how fast is fast?

Buckeye757

Buckeye757

Well-Known Member
A few days ago I was on a flight from ATL to PHL on a 757 when the capt. came over the PA and said we were criusing at 585 mph (he had to dumb it down for us). I've been flying for years now and for some reason when he said 585, that just didn't sound too right. Is this a normal cruising speed for a 757?
 
He most likely gave you the ground speed. Although that is a pretty good speed considering you were going west bound. Somebody who flies the 757 (Don?) could give you the exact mach number that they normally cruise at but I am betting it is between .75 and .8. You would then have to look at what altitude you were cruising at and translate that into a airspeed. That said, I have seen low 500 ground speeds before in the CRJ going east bound and we cruise at .74 mach so it is very much possible that the number is correct.
 
Normal econ cruise on the 757 is .79-.80 mach. At typical altitudes, about 460-480 KTAS, so with a little tail wind, 510 or so knots groundspeed is very possible. ( I saw 610 the other day LAX-ATL)
 
BobDDuck said:
I have seen low 500 ground speeds before in the CRJ
Click to expand...

My buddy sent me a camera phone picture of 6-0-0 knots GS taken off the MFD in level flight. That's hauling butt for a -200 :)!

~wheelsup
 
Yeah, that's what i was thinking Doug . As soon as I heard that I thought to myself "that's awefully close to the sound barrier."
 
TAS would have to be close to mach, not the ground speed. If you are traveling .8 mach, the tail wind can be 200 knots and ground speed can be 700 (KTAS + tailwind), you are still only doing .8 mach
 
wheelsup said:
My buddy sent me a camera phone picture of 6-0-0 knots GS taken off the MFD in level flight. That's hauling butt for a -200 :)!

~wheelsup
Click to expand...

What? He had his cell phone on in flight? Shame on him.

True story... I'm normally pretty good about turning my phone off, but for what ever reason I forgot to the other day. We are heading from SDF to Washington and lucky us we have a Fed in the jump seat. Well, everything is going as well as could be expected (he dinged me for not setting the standby altimeter to 29.92 above 18,000) when all of the sudden as we are decending into DC, my cell phone goes off. Oops! Of course the irony is that it was crew scheduling, and about 30 seconds after I didn't answer it we got an ACARS message for me to call them.


600 is pretty good. I think I saw 585 once heading east bound. That and it was the captain's last leg and he was trying to make a flight home. Barber Pole anyone?
 
Buckeye757 said:
Yeah, that's what i was thinking Doug . As soon as I heard that I thought to myself "that's awefully close to the sound barrier."
Click to expand...


In the upper FL's TAS for .78 mach is about 475kts. I think the speed of sound at ISA temp is around 600 kts. So use TAS...not groundspeed. Still a good margin under it.
 
mtsu_av8er said:
Most camera phones have an "Airplane Mode", that allows everything to work except for the telephone!!;)

:)
Click to expand...

True, and my company's policy is that they need to be turned off even if they have an airplane mode. No reason for it... just the policy they have.
 
BobDDuck said:
True, and my company's policy is that they need to be turned off even if they have an airplane mode. No reason for it... just the policy they have.
Click to expand...

Wow - really? That's called silly where I come from!!

I haven't encountered that silliness yet - just a matter of time, I'm sure!
 
jonnyb said:
Just wait 'till NJA_CAPT gets ahold of this thread. Here we go.....

:D
Click to expand...

Yea he is a huge braggard isn't he! My jet is faster then yours both in a climb and at cruise. It can fly in the upper flight levels while your puking around at FL350.

Sound bout right?

:D

-Matthew
 
Maximillian_Jenius said:
Yea he is a huge braggard isn't he! My jet is faster then yours both in a climb and at cruise. It can fly in the upper flight levels while your puking around at FL350.

Sound bout right?

:D

-Matthew
Click to expand...

Reminds me of that story where a 152 asks ATC for a groundspeed check. "90 knots" says ATC. Then a baron checks in, asking for a GS check. Followed by an airliner of some sort. After that, a USAF Fighter asks for a GS check, besting everyone.

A few seconds later an SR-71 asks ATC for a GS check. "1850 knots" (or something like that) says ATC. There weren't any more GS requests :).
 
I don't know what's so exciting about an airplane that can get to FL510. It's how LOW you can go that makes you a real pilot. :D
 
You must log in or register to reply here.
Back
Top