Zero thrust pa31-310

[porterpat]

Anyone got zero thrus settings for pa-31-310,
I have chieftan settings from poh but can't find -310 settings, thanks.

[27/09]

I'd guess that they are not all that different, and for most situations it probably doesn't matter all that much how exact you have the zero thrust. It's the drills and procedures that matter most.

[MakeItHappenCaptain]

Use the same as the 350. If you have a trusted a/c and company ops will allow it, a trimmed shutdown followed by a restart and power applied the the same fight condition will work.

Remember zero thrust settings vary with weight and altitude.:ok:

[Tinstaafl]

...and with speed.

[A37575]

for most situations it probably doesn't matter all that much how exact you have the zero thrust. It's the drills and procedures that matter most.

The usual simulated engine failure procedure in a piston twin is throttle closure. Mixture cuts are potentially dangerous especially if the engine fails to start immediately you select mixture back to rich. Once the problem is identified and the pilot simulates the drills the instructor then sets zero thrust which simulates a feathered prop.

However - the danger is a simulated engine failure after take off - in other words low altitude. When the instructor closes the throttle against the aft stop it not only simulates a windmilling condition but it is actually windmilling and that means lots of drag.

If the student faffs around going through all the "mixture up - pitch up - power up etc drills he must remember the windmilling prop ensures the aircraft will not only lose speed rapidly but also go downhill. Which is precisely why twin engine aircraft have a prop feathering system to remove windmilling drag.

While the exact manifold pressure and associated RPM to simulate zero thrust will vary with conditions, it is vital that the instructor applies zero thrust within a few seconds of pulling back the throttle to its stops to simulate the engine failure.

Because speed/altitude/directional control and climb performance is so critical during simulated engine failure immediately after take off it becomes a serious flight safety issue if the instructor delays setting zero thrust while waiting for the student to go through all the drills up to when he would normally press the feathering button or pull back the pitch lever into feather.

As long as the instructor gets some power into the simulated dead engine literally within seconds of pulling back the throttle in the first place it doesn't matter too much if the zero thrust setting is not exactly correct - as long as the setting is not LESS than zero thrust. Far better to err on the cautious side.

[27/09]

However - the danger is a simulated engine failure after take off - in other words low altitude. When the instructor closes the throttle against the aft stop it not only simulates a windmilling condition but it is actually windmilling and that means lots of drag.

If the student faffs around going through all the "mixture up - pitch up - power up etc drills he must remember the windmilling prop ensures the aircraft will not only lose speed rapidly but also go downhill.

This is a very very good reason not to be too enthusiastic in conducting such training too close to the ground. My personal minimum is 300 ft AGL.

Sure engine can quite at any time and altitude, but there's no need to be silly and practice at stupidly low altitudes when someone is learning the ropes or carrying out recurrency training. If the student can get it right at a safe altitude then its reasonable to assume they will get it right down low if or when that ever happens.

[Centaurus]

This is a very very good reason not to be too enthusiastic in conducting such training too close to the ground. My personal minimum is 300 ft AGL.

Pity the Darwin crew of the Beech 1900 didn't think of that when someone pulled back a throttle seconds after lift off and crashed with fatal consequences. Although I understand that a Citation operator in Queensland used to pull back an engine at V1 on the runway to test the student's reactions.
Overconfidence perhaps in his own ability to take control if mishandling occurs. If CASA is aware of this practice they haven't stopped it.

[27/09]

Pity the Darwin crew of the Beech 1900 Might you be thinking of the Embraer crash?

I understand that a Citation operator in Queensland used to pull back an engine at V1 on the runway to test the student's reactions.Very brave or is that stupid person.

[nitpicker330]

In Ansett in the 80's doing my first Jet endo base training at AVV the checky closed the thrust on one Eng at V1. I found the machine much easier to fly than the damn Sim :ok:

I think we also did this in base training on the 744 and 777 in CX.

Funny how I can remember what I did 25 odd years ago but not 10 :sad:

[DirectAnywhere]

I used to be a Multi IFR instructor and daily I used to pull throttles or mixtures at 2-300'.

