multiengine instrument: dead engine questions

[clumpinglitter]

I'm finding that it's a pain in the ass to deal with a dead engine under the hood. When you're visual, it's natural to just react to the yaw, and I have no problem keeping my heading pegged. But under the hood, it's not quite so easy. I hope this will just get easier with practice?

Do any of you have a rule of thumb for when to start the descent on a single-engine approach? It's not too bad when I know my distance from the MAP, but I'm not counting on the DE letting me use the GPS for this. Timing is almost always inaccurate, and I don't want to get caught too low and too far away from the MAP.

Do you pretty much always leave the gear up until short final, or do you lower it over the FAF like usual? Does it depend on whether the approach is precision or nonprecision?

Do you do the descent to the MAP at blue line? I find that I prefer to descend faster with some power in, because blue line just seems way too slow compared to the normal approach speed.

Not to mention, it's also a pain to track a radial single engine. But that's another issue. I'm flying a Duchess, if that matters.

-C.

 

[momike]

Feline Pine?

 

[gkrangers]

Theres a different answer for each question based on when the engine fails...

Failures under the hood didn't bother me, maybe because me and my MEI did more hood work than visual to start out. Don't know what to tell you there.

As far as descending, if its precision, following the GS.

If its non precision, you'll need to make a judgement call, or atleast thats the way I see it.

On a terminal approach you can probably safely descend following the procedure turn (not all, but many are like this) and 10/10/cleared. However, thats going to make for a long period of time at the MDA far from the runway. Just feel your way through it. If its a GPS approach, I'll typically wait for the FAF before starting my descent, since there is no reason to be 600' AGL over the water 8 miles out. This is going to be different for every approach tho...and is easier when using a GPS.

Landing gear...if I'm already single engine before the FAF, I won't lower the gear just yet. I'll get closer on the ILS, or into the circle to land or nearer the runway on a straight in for non precision.

If my gear is already down and I'm past the FAF when the engine failure occurs, I will probably leave it down as long as the airplane is performing ok. Theres no need to raise the gear and then lower it again a few seconds later when well into an approach.

Blue line or better. If the airplane can do better than blue line on one engine, go for it. If you are diving down to the MDA, you will pick up speed and go above blue line. When you level off, just keep it at blue line or better if you can. The Duchess does an ok job of this IMO, I never had a problem with holding altitude near sea level.

And if you have to circle to land, and you have to turn into the good engine to do so, make sure you give yourself a ton of room to make the turn so you don't overshoot the runway on your checkride like I did...

This is just my opinion and the way I flew when training for the CMEL a few weeks/months ago. Keep in mind that the DE has a lot of discretion when it comes to single engine approach. I flew most of the GPS approach on two engines, and he didn't retard the throttle on one until we were close in and getting ready to circle.

 

[Amish RakeFight]

I just checked out your website. Awesome photos.

 

[momike]

I just checked out your website. Awesome photos.

And, unlike so many air hogs, she appears to be pretty doable...

 

[minitour]

...and you have to turn into the good engine to do so...

This is the fourth or fifth time I've heard this recently...starting with training for the MEI.

When I did my CMEL add-on, the examiner told me it was pointless to say always turn into the good engine because there may be terrain, a missed approach course you need to follow, etc. that causes you to turn away from the good engine.

Now, aside from the obvious reasons for turning into the good engine...why does it seem like people are insistant upon either one way or the other?

Opinions? Personal experiences?

-mini

 

[gkrangers]

This is the fourth or fifth time I've heard this recently...starting with training for the MEI.

When I did my CMEL add-on, the examiner told me it was pointless to say always turn into the good engine because there may be terrain, a missed approach course you need to follow, etc. that causes you to turn away from the good engine.

Now, aside from the obvious reasons for turning into the good engine...why does it seem like people are insistant upon either one way or the other?

Opinions? Personal experiences?

-mini

No nono nonononono...you misread me. I was just saying that if you were on a right downwind, and the right engine was running, to make sure you give yourself a lot of room to make the downwind-base-final turn to make sure you don't overshoot.

 

[minitour]

No nono nonononono...you misread me. I was just saying that if you were on a right downwind, and the right engine was running, to make sure you give yourself a lot of room to make the downwind-base-final turn to make sure you don't overshoot.

Gotcha...when you were doing the training, were you slapped for turning away from the good engine, or was it "whatever it takes"?

-mini

 

[gkrangers]

Gotcha...when you were doing the training, were you slapped for turning away from the good engine, or was it "whatever it takes"?

