Opinion wanted from real pilots...

[BrzI]

Hi,

I set up a flight from LYBE to LIRF. Cruise level is at 30000ft. There is a lot of turbulenceup to FL250.
I programmed the FMC for straight climb to 30000ft. What I notice is that around 25000ft. the air speed drops to under 200KIAS. I suspect that it would eventually stall and not be able to reach the desired flight level. If I have an intermediate altitude at 22000 where I let the bird build up some speed then the climb to 30000 ft is not a problem.

My question to people with the relevant experience is this:

Is this behaviour normal ? Was the 737 just too heavy to continue climbing at such altitudes at such low speeds ?

Enclosed is the flight plan and the flight. I used it to have generic ATC and imported it into the FMC. Also enclosed is my aircraft.cfg file. For those that have Lago's Scenery Enhancer you can find the files for LYBE and LIRF. You will be cleared for takeoff from RWY30 at LYBE.

http://members.home.net/givaz/LIRF.zip

http://members.home.net/givaz/LIRF.jpg

Thanks folks

[jase439]

Sounds like you're using TRUE airspeed instead of INDICATED. This is the most common reason for high altitude stalls.

[BrzI]

Nope..using IAS..

[margeorg]

Hi Goran!


looks like you experienced the "Cold Climate" bug that was found recently. Are I´m right that you had extremely low outside temperatures? A fix is currently tested by the beta team.

Another hint: Flying at FL300 (there isn´t an altitude 30000ft, only flight levels. You will have to set your altimeter to standard pressure) is not correct. At the moment separation above FL290 is 2000ft so you would have to choose FL310 or FL350 for westbound and FL290, FL330 or FL370 for eastbound Flights.

A procedure called RVSM (Reduced Vertical Separation Minima) will be put into trial service on january 24th, 2002 in Europe. It will allow for 1000ft separation above FL290.


Yours,
Martin Georg/EDDF

[OS737]

Or did you use (at least once) Load Master? There seems to be a problem with International Settings and/or Windows XP that produces exactely the problem you mentioned!

Walter

[BrzI]

Actually, the outside temperatures were not extremely low. Takeoff temperature is 14C and temperature at FL300 (Ok it is wrong..I know) is -10C.

But thanks for the flight level tips. You never know where you will learn something new.

If you have the time try to fly it and tell me what you think.

Thanks

[BrzI]

I definitely used Load Master. I do it all the time. But I don't use XP and I don't think it is a measurements problem.

Thanks anyways. I appreciate it.

[OS737]

I don´t know if the "Load Master" - problem has really anything to do with Windows XP. Nevertheless the problem I have sounds exactely like yours but I only experienced the problem AFTER I used Load Master for the first time. When I uninstalled the DF737 and then reinstalled it the problem was gone...until I used Load Master again. If you make a copy of the aircraft.cfg BEFORE you use Load Master you can try if the "original aircraft.cfg" solves your problem.

cf.:
http://www.flightsim.com/dcforum/DCForumID3/3918.html
http://www.flightsim.com/dcforum/DCForumID3/3746.html

Walter