In hindsight I reckon it was some of the stupidest s&@t I ever did in my life. Would never go back and do it again. Thread drift I know but there's my 2c worth.

[JustJoinedToSearch]

When the instructor closes the throttle against the aft stop it not only simulates a windmilling condition but it is actually windmilling and that means lots of drag.
Which is what happens if you have a total engine failure.


If the student faffs around going through all the "mixture up - pitch up - power up etc drills he must remember the windmilling prop ensures the aircraft will not only lose speed rapidly but also go downhill. Which is precisely why twin engine aircraft have a prop feathering system to remove windmilling drag.Yep, once again what actually happens.


While the exact manifold pressure and associated RPM to simulate zero thrust will vary with conditions, it is vital that the instructor applies zero thrust within a few seconds of pulling back the throttle to its stops to simulate the engine failure.Can't agree with this at all, if after pulling the throttle back to simulate failure, the instructor sets zero thrust quickly, what is the point of the student doing the drills?

The way it was done when I did my inital multi was throttle back to simulate failure, when I got to the 'feather' part of the checks i would tap the correct pitch lever (to indicate that's where I would feather) and my instructor would set zero thrust. If you just set zero thrust quickly, you are teaching the student that the situation is going to magically get better after a short time, which it won't untill they get the thing feathered. What good is that?


Because speed/altitude/directional control and climb performance is so critical during simulated engine failure immediately after take off it becomes a serious flight safety issue if the instructor delays setting zero thrust while waiting for the student to go through all the drills up to when he would normally press the feathering button or pull back the pitch lever into feather.
Don't even slightly agree. I don't think the instructor should set zero thrust until the student is ready to 'feather' the failed engine. If things get too out of shape, push the throttle forward and you have normal 2 engine climb to complete a circuit and try again.


As long as the instructor gets some power into the simulated dead engine literally within seconds of pulling back the throttle in the first place it doesn't matter too much if the zero thrust setting is not exactly correct - as long as the setting is not LESS than zero thrust. Far better to err on the cautious side.
Still don't agree, and yes zero thrust is a pretty rough figure.

[MakeItHappenCaptain]

Just Joined,

Agree totally on comments about not setting zero thrust until student has signified the failed engine has been feathered.

I get the student to actually move the pitch lever one inch while I guard the lever against moving past the gate. This is so they don't get into the habit of merely touching the lever; very dangerous if they revert to this behaviour in an actual emergency. (Don't laugh, I've seen it happen!)

If they forget to "feather" the failed engine, the experience reinforces the completion of the EFATO drill. Continued loss of height is a strong incentive to get it right.
"Whay are we losing height, Bloggs? Repeat the drill."

Similar pitfalls include forgetting to clean up the airframe (eg. leaving gear down during a go-around and not manging the live and securing the dead engine.) These drills MUST be practised IN THEIR ENTIRITY until they are second nature.:ok:

[Centaurus]

Might you be thinking of the Embraer crash?

Oops! My error. Thanks for pointing it out:ok:

[Tee Emm]

Don't even slightly agree. I don't think the instructor should set zero thrust until the student is ready to 'feather' the failed engine. If things get too out of shape, push the throttle forward and you have normal 2 engine climb to complete a circuit and try againThe purpose of automatic feathering in some aircraft was to instantly reduce the drag caused by a windmilling propeller. This safety feature is not fitted to light twin engine training types. The usual method of teaching the actions for engine failure after take off includes having the student verbally state each action he intends to take culminating in the simulation of manual feathering by the instructor setting zero thrust. Verbalising each action takes time whereas an experienced pilot needs only to glance at each item to ensure full power on the live engine, that the mixture is rich or the appropriate setting for a high density altitude airport.

Prompt reduction of drag caused by a windmilling propeller is of paramount importance. Every second delay in feathering the dead engine propeller results in loss of airspeed. Indeed, in some propeller systems it may not be possible for the propeller to feather if the windmilling RPM gets below 800 RPM. So the instructor must ensure the student is aware that the step by step method usually taught on initial twin engine endorsements has its limitations in real life.

