Proper takeoff procedure...

[michal 44]

Makes sense except one thing. We are talking about aircraft climbing till 1000 ft so what practical difference can there be between runway track or heading ? Unless winds are of hurrican strength we are talking of inconsequential difference. BTW, controllers would probably gladly take someone who can maintain runway track but they must figure it is either impractical (heading will soon change anyway) or too much extra load for pilots in this critical phase f flight. Michael J.

[Guest HPSOV]

The reason they do heading not track is due to the inability of aircraft without inertial NAV systems to accurately maintain runway track.The controller does factor in the wind in his expectations of where the aircraft will end up if it maintaining runway heading, which can have separation implications for airports using parallel runways.It is not uncommon to maintain runway heading till 3000-5000ft, where winds could quite possible be in excess of 50kts (just fly out of Perth, Australia to experience low-level winds).It is therefor important to do as you're instructed and maintain the runway heading not track!

[Guest]

How could I get the pure auto pilot environment after taking off, that is, the V/S and HDG HOLD always illuminates atfer engaging CMD above 400ft even I click off and on the FD to clean the previous auto pilot mode. Thus I cound't follow the instructions to engage lateral mode above 400ft and then engage vertical mode above 1000ft.

[michal 44]

Not sure what you mean by "pure" AP environment. You do get V/S and HDG HOLD when you engage CMD at 400 ft and above - by default. Then you can change it to whatever mode you want - say HDG SEL and FLCH.Michael J.

[Guest]

>Not sure what you mean by "pure" AP environment. You do get >V/S and HDG HOLD when you engage CMD at 400 ft and above - >by default. Then you can change it to whatever mode you want >- say HDG SEL and FLCH. >>Michael J. Maybe is clean, no one of AP modes engaging when CMD illuminating. So procedurally we could engage both lateral and vertical AP at or above 400ft. Are there rules that limit the priority of lateral AP should be firstly engage? If V/S engaging is default, how much is the rates between, is it fixed? Thanks~~:D

[Guest Ian_Riddell]

>Maybe is clean, no one of AP modes engaging when CMD >illuminating. So procedurally we could engage both lateral >and vertical AP at or above 400ft. Are there rules that >limit the priority of lateral AP should be firstly engage? >If V/S engaging is default, how much is the rates between, >is it fixed? Thanks~~:DAs far as I know, there are no airplane (767) computer logic rules regarding which axis (pitch or roll) needs to be engaged first (above 400'), so it's up to you/your airline, to decide which axis you select first (this of course, depends on the type of departure ATC has given you). As a sidenote, the 747-400 (airplane logic) allows LNAV engagement at 50' and VNAV at 400' (the 767 may be similar), but it's unlikely that you'd be able to engage the A/P so soon after takeoff (The airplane would reach 50' within seconds.... and you'd have your hands full retracting the gear, etc).The default modes (V/S and HDG HOLD) only activate if you engage the A/P or FD after takeoff (for the first time). If you engage the A/P first (i.e. push a CMD button with no FD's on in the air), all the Autopilot will do is maintain your current vertical speed/heading (which, depending on your piloting skills, could literally be any vertical speed or any heading). If you pulled too hard on the stick producing an excessive V/S, then pushed a CMD button in the air, the A/P would attempt to hold the same excessive V/S and the aircraft would eventually stall. This is not desireable).It is standard (Boeing) practice that you select the FD on before takeoff (giving TO/TO on your EADI) ... Therefore, if you engaged the A/P at, say, 400', and if you hadn't selected any other modes, you would find yourself in TO/TO guidance mode rather than V/S and HDG HOLD mode ("TO" as a pitch mode is far more benign than V/S...and is designed to give you the ideal target airspeed of V2+15kts after liftoff. If you maintain the ideal airspeed, the vertical speed of your aircraft will vary depending on aircraft weight and engine thrust... there are no default V/S's). The first part of the takeoff is flown manually. It is up to you to make sure that you adjust your pitch (with your control column and Stab Trim) to maintain a speed of V2+15kts. Use the FD and your airspeed indicator to help you maintain that speed.As HSPOV suggests, make sure that you are in the desired APFD mode before pushing the CMD button to engage the A/P.There appears to be a variety of airline procedures which may be a confusion factor. According to Michael, some 767 airlines select (arm) both LNAV and VNAV before takeoff. This means that the switchover from TO/TO to LNAV/VNAV will be automatic (LNAV cuts in at 50' if it is armed before takeoff. VNAV cuts in at 400'. Other airlines may select these modes after takeoff, above 400'.Hope this clarifies things.Cheers.Ian.

