twin engine climb on one engine

[310]

http://www.aopa.org/members/files/topics/leaveout.html

This is the location of the article with the info from above.
I think you have to be a AOPA member to access.
The 310 I fly is a C model and is the lightest one built with 260hp per side so maybe it performs better that other 310 models.
Book SE roc is 430 fpm.
I have had instructors pull one several time just after rotation and have always climbed out on one without having to put the pulled back one back into the game.
But be very careful on approach- with gear down and flaps 20 it will not hold altitude with full power on one; so don;t get too dirty too far out and low. It has nine feet of slip flaps per side.
Big Barn Doors.

 

[310]

yes, I think we are talking different models- in what model/year 310 did you experience this?

 

[Timebuilder]

Jetdriven, that's the "real world" answer I expected for the Navajo.

I have a friend who lost a motor in a Navajo near Limerick, Pa, and flew it fully loaded to land at PHL because of the fire apparatus that was available there. He was at about 2,000 the whole way, if I recall correctly.

 

[surplus1]

In general, the problems associated with the marginal performance of light twins operating on one engine are perhaps more complex than those of transport category aircraft. Be that as it may, dealing with the sudden loss of 60% - 80% of your available power is no cup of tea.

As we look at Part 23 certification criteria, we must consider that these are minimums. Some Part 23 aircraft can do better than the minimum requirement while others can't. We should know where our particular aircraft fits into the picture. This knowledge must be acquired much before we ever have to use it. Yes, you can get a "multi-engine rating" in less than 10 hours, but you sure can't learn what you really need to know.

It also does us well to think about the fact that "book values" are determined for "like new" aircraft, with everything functioning at its best. An "old" engine, turning an "old" prop on a "dirty" airplane is not likely to do as well as a shiny brand new airplane flown by a test pilot. You know, like the one they used to develop those "numbers".

Engine failure at cruise requires very different analysis and planning than does engine failure on take off. If managed well, and that's a big IF, most light twins will give you time to consider your options (if the terrain isn't too high) and probably one shot at a good single-engine landing on the airport.

On the other hand, engine failure on takeoff really doesn't give you any options that I would consider capable of eliminating the pucker factor. Maybe your airplane can climb at 50 FPM or even 150 FPM. Assuming that it can, consider this:

How long is it going to take you, with your climb rate, to reach an altitude that will allow you to manuever for a landing on the airport of departure? What was that density altitude again? Is the air smooth as glass ... or do you have to deal with turbulence too? What distance will you cover during that time? What will happen to your "climb rate" when you make a turn or hit a downdraft? What are the obstacles, obstructions, etc., between you and the final approach? Will you be able to climb over them or at least fly around them? What will your "pattern" altitude really be as you manuever for this approach/landing? Will you fly the pattern at 50 ft, 100 ft, 300 ft? How many times have you done that and how does it affect your judgment and ability to set up the approach? What if you don't get it "right" .... the first time? Should you climb into the overcast or manuever underneath it? If you do climb into it, can you get to the intial approach altitude? What will you do if you can't? Can you "miss" this approach? When will you lower the gear? What about the flaps? How good is the "good engine"? That's not the one with the questionable mag drop is it? How long will it run at max power? Should you really have feathered that propeller .... or could you do better by keeping it running at reduced manifold pressure? Did you really lose the engine .... or was it only the turbo charger? Finally, are you alone ... or is your airplane full of non-pilot passengers who just might not sit silently while you demonstrate your skill?

Two more questions ... when a single-engine aircraft has an engine failure on takeoff .... how many pilots have been able to make a 180 and land downwind ... what are the chances of that? When a light twin loses an engine on takeoff ... how many successful landings have resulted from climbing out and returning to the airport? I'll bet the stats are not very different from the 180 and downwind landing in a 172 (or whatever).

I doubt you'll find many good answers to those questions no matter which light twin you happen to fly. I also think you should have a pretty good idea of what the answers really are, today, on this takeoff, in the real world!

I would urge all of you to consider the problems before each and every departure and develop a "plan" of action that you can reasonably expect to follow successfully, then follow it. A sudden and unexpected engine failure is not conducive to planning. Given the marginal performance of light twins, you'll have your hands more than full just trying to fly the airplane if you should be unlucky enough to have that experience. If you have no advance plan, the outcome is seldom successful. Please consider that a controlled crash always has a better outcome than an out of control inverted landing or a head on collision with an obstruction.

No matter how good a "stick" you may happen to be, you can't make the airplane do anything of which it is incapable. Therefore, I suggest that you know the capabilities and conciously select the "lesser of evils". It has been said that any landing you can walk away from is a good one. That includes an off-airport landing when necessary.

