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Help on Correct Takeoff Procedure!!

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Hello All!! Can anybody help me on the correct takeoff position regarding the Autopilot on the 767 PIC??? Im having trouble in the following way: I set the autopilot altitute for 10000 ft and speed hold for 250 Kt to comply with the speed limit below 10K feet. Once i retract the landing gear after takeoff, I enable the autopilot.....At first, the aircraft exceeds the climb rate almost to the stall situation.........over 5000 ft/min even when I set the V/Speed to 2000 ft/min........Then it comes down that makes my plane descend instead of climb!!! Have no idea what im doing wrong.....>Can anybody Help On This Pleasee???Thanks In Advance!!Javier

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Javier,If you want to engage AP as soon after takeoff as possible and do it "elegantly" the best way is to do this - while still on the ground press LNAV and VNAV - btw, these are the only 2 AP modes that you can select on the ground. But AP itself remains obviously disconnected. Then soon after takeoff, after you retract gear, bring the plane nose slowly up until it overlaps with position commanded by the flight director. When this happens you will suddenly see both LNAV and VNAV displayed in green and with green boxes around them - it means the LNAV and VNAV modes engaged correctly. Now only engage the AP by pressing one of the CMD buttons.Of course, you can only do it if your preflight on FMC is complete.Befor takeoff make also sure that Auto Throttle switch is flipped to the ON position and Flight Director is turned on too.If you do it this way and fly in VNAV - your 767 will automatically comply with 10,000/250 restrictions.In case you do not want to bother with LNAV and VNAV modes - after takeoff you assume the pitch that will give you a reasonable climb rate, say 3000 fpm. Then engage the AP. With no other modes selected your AP will default to keeping your current heading and V/S. And then you can dial different climb rates or select other modes as you wish.Michael J.

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* For Use With PIC, FS2002 ( and optimized with: FSASSIST, FDC and RCv3 )Please advise on details or items that require correction.Thanks,- AlexNormal Operating Procs+Checks============================================================== TAXI CHECKS [ ] RWY TURN-OFF LTS+TAXI LTS T ON[ ] PKG BRAKE

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Guest

Alex,Why a missed approach procedure on takeoff? Should be aborted takeoff. ;-)Greg

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Guest

Isn't a Aborted takeoff a Rejected TakeOff utilizing RTO between 80 knts and before V1 with intent to stop the AC and abort flight?If after V1 and AC is Flightworthly then would a Missed be conducted once Airborne?The Missed Approach line item is there in the event of a return to the airport is required.I will gladly change my checks to be most logical, as I posted them for feedback.Thanks for the help! ;)Cheers,- Alex

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Personaly I never engage LNAV on the ground prior to takeoff always HDG SEL set to the runway heading, the reason being (especially on VATSIM) that ATC probably wants you to fly runway heading before vectoring you onto your course... if you engage LNAV right after takeoff, it'll turn you right on to your course and that could be disastrous depending on traffic. VNAV before takeoff is fine though.

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Hi everyone!Engaging LNAV(+VNAV) or Hdg Select really depends on where you're flying.I guess in the USA hdg select would be more useful, just for the reason "Tabs" pointed out. However, here in Europe, most runways have a special departure procedure (still called SID) which will keep you clear from all incoming traffic and VFR traffic. Sometimes, after departure, you will turn away from runway heading and fiddling with the hdg selector is not very efficient (still rather low), so LNAV is very useful.I would not use VNAV if LNAV is not engaged because maybe the computer could get confused if you were not flying towards your active waypoint and you had an altitude restriction programmed for it. In that case I would use either FLCH or V/S.Remember though, you can only arm LNAV + VNAV on the ground, and also only if a F/D is on. For the other modes, you have to be airborne.Hope this helped,Mark

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Guest fwsov

G'dayNot sure what U.S. operators do but Australian (in particular Qantas) and HPSOV can confirm this, that they are not allowed to engage LNAV and VNAV while on the ground (only the 744's can do that.)So to add what the other guys here have said here's what i usually do:Put the clearance altitude in the MCP that you recieved from ATC.Re-cycle the FD's to remove any modes engaged (make sure no AP is selected)-this will then put "TO and TO" in the EHSI. What this now does is set the plane up for TO, and when you lift off the FD's will command a pitch that will give you a speed around V2+15 and whatever associated V/S with your particular aircraft weight. To fix the problem where you get an extremely high V/S, you have to (especially if you're light) put in a de-rate. A de-rate won't be accurate as you don't have the take off charts that real pilots have but a good figure for a very light plane (only about 2hrs endurance) would be +55 C. (refer to manual to learn how to put this in the FMC) The result of putting a de-rate in will command a different N1 setting, depending on how much power you need, and reduce such a vicious climb out.So to begin your take-off:Have the EHSI showing "TO and TO" with FD's engaged.Engage the Auto-throttlePress that area that makes the speed bugs on the ASI go to flaps speeds, and also this will wind the speed bug back to V2.make sure you're flaps are set for T/O and observe that flaps limit speed.Now you can start to advance the throttles to 70% N1 and monitor engine parameters are ok and that the engines are producing rougly the same power. Now press the "N1" button on the MCP, this will advance the throttles using the A/T mechanism to the reference N1 shown in green on the EICAS above the N1 read-outs, and it will read "TO."Now you're rolling! just track the centre-line and at V1 you can take your hand away from the throttles as you are committed to take off and at Vr you can rotate-doing it slowly!Raise the nose to the Attitude commanded by the FD, maintaing runway centre line and raise the gear.have a look at the speed and you can make your own adjustments to the attitude to maintain about V2+15 to V2+25.At about 400ft you can engage a roll mode (using either HD sel. or LNAV) and follow the FD to your new command-continue climbing at V2+15!Once you reach 1000ft Above the aerodrome you engage "climb thrust" using the Thrust reference selector (note that the readout above the N1 dials will read "CLB") and engage a pitch mode (whether it be FLCH or VNAV, this will then command a pitch down so the aircraft can accelerate, as it accelerates retract the flaps so they don't overspeed, your initial climb speed should be about Vref30+80.Now you can just follow the flight directors or engage an AP and sit back and relax!This takes a lot of practice and things go very quickly! So don't worry if you miss some things on your first couple of goes! I will try to post some screenshots.Hope this provides some help despite the rather large and ill-planned ramble i've just typed-I'm sure HPSOV and other's will make some ammendments/type a post that makes sense.Good luckBest regards,Andrew (Sydney, Australia)

