Archived

This topic is now archived and is closed to further replies.

Guest lszh

MD-11 FMS Take Off Page FLEX

Recommended Posts

Hi folksJust reading the manuals and preparing myself for the first flight. One thing I don't understand is the FLEX entry in the FMS Take Off Page:What does this temperature TAT to 70'C indicate? I guess the reduced t/o power depends on the GW, runway length, temperature and altitude. But how do you calculate/evaluate the value?In real, if you've to read this values out of the performance charts, how can we set a reasonable value for a derated thrust t/o?Thanks for helpBrunoLSZH

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Hi GeorgeThanks for the link and comment concerning TAT. But, according manuals, I've to enter a value to the FLEX field. How do I calculate this value? I can't find a notice that the FMS will do this for me...Best regardsBruno

Share this post


Link to post
Share on other sites

George, I'll check that later. No indication in the manual but I'll give it a try.Thanks for helpBrunoLSZH

Share this post


Link to post
Share on other sites

Does the aircraft give us the max FLEX temp with a minimum margin? I would assume like on other aircraft real world crews have laptops onboard with software like TOPCAT.ThanksRob

Share this post


Link to post
Share on other sites

>Does the aircraft give us the max FLEX temp with a minimum>margin? I would assume like on other aircraft real world>crews have laptops onboard with software lYour assumption is correct. To use the Flex Temp field to derate thrust you either need tables or a software containing this information, like Topcat which is precisely what pilots use these days.The FMS is not capable of doing this calculations for you.Regards,Markus

Share this post


Link to post
Share on other sites

Ok thanks Markus, I just need to pray the TOPCAT developer get's hold of the correct documentaion but I have feeling this is very unlikely with this aircraft. Great Job on the new girl!Rob

Share this post


Link to post
Share on other sites

Rob,I say forward your interest to the TOPCAT developer anyway, who knows what he might be able to accomplish if there are enough people showing him interest and support!Markus

Share this post


Link to post
Share on other sites

FWIW,Flex value of 50 C for PW is the most you can flex. In most(85 to 90% of the time) real world line ops flex 50 is more than adequate. this flex value should yield 1.44 EPR to T/O.hope that helps a littleT. ReynoldsWorld MD11

Share this post


Link to post
Share on other sites

Hi GeorgeThanks again for help. I just completed the tutorial flight last night, entering the FLEX manually.I'll play with the FLEX settings later this week. I'll keep you informed.Best regardsBrunoPS: Save first manual landing at LSZH!

Share this post


Link to post
Share on other sites

Hi Markus, Hi GeorgeMarkus got the point. You'll need performance charts or a tool to evaluate the FLEX ==> derated t/o thrust for a certain situation.This is the only possibility to avoid overshooting the runway or climbing like a rocket...Airlines have different company procedures and my hometown airline has always used Flap 22 for t/o with corresponding derated thrust settings. So, I've to see if I can organize original MD11 performance charts :-shy The other possibility will be to wait until Topcat has done the job for us.Thanks for help!Best regardsBruno

Share this post


Link to post
Share on other sites

Hi guys:Thought i would bump this topic up as i am awaiting a response from the Topcat guys. Given the discussion that i had with Robert regarding the Perf Data that (so far) Boeing are unwilling to release, it seems that the TopCat guys are going to have a bit of a mission on their hands to get this going.as so many PMDG users wish to have access to topcat, and ideally for Topcat to suggest an optimised Dial-A-Flap setting, perhaps that this is something the two companies, PMDG and Topcat, could consider a collaboration on. I appreciate that the Boeing data is sensitive, if somewhat redundant unless they are planning on building more MD-11's, however as PMDG were permitted to use the data for creation of the aircraft, it could be argued that in order to create a more 'complete' product, that the TopCat team should be permitted to utilise the data within TC. Certainly, some sort of NDA would have to be signed i should imagine, but surely it is not out of the realms of possibility?Just my $0.02CheersPaul

Share this post


Link to post
Share on other sites

Hi Guys:Me again ;)Had a response from Christian at TopCat, seems that he has been in contact with Robert, and so far, there is not a lot that PMDG can do due to their NDA with Boeing.Looks like i am going to have to start doing some test flying then.CheersPaul

Share this post


Link to post
Share on other sites

Hi guysThe only thing that helps right now are performance charts.My home town airline used standard flap 22 and FLEX up to 50.Is there any airline (maybe cargo airline) that really uses optimized dial-a-flap settings in daily operation???Best regardsBruno

Share this post


Link to post
Share on other sites