Commercial aircraft climbing speed

[earthgoodboy]

Hi all,

I am wondering which speed is used for the commercial aircraft to climb after take-off. I have heard that aircraft climbs at constant airspeed until reaching a certain mach number and then continuing with constant mach. Is that the most common procedure for jet aircraft? and what kind of airspeed is it? is it EAS or TAS? Finally, since the engine performance varies with altitude, how can the pilot maintain constant speed while climbing without having to keep adjust the thrust setting? I also know that there is a certain thrust setting for climbing for climb, if so, how can it related to airspeed?

thanks you

 

[dgapilot]

14 CFR 91.117 will get you up to 10,000 ft.

 

[rb1957]

it's EAS. climb speed will vary with each plane and throttle setting will depend on a/c load (and atmospheric conditions)

there's a thing called an auto-pilot and an auto-throttle, so the pilot tells the computer what to do, then "just" watches ...

whilst ideally the plane is flying with constant speed, i suspect that it's really being flown with a reasonably constant vertical speed (rate of climb). but remmebr most airports have a low noise take-off climb ... you know, there's a point in the climb when they throttle back, nose down (reducing the climb, not descending) and the plane feels like it's hanging there (personally, really horrible), then about a minute later it's "game on" again.

these are odd questions for a professional engineer to ask ?? maybe a student post ??

Quando Omni Flunkus Moritati

 

[IRstuff]

You just described Santa Ana Muni Airport to a tee; wouldn't want the folks living in Newport Beach to suffer a bit of airplane noise from an airport that predates their houses being built, after all. First time that happened, I was almost expecting to be in Newport Bay in a few seconds...

TTFN
faq731-376

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[berkshire]

IR Stuff, come down the coast 30 miles to Oceanside. You have to take off to the west, noise abatement proceedures are in effect. you cannot make turns until you are over the ocean because you have a Monastery to the north and a real estate development to the south. If you ever lose an engine god help you.
B.E.

 

[rb1957]

at least god (or at least one of them ?) is nearby (at the monastery)

Quando Omni Flunkus Moritati

 

[GregLocock]

Here's an account by a RL pilot

" Phase one of the climb we pitch for best single engine rate of climb which produces an impressive initial rate of climb. Above a safe altitude, we pitch over to 250 knots indicated. Still a huge rate of climb but not like safe single engine. An engine failure or any loss of directional control initially is an emergency and all the checks are memory items. Now, at 250 KIAS, an engine failure is an issue, but one we'll deal with in less haste.

Above 10,000 MSL, we'll pitch over to cruise climb. That speed varies somewhat with weight. It's a compromise between moving quickly over the ground and getting to an efficient cruising alititude. Now with RVSM (more accurate altimetry) we can use 1000' separation all the way up to our maximum operating altitude. That opens twice as many flight levels to us from before RVSM. That's important in the US. The rest of the world is just not busy enough to care. Climb for the short flight from IND to Cleveland is quick. We'll only go to FL 310. Any higher and we use too much fuel in climb. Any lower and we consume way too much fuel in cruise. Our accountants and engineers determined that cruising at Mach .82 is the most efficient speed. So, that's where we'll cruise for this and every other flight in the system. Woe unto the pilot who has to explain going fast to the Chief Pilot. We could push the throttles up and hit Mach .86. Nice to be able to do that, but you better be planning your retirement if you do. "



Cheers

Greg Locock


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