A few years ago, there was a fatal accident with a Duchess at Camden when the instructor (30,000 hours) decided to cut the right hand engine mixture control during a touch and go and shortly after the student (a 16,000 hour current B767 captain) had selected gear up. The drag caused by the windmilling propeller was so great that airspeed fell quickly well below best single engine rate of climb before the instructor could re-start the engine and re-introduce power. The aircraft clipped tree tops which reduced speed further and the aircraft stalled and belly landed on rising terrain. Both pilots were unhurt as the aircraft slid to a stop. Unfortunately, a fuel tank ruptured after the aircraft hit an iron girder as it stopped and the aircraft caught fire. The instructor later died of his burns while the student was seriously burned.

Years before a Cessna 404 (?) had an engine failure shortly after lift off from Essendon runway 35. The aircraft was unable to gain altitude and in attempting to avoid power lines flicked inverted below Vmca. All aboard were killed. The propeller of the failed engine was windmilling because for some reason the pilot (10,000 hours plus) failed to feather the propeller.

Another accident occurred at Essendon when a Dove departing from runway 17 suffered an engine failure seconds after lift off. The pilot (13,000 hours) selected gear and flap up as per his training but never got around to feathering the engine due to his pre-occupation with selection of the gear and flap handles. The aircraft crashed into houses wings level and everyone survived with only minor injuries.

Each of the pilots involved in these three accidents were highly experienced. In each accident the drag of the windmilling propeller proved to be the critical factor in loss of climb performance.

No doubt, students undergoing initial twin engine endorsements have never heard of these three accidents and probably their instructors have not, either. The point being that instructors are not infallible and that allowing the airspeed to rapidly decrease because of a windmilling propeller to below safe single engine climb speed while the student talks his way through the engine failure drills is not a good instructional technique. Call it practicing bleeding if you like.

The instructor must be prepared to set zero thrust quickly to prevent a potentially dangerous airspeed loss even though the student is still working his way through whatever emergency drills he has been taught. Some students have difficulty coordinating their words with their actions which is the same problem that many trainee instructors have when undergoing an instructor course. Stumbling over words while trying to control the aircraft from yawing caused by a windmilling propeller, is difficult enough for an experienced pilot let alone a student on his first twin.

Instructors have a duty of care and that includes the safe operation of the aircraft under their command. Teaching the skills to handle an engine failure shortly after take off, carries with it a higher risk than normal. If setting zero thrust before the student has got around to it is considered poor teaching technique by some Ppruners reading this thread, then it is suggested they may learn from obtaining the ATSB reports on the three asymmetric accidents described here.

[quagmire]

Sorry Porter I've only got the chart for the 350s not the 310s.
Personally i always used a generic power setting in lieu of looking up a setting relative to the applicable aircraft/IAS etc every time I failed a donk.

I can bang on endlessly with my opinions on other stuff you haven't asked for but that probably won't help you much.....:ugh:

[MakeItHappenCaptain]

TM,
It should be made perfectly clear that many, if not most multi-engine accidents occur during training exercises. The first statement made by my ATO when I went for my META was,

"This is a whole new way for students to try and kill you."

I know it is probably not the light in which you were portraying the examples, but
when the instructor (30,000 hours) decided to cut the right hand engine mixture control
airspeed fell quickly well below best single engine rate of climb before the instructor could re-start the engine and re-introduce power.

Why cut mixture when you can just close a throttle and have the engine instantly available? Piper is one manufacturer who specifically warns against using either mixture or fuel cuts to simulate engine failure. I will admit I was taught to conduct simulated failures using mixture, but after researching the topic with several engineers and senior colleagues, I changed to throttle cuts. If something goes wrong and it was found you acted contrary to manufacturer's recommendations, guess who gets the blame?

The accident report in this case also makes mention of the ATO simulting the failure at a point where safe continuation of flight (the path ahead) could not be assured. The impact speed was determined to be about 55 Kts, WELL below blueline and only just above the stalling speed. Additionally this flight was being conducted at night, the dangers of which were referred to with reference to the Metro that went in at Tamorth during night asymmetric training. I think there was more to this accident (as is often the case) than just a windmilling prop.

for some reason the pilot (10,000 hours plus) failed to feather the propeller.


