Flap Extension Times

[jon b]

>Isn't it incredible? A real pilot measures things during an>actual revenue flight to collect data for this simulation. You>may say he performs non essential cockpit tasks during the>busy (descent) phase of the flight. ;)Even I have enough spare mental capacity to start and stop a stopwatch with the autopilot still engaged,it wasn`t that hard to do honest.Jon

[Guest D17S]

Very true. Engines never unspool below something called "Flight Idle" while in the air. This is an idle setting above the idle you will see on the ground (called unsuprisingly, Ground Idle). It's modeled in the PMDG engine configuration. Note the N1/N2 rpms on the ground before TO, then at TOD when VNAV PATH pulls em back to idle for your descent. Then again on final, pause over the threshold when you pull em back to idle again. You can watch it in the sim. Report!Watch both N1 and N2 RPMs. On these modern fans, there are two completely independent fan/turbine assemblies in there. N2 is in the middle and N1 is a fan and a turbine on either end of the N2 fan/turbine assy. It's quite the deal. Roll Royce has an N3 spool. What a mess that is! Fuel lights and then blows across the N2 and then N1 turbines to drive the N2 and N1 compressors (up front). But the real deal is to spin that gigantic N1 fan at the very front of the engine. That's where these engines get their name, Turbofan. 90+% of the thrust comes from that huge, fixed pitch, multi-bladed propeller. So a 747 is powered by a big ol' dumb fixed pitch prop with a giant (nose) cowl around it. Who would have guessed? (Hard to scoff too much at 50,000(ea) X 4(engines) = 200,000 lbs/thrust of get-a-long, though.)But all those turbines and compressors are a huge mass to accelerate. From ground idle to takeoff, 10 seconds can be within limits for one of those old JT9s that I work with. You push

[macpac22]

>>Even I have enough spare mental capacity to start and stop a>stopwatch with the autopilot still engaged,it wasn`t that hard>to do honest.>>JonInteresting..i remember for the ITVV DVD that part of the flight there was constant interaction with ATC, maybe thats the way it was edited i would have thought that after the descent briefing things get a lot busier for yourself and the first officer. I guess it depends on how busy SFO was that day with traffic etc. Ha like i have any idea what the workload is for a B744 pilot! :) My other query, is there anyway to lock the controls during cruize? I was thinking what if a pilot mistakenly hit the flaps selector during cruize or knocked the tiller or the yoke or even knocked over a cup of coffee on the fmc? :) yeah i know its far fetched but the cockpit seems cramped when the pilot is in the seat.

[Qavion]

".... is there anyway to lock the controls during cruize? "No."I was thinking what if a pilot mistakenly hit the flaps selector during cruize..."The flap lever sits in metal slots at each position. You have to pull against a spring to get it out of the slot. Some positions are gated, which involves extra manipulation to move the lever past certain critical points."... or knocked the tiller"Nosewheel steering is automatically disabled with the gear up.".... or the yoke"Possible, but it's not like a computer joystick. You have to exert a few pounds of force and move the yoke a certain amount before the A/P will disengage."... or even knocked over a cup of coffee on the fmc?"Possible, but there is another fully functional CDU in the cockpit.Cheers.Q>

[macpac22]

"The flap lever sits in metal slots at each position. You have to pull against a spring to get it out of the slot. Some positions are gated, which involves extra manipulation to move the lever past certain critical points"i never knew that thanks Q

[jon b]

One of the gates is at flap 20, its designed for the go-around to stop you selecting anything less than flaps 20 in the heat of the moment eg 30 to 10 which would cause a horrible sinking feeling!Q you don`t happen to know the exact force required on the colum to dissengage the AP do you? I`ve often wondered as its always being knocked about as people get in or out of the seat. Paul,just for you interest at SFO they normally set you up over the SFO VOR at 10,000ft and tell you to leave the vor heading 140 degress.Its then a dive downwind to land on 28L.They always tend to turn you in too soon so the quicker you can loose hight on the down wind the better.Someone once gave me the top tip of getting flaps 5 out by the time you`re over the vor so you`re set up for a quick descent.Which is what I do so it was still nice and quiet at that stage.They still turned me in too soon though! had to get gear down flap 20 on base leg to stand a chance!But at any stage of the flight its not too hard to check the flaps,its a bit different from the sim in real life,there are lots of little thing we are looking at and doing all the time during the approach so we`re quite used to multi-tasking!regardsJon

[macpac22]

thanks jon, i must try that on my next lon-sfo long haul. i know at LOZIT ive prgrammed in for 250knots at 11000ft so the SFO VOR ill try program in 10000ft for a more accruate arrival, i normally use vertical speed from transition altitude to LOZIT i find it gives me more control over my speed. Then after passing SFO and over the airport i use radar headings as it gets a bit tight. Is that left hand turn for LOC intercept for runway 28L really that steep? i try and ease it in as best i can while reducing speed. hopefully ill get to fly that route someday and sample the "other" british trans atlantic carrier :)

[jon b]

Paul,If they have traffic landing on 28R they will sequence you in with them,and so they leave you down wind for longer allowing you to loose the height.When we came in it was very quiet, so they turn you in sooner,as soon as you can see the airport then issue you a visual approach,at that point I estimated I was about 1000ft higher than I needed to be.An early configuration change to gear down flap 20 was needed and I managed to intercept the glide still well outside of the brijj NDB.Its funny how EGLL can give you superb vectors with about 10 other aircraft on frequency,but in the US even when its quiet they just point you at the airport and say in effect sort it out yourself!regardsJon

[macpac22]

what do you think thats down to jon? would EGLL have different rules and procedures compared to KSFO or is that the way its always been? sorry for all the questions off topic.

[jon b]

A lack of appreciation of heavy jet performance characteristic especially on approach, sadly ,seems endemic throughout the US ATC system.Jon

[macpac22]

thats suprising to hear i always thought ATC would give extra attention to detail for heavy jets such as the B744

[michal]

>also, can one take into consideration the type of computer>being used. Nope, that should be irrelevant.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

[Guest A32X]

Just pressed the TOGA switches and the engines took ~13 seconds to reach takeoff power. The increase in power was not linear. The acceleration of the N1 fan decreased markedly as power increased. Does anyone have any real data on engine spool up curves?-Paul