TOPCAT Working on MD-11 FLEX/assumed temp!

[PinkPony 171]

Finally guys!TOPCATSIM has confirmed the work on the MD-11 Takeoff and landing performance data. If you check out www.topcatsim.com you will see that the MD-11 is listed as "work in progress" :DNo more guessing the FLEX temps. and hoping for sufficent runway on T/O :( Leo :(

[aentwis 61]

Interesting news...As regards runway lengths on takeoff, I have noticed a real difference between V1 and Vr/V2 on shorter runways, so I assume that the logic calculates for the runway length entered (when you select the takeoff runway to be used)...I will do a test with time... EDDV has two parallel runways, totally different lengths though... Using the same conditions for both runways, I will see what V1, Vr, and V2 are calculated... I would assume the same Vr and V2, but different V1 values...Let's see...Andrew

[CapP 0]

TOPCATSIM has confirmed the work on the MD-11 Takeoff and landing performance data.

Finally! No more take-offs like this one... :(

[aentwis 61]

If in doubt, don't use FLEX... what was your V1 then?You can use the whole length of the runway to take off, but obviously, if your V1 was such that you would never have been able to stop in the remaining runway available, you have done something wrong...Andrew

[CapP 0]

You can use the whole length of the runway to take off, but obviously, if your V1 was such that you would never have been able to stop in the remaining runway available, you have done something wrong...

Indeed, I obviously did something totally wrong. I guessed the flex-temperature but it turned out to be a bit high...

[aentwis 61]

Yes...You shouldn't have guessed the flex temperature on a shorter runway... if in doubt, don't use FLEX...Which 32R is that, and how long is the runway?By the way, I am not arguing that you don't need tables or some calculation tool... I am just saying that you can still simulate safe operations without them, just requires a little more preparation work... :)Andrew

[mikkel 9]

It's not _that_ hard to find a flex chart, and takeoff/landing data for the md-11 :) hints and links has been posted on this forum several times...

[aentwis 61]

The real issue is that such calculations in the real world are often runway specific, so you would need a set of charts for each runway the aircraft flies off and onto...Of course, there are tables and calculations for generic runways... and some of these charts have been posted, albeit most likely in breach of copyright, on various sites...With runway limited operations, I tend to be a little careful with operating weight, and any runway shorter than around 2200m, I wouldn't use assumed temperatures, not unless I were almost empty...Andrew

[CapP 0]

You shouldn't have guessed the flex temperature on a shorter runway... if in doubt, don't use FLEX...Which 32R is that, and how long is the runway?By the way, I am not arguing that you don't need tables or some calculation tool... I am just saying that you can still simulate safe operations without them, just requires a little more preparation work... :)

I totally agree with you this was a terrible mistake. The screenshot is from one of my first MD-11 flights and more or less meant as a joke. Anyway: I now know it is even prohibited to use flextemp in these weatherconditions, also I was fully loaded for a flight from EDDK to VHHH (107 tons of fuel). Runway was quite long (12516ft) but with this GW it doesn't matter.

[trisager 2]

Not new, but just in case you haven't seen it before:

Tom

[CapP 0]

Not new, but just in case you haven't seen it before:

Russian roulette :(