-mini

I don't think my MEIs made a big deal out of it. Make whatever turn you need to make. Thats my 30 hours talking.

 

[Amish RakeFight]

I'm finding that it's a pain in the ass to deal with a dead engine under the hood. When you're visual, it's natural to just react to the yaw, and I have no problem keeping my heading pegged. But under the hood, it's not quite so easy. I hope this will just get easier with practice?

Agreeably, it is easier to handle the engine-out by observingthe nose visually. Under the hood you may feel a lot more motion and confusion. With the foogles on, when you begin to feel the plane sway, look directly at the AI. Your first reaction should be to call out (or say to yourself) "WINGS LEVEL - BALL CENTERED." - Use the ailerons to keep the miniature airplane on the AI level and use what ever rudder it takes to keep the ball in the inclinometer centered. When you experience an engine failure, this initial reaction will slow things down and help establish a reference point of more controlled flight. Once you've accomplished this, you can go through the fix or feather routine. You instructor may teach you one method, but here's what I've been taught.

After you've leveled the wings on the AI and centered the ball, you would go ahead and bring the gear up, flaps up, mixture, props and throttle full forward. This should all be done while pitching to, or maintaining Vyse. Once you have cleaned everything up, you'll want to determine which engien has failed, the only reliable way of figuring this out is to see which is the "dead foot". Never rely on power indications. Once you have determined the "dead foot," bring back the appropriate mixture, prop and throttle. DO THIS VERY SLOWLY. Rushing only saves a few seconds and its well worth sacrificing a little time as opposed to pulling the wrong engine.

One other thing, even if you think you know the gear or flaps are up because of the phase of flight you might be in, ALWAYS verify they are in the correct position. This is a routine that should always be followed.

Do any of you have a rule of thumb for when to start the descent on a single-engine approach? It's not too bad when I know my distance from the MAP, but I'm not counting on the DE letting me use the GPS for this. Timing is almost always inaccurate, and I don't want to get caught too low and too far away from the MAP.

As a rule of thumb, if at all possible don't put yourself in a position where you'll need to go around with an engine out. Some basic things to keep in mind are keeping the plane as clean as possible, that means defering things like flaps and gear for as long as possible.

Determining the distance to or arrival at the MAP shouldn't be much different from your instrument training. If you are doing you instrument training along with your ME, then you've got a lot going on.

Timing is not as inaccurate as you think. Amazingly, it does really work. It's never going to be exact, as winds change in speed and direction as you descend. Your IAS may fluctuate as well, durng your pitch excursions while maintaining the glideslope. By the way, your corrections will always be towards the left when descending as the wind shifts left closer to the ground due to the friction. Getting back to timing, you're going to need to estimate your GS based on the IAS you hold along with the average headwind you'll encounter. At any rate, there will be very little variance in timing for MAP arrival if done right.

Do you pretty much always leave the gear up until short final, or do you lower it over the FAF like usual? Does it depend on whether the approach is precision or nonprecision?

When conducting a enging-out precision or non-precision approach, you'll want to leave the flaps up until you've got the runway insight and the landing is assured. Gear should still come down upon GS intercept. On a non-precision, two engine approach, you'' usually drop everything a little earlier before arriving at the FAF.

Do you do the descent to the MAP at blue line? I find that I prefer to descend faster with some power in, because blue line just seems way too slow compared to the normal approach speed.

A litte faster than blueline is fine on the descent to the runway. You should allow yourself a buffer - just don't go below Vmc. Remember, Vmc is greater with a higher power setting and blueline is based on he worst case scenario. On the descent, you'll have a lot less power on the operating engine so there won't be as much yawing. Since some of the yaw is induced by p-factor, p-factor is actually reversed with a nose-low attitude such as during the descent. The yaw encountered will be in the opposite direction or towards the good engine.

 

[clumpinglitter]

Now, aside from the obvious reasons for turning into the good engine...why does it seem like people are insistant upon either one way or the other?

Opinions? Personal experiences?

I wasn't told to turn either way -- just do whatever it takes. This makes me wonder, however, if the instructor/examiner decides which engine to fail based on what way you'll be turning to circle to land.

-C.

 

[clumpinglitter]

Thanks, everyone. Here's what I got, generally:

1. When an engine fails, level the wings and do a "wings level, ball centered" callout. Get stabilized and then go through the "engine out" routine.
2. Unless inside the FAF, do clean up the airplane. This is what my instructor says as well, but I'm unsure about it, since I've seen that pitching for blueline can make the airplane gain as much as 500 feet.
3. Stay at blue line when flying level. If descending, it's ok to go somewhat faster than blue line.
4. Use your best guess as to how to descend -- use DME or timing to plan. On a normal instrument approach, I like to use groundspeed to figure out how fast to descend to get to a nice visual descent point, so I'll try to keep using that for the single-engine approach.