That the countryside is not littered with the aluminum of light twins (or of single engine aircraft) is generally not attributed to the skills of their pilots or the performance capabilities of the airplane following engine failure. The good statistics are earned by the engineers and the mechanics, not the pilots. Thanks be to them, and the Almighty, catastrophic powerplant failures are very rare.

Neverthless, we need to prepare ourselves for those things that "almost never happen", better than we do for the routine. Meanwhile, if you can get into a T-category aircraft, by all means do it. The life you save may be your own.

Fly Safe.

 

[pilotshan]

I'm going by memory here, so take the info accordingly; here are the requirements:

MTOW < 6000 lbs, Vs1 < 61 knots: Recorded gradient of climb or descent at 5000 feet pressure altitude, standard day, clean configuration, inoperative engine windmilling.

Vs1 > 61 knots: Positive climb gradient of 1.5% at 5000 feet pressure altitude, standard day, clean configuration, inoperative engine windmilling.

MTOW > 6000 lbs: Positive climb gradient at 400 feet and 0.75% climb gradient at 1,500 feet. Takeoff power at 400 feet, MCP at 1,500 feet. Standard day, clean configuration, inoperative engine windmilling.
*Turboprops: Not only previous, but also capable of a 1.5% climb gradient at 5,000 feet pressure altitude, and 0.75% climb gradient at ISA +40 degrees F. Same configuration as above.

The correct conditions are: 5,000' pressure altitude, std. day, clean, max power on good engine, and critical engine feathered. All found in part 23.67.

I have about 300 hours of dual given in Piper Senecas (IV) and Seminoles so here is my insight (and I in no way claim to be an expert, just in a slightly more advanced stage of learning about these things than I was when I was a student):

-know what your airplane is capable of. The Seneca will happily climb to pattern altitude and fly you back to the runway with one engine out, the Seminole might not.

-know that when you lose an engine in a twin you lose 50% of your power, but 80% or more of your climb performance. These numbers are spelled out in a previous post on this thread (I believe they are directly from "Always Leave Yourself An Out", previously mentioned also), but here's what I use to drive that point home with the students:
The Seneca IV has 220HP/side, so with both engines running, you have 440HP available. It takes about 175 HP to maintain straight and level at max weight, leaving 265 excess HP to climb with. Not too bad. But, when you lose one engine, you cut your available HP in half to 220. The aircraft still needs 175 HP to maintain straight and level, leaving you with a measly 45 HP left to climb with. Not so great. Especially after you have to reduce the power to 200 HP because you're at your 5 min. limit for 220 HP.

-be aware of your surroundings. In a single, I'm always looking for the best place to make an off-airport landing. However, in a twin, I'm keeping track of the nearest suitable airport. That airport isn't always the closest, but the one with the runway long enough to minimize the chances of overshooting and a possible go-around. Because we all learned in our training that single engine go-arounds are not only bad, but in many cases, impossible. Crosswind factors also factor into our decision because we have enough to worry about without picking the runway with the 20 knot direct crosswind.

-realize that eventhough you may overshoot, it's always better to run into the fence at the end of the runway at 20 knots than it is to crash into the trees at 90 knots because you tried to execute a go-around.

-always remember that the only thing that second engine is really good for is flying you to your crash site.

"Always Leave Yourself An Out" and "Flying Light Twins Safely" are both excellent publications, which all of my students receive. For additional material, which has been very useful, do an internet search for "See How It Flies". It has a multi-engine chapter which is excellent, but the rest of it is very good also. I wouldn't reccomend it to students because it's somewhat technical, but instructors should find it informative.

Hopefully, this has been useful... my expanded 2 cents.

 

[172driver]

Not that it affects the overall point of this thread a whole lot but all of the previous statistics are a little misleading as far as Part 23 goes. The regulation for demonstration of climb performance changed in 1983 and only applies to twins certified after 8/18/83. As far as I know, no twins fall in that category.

For twins certified before 1983:

MTOW<6000 and Vso<61 stays the same. Climb/descent performance must be demonstrated.

MTOW>6000 OR Vso>61...Climb performance must be .027 x Vso squared in fpm @ 5000' on a std day.

Great post surplus. You hit it right on the head. Tough to get this point across flying brand new Seminoles, in flat Florida, in the winter, from 10,000 ft. runways. All we MEI's can do is teach it religiously on the ground and in the sim. Pound the dangers of a continued SE takeoff into their heads. Make them explain repeatedly what they would do if any one of those factors was different. Show them the different factors in the sim and make them evaluate performance before trying to continue. Teach decision making rather than rote procedures.