Gear/Flaps During Engine Out Approach?

[ndugu]

It's been awhile since I've flown a light twin and was trying to recall the procedures for gear/flap extension during a single engine approach in instrument conditions. As I recall, during a nonprecision approach, the gear/flaps remain retracted until the final descent from the MDA, the reasoning being that it may be impossible to arrest your descent upon reaching the MDA with your gear/flaps extended. On a precision apporach, the gear and flaps (if you elect to use flaps) are extended at glideslope intercept since, after that point, there will be no need to level off again. Correct, incorrect, additional considerations?

 

[Deftone45075]

Sounds pretty good to me. In single engine procedures I would not go to full flaps at all. If the airplane can be slowed reasonably easily without flaps, than begin a Non Precision approach without them. When Leaving MDA with the field in sight, extend the gear and flaps, but leave out the last setting.

On a precision approach, extend the gear and flaps, again using he minimum flap setting, by the FAF.

 

[bobbysamd]

Gear/flap extension

Sounds pretty good. You want to keep things as normal as possible during an approach with an engine inoperative. For the typical Seminole-type light twin, I would drop gear one dot above glideslope centering or even at glideslope centering - whatever you use for a normal ILS. I would drop gear at the FAF for a non-precision approach. Keep power where it is; chances are the gear down will establish the perfect rate of decent to hold the glideslope. Keep your procedure as much the same as possible as a normal approach. I might not even use flaps at all for a couple of reasons: (1) Vmc implications and (2) you don't want to haul all the extra drag around at MDA because a light twin with an engine inop ordinarily won't have enough power to overcome that drag.

In that regard, I realize that you cannot bust mins on a non-precision approach. That is absolutely true for an approach with both engines operating. You take a miss in that situation. However, look at it this way: for one thing, an approach with an engine inoperative in a light twin in IMC is an emergency situation. You will land. You are not taking a miss. Another point is if you execute the approach well you should have enough runway for your after-landing rollout. In line with that are two more points: (1) Most runways served by an ILS are plenty long enough to land a light twin flaps-up with an engine inop and (2) in the real world you are going to declare and request vectors to the nearest airport with an ILS. Engine-inop non-precision approaches are something that you must know and are excellent training, but something that you must avoid if at all possible.

Hope that helps. Good luck with your twin training. Good interview question, by the way.

 

[bobbysamd]

Engine-inop go-arounds

As for dropping the gear and flaps on the non-precision, I would just add one thing to the above: It is a decision that you make, based on experience. Will this plane be able to maintain altitude at MDA with the added drag? How much do you trust the gear that it will retract quickly and effectively in a quick go-around situation?

But that's my point. You do not go around in a real engine-inoperative approach in a Seminole-type light twin (or even a Baron)! You land. Balking the approach is not an option.

That's why a non-precision approach with an engine inoperative is somewhat bogus. You look for an ILS. However, you still need to have engine-inop non-precision ability in your bag of tricks, just in case. Just like single-engine holding. Single-engine holding is fun to practice and great training, but accepting a hold with an engine inop would be horrendous judgment.

 

[avbug]

It all depends on the airplane. In general, you shouldn't do anything any different than you do with both engines turning. This is especially true of the gear. You need to keep energy conservation in mind, in that you have limited power, and limited altitude, and in most cases, not enough power to hold or gain altitude.

You're not going missed in most piston twins, so planning for a missed isn't realistic. (I once had an inspector demand it on a checkride. I told him I wasn't doing it. He told me he was demanding it because he felt it was required to meet ATP standards. I told him not in that airplane, and not with me. He suggested I'd fail the ride if I refused. I asked him if he wanted to get out now, or wait until we turned around and went back to the airport. He shut up, we finished the ride, I passed).

In some airplanes, the gear is very draggy, and may need to be delayed, and in some airplanes, the flaps are draggy. The types of flaps and gear, and the effects of both should be considered. However, it's very easy to get caught up in dealing with abnormal events and forget gear or other things unless they're applied per normal proceedure. Accordingly, run checklists religiously, and try to keep everything as standard as possible.

 

[ProLine4]

If you are flying a non-precision approach that requires maneuvering (such as the "arc" approach in NM... believe it is Las Vegas NM? Not sure), wait on the gear and flaps until you are sure of the landing. You just want to make sure you will have enough time to drop the gear, ensure they are down, and if they are not down to do the emergency extension procedure. That emergency procedure is fairly simple in the Seminole I fly now. If you are flying something where it will take 300 motions to pump the gear down, you may want to think about the gear earlier... or just be prepared for a gear-up landing.

FlyChicaga, there's no reason why you should have the gear and flaps out on a DME Arc. When utilized on either a precision or non-precision approach, the arc's function is to take you to the final approach course, after which you would then wait for the FAF if non-precision or a dot above the glideslope intercept to extend the gear and flaps.

About the only exception to this gear and flap rule would be if you were at a very high weight with a very high density altitude, and dropping these two would create such a high amount of parasite drag that you know you'd descend and auger it in on final approach. Then you'd want to wait as long as possible before you dropped gear and flaps. By high I mean something along the lines of at gross weight in an underpowered light twin at Leadville, CO on a horribly hot day...IE, a situation that is not typically encountered.