This is all pretty much what my instructor has said, but it helps to get more opinions and think through it. I have another lesson today, so we'll see ...

-C.

 

[minitour]

I wasn't told to turn either way -- just do whatever it takes. This makes me wonder, however, if the instructor/examiner decides which engine to fail based on what way you'll be turning to circle to land.

-C.

I dunno about deciding which side to kill based on the approach/landing.

For my CMEL, I had a HARD right crosswind and he killed the right side.

What a pain that was.

-mini

PS
Thanks for the info about the turn...I didnt figure it was a big deal...whatever it takes.

 

[MauleSkinner]

Thanks, everyone. Here's what I got, generally:

1. When an engine fails, level the wings and do a "wings level, ball centered" callout. Get stabilized and then go through the "engine out" routine.
2. Unless inside the FAF, do clean up the airplane. This is what my instructor says as well, but I'm unsure about it, since I've seen that pitching for blueline can make the airplane gain as much as 500 feet.
3. Stay at blue line when flying level. If descending, it's ok to go somewhat faster than blue line.
4. Use your best guess as to how to descend -- use DME or timing to plan. On a normal instrument approach, I like to use groundspeed to figure out how fast to descend to get to a nice visual descent point, so I'll try to keep using that for the single-engine approach.

This is all pretty much what my instructor has said, but it helps to get more opinions and think through it. I have another lesson today, so we'll see ...

-C.

IMO, there is no reason to SLOW to blueline prior to landing just to be at blueline. Blueline is what you use when full throttle on the good engine is necessary for the current operation (assuming MGW, of course). Climbing, struggling to maintain altitude, stuff like that. If you gain 500 feet just to get to blueline, it's not the appropriate speed.

Remember, too, that constant airspeed is one of the criteria in the PTS...gaining knots in the descent and slowing back to blueline on a NP approach can cause a bust.

As far as gear and flaps, I put the gear down at the "normal" spots if at all possible...I'll shoot approaches with reduced/delayed flaps, but changing from normal procedure on the gear during an emergency is a good way to land gear up. IOW, keep it as normal as possible.

It's been a while since I got my whopping 7 hours in a Dutchess, but the rule of thumb for most of the stuff I fly is only one less flap setting than would be used with both engines.

As far as the "under the hood" stuff, you might consider ignoring the ball...most people do when they fly anyway. If the wings are level, and there's no rotation of the DG (and if your scan gets far enough to look at the TC to see no turn), the ball is going to be centered. I'm a "needle-and-ball" guy myself, but I know so many people who can't/don't use the instrument that it becomes its own emergency if they have to look at it.

Fly safe!

David

 

[avbug]

An engine failure isn't an emergency; it's an abnormal operation (unless you're in a radial engine airplane, then it's a normal operation). Try to make as much of it as you can normal. Drop the gear at the normal time. If performance will allow, put your flaps down at the normal time. Make your radio calls, turns, turn directions, proceedures, callouts, cadence, etc, per normal. Request priority if you need it, take what precautions you need in accordance with your needs...but strive to do everything per your standard proceedure.

 

[SPilot]

"wings level, ball centered"

The ball in the inclonometer shouldn't be centered when you have an assymmetrical thrust situation. You should try to fly the airplane with minimal side slip. With assymmetrical thrust, wings level and ball centered, the airplane will be slipping due to the operating engine pulling the airplane slightly sideways. Therefore you should compensate by putting the ball slightly (approx. 1/2 the ball width) into the operating engine (more rudder pressure). And also as widely known, bank 3-5 degrees into the operating engine to use the horizontal component of lift to counteract the rotational effect resulting from the assymmetrical thrust.

If you've ever done drag demos, you'll appreciate a noticable difference in performance when flying the airplane "wings level, ball centered" versus "sideslip eliminated, bank slightly into operating engine". Vmc changes also, because you're utilizing more sources of counter-forces to maintain directional control - not just the rudder.

The ultimate proof and expedient method of understanding this, is by attaching the yaw string to the windshield and try for yourself.

