Spirit MD80 T/O @ FLL: How "normal" was that?

[TonyC]

I sometimes "bump" the numbers, or just go MAX on the shorter runways. Anyone else do the same?

Food for thought:

I forget the exact number; I'm sure someone will chime in with some help. Something on the order of 96% of all jet engine failures during takeoff are at MAX power vs. reduced power.

Electing MAX power on the "shorter" runway actually increases your odds that you'll get to REJECT on that shorter runway.

 

[Sunnfun]

ASAP is an Aviation Safety Action Program. It's the Part 121 equivalent of the NASA form, for those airlines that have the program approved with the FAA.



Flex is one name for reduced power during takeoff. By using an "assumed temperature" that is higher than ambient, you can find a power setting that will let you just barely make your climb profile, instead of making it with lots of altitude to spare. It saves wear and tear on the engines, and the remaining power is always available if you do lose an engine, or if you are taking off behind a heavy.

Thanks, great explanation!

Just one more question, if you use reduced power for a takeoff, at what point would you go FULL power? Is there a provision at all to do that? I'm just speculating but if the Spirit guys noticed during the take/off roll, that they might be a little light on the power would you just add power or go with what was supposed to work according to your computed t/o data?

Cheers,
Sun'n Fun

 

[chperplt]

Just one more question, if you use reduced power for a takeoff, at what point would you go FULL power?

You wouldn't go to full power unless you had a situation requiring it.. If you were on the take-off roll and felt as if you needed more power, you would use more power.

At my company, we stay at flex power until 10,000 feet, when we switch to climb power.

 

[EagleRJ]

You could add power at any time. If you have an engine failure, windshear, vehicle on the runway in front of you, etc, just push it up. For most FADEC-controlled engines, that means just pushing the thrust levers all the way forward and the computer will give you everything (and most planes will do it automatically in the case of an engine failure).

With older jet engines and most turboprops, you still need to manually set maximum power by looking at the gauges. If the FLEX/reduced power setting is lower than it should be, it could have been caused by a mistake in reading the charts, or it could be erroneous engine data (like Air Florida #90 at DCA). The remedy is just to push the levers up to the maximum setting. One nice thing about the older engines (which can also get you in trouble) is that you can spool the engine up to more than 100% of rated power. In an extreme emergency, you can get 110% or more for a short time. You'll destroy the engine, since the internal temperatures will soar above the limits, and you can get other problems like case rub, but the power is there if you really need it.

 

[Jeff Helgeson]

MAX power and engine failure

Food for thought:

I forget the exact number; I'm sure someone will chime in with some help. Something on the order of 96% of all jet engine failures during takeoff are at MAX power vs. reduced power.

Electing MAX power on the "shorter" runway actually increases your odds that you'll get to REJECT on that shorter runway.

At TWA, they check pilots always told us there had never been an engine failure at the company while using reduced power for T/O. They would encouarage the line pilots to use reduced power (or T/O FLEX for the MD80) even if it were reduced only by 1 degree (temp. setting) or ruduced by .01 EPR for the DC9.

I was never sure if that were true or just a way of getting us to follow company procedure. However, I believe TONY C is correct about the stats. of engine failures on T/O occuring with MAX power.

Jeff

 

[flx757]

The captains that rotate to 15 degrees in 2 or 3 seconds get me puckering a little. I guess its just a pet peeve of mine.

No problem, my friend. 15 degrees in 2 or 3 seconds would have me doing a little more than puckering, I think....