Rolling t/o?

[CF104 0]

Nick,The way you posted your comments made it look like you were doubting the statement you quoted based on your CRJ example.Once you start getting into MTOW's above 175,000 lbs, the penalties that can be incured on types such as the CRJ with rolling takeoffs are minimal.Just to alleviate any confusion on the subject regarding the 744, here is the entire quoted text from the 744 FCTM regarding rolling and standing takeoff techniques:********B744 FCTM************************A rolling takeoff procedure is recommended for setting takeoff thrust. It expedites takeoff and reduces risk of foreign object damage or engine surge/stall due to a tailwind or crosswind. Flight test and analysis prove that the change in takeoff roll distance due to the rolling takeoff procedure is negligible when compared to a standing takeoff.Rolling takeoffs are accomplished in two ways:

[Guest Ian1969]

Hiy Guys,This is an interesting debate, and I see you are nearly all focusing on the performance of the A/C regarding the pros / cons of a rolling T/O. However, I hope to clarify the issue, having been brought up in HKG in an aviation family for many years, and from personal experience from a Controller's point of view, the situation at Kai Tak was as follows:Kai Tak was a very busy single runway operation, with movements happening every 50 seconds (less than a minute). The clearance was issued to the departing A/C at the holding point as a way of ensuring that the departing A/C didn't stop on the runway and perform his T/O Checks, switch his lights on, put the coffee cup away etc.... The fact that there was already an A/C on short finals into Kai Tak when the flight was cleared to T/O ment that they couldn't afford for the departing A/C to hang around, otherwise it would result in a go-around for the arriving A/C followed by a lengthy hold trying to feed him back into the pattern. Crews were positively encouraged by ATC when cleared, to execute a rolling T/O. Traffic seperation on departures was achieved by feeding in an arrival between departures, hence achieving at least 3 mins (minimum seperation) between departures. The same is true at Gatwick and other similar busy single runway operations. The situation now at Chek Lap Kok is ironically the opposite.... with a 2 runway operation, the Southern is designated for departures whilst the northern one is designated arrivals, A/C departing line up and hold for 2 minutes pending the clearance to allow for the minum 3 mins between departures to ensure adequate seperation, despite the fact that at busy times, the taxiway is lined with traffic waiting to depart.I hope this answers the original question.....Regards,Ian

[CF104 0]

>I hope this answers the original question.....>>Regards,>>IanHi Ian,Thanks for the interesting info on Kai Tak Ops. Although it may answer that particular video, the question was in regards to rolling takeoffs in general with the 744, not just Kai Tak. The question being that PMDG documentation states all takeoffs should be from a full stop(Standing Takeoff) while the video shows a rolling takeoff. As stated, Boeing recommends a rolling takeoff and the video from Kai Tak just confirms this. I have other 744 vids that also show rolling takeoffs as well as standing takeoffs but, in the end, the question was regarding rolling takeoffs and not Kai Tak just to clarify.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.sstsim.com/images/team/JR.jpg

[Guest BlueRidgeDx]

Hi John,I think I see where the confusion lies...tell me what you think:Does Boeing really consider a takeoff as "standing" (or "Static") simply because the aircraft comes to a full stop after lining up? I ask because, in my experience, a static takeoff has a very specific meaning: Takeoff thrust is set prior to brake release. Therefore, coming to a complete stop before initiating the takeoff does not necessarily qualify that takeoff as "static". There are plenty of times that we'll be holding in position, and when cleared for takeoff, initiate a "rolling" takeoff.Of course, we all agree that static takeoffs are not the norm. For the CRJ, we only do it for performance considerations. Setting takeoff thrust before brake release can give us a substantial boost in performance, but its uncomfortable for the pax, so we only do it if its really necessary.Anyway, I haven't read the PMDG manual recently, but I suspect that the recommendation to initiate the takeoff roll from a full-stop is to ensure positive directional control, and does not imply that a true "static" takeoff is desired.Yay or nay?Regards,Nick

[CF104 0]

Hi Nick,Boeing classifies their takeoff procedures as 'Standing' or 'Rolling'. 'Standing' takeoffs, as per Boeing, are from a complete stop with brakes held during initial application of power until the engines are stabilized. Brakes are then released and TO/GA power applied. A 'Rolling' takeoff can be either an uninterupted taxi to takeoff or from a stop but the brakes are released prior to any throttle application as per what you said.I think some of the confusion in the PMDG manuals is that they state a 'Running Takeoff' is not allowed which I will presume is a full 'Rolling Takeoff'. They do however state to release the brakes before applying power so in actual fact PMDG are saying to do a 'Rolling Takeoff' but not from a taxi. A little contradictory to what Boeing says but in the end it's still a 'Rolling T/O'.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.sstsim.com/images/team/JR.jpg

[Guest airspace]

If you push the TO/GA then will the 747 do an auto take-off or do you still have to fly it manually off the ground?Darren

[Guest Loiosh]

You still have to fly her up. You can arm LNAV/VNAV but it will not activate until a certain height AGL.