Shutting off the fuel in a Seneca I

[JimNtexas]

"I'm aware if you feather the prop it will stop turning. I think I'm being misunderstood. The situation that I'm concerned about is when he shuts off the fuel. When he does that the prop is still turning (not feathered). I'm just concerned about what happens if I botch the approach and I need to go around."

That's easy. Try to go around in a Seneca with a dead engine and windmilling prop, and you die.

 

[labbats]

Hey Jim, why don't you lighten up?

This is the training forum last I checked, and people come here to ask questions that they don't know the answer to.

 

[CaSyndrm]

I got a crap load of Seneca and Aztec time and have shut down both with the fuel control.. Never had a problem and find it a great training tool because the student doesn't expect it and doesnt't see your hand pulling the throttle back.
Relax and have fun, don't take it too seriously. You will live through the training and instructing process.

 

[Alchemy]

I see nothing wrong with failing an engine using the fuel selector assuming you're above 3000 AGL. Call me paranoid but I wouldn't want to do it lower than that. Having the throttle at idle on one side really isn't that much different, and it really isn't much less of a surprise to reach over and grab a throttle than it is to move the fuel selector.

 

[avbug]

If you're going to shut down an engine in flight, regardless of how you accomplish it, be prepared to not get it back. Regardless of weather you're 3,000', or 3'. Unless you're fully prepared to deal with that consequence, then don't do it. Period.

Killing an engine with the fuel selector is fine and dandy, except that you're starving your fuel-wetted/lubricated components, primarily the engine driven fuel pump. That increases wear, and also the possibility of a failure. Not just at the time you're simulating the engine failure, but later.

Stopping fuel flow introduces air throughout the fuel system, leading to an increased possibility of hydraulic lock, as well as the near-certain liklihood of pump cavitation.

Killing the engine isn't necessarily a bad thing; if one is prepared to land the airplane it doesn't matter how high it's done. During my ATP ride, the examiner killed the engine at 200'. I had made it clear that if the engine quit below 400', we'd consider it an emergency and treat it as such, and I did. Unable to mount much of an effective climb, and unwilling to seek a restart there, I returned to land on an intersecting runway, with a very low pattern. I'm not going to second guess the examiner in that case; he was outside of the Administrator's guidelines...however, we were continuously in a position to make a safe landing, and we did. He also pulled the engine using the throttle.

He also knew that I've spent a great deal of my flying career below 200', and that it was a comfortable environment for me. I don't know if he would have done that to someone else, or not.

I don't have a lot of seneca time. About four hundred fifty hours of so. The Seneca II or III will easily hold 8,000 MSL with one engine out and feathered, and the airplane full of fuel and people. It's got quite a high single engine service ceiling. The Seneca I doesn't have that high a service ceiling, being normally aspirated, but it's still high enough, so long as one engine is feathered.

Messing with fuel selectors during taxi is not a very wise thing to do. Releasing debris that may be trapped behind selectors, or having a selector fail without your knowledge in an intermediate position or an off position, can get you killed. You may have just enough fuel between that failed selector and the engine to keep it running through the takeoff...and then you lose it. It happens. Debris that may be trapped behind the selector valve can be released, just in time to mess with a fuel controller, injector plug, carburetor jet, etc. Just not a wise idea...because it's quite likely to get to the worst possible place, at just the worst possible time. Leave those selectors alone. Either check them before start on the preflight before a long taxi and runup, or don't touch them until you're over a safe landing site once airborne.

Block rudders for engine-out work and Vmc work, stick with zero thrust for most single engine work (using a throttle), and always warm up an idled or killed engine before going again. For those of you conducting single engine approaches, no go-arounds. Land, warm that engine back up, and go again. If you've shut one down, warm it up.

On the subject of going around single engine, I once had an examiner demand to see a single engine go-around in a Seneca II. He told me I would be flying a single engine ILS under the hood, then executing a single engine go around. I told him I wouldn't. The checkride was for a small 135 operation. He told me I'd not pass, I told him I didn't care. He told me it was a test standard, I told him it wasn't. Not unless it's a part 25 airplane, and the Seneca II definitely isn't. He got lippy, told me I was goign to fail the ride. I told him that would be fine, and asked him if he preferred to get out now, or wait until we got back to the airport. He shut up and finished the ride, I passed.

He asked what I would do if I flew a single engine approach in the airplane and found the runway fouled on arrival. I told him I'd land anyway. But what if the runway is blocked? I'd land adjacent to it. Wassamatter, Mr. examiner? Never landed on grass? In snow? On anything but hard dry pavement?