I think this just illustrates the importance of getting the drill right. The pilot indicated he was feathering the engine, but the investigation found this had not been done. Maybe the rpm had decayed below min rpm for feathering??

The pilot (13,000 hours) selected gear and flap up as per his training but never got around to feathering the engine due to his pre-occupation with selection of the gear and flap handles.

I know for a fact that even a Duke (380 BHP/side which would seem to be more than enough on one engine) will not perform with gear out.
In any case,
Analysis of DH-104 performance indicated that, at the time of the right engine failure, it was possible for the aircraft to achieve a positive rate of climb, assuming that the engine failure drills were performed promptly and correctly, and proceeded without interruption. However, when the landing gear failed to retract on the first attempt, any possibility of the pilot being able to attain the required aircraft performance was lost. As a result, he was probably forced to abandon completing the emergency procedures in order to maintain control of the aircraft.


It is interesting to note that while the pilot became preoccupied with the gear, he still has the presence of mind to reduce power on the operating engine as Vmca was approaching to maintain control.

All being said, there is no one correct answer to the questions that have risen here. Every situation is different. I'm not saying my way is the perfect one. I am open to and have have made changes to behaviour patters (ie. LEARNING) in the past. All we can do is look at the available facts and make the best decision according to the circumstances. The trick is making an INFORMED decision, not just acting because that's how your instructor said to do it. Understand the reasons behind the actions.

Not saying these are the only interpretation of these incidents, but again students cannot be babied along thinking they can handle the situation.
This stuff will kill you if you don't get it right (and that goes for instructors too). The stress imposed by a descending (non-performing) aircraft due to the incorrect configuration (be it gear out, flaps extended or windmilling prop) can be a very good motivator for the student to get it right.

I'm going to drift a little here onto decision speed vs decision point. I have heard several variations on the continuing portion of the engine failure brief.
One of these variants is "when there is no runway left over the nose, we are going to continue."

If you are below Vmca, we lose control.
If below Vyse, the only way to regain speed is to lower the nose = descent.

Why not put the aircraft back on the runway if below Vyse?
We are talking about FAR23 aircraft here, so forget V1 speeds. FAR23 guarantees control with an engine failed, whereas FAR25 (>5700kg) = performance.
Even if it means you go through the fence at 40 kts, surely this is better than trying to reach blueline while avoiding the terrain?
Guarantee, most people will keep raising the nose as they see the ground approaching, neglecting the impending loss of control.

Marathon completed.

[Centaurus]

One of these variants is "when there is no runway left over the nose, we are going to continue."


Well reasoned argument throughout the post. However one has to be very wary of the high-lighted statement. As part of the Essendon Dove accident investigation, ATSB arranged for trials in Canada to take place which measured the amount of runway used for a Dove to lose an engine shortly after lift-off then bunt over and land straight ahead on the remaining runway length. I don't know the figure off the top of my head but I do recall it was surprisingly long. I recall the test pilot allowed a few seconds of decision time uncertainty before closing both throttles to get back on the ground. Fine with an 8000 ft dry runway in front of you but not so good if the surface is wet.

It doesn't make sense to blindly decide to landing ahead on the runway when neither the ME instructor nor his student have practiced such a dangerous course of action. With long runways, by the time the pilot loses sight of the runway ahead which could be at an altitude of between 100 to 500 ft assuming things are normal up to that point, his airspeed should have been well beyond safe climb speed depending when the engine failed. At night with only runway lights for guidance it is difficult to know exactly how much runway ahead is available as it disappears under the nose in the climbing attitude.

To blindly use the "advice" of the disappearing runway view as a decision point, is unwise - as is the other spurious advice of deliberately delaying gear retraction until you gauge you can no longer land safely on the remaining runway length. The drag caused by extended wheels means it takes longer to accelerate towards safe single engine climb speed so the pilot is digging his own grave for no good reason.

The key is to retract the landing gear without delay after lift off and accelerate towards safe single engine climb speed as soon as practicable. Accept there will always be a "dead man's gap" of three to five seconds before the landing gear lever is selected up in which there is no choice but to abandon the take off if the speed is rapidly decaying because of an engine failure.

