In Thomas Metzingers excellent 737NG tutorial it says that after entering the gross weight and flaps etc. info, pressing the lsk 1,2 and 3 keys will populate the V1 VR and V2 speeds with the FMC calculated speeds. That is not working for me, I have to do my own calculating and entry. Am I missing something ? Jerry Sterner

In Thomas Metzingers excellent 737NG tutorial it says that after entering the gross weight and flaps etc. info, pressing the lsk 1,2 and 3 keys will populate the V1 VR and V2 speeds with the FMC calculated speeds. That is not working for me, I have to do my own calculating and entry. Am I missing something ? Jerry Sterner

Jerry, have you selected a runway for takeoff ?. If not, the speeds calculation is not possible.

Jerry, have you selected a runway for takeoff ?. If not, the speeds calculation is not possible.

Hi,Sorry but I disagree (see link with previous post - on the very same topic - below)http://forums1.avsim.net/index.php?showtop...t&p=1747227Bruno

Hi Bruno,It seems really strange that anyone (being electronic or human) could reasonably calculate at least V1 without knowing the length of the runway.Well, the fact is that I haven't flown my 737 in the last weeks, but I will take it out of the hangar tonight for a quick speed-calculation test.

Hi Bruno,It seems really strange that anyone (being electronic or human) could reasonably calculate at least V1 without knowing the length of the runway.Well, the fact is that I haven't flown my 737 in the last weeks, but I will take it out of the hangar tonight for a quick speed-calculation test.

Don't you mean the other way around: "at least V2 and Vr"? V1 is dependent on length of rwy - if rwy is infinitely long, you can abort whenever you like.Phil

Hi Bruno,It seems really strange that anyone (being electronic or human) could reasonably calculate at least V1 without knowing the length of the runway.Well, the fact is that I haven't flown my 737 in the last weeks, but I will take it out of the hangar tonight for a quick speed-calculation test.

Hi Jos

I am just stating that, in PMDG's sim, you don't need to select the runway to have the sim automatically fill-in the V fields in the FMC.Bruno

Just tested it myself...and you are right Bruno.

Having said that, most A/C manufacturers publish V speed charts as a function of weight, not runway lenght, probably (and this is only a guess on my part) since they assume a specific plane (737 in this case) would not be operated from a runway that doesn't meet minimum lenght requirements.Once again, it would help if a rw pilot or dispatcher (or indeed any person knowledgeable on this topic) could step in and help us. :(

I believe slope is the only runway specific factor. I did some double checking, and it seems a confusing subject if the other boards are any indication.I've worked for 2 operators on the 737. One company, it was easy: punch the numbers in the ACARS (desired RWYs, temp, derates, etc) and it would spit out the results. Lately we get out the book. We add up all the penalties (low QNH, wet/slippery runway, tailwind, MEL/CDL) and find our Vspeeds for each specific runway.All this seems a bit academic to me since you wouldn't be calculating your Vspeeds without selecting a runway in the first place.

I believe slope is the only runway specific factor. I did some double checking, and it seems a confusing subject if the other boards are any indication.I've worked for 2 operators on the 737. One company, it was easy: punch the numbers in the ACARS (desired RWYs, temp, derates, etc) and it would spit out the results. Lately we get out the book. We add up all the penalties (low QNH, wet/slippery runway, tailwind, MEL/CDL) and find our Vspeeds for each specific runway.All this seems a bit academic to me since you wouldn't be calculating your Vspeeds without selecting a runway in the first place.

Thanks a lot, Matt.Much appreciated...as always ! :( Regarding, runway choice first, you're right, off course. I only wanted to point to the way the PMDG sim works.BrunoPS : I just Googled MEL/CDL and found : Minimum Equipment List/Configuration Deviation List. I didn't know you had to take those into account as well.

PS : I just Googled MEL/CDL and found : Minimum Equipment List/Configuration Deviation List. I didn't know you had to take those into account as well.

Sorry about the jargon. Some MEL/CDL items require you to "take a weight hit." Some of them are pretty small (500 pounds) and some, like anti-skid inop, are big (17,300 pounds!). That type of hit can quickly cancel your flight, or at least turn it into a ferry flight.Keep in mind you base your Vspeeds on the actual weight and not the "assumed" weight. :(