as you can see it requires a temperature, under SEL, but where do i get the information, is it just the current temperature outside?thanks.http://forums.avsim.net/user_files/189498.jpg

Hi Clayton,The current temperature is already there, under OAT. The SEL is for a selected, or assumed temperature. For more on the assumed temperature, see here: http://ops.precisionmanuals.com/wiki/Assum...take-off_chartsRegards,Tim

ok so where do i find the chart they are talking about?thanks

You can't find charts like those in the example easily; they are generally prepared by the airline/company for each airport. However, with some study and thought, you can use the data that PMDG has given in the pdf files that came with the plane - specifically the 01_takeoff_data_747_400 file, or for the 737's the 01_takeoff_performance_73702... file.DJ

ok thats i will delve deeper.

Clayton,TOPCAT is a takeoff performance calculation tool which can provide the temp for you. See http://topcat.ofplan.netGreat program and works well with the PMDG 747.Subin.

ok thanks for this will check it out!

Yep "derated takoff" is the common term for what the SEL field lets you do. It saves wear and tear on the engines.

so do i need to fill in the SEL field if i do not want a de-rated takeoff?

If you don't want a de-rated takeoff, you leave the SEL field blank.Regards,Tim

I would urge you use TOPCAT- it is available as freeware, but I would also urge you support Christian by purchasing- it is a superb piece of software.Ryan is correct in that derates do save wear and tear on the engines- and the resulting costly hot sections and overhauls; however, more importantly they allow for proper time frames during T/O acceleration, and the resulting ability for the pilot to properly monitor performance and initiate an RTO if needed.A lightly loaded 744, at full T/O thrust accelerates as though shot out of a catapult. The pilot is simply UNABLE to keep up with the required monitoring and decision making and gets "behind" the airplane- never a good thing!Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Creative X-Fi Fatal1ty | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

>If you don't want a de-rated takeoff, you leave the SEL field>blank.>>Regards,>>TimWell, I normally fly very short hops with the 744 and I only load 30 Tons of fuel (I am quite light as you see).So I usually select directly TO-2 and CLB-2 but I have never filled the "SEL" prompt (I didn't know what was used for), but even without entering any value there I can read TO-2 in the Eicas and a very low target TakeOff N1.Am I doing anything wrong?.

Go for Topcat mate. You can use those charts at those specific areas but they won't be much use to you at other fields. They are good fun to use at those fields though. If you should use them, I have a takeoff data sheet I created in Excel you could use if you like, based on the virgin one.

Jose,the problem with TO-2 is you will just derate thrust without any calculation base for runway length, in other words using TO-2 you don't really know if the lower thrust is still suitable for your departure runway.Best regards,Markus

Thanks Markus, I think I've caught it now.I have downloaded TopCat and will give it a try.