[Guest]

HPSOV or any PIC user, does anybody know why when I click on the VNAV button usually at about 1000 after takeoff, the aricraft starts to climb at (and sometimes over) 4000 feet per minute? Is that too much? How about the real B767, does it climb that fast?The problem is that whan I fly on VATSIM, I usually get an initial altitude of 5000 on my clearance, and by the time the VATSIM departure/approach controller gives me a higher altitude, I am alredy at 5000 just because my B767 climbs soooo fast with VNAV.I just wonder if in real life, with real ATC, pilots simply set the A/P to 1000-1200 vertical speed (or manual hand-fly) instead of using VNAV or FLCH to climb slower and so avoid having to level off at 5000 and then again at 16000 while Center gets you higher to your final cruise altitude.Or maybe, real life ATC is more responsive than VATSIM controllers and they get you higher right after your initial contact. If that's the case, I wish VATSIM controllers would get pilots higher much faster to make it closer to real ATC practices.Best regards,Kerke

[Guest]

I think all this vertical speed confusion is due to the poor autopilot modelling of previous flight sims. Why would you NOT want a fast climb??The only value that matters is airspeed. You use pitch to control airspeed. If the a/c is light, then the pitch which would hold the desired airspeed for a given thrust setting would, indeed, result in a high vertical speed, which simply means you get to altitude (and economy fuel flow rates) more quickly, which is exactly what you would want.Again, you climb an aircraft based on airspeed, not vertical speed. Vertical speed is the RESULT of thrust+pitch. If you find it's climbing too steeply, you are simply flying a light aircraft without a de-rate. In real life, a de-rated to/climb thrust setting would match the particular field/obstacle/weight combination giving the right balance between economy, angle of climb, and rate of climb.Just fly the airspeed...if you think the pitch is too severe for passengers, you should have flown in a DC-9 out of Pearson (toronto) while sitting in the back row!michael

[Guest ilh]

The back row pitched more then the front row? ;-)Lee Hetherington (KBOS)

[michal 44]

>Therefore, if you engaged the A/P at, say, 400', and if you >hadn't selected any other modes, you would find yourself in >TO/TO guidance mode rather than V/S and HDG HOLD mode ("TO" >as a pitch mode is far more benign than V/S...and is >designed to give you the ideal target airspeed of V2+15kts >after liftoff. Ian, this is not the case for me when using the PIC. I do everything right, arming FD on the ground, not selecting any other modes, etc, etc, and as soon as I press CMD at 400 ft AGL or above TO-TO FD mode disappears and is replaced by V/S and HDG HOLD. I never saw autopilot actually engaged in the TO-TO mode, never happened to me - tried many times. So as far as I am concerned TO-TO only exists as the FD mode, not the CMD mode. If there is someone here who can actually testify here that he/she saw the TO-TO CMD mode with his/her own eyes I would like to hear about it.Michael J.

[michal 44]

Just verified with PMDG developers next door (they modeled 757 for FLY) and with smartcokpits web site, PIC documentation, etc. and it becomes clear that TO-TO are the "FD assisted" modes only, not CMD implemented. In 777 however they are avilable in the CMD mode as well.Michael J.

[Guest Ian_Riddell]

"Just verified with PMDG developers next door (they modeled 757 for FLY) and with smartcokpits web site, PIC documentation, etc. and it becomes clear that TO-TO are the "FD assisted" modes only, not CMD implemented. In 777 however they are avilable in the CMD mode as well."Sounds like this is worth some extra investigation, Michael ;-) In some manuals, the same is said of the 747-400, that TOGA/TOGA is only an FD mode, but on further investigation/reading, we find that this is only true on the ground (I got a response from a guy from Collins (the manufacturer of the autopilot) on this issue on the 747-400 many years ago confirming this).This area is rarely explored because modes are automatically changed at such low altitudes (especially when VNAV/LNAV are pre-armed). The 767 Maintenance Manual also says that "TO" is an FD only mode, but I assumed that this was like the 747-400 where the mode becomes an A/P mode after liftoff.Like everything, it may be an option (activated by earthing electrical pins on the back of the FCC's (Autopilot computers)). E.g. If it is not active on the 767-300, it may be active on the 767-400.Anyway, I'll see what I can come up with in the next week.... If it's not an A/P mode, they should pay 767 drivers more money :-lolCheers.Ian.

[Guest Ian_Riddell]

>Like everything, it may be an option (activated by earthing/grounding >electrical pins on the back of the FCC's (Autopilot >computers)). E.g. If it is not active on the 767-300, it may >be active on the 767-400. Speaking of which.... I just found an option pin on the Collins FCC which sounds like it could do the job... Pin AG2, "A/P ENGA TO/GA". No explanation of what it does in the wiring manuals, tho'.... but at least it's a starting point.Cheers.Ian.

[Guest HPSOV]

Those vertical speeds are not uncommon for a light aircraft. You can select CLB1 or CLB2 to reduce these, or cram on a bit more cargo to make the aircraft heavier!As far as using V/S, this isn't recommended during climb, you wouyld always use VNAV or FLCH which will put the autothrottle into N1 mode, which will give you the best rates of climb, getting you to cruise altitude as soon as possible, which is the most efficient way to operate the aircraft.

[Guest HPSOV]

I haven't tried it in PIC, but in the real aircraft you can engage the autopilot at 200ft in TO & TO mode.If this cant be done in PIC then you're just going to have to hand fly it in these modes until you select something else! (no dramas there, as you would normally hang fly the aircraft until flaps have been retracted anyway).