Max continous thrust

[Black_Dawn]

This is for MD80 drivers: your point of view!

usually, after the take-off phase, we select the Climb thrust setting.

Would you, in normal operations, select the Max continous thrust setting (MCT on the TRP),let's say for about 4 to 5 minutes, to have a better climb performance? (eg. ATC requested you to be levelled at XXXFL in XX nm).

Thanks
B_D

[alatriste]

Not bad, but I guess you wiil not gain much as you climb while stressing engines.
And by the way, I would like to Know " how could be MCT less than CL above FL 330?"
JT8D-219, 217 Engines.
It doesn´t make sense at all, this discrepancy is only sensible on analogic TRI ( Electromecanic engine panel). Tipical EPR LIM for MCT is 2.02 and for CL 2.05 ?
MCT is always higher than CL but as you climb diference is reduced until you reach aprox FL 330 (make sense), above this FL MCT is lower than CL and the spread is greater till you reach max. certifies ceiling FL 370.
REGARDS

[Black_Dawn]

Hi Alatriste

you are right about the decay of MCT reaching high levels.

What about using MCT between 150FL and 250FL.
Would you use it?

I don't mean a use of MCT as a standard proc, but in those really rare occasion when ATC urges you to climb!

best

B_D

[alatriste]

Yes I would use it, in very special ocasions, but sincerely I guess it will not make a big difference.
It would be better to climb at max angle or max. rate depending on their request.
In most of the cases ATC ask for an expedite climb, above FL 100, I do´nt change my climb speed.

[PAXboy]

Outsider's dumb question coming up!!
I don't change my climb speed. If you do need to get higher more quickly, do you simply increase the angle of attack?

[Black_Dawn]

Paxboy

what i really do, when ATC wants me up quickly, is:

Let's say I'm climbing at 320 KIAS (indicated airspeed) at climb thrust, receiving the ATC request, I select 270 KIAS on the autopilot, maintaining the thrust as it is, the only way for the aircraft to catch up the 270 KIAS is to change the AOA(Angle Of Attack) and consequently the attitude (the airplane will point the nose more up); this way I obtain a very good rate of climb (in the order of 3500 to 4000 feet/minute: it depends on the aircraft's weight), will not last long (a bit longer if i use MCT) . When the energy has dissipated, the rate of climb will settle down at say 1500 feet/minute and 270KIAS, but ATC has seen its altitude readout spinning really fast!

We cannot always satisfy ATC; sometimes they want performance the aircraft can't make; we tell them: so they give us altitude restriction or heading to steer to momentarily.


hope this can help

best
B_D