become a propeller driven air pump which can be revived with the addition of a modicum of fuel to the existing spark and air. As for the movement of levers, I insist that all levers be moved at least an inch or so to indicate that the candidate is actually completing the drill. Often, there are long periods of inactivity (when surprised or chasing Vyse) and it is sometimes difficult to discern whether the vital actions are in fact being completed. One pilot had a predilection to reduce power at 300' after T/O. Coincidentally, his EFATO occurred at just this point! PF proceeded to chant "rich pitch power etc." and point at the colourful knobs, but failed to select radar pwr on the remaining engine. At climb power only on the good one gravity was winning. PF ran out of ideas and after about 30 secs of falling airspeed and about 200' AGL out over the bay I ran out of Kahounas and restored the failed. I have seen this frequently, trainees who talk the talk, but fail to walk the walk, and I have to wonder whether this is negative transfer from training. What is it the forces say; train the way you fight?
Lest it seem that I am careless in letting the checkee yank levers with reckless abandon, the next thing that the hand that closes the mixture lever does is to open up and BLOCK ALL OTHER LEVERS ON THE QUADRANT! If Shagg's is going to yank the wrong lever he will have to get it past my steely grip first!
Keep it coming everyone...

[Chuck Ellsworth]

I Fly:

Safety is my prime consideration.

Practicing fully feathered landings is by definition setting yourself up for disaster should some outside forces or just plain human error put you, your student and the airplane in an unrecoverable position.

Your own argument would support my position. For example you state that there is a signifigant difference between fully feathered and simulated as to complexity and difficulty in performing, therefore you teach them to overcome this complexity and difficulty in handling by exposing yourself to such a difficult situation without the safety of having power immediately available in the event it all goes to hell.

I am sure you truly believe in your methods and I do not wish to insult you, rather I am giving you something to mull over and think about.

In a lighter vein, I take it from your post that your Government Officials know what they are doing and are first class experts. I bet you guys down under had first choice and left us with all the morons.

Anyone wish to comment on where you draw the line outside temperature wise when feathering a piston engine?

...........................
The hardest thing about flying is knowing when to say no.