 

[UndauntedFlyer]

The ball in the inclonometer shouldn't be centered when you have an assymmetrical thrust situation. You should try to fly the airplane with minimal side slip. With assymmetrical thrust, wings level and ball centered, the airplane will be slipping due to the operating engine pulling the airplane slightly sideways. Therefore you should compensate by putting the ball slightly (approx. 1/2 the ball width) into the operating engine (more rudder pressure). And also as widely known, bank 3-5 degrees into the operating engine to use the horizontal component of lift to counteract the rotational effect resulting from the assymmetrical thrust.

If you've ever done drag demos, you'll appreciate a noticable difference in performance when flying the airplane "wings level, ball centered" versus "sideslip eliminated, bank slightly into operating engine". Vmc changes also, because you're utilizing more sources of counter-forces to maintain directional control - not just the rudder.

The ultimate proof and expedient method of understanding this, is by attaching the yaw string to the windshield and try for yourself.

Spilot: With all due respect, what you have written here is really not correct. First, when an engine fails it is most important to increase to full power, level the wings, center the ball and hold heading. The ball needs to be centered in order to be sure of just which engine has failed using the dead foot dead engine method. Allowing the ball to be displaced during this procedure can result in a misidentification of which engine has failed. Second, once the inoperative engine is determined and secured then the "zero side slip" technique may be used if you think that will enhance performance. Personally my experience is that the "zero side slip" technique doesn't do much of anything for performance but it does give your leg a rest. And finally, you have indicated that by attaching a yaw string to the windshield that this will show how important it is to use "zero side slip." This statement makes me wonder if you have ever really done this yourself or just looked at drawings in manuals. I have personally done this yaw string test many times and it really shows no difference in deflection with an engine out (feathered) and the ball centered or with the ball displaced half a ball width.

Placebo effect is a very powerful influence.

 

[nosehair]

When you're visual, it's natural to just react to the yaw, and I have no problem keeping my heading pegged.

Heading! Heading! Heading! The Heading Indicator is the instrument that replaces your visual of the nose. Heading is the most important instrument to control. Heading, altitude, & airspeed; those are the only 3 we have to control, and we should usually prioritize them in that order. If the Heading stays constant, the wings stay level. If the wings stay level, the altitude is more likely to stay level. In a constant power-constant pitch situation, the airspeed remains constant, so that reduces your scan to 2 instruments: Heading and Altitude.

The only point I'm making is that you should pay more attention to Heading.
The whole point of the Instrument Reference-Visual Reference method of learning to fly is that you should be attuned to automatically going to Heading Indicator when you lose visual reference to straight flight.

When you initially lose an engine, the heading change won't lie.
Sometimes, in turbulent air (natural or pilot imposed), the ball is bouncing around so that it can be confusing. Wait until you have stabilized Heading before you consult the ball.

 

[gkrangers]

In my limited experience, the yaw string does do a good job of displaying zero side slip.

 

[MauleSkinner]

In my limited experience, the yaw string does do a good job of displaying zero side slip.

...but unfortunately Undaunted's experience seems to override the rest of ours

Fly safe!

David

 

[clumpinglitter]

...but unfortunately Undaunted's experience seems to override the rest of ours

David

My instructor and I taped a yaw string to the Duchess the other day, but after we took off, it just hung down instead of going up over the windshield. I think the end of the string caught on something. Pissed me off.

-C.

 

[UndauntedFlyer]

In my limited experience, the yaw string does do a good job of displaying zero side slip.

I believe you will find that the yaw string does show yaw just as it is supposed to do. If you are flying with an engine inoperative and windmilling plus using bank and no rudder correction the yaw string will show lots of side-slip yaw. But if the failed engine is feathered (or set to zero thrust) and you're holding heading with the ball in the center or whether it's off one-half ball width while still holding heading, the displacement of the yaw string is almost nothing from one situation to the other and neither situation has the yaw string more aligned with the longitudinal axis than the other as can be seen.

 

[SPilot]

UndauntedFlyer, thanks for your reply.

I rest my case.

But I have tried it, and noticed better performance with 5 degree bank and offset ball, compared to wings level and ball centered.

I have however not tried to compare performance just with or without offset ball, using 5 degrees of bank in both cases.
And also with the string on the windshield, I've not attempted to look for any difference between ball centered and ball offset, but I have noticed significant difference on the string between banking and wings level.
On the Seneca I flew, the string was sort of "sticky" because of moisture combined with dirt and bugs on the windshield, so it was difficult to see small differences (it took a large change in yaw to convince the string to rip loose and move).

In any case, the minor difference in performance is not all that interesting during practical flying. I'm probably not able to fly the airplane with such extreme precision during an emergency anyway.

 

[UndauntedFlyer]

I have not tried to compare performance just with or without offset ball.

That is the whole point of the yaw string test and your instructor didn't do it?

