How to cruise with no auto-throttle

I

I_moved

New Member
Hello, another question relating the jet aircraft which do not have A/T (auto-throttle). I know the mach cruize speed for the CRJ is .74 mach but with out the auto throttles what do you usually cruise at, I seen a video of some Swedish airline and the ERJ the pilot was in was doing something like .79 mach which was way over the recommended cruise speed. So does the pilot have to be as close to it as he can or is it at his discretion?

Thanks
 
We usually just set the N1 about 1-2% below the fadec computed cruise calculation which usually gives about M.80. If you match up the max cruise calculation you can usually get M.82-.83. Then of course you get the:
"United...say Mach"
"point 74"
"roger, everyone else slow down" or something like that
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"It depends".

Sometimes you're flight planned at various mach numbers because of things like economy and schedule.

In the MD-88, we might cruise at .79 when we're behind schedule, or might cruise as slow at .73 for economy. There really isn't a 'recommended' cruise speed for any aircraft.

Also, ATC may request you fly a faster or slower mach number in order to mnaintain traffic separation.

Authrottles have absolutely nothing to do with cruise speed.
 
At ExpressJet our release has our cruise speed on it, so all the calculations dispatch did prior to the flight (fuel burns, arrival time, etc) are based upon this speed.

On our older non-wingleted aircraft it's .77 (*i think), on the newer -XR is a bit more .78-.79. Usually though if it's smooth air we're going ludicrous speed (as fast as possible).

I use whatever power I need to keep it there, usually it's less than the what the FADEC calculates as cruise thrust, so that means coming out of the detents.
 
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We usually just set the N1 about 1-2% below the fadec computed cruise calculation which usually gives about M.80.

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And N1is? Sorry I'm still stuck on props haven't moved my mind set up to jets just yet!

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-matthew
 
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We still need your security info young man!
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Are you serious....I hope not....



I believe N1 has todo something with the inner engine rotation or something along that line, I believe N2 is the larger fan on the outside or vice versa
 
I have really enjoyed your post here thus far there very informative!
I'm 28 soon to be 29 this July and already have my PPL and will be completing all my rating next summer. So I'm farther along then you.
But it sounds like you know more then me (you and that 13 yr. old someone mentioned).
The mere fact that your asking these question ,hell that you even know to ask these question puts you ahead of most.
Something my mom always used to to tell me. "Asking questions is the true sign of intelligence."
However don't let your youth pass you by. It's good that you know alot of stuff about airplanes.
But don't forget how to act like a 16 yr. old. Go out and kiss a girl, get a girlfriend or feel free to possibly consider taking the other option
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Just enjoy your youth while you have it.
So keep asking those question and never ever get enough of learning....lastly glad that we didn't scare ya off!

-Matthew
 
Almost Allentown....N1 is the speed of the fan blades you see at the intake. N2 is the speed of the compressor section inside.
 
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[ QUOTE ]
Go out and kiss a girl, get a girlfriend or possibly take the other option
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.

[/ QUOTE ]

grin.gif
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Hey it's 2005 I don't want to limit peoples options!

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-Matthew
 
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
Go out and kiss a girl, get a girlfriend or possibly take the other option
cwm27.gif
.

[/ QUOTE ]

grin.gif
grin.gif
grin.gif


[/ QUOTE ]

Hey it's 2005 I don't want to limit peoples options!

grin.gif




[/ QUOTE ]

Nothing wrong with that!!
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"It depends".

Sometimes you're flight planned at various mach numbers because of things like economy and schedule.

In the MD-88, we might cruise at .79 when we're behind schedule, or might cruise as slow at .73 for economy. There really isn't a 'recommended' cruise speed for any aircraft.

Also, ATC may request you fly a faster or slower mach number in order to mnaintain traffic separation.

Authrottles have absolutely nothing to do with cruise speed.

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Same for the CRJ. We usually cruise at.74. But if we are behind schedule or if the captain is below guarantee that month wants some premium the jet can do .8 or so.
 
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N1 is the speed of the fan blades you see at the intake. N2 is the speed of the compressor section inside.

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Is it the blades or the drive shaft? I've heard both, so maybe it depends on the a/c.
 
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N1 is the speed of the fan blades you see at the intake. N2 is the speed of the compressor section inside.

[/ QUOTE ]

Is it the blades or the drive shaft? I've heard both, so maybe it depends on the a/c.

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The blades MUST be rotating at the same speed of the shaft that drives them, or something is gonna snap!
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We still need your security info young man!
Smilecrunch.gif


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Are you serious....I hope not....



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Make sure you include your credit card info . . .
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That's easy, just tell the engineer to set cruise power! He's got to figure it out, might as well have him set it
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Ok, i'll crawl back into my ancient jet and hide......
 
We normally cruise around .83-.84. We can easily do .85, but we are normally following an 80 into ORD and have to slow down. Of course we never exceed .83 in RVSM though.
 
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