747-400 Overspeed????

[stevewilson]

What is the normal crusing speed of the 747 and 737 series aircraft?

I've only just start to fly these big boys and I'm always getting the overspeed warning sign and clicking. The thing is I'm crusing at about 370 knots. It seems to me that, that is slow for these guys.

If it is slow is there a way to change the overspeed setting so the warning doesn't come on so quickly?

Thanks.

[BiggBaddWolf]

I usually set my IAS to around 330-340 and it usually wont come on  :o
I have heard there is no way to disable the overspeed thing, but there may be, maybe someone else knows how

[Pc-Shark]

I think it is around 500 kts

[Nexus]

For the 747-400 Mach 0.85 will do just fine.
737-400: Mach 0.74 - 0.75

Don't use KIAS over 27.000-29.000ft (depending on mach crossover altitude)

[Billerator]

Yeah, you will find that your mach number gives you the correct speed at higher altitudes, so ignore the KIAS .

[stevewilson]

Thanks all for the info. Will give them a try tonight.

[Capt. Farhan]

very simple
           always see the ground speed, i think in 737 it is 477kts , 276 kias.the more higher the altitude the more the speed. in 737 attain FL360 and in  747 attain FL400.
every thing will go fine,and keep N1 at 76 . . if overspeed alarm  sounds reduce the N1 slightly  ;)

[Nexus]

The effect of wind at a given altitude is to change the groundspeed.

Tailwind= Higher groundspeed
Headwind = lower groundspeed

All this while your mach indicator will show the same.

You can cruise at M .78 and have a GS of everything from 410 to 460.

Always set your cruise speed in MACH, nothing else.  :)

[IanK]

Hi Steve,
get the manual from:

Aircraft Performance Data
http://perso.wanadoo.fr/hsors/FS_Soft/acftdata.html

Ian

[hiflyphil]

Hi

Just to add my 2 cents...

You should be cruising between 35-38,000 feet and set the mach to 0.85.  This should give you a ground speed around 520 knots, not bad for an ocean liner in the air.

Your air speed will only read aroud the 330 knot mark though, why is this? because air density at high altitudes is less than an sea level, so your instruments tell porkies.  Being in these les dense air streams also means your aircraft can cut through the air more easily, but your engines efficiency starts to suffer.

So experiment and try to find the "sweet spot"  ;D

Regards


Phil

[stevewilson]

I sure am glad that no one can see me as I am taking this big bird up Trying to find that "sweet spot", I've over ran the runway, drag the tail, shot up to fast and stalled. It really saves a buck or two to have new pilots train on a sim .

All kidding aside, I well look at the manual and apply what I have learned here and practice practice....

Thanks to all for the info.