Providing the pilot is competent at handling the aircraft on single engine and he promptly feathers the propeller on the failed engine, then a one engine inoperative climb away is feasible. Another key to success is prompt lowering of the nose from the normal climb attitude to level flight attitude to prevent further speed decay. It is probable that most accidents involving an engine failure on take off in twin engine aircraft are the result of mishandling by the pilot - not because of aircraft performance limitations.

But to deliberately crash land straight ahead because of a pre-conceived decision point such as losing sight of the remaining runway, smacks of desperation. The subject has always attracted various opinions. For that reason it is important that the instructor gives informed carefully reasoned advice to his student, rather than a rote briefing that attempts to cover all circumstances. At the same time it is the responsibility of the ME student to diligently research the subject of asymmetric handling rather than rely almost totally on the opinions of others -including his instructors. But then, that applies to all facets of flying.:ok:

[PLovett]

Centaurus, I would be interested to hear your views on the procedure of leaving the undercarriage retraction until the aircraft has reached blue line.

When I did my initial multi-engine rating I was taught to use the blue line as a go/no go speed. Engine failure before then, close the throttles and either stop on the runway or land on what runway remained even if that meant going through a fence or overrun the runway. Engine failure after blue line then Phase 1 actions etc.

The rationale was that the aircraft was unlikely to accelerate to blue line with an engine out so it was better to put it down in a controlled manner than to lose control at VMCA or such by trying to make it fly. By leaving the undercarriage down it made the job of putting the thing back on the ground that much easier.

[Stationair8]

Bit like the "ace instructor" who teaches the student to hold the twin on the ground until they get blue line speed then rotate.

Very funny to watch the PA-30 hurtling down the runway with the nosewheel still firmly planted on the ground while the mains are airborne!

[JMEN]

From memory my initial training which has stuck to mind -

Mixture Up
Pitch Up
Power Up
Gear Up
Flap Up

Maintain Control
Dead Leg = Deg Engine
Feather

But never fear even first taught Aviate, Navigate, Communicate...

:ok:

[PLovett]

S8, if that comment was directed at my post, then no, nothing like that.

[Centaurus]

When I did my initial multi-engine rating I was taught to use the blue line as a go/no go speed.

Every instructor has his own theory re decision points on engine failures during take off. I don't recall any aircraft flight manual published by the manufacturer that uses the blue line speed as a "decision" to go or crash.

In any case, the second an engine fails after airborne, airspeed will reduce unless immediate action is taken to lower the nose. Thus, if an engine chooses to fail at blue line reading plus five knots and you had already decided to go because you have passed blue line, it is highly probable the speed will have decayed below blue line and you are now left with another decision.

Blue line is not a controllability speed. It is nothing more than the published best rate of climb speed depending on configuration. You will get some rate of climb either side of blue line but not necessarily best

Best angle of climb (obstacle clearance) speed is often less than blue line speed. And in any case Vmca is minimum control speed and that is usually a lot less than either blue line or best angle of climb.

In light piston twins the faster you accelerate on two engines through blue line the easier it will be to control an engine failure if one should occur. You will usually accelerate faster with landing gear up than with landing gear down. Every second of acceleration on the initial climb out on two engines changes the dynamics of an engine failure. That is one of the reasons it is unwise to have set rote airspeed or altitude readings as "decision" points.

It is entirely different to bigger aircraft which come under different performance rules. All you know for certain in a piston light twin is that you should get a positive rate of climb on one engine providing the propeller on the failed engine is feathered, the aircraft is in the clean configuration and you have full power on the live engine. And of course depending on the density altitude.

You can make up all the gimmicky rules you like whether your own viewpoints or accepting the advice of someone else. But don't tie yourself down to absolutes like airspeed indicator or altimeter readings. Or even using a guesstimate on how much runway (wet or dry) you have left to land on after losing sight of the runway over your nose on climb out.

Some flight manuals are vague on the subject of go or not to go if an engine fails after lift off. That gives you the hint that there is no right answer for your aircraft type. It becomes your responsibility as pilot in command to assess the situation when the engine fails.

[PLovett]

Thank you for thoughts Centaurus.