I don't know that I'd agree that going around will kill you...but it won't do you any good, and your odds aren't great of success. Especially at any significant density altitude of note.

 

[starvingcfi]

That's easy. Try to go around in a Seneca with a dead engine and windmilling prop, and you die.

wow. i thought the seneca did pretty well on one engine. granted, i never went around with one windmilling...but i got a pretty good rate with sim-feather. also, this was just 135 training stuff. i've never instructed in one.

just from what i've seen the seneca does a great job on one. i'd rather lose one in a seneca than a 402. what a pig.

 

[tathepilot]

Thanks for all the insight! I just got back from another training flight with my mei. Single engine ils's in imc. (very fun!) What my instructor did today was fail the engine (fuel selector) and than turn the fuel back on at around 500'. I think that is a lot better than waiting until rollout. At least if the engine doesnt respond, we'll have more time to figure out a solution.

 

[Timebuilder]

Messing with fuel selectors during taxi is not a very wise thing to do. Releasing debris that may be trapped behind selectors, or having a selector fail without your knowledge in an intermediate position or an off position, can get you killed.

Our checklist mandated that this fuel selector check be done on every taxi. This keeps "debris" from being there in the first place, making the fuel valves just another component that is moved regularly. Our feds and DE's approved of the procedure, too.

Mind you, moving the selectors in flight means being prepared to lose that engine entirely, just as Avbug said. Returning the selctors to "on" before reaching the runup area virtually assures you that there is no lingering fuel problem, as the engines cannot run on the fuel remaining in the system downstream from the selectors long enough to complete the runup and taxi into position on the runway. Even so, be ready to abort every takeoff, and make it your mindset. Expect trouble.

Either check them before start on the preflight before a long taxi and runup, or don't touch them until you're over a safe landing site once airborne.

Yes.

Shutting down the engine during training is a real world sceanrio that CAN become an emergency. That's why sufficient altitude is require by our training syllabus (the aforementioned 3,000 AGL) along with easy reach of a suitable landing field. Altitude is your friend, since it gives you time to collect your wits, make a radio call, run the checklist, and prepare to follow your training. And we are talking about training, here, so let's mitigate as much risk, and add as much time for learning and thinking, as we can. Altitude can help you to have that time at your disposal.

Block rudders for engine-out work and Vmc work, stick with zero thrust for most single engine work (using a throttle), and always warm up an idled or killed engine before going again.

Absolutely. Some have said that a rudder should not be blocked, but too many people die during multi training to put me in that camp. I think we had a discussion about that here, or was it on the old board? I don't know. I tried to limit my engine shutdowns to no more than two per hour in flight, and always warmed the engine before loading it again.

I don't know that I'd agree that going around will kill you...but it won't do you any good, and your odds aren't great of success. Especially at any significant density altitude of note.

The question of the ability of the Seneca I to go around on one engine is a good reason to simulate the single engine scenario using throttle and zero thrust. That way, you have a better chance of having a learning experience instead of a final experience.

Multi pilots in this airplane need to remember that the single engine specs are ideals, and are limited by density altitude, which can be incredibly low in the summer. Now, take that limited ability of the aircraft, and add in the element of shock and disbelief, and you have the fabled "swimming in glue" scenario that takes what precious little time you have to do everything perfectly during an unexpected engine failure, say for instance during or just after takeoff, and effectively reduces that time you have left to almost nothing. In training, you are expecting things to go "wrong" in a relatively safe and predictable way. After training ends, you no longer expect all those failures, and you can become complacent. Don't.

ALWAYS expect to lose an engine at the most critical times. Don't be one of this year's stats in an NTSB report.

wow. i thought the seneca did pretty well on one engine. granted, i never went around with one windmilling...but i got a pretty good rate with sim-feather. also, this was just 135 training stuff. i've never instructed in one.

The sim feather will give you a good rate most of the time, that's true. I never had a problem as a student or as an instructor, but to try and go around with the drag of a windmilling prop is very unlikely to be a success. Don't confuse the powered prop in a sim feather with the draggy prop of an unfeathered DEAD engine. Get some altitude with the instructor and check your performance with one windmilling. It isn't pretty. Know the failure procedure and perform it methodically. Pilots HAVE feathered the wrong engine, with disastrous results.