Of course the 5 degrees of bank would only be along with the ball at half-scale deflection. And that would be compared with the ball centered and the wings almost level level or the airplane would be turning. And in this test you will see that there is no measurable change in the yaw string. The point being that zero side slip is not all that it is supposed to be in terms of greatly reduced drag. In reality all that it will do is give your leg a rest. The performance enhancements are minimum if they can be seen at all.

Personally, I file all reports of greatly enhanced performance as a result of "zero side slip" configuration under the title of placebo effect.

 

[gkrangers]

I believe you will find that the yaw string does show yaw just as it is supposed to do. If you are flying with an engine inoperative and windmilling plus using bank and no rudder correction the yaw string will show lots of side-slip yaw. But if the failed engine is feathered (or set to zero thrust) and you're holding heading with the ball in the center or whether it's off one-half ball width while still holding heading, the displacement of the yaw string is almost nothing from one situation to the other and neither situation has the yaw string more aligned with the longitudinal axis than the other as can be seen.

I can't be positive as its been over a month since I've done this now, but I do know at times there would be a considerable difference between ball centered and setting up for zero side slip, in our Duchess.

Could depend a lot on the airplane and the way the string is attached perhaps.

I know you have far more experience than I, just stating what I've observed.

I'm not talking performance differences, just centering the string along the longitudinal axis of the aircraft.

 

[nosehair]

Keep in mind that a small, insignificant performance improvement in a small training airplane may convert to a larger, more impressionable performance improvement in a larger engine airplane.

 

[minitour]

Keep in mind that a small, insignificant performance improvement in a small training airplane may convert to a larger, more impressionable performance improvement in a larger engine airplane.

...and sometimes a small, insignificant (100fpm) performance improvement in a small training airplane may be the difference between a controlled crash and staying airborne.

-mini

 

[gkrangers]

...and sometimes a small, insignificant (100fpm) performance improvement in a small training airplane may be the difference between a controlled crash and staying airborne.

-mini

I would call 100fpm significant. Anyone know, lets say on average or at standard atmosphere how much improvement zero side slip gives in a Duchess, Seminole, or anything really ?

 

[A Squared]

Personally, I file all reports of greatly enhanced performance as a result of "zero side slip" configuration under the title of placebo effect.

Ummm yeah, it's just "placebo effect" RIghty, last time we discussed this, the guy who was a Navy Test pilot, the one who had actually done extensive test profiles on this, with a highly instrumented aircraft, and his systematic, carefully measured flights under controlled conditions showed a significant increase in climb (not sprctacular, but significant) yeah that was probably "placebo effect"

OK, undaunted, I'm going to get personal here for a moment.

Look. You bring a lot of good things to this forum, a great deal of experience, an enthusiasm for General Aviation, the perspective of an actual examiner, and you've sparked some interesting discussions. That's all good. But for some reason, you have a bug up your a$$ because you think the zero sideslip concept is a myth. That's fine as far as it goes. I, like you, believe that dogma should be challenged, and I'll be the last to claim that everything in an FAA text is true. However there comes a time to admit that you are in fact wrong. The time for you to admit that you are wrong was when a trained, navy test pilot showed you from his flight test records in GA twin with test instrumentation that the zero sideslip concept actually *DID* yield performance improvements. Yet, unbelievably, you insist that there is no value to "zero sideslip" that it's all "placebo effect" .

I gotta ask, what is wrong with you? why do you keep tilting at this windmill when you've been shown to be wrong? Do you think that your casual dicking around in a duchess with a string tied to the windshield is more accurate than a trained test pilot flying specially instrumented aircraft through a carefully planned test sequence? Or are you just so convinced of your omniscience and omnipotence, that nothing anyone says or does (even trained test pilots) will make any difference to you?

Sorry for getting personal. Like I said, I do think you contribute some positive things to this forum, but your "just say no to zero sideslip" campaign is not a positive contribution.


FOr those of you scratching your heads wondering what the deal is here, take a look at this thread.

http://forums.flightinfo.com/showthread.php?t=74012

Take a look at Skiddriver's posts. He's the test pilot. Notice how Undaunted goes from saying that performance increases from zero sideslip is a myth at the begining of the thread to conceding that the performance improvements exist. Now, for some reason he's back to insisting that they are due to "placebo effect" I don't get it. All I can say is that I would point out to Undaunted Flyer that this foolishness undermines his credibility on other subjects.

 

[Metro752]

i woulda failed my multi checkride if Al was my DE. i was flying around half the checkride in a zero side slip condition