Performance after failure of engine on takeoff, and SE procedures (was SE T/O Perf)

[Dale Campbell]

I have a H model and airspeed is in knots. My blue line is 90 knots
and that is what I climb at or above. I fly out of a short field 1995
feet long to be exact. I rotate at 80 knots level to 90 knots to clear tree line. After that I climb to altitude at 120 knots to keep engines running cool. I was at 90 knots when instructor pulled front engine to idle. Thats going by my flight manual. Best rate of climb single engine, 90 knots. If you read my posting that is what I did. I left the 1/3 flaps in to give me more lift.

[Jerry De Santis]

Thanks Dale, I now have better understanding of what you did. I do however question the wisdom of your instructor to pull an engine after rotation on a 1900 + foot runway. Yes! I know, engine failure doesn't care how long the runway is, but as described, much to macho for me. It will make more sense to me to practice engine out failure on a more suitable field. On a 1900 foot runway with trees ahead, one other slipup and you have a real crisis on your hands. Like to hear from some of you instructors on this point.
Jerry

[kevin]

In my '73 P337, I fly as taught at Recurrent Training Center. I rotate at 80 mph, and put the gear up when I have a good positive rate of climb (which is always above 102 mph blue line). I'd say this happens at about 200', although I've never looked closely at the altimeter.

In case of engine failure, except in the case of a VERY long runway, RTC's procedures (which are Cessna approved) are that if the gear is down, land, even if there is not enough runway ahead. If the gear is in transit, or up, then go. My normal climb speed is 130 mph unless best rate (110) is needed for some reason.

Obviously, this has to be tempered with the reality of how much runway you have left. If my gear is still down, obstacles are very low, and there is almost no runway left, I might go. But according to their training, this is what often kills people. It is better to run off the end of the runway (on the ground) and hit an obstacle at 40 mph than it is to hit in the air at 100.

When and if this eventually happens to me, will have the discipline to pull the throttle back on the good engine and land, knowing that it will be a crash? I hope so. But I hope more that I am not faced with this choice...

As for truly short fields, all this goes out the window. I have RSTOL, and for a truly short field, I rotate at 60 mph and climb at 75 mph, with gear down and flaps at 2/3, until the obstacles are cleared, at which point I start adding airspeed, milk off the flaps to 1/3, raise the gear, and then get rid of the last 1/3 of flaps. An engine failure during the early part of this procedure is very definitely a crash straight ahead event, just like a single, and is part of the risk I take when operating out of short fields (not often).

I sometimes use the RSTOL procedure in moderate length fields (say 3000') if there are lots of obstacles ahead, preferring to get as high as possible as fast as possible, rather than follow the normal procedure and buzz the obstacles at a higher speed. I am not sure this is the right choice. An example of a field where I use this procedure is Nelson BC, if anyone has been there.

I will be interested to hear your comments.

Kevin

[WebMaster]

I read with interest about 2/3 flaps for takeoff. I always use 1/3, and only 1/3, for takeoff. Is it the RSTOL that permits takeoffs with 2/3 flap?
Mine is normally aspirated, so not the same as the turbo models, but POH says 1/3 for all takeoffs. Even at Newmans, 2500 ft grass, I use 1/3.
For GRR, 5000 & 10000 ft paved, I lift nose at 60 (MPH), rotate at 80, level for 100, then gear and flaps up after 500 ft, then engine back to 25 and 25. Climb out at 120.
Is there an advantage to 2/3 flaps? Maybe I have to go read the short/soft field procedures again?
I have to say, I never use 2/3 flaps, because I go from 1/3 to full on final, and from 1/3 to none on take-off.
Thanks for your interesting comments, have to go read some more.

[kevin]

I use 1/3 flaps for normal takeoffs, and 2/3 for landing. 2/3 flaps for takeoff is an RSTOL thing, not applicable to non-RSTOL aircraft.

Kevin

[hewilson]

I recently read through Sky Smith's book on "How to Buy a Used Skymaster." I note that over the production lifespan of our favorite plane that the gross weight generally increased as the single engine rate of climb in FPM declined.

Now, I hate to expose my ignorance yet again but...did Cessna make design modifications in the airframe or control surfaces that resulted in these changes or is it simply a mater of how they were recorded/calculated? In other words, did they just take empirical data regarding weight vs. rate of climb and quote them at different points on the curve each year or did they actually modify the aircraft? The engines seem not to have changed so I am assuming it would have been the airframe.

This is an important distinction to a novice shopper. If the different models are structurally identical and differences in climb performance data are really just a matter of how the aircraft was tested, well then that eliminates a significant variable in the selection process. Among my many interests in the Skymaster is safety in an engine out on take off situation. A greater rate of climb in an engine out situation would be a significant plus in my considerations. But if SE performance is calculation dependent and not model dependent, well then I have many more options.

What say the well informed?

Hugh

[Mark Hislop]

Hugh:

Planes are like people...they get heavier as they get older. As the model line evolved, the aircraft had options and features added. As you noted, the engines stayed the same, except for the addition of turbocharging. More weight with the same horsepower equals less performance.

I was always under the impression that the airframe and controls stayed the same thoughout the model line, except for changes needed for the P models. But I don't know that for a fact.

Mark

[Paul Sharp]

For me, the two critical factors are the gear doors IN TRANSIT and the FEATHERING of the inoperative prop. My '67 has hydraulic pumps on both engines, so it was an option at least then (the buyer had to order it, though).

I had the rear engine quit once on short final. Time I realized what had happened I limped to the end of the runway with the front engine at full power. I started asking some questions and the input I got from all here was that an unfeathered prop would create real drag. I believe it!

It could be easy for us to get complacent about the I-V-F mantra, but due to the critical need feather a dying engine's prop, I've taken to trying to ingrain that into my thinking on all take-offs.

[hewilson]

Paul,

Was there time for you to feather the prop in that incident or did you make the runway before you could feather it?

Hugh

[Ernie Martin]

Sorry, Paul, what's I-V-F?

Ernie

[Mark Hislop]

I-V-F = Identify (the dead engine) Verify (the dead engine) Feather (the dead engine)

[Ernie Martin]

Hadn't heard it referred to by the initials. Always seemed critical to me that the pilot NOT panic and feather the wrong engine. There is time to do it carefully.

Ernie

[Mark Hislop]

Ernie:

Yes, but it is amazing how often the pilot inadvertantly shuts the the one remaining good engine. And of course, with our CLT, the old "dead foot dead engine" routine doesn't work.

Mark