Treat "blue line" as gospel. If pitching to blue means you are descending, you ARE going to be landing shortly. It is far better, in terms of accident survivability to land bottom-down, and not on your roof due to a Vmc roll as you try to stretch your glide.

There are two publications which I don't have handy that should be required reading for twins.

Flying Light Twins Safely and

Always Leave Yourself an Out

 

[nosehair]

Go-Around!!!

I always practice single-engine go-arounds when doing multi-engine training. With simulated zero-thrust, not an actual feathered engine. Sometimes, we climb and sometimes we don't, very much, but the student gets a real work-out in heading and pitch control. With practice, the student can see how he can "play" the Vyse. The published Vyse is, of course, full gross, and the actual Vyse is usually a little below, depending on weight. The student gets some real live experience in determining actual best rate speed to coax a climb, and to make a low shallow turn to downwind or another runway.
C'mon, I thought this was standard practice in training. Sure, you want to avoid a go-around, and I might elect to land in the grass next to the runway, but I also might elect to go-around if I'm light. I want the skill and experience to make a judgement - not a rote procedure, and in any case, the training in basic aircraft control is invaluable.

 

[Timebuilder]

C'mon, I thought this was standard practice in training.

It is standard procedure, using the fake feather so you can get it back if you need it.

What I am advising against is a feathered or shutdown engine that leaves you no alternatives in a training situation.

That is not standard.

 

[dmspilot00]

"Sometimes, we climb and sometimes we don't, very much, but the student gets a real work-out in heading and pitch control. With practice, the student can see how he can "play" the Vyse. The published Vyse is, of course, full gross, and the actual Vyse is usually a little below, depending on weight. The student gets some real live experience in determining actual best rate speed to coax a climb, and to make a low shallow turn to downwind or another runway."

Sounds dangerous to me. Isn't flying about minimizing risk?

Who says you have to be at 50' ready to land to "practice" a single-engine go-around?

Although I've yet to fly a multiengine airplane, it would seem that the best of both worlds would be to simulate a single-engine go-around at, say, 3000AGL. Just an observation.

 

[Cat Driver]

Find another instructor.

 

[Timebuilder]

Although I've yet to fly a multiengine airplane, it would seem that the best of both worlds would be to simulate a single-engine go-around at, say, 3000AGL. Just an observation.

You can practice a lot of things at altitude. Drag demos, for instance.

You can do a single engine go-around from short final, and usually with no problem. Just don't paint yourself into a corner by shutting down and/or feathering a prop before you try it. A zero thrust setting should be all you need to simulate a feathered prop, while keeping the engine running and ready for almost instant use.

At altitude, you can try the go-around with a windmilling prop and a shutdown engine, to simulate the condition of an unplanned failure, and see how little performance you really get. It isn't much.

 

[avbug]

...virtually assures you that there is no lingering fuel problem, as the engines cannot run on the fuel remaining in the system downstream from the selectors long enough to complete the runup and taxi into position on the runway.

A lot of folks have thought that way, and learned otherwise...the hard way.

You might be surprised just how long that fuel will last. I've also seen fuel selectors shear off, either closed, or partially closed. They'll support fuel flow at idle, but not at takeoff power settings. As the fuel reserve in the header tank, gascolator, or other source is used up during the roll, the engine fails shortly after liftoff.

Any debris introduced into the system by moving the selector valve may not show up until the takeoff, when the highest fuel demand/fuel flow exists.

Every year one or two airplanes get away when someone forgets to tie them down during hand-propping. Old sage advice says to put the fuel selector in the off position to prevent the airplane from going anywhere during the handpropping exercise, especially if you're the only one present. However, even with the selector off, airplanes make it into the air every year, with no one aboard...and then fall from grace when the fuel finally runs out. Just how long that engine will run with the fuel shut off can be surprising...especially if you have a leaky valve or it's bypassing through your primer line. It happens.

 

[Timebuilder]

You might be surprised just how long that fuel will last.

You're right, I might have been.

That is, until one day that a little experimnet revealed that the engines stopped before the runup was complete. I thought there might have been a substantial difference in the time an engine would run following a change from cross-feed to "on" (simulating a malfunctioning valve by selecting "off") when compared with how long an engine would run after "off" is selected in a training scenario at altitude. Pretty much no difference. Since the fuel flows were higher during runup power than during the cruise setting, they stopped running a little sooner on the ground.

So, we decided to stick with the checklist for the airplane, and observe the engine performance during the runup at near-takeoff power. We also were mentally prepared for a failure at the most critical time.