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Guest HPSOV

I have taught him well :-)(Or he has listened well)

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Guest J_Niny

>, that they are not allowed to engage LNAV and VNAV while on the >ground (only the 744's can do that.)Hi Andrew,I think that you are absolutely correct, and I guess that Eric already said the same in the old Forum.In the 767, LNAV and VNAV AREN`T engaged on the ground.Those are 747

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Guest WorkingStiff

Here's one of Eric's old posts explaining this:Hi DW,Q: Should I be able to enable the A/P on the ground (i.e.have the middle A/P button light-up) - before OR after enabling the FD and A/T?There is an airplane limitation for engagement of the autopilot of 1000 feet above field elevation. It is not possible to engage the AFDS in CMD mode on the ground. Although it may be possible to engage CMD after takeoff, it is prohibited by the above limitation to engage the CMD mode until above 1000 feet AFL.Some info for you. On the ground with the FD selected, the AFDS is in the "takeoff" mode. TO is annunciated for the pitch and roll modes. If you attempt to engage the AFDS in CMD mode with takeoff mode active, the AFDS will default to HDG HOLD and V/S modes. The same is true if you engage the CMD mode without the FD selected ON.Procedurally, you must takeoff manually (sorry, there are some things pilots are still required to do . Then above 400 feet AFL engage the desired lateral mode (HDG HOLD, HDG SEL, or LNAV). Then above 1000 feet AFL engage the desired vertical mode (V/S, FLCH, or VNAV). At this time you can now engage the CMD mode if desired.Thanks.Eric.

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>In the 767, LNAV and VNAV AREN`T engaged on the ground. >Those are 747

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Guest Ian_Riddell

Don't know about anyone else, but I'm still confused. :-)I think we're getting our engaged/armed terminology mixed up folks. On a 747-400, you can arm LNAV/VNAV, but you can't engage these modes on the ground. You can, however, engage most of the other modes on the ground... i.e. select CMD and not have the A/P trip off.The FD will give you guidance to maintain runway track after T/O (if you have TOGA/TOGA selected), rather than runway heading... and if you hit the CMD button, the A/P will follow the FD bars. Actually, runway track is probably a simplification: At liftoff, the track is sensed.... so if you are not following the runway centreline (e.g you decide to veer off onto the grass at the last moment) you may end up following a slightly erroneous track in the air, too). I'd say that the 767 would be similar in this respect.re (real) 767 A/P's in general... I may need a refresher course on this before I pass comment ;-)Cheers.Ian.

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Guest fwsov

Ok, I should've been a bit more specific in the LNAV & VNAV department, what I meant to say was "Don't ARM LNVAV and VNAV" (Besides, you can't ENGAGE them on the groud no matter how hard you try.)So as final advice, don't touch LNAV and VNAV while you are on the ground. :-)Regards,Andrew

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Could you or other real pilots tell me why?I believe that some European carriers that fly the 75/76 do arm LNAV+VNAV on the ground, but have to check to be certain.

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Guest HPSOV

OK, you guys have managed to get yourselves all confused about this one! I'll try and clear a few things up.First thing, I have a feeling this is all going to vary based on airline procedures and limitations, and the type of FMC/AFDS used by each carrier. We operate a lot of different variations of the 767, and I think the procedures are based on the most limiting type (ie 762 with no speedtape, basic (non-PIP) FMC, standard EICAS computers etc).We are NOT allowed to use any modes for takeoff, other than TO. We are not allowed to ARM ANY modes on the ground. (The debate as to whether modes will engage on the ground, or whether CMD can be selected on the ground is totally irrelevant because there is no circumstance when you would ever want to do this... what will it achieve?).After lift-off you follow the guidance provided by TO pitch and roll modes. The pitch will command V2+15-25, and roll will command your track at 5ft RA after takeoff.You MAY select (arm or engage) a roll mode any time after takeoff once the climb has been "stabilised", however standard procedure is to select a roll mode at 400ft. This will normally be LNAV provided the map position is accurate (our aircraft dont have GPS), however it does not preclude you from remaining in TO mode if the departure calls for maintaining runway track.Pitch mode will remain in TO until flap retraction altitude (normally 1000ft, may be higher due to terrain/noise considerations). At 1000ft select climb thrust on the TMCP, and select a pitch mode. This will usually be VNAV, however FL CH or V/S may be used (I can't think of a situation when V/S would be used, as it will not provide maximum efficiency, and will not provide stall protection on climb).You may choose to hand-fly this whole procedure, or you may, at any altitude above 200ft engage an autopilot to CMD mode.Hope that clears the takeoff procedure up a little!

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