May it be safer to use less power on takeoff?

Bradley W

Bradley W

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American459
Max power is damaging to the engine with readings of well over 100 N1.
Look at the American in Chicago
 
In winter in Alaska I would use 25 squared in the 207 for take off.

Density altitude in the minus 4000 range.
 
Well, if I️ don’t hit 88 mph, it’s a waste. The flux capacitor never kicks in. The AOA indicator reads zero.


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GlennAB1 said:
Those engines could produce lot more thrust, so technically, they never use max power.
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In addition to using "max" power vs the flex power setting, we also have a "thrust bump" button on the throttles. In theory it's suppose to give roughly 7% more power I believe??
Truth be told I've never used it. We let the FMGC figure it all out and it lets us know what we need.

Edited to add: it's an A321
 
Zeldman said:
In winter in Alaska I would use 25 squared in the 207 for take off.

Density altitude in the minus 4000 range.
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The mighty sled!

If I have a good amount of room (for a skywagon) I'll still go full power, but leave the prop back a fingers width
 
They have very specific operating parameters, stay within those parameters and you can run them as hard as warranted.
 
I dont know, I just put the thrust levers in the takeoff detent and say "set thrust". As someone mentioned above, we rarely use "max" thrust unless theres windshear or thunderstorms or the ACARS says to do so
 
Having been the "second set of eyes" on numerous engine type, high power adjustment/test, trim runs, I can assure you the engines can produce more than indicated.
The manufacturer determines what is an acceptable tradeoff for max power vs. reliability.
 
GlennAB1 said:
Having been the "second set of eyes" on numerous engine type, high power adjustment/test, trim runs, I can assure you the engines can produce more than indicated.
The manufacturer determines what is an acceptable tradeoff for max power vs. reliability.
Click to expand...

And I believe I was there with you for a few.
 
Bradley W said:
Max power is damaging to the engine with readings of well over 100 N1.
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100% indicated is based upon factors such as barometric pressure and temperature, its a reference, it is not uncommon for a reading above 100% to be required to achieve take off power. Engine exceedance is another thing. Reaching 105% when 100% is the takeoff setting for conditions could be bad.
 
I've never flown anything that had enough power where you'd use less than wide open throttle. All my PIC time is behind an 0-235 or 0-320.
 
Don't know about jets but lots of turbine helos have protection systems in place. In an overspeed, the engine will automatically reduce fuel to a specified lower setting. If temperatures hit a predetermined level, fuel flow will once again be reduced. Torque is generally our enemy and I don't know of any helo that protects for it.

Also, I think jets are similar in that 100 % really isn't 100 % of what the engine is capable of. It's generally max continuous but the are many that have max continuous above that and many that have transients above it. Even when you accidentally overspeed and engine and hit 117 % Np and ground the aircraft, some geeky mech with a "secret" engine manual comes back and says "nah, my book says as long as you were below 120 % for no more than 10 seconds, you're good." :confused:

So yeah, you're never really using max power during normal conditions and the engine is designed to operate within the limits of the flight manual.
 
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Crashing because you weren't at full power is pretty damaging to the engine too, not to mention the occupants. That's just dumb.
 
WOT, but I give the prop control a 1/4-1/2 turn so not at max RPM, makes it quieter for neighbors, unless I need max performance.
 
Bradley W said:
Max power is damaging to the engine with readings of well over 100 N1.
Look at the American in Chicago
Click to expand...
Idle is also damaging to the engine, as well as every other power setting. Even car engines wear out from damage built up during use. Better to not run an engine at all.
 
In all honesty in a light airplane just go full power unless you truly know how to do a reduced takeoff. That would require setting the power at a setting for a higher temperature value on the charts that still meet runway and obstacle clearance requirements.

Too much work / risk without reward for a light airplane. That's why the manufacturer doesn't publish it.
 
Always used reduced for takeoffs except certain conditions. FADEC controls it, constantly adjusting thrust during takeoff roll.
 
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I use 124% original power on takeoff (from original configuration). Could use a little more.
 
We use “max” power for every takeoff. We can change the max by assuming or flexing to a higher takeoff temperature but in essence the takeoff is max for those conditions. For those who are itching to argue that it isn’t a balls full out max, you’re correct...but we have FADEC that controls temps and pressure.

Now! The one thing I haven’t read in any of these posts about using less than full power is cooling. Pull the power back to a lesser power (please show the data as to the power required) you are pulling the throttle and the carburetor below the power enrichment valve range which now puts you into a leaner mixture and squarely into higher heat and pressures. Injected? Same thing.

WOT LOP SOP
 
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