As for encountering gear problems, well, that would be a very rough day of flying when compounded with an engine failure in a twin, but I don't think any pilot would knowingly resign themselves to land gear up on the basis that they didn't want to deal with two problems at once...that would be incredibly stupid. This very scenario occurred on my friend's ATP checkride: Gear failure at the FAF on a non-precision approach while single engine. He had to demonstrate the full procedure while safely flying the airplane to ATP tolerances.
To use a real example, the hydraulic system on an Aztec is driven by a pump on the left engine. With a failure of the left engine, a pilot will have to deal with the engine-out AND pump 30-40 strokes on the emergency gear extension handle so they can get the gear down for landing.

Your boss, passengers, and insurance company would have your head if you told them "I landed gear up not because of a mechanical problem, but because I was just too occupied flying the airplane." Good luck finding a new job too. Just trim the airplane out, keep it above Vmc, drop the gear by whatever means necessary, and land. It's a lot of work, but it can be done.

 

[avbug]

One might or might not drop the gear on the arc, but in most cases, I'll have some flap in at some point on the arc, having passed the IAF. I try to do everything the same, where feasible. That includes configuring at the same point. I may have my initial or second flap setting on the arc, though the gear may wait until established inbound, or approaching the GSIP or FAF.

 

[sf3boy]

I would throw the gear at the FAF and possible a setting of flaps. Remember that lighter twins do not fly approaches at 130-160 kts. They will get slowed down in plenty of time. My personal choice would be to hold on the final flaps until landing is assured.

On the Saab, we did not put the final flaps in on a nonprecision single engine approach until leaving MDA for landing, just in case a missed would be executed. In the AVR-146, we do nothing different on a 3 engine compared to a 4 engine approach. It is not an emergency, according to the airline.

 

[maverick_fp00]

A flight school here in Panama City teaches that, non-precision or precision, gear doesn't come down unless you are gliding distance from the runway if the other engine was to fail. Go figure! Everybody has their own ways of doing things, one might be safer than the other, but whateverworks I guess...


(I don't particularly like the way they teach over there anyway.)

-Nick

 

[ksu_aviator]

It's been awhile since I've flown a light twin and was trying to recall the procedures for gear/flap extension during a single engine approach in instrument conditions.

I didn't see anyone say the obvious here so I will. Check the Operating Manual for your aircraft.

The above, for the most part, is correct as a general practice for a generic light twin.

Now as for this quote:

You do not go around in a real engine-inoperative approach in a Seminole-type light twin

I've said it before, and I'll say it again...categorically removing the option of a go-around is dangerous and stupid! I'm not trying to attack someone's intelligence, I'm just trying to get my point acrossed. If you fly a single engine approach and you are chasing the needle right and left you should consider a missed approach. Now, if your aircraft won't do a missed single engine maybe you shouldn't be up there in the first place. That is a risk you take (not unlike flying a single engine). If it will go missed then don't categorically dismiss the missed.

 

[bigD]

As much as it makes me ill to agree with a KSU fan - I agree that you have to leave your options open with regards to going missed on one engine. I'll need a VERY good reason to do it, but if the approach is going the hell, I'd much rather take it around than muck around searching for the runway in IMC. Obviously it all depends on the conditions, but I should have thought about all of the performance numbers during my preflight planning so I can make a decision instantly in the air.

I dunno...with the Duchess I fly at about a hundred pounds under gross on a medium warm day, I get about 300-350fpm during a single engine go around. Yeah, its not much. But it some situations it's better than the alternative.

 

[bobbysamd]

Single-engine go-around

I've said it before, and I'll say it again...categorically removing the option of a go-around is dangerous and stupid

And so is trying a single-engine go-around in Leadville or Aspen.

Perhaps you might in a Part 25 airplane, but trying to go-around on one in IMC in the typical light twin is dangerous and stupid. I don't think that one can be assured of making the prescribed climb gradient in an engine-out Seminole.

Engine-out in a light twin might give you more time to weigh options compared to losing your engine in a single. But that's the primary advantage. Otherwise, you're going down, just as if you lost your engine in a single.

Instead of giving 2¢ opinions and engaging in conjecture, why don't we review how one of our members dealt with a real-life engine-out situation? Click here to read how my good friend Skyking1976 recently dealt with losing one.

 

[skyking1976]

Thanks Bob! To reiterate what KSU Aviator said, engine out and single engine go-around procedures in twins all have one thing in common. The proper procedures are listed in a manufacturer approved checklist or POH. Instead of listening to flight school or MEI rhetoric, (which may differ from manufacturer procs) shoot some single engine ILS's to missed in a twin, do it the manufacturers way then do it someone else's way. I'll bet you 9 out of 10 times the manufacturer's procedures will result in better performance the other's.

Look over single engine climb charts too especially at high density altitude airports. They will give you a good idea whether or not a single engine go-around is even possible. For example: I did a max-gross V1 cut at Las Vegas in the King Air 350 sim and I had to fight to get 100-150 fpm climb and that was with a turboprop. Anyone who has flown Simuflite's BE350 sim will know exactly what I am talking about. And Bob, I am cringeing thinking about Aspen and Leadville on a hot day with one engine.

Getting the tires safely on the pavement is all that matters, folks. Go-around or not.

Cheers,
Skyking

 

[bobbysamd]

SE Go arounds at high DA

I am cringeing thinking about Aspen and Leadville on a hot day with one engine.

For that matter, doing one in a Seminole, etc. at Centennial or Prescott on a hot day in August or in a Baron in Farmington on a similar day would be less than thrilling for me.