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Guest alpha2003

Takoff procedure

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Guest alpha2003

Hi everybody.I have one big understanding problem.I should set the V2+10 in the MCP IAS Selector.So when i am doing the takeoff the FD always should show me the correct pitch (v2+10) its the toga mode.But when i am setting the v2+10 in MCP panel the FD shows me the pitch i insert in the MCP +10. so dont i have to set only v2 so the FD shows me then the correct pitch.And in the climbout procedure the airplane is in N1 mode (takeoff thrust) at 1500 agl it have to accelerate to the clean speed.So do the pilots always set in MCP IAS Panel the clean speed. or do they only use the half v/s mode and at Flaps 5 they select THR and FL so the speed at moment is selected automatically?But when i am setting the Speed to Clean and the Pitch mode is in Toga i must show me the speed +10 or not?And why dont the pilots use V/S pitch mode for climbout?3. And why does the Fd director always show me the correct pitch when i dont selecting the AT. I am using the manual thrust setting.Get the FD director his information from the speed window? Is it like the speed bug in the 747-200?

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You always want to set V2+10, unless there is something that prevents that setting. V2+10 gives you a nice safety margin on take-off if any emergencies come up.Pilots don't use V/S pitch because you're pitching your aircraft to keep a certain speed. You adjust the aircraft to keep the set speed with a certain throttle setting. The throttle setting changes on take-off when you have A/T on, as it changes to CLB thrust at a certain point (normally Flaps 5). Because the thrust setting changes, you must also adjust the pitch of the aircraft, which changes the V/S.The F/D is independent of the A/P and the A/T. Though it uses the information from the MCP (speed window), it doesn't require A/P or A/T to work, which is why you can still see the correct pitch.


Kyle Rodgers

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Guest alpha2003

Ok thanks.But how to do the corret takeoff?1. I have to set the V2+10 in MCP2. At 1500 AGL (I dotn use vnav) what have i got to do. Do i have to increse the speed at the IAS Speed Indicator to Clean speed and let the toga mode active? Or should i let the V2+10 IAS in the MCP and set the V/S i have during takeoff to the galf and wait until i reach Flaps 5, then i set Climb Thrust and after Clean speed i select Fl Change or Vnav?Greets Markus

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>You always want to set V2+10, unless there is something that>prevents that setting. V2+10 gives you a nice safety margin>on take-off if any emergencies come up.>Pilots don't use V/S pitch because you're pitching your>aircraft to keep a certain speed. You adjust the aircraft to>keep the set speed with a certain throttle setting. The>throttle setting changes on take-off when you have A/T on, as>it changes to CLB thrust at a certain point (normally Flaps>5). Because the thrust setting changes, you must also adjust>the pitch of the aircraft, which changes the V/S.>The F/D is independent of the A/P and the A/T. Though it uses>the information from the MCP (speed window), it doesn't>require A/P or A/T to work, which is why you can still see the>correct pitch. Some airlines use V2 +10 (UNITED is the only one I know of) but not others like Virgin etc. As with the 737, you set V2. The F/D already gives you the margin after liftoff. Boeing says to set V2 - this should really settle the issue unless one is replicating UNITED..Best,Randy J. Smith<<>>


Randy J Smith

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Hi Markus,As was mentioned before it is not necessary to set V2+10 in the MCP window. Standard Boeing procedure is to set V2 although there are a few airlines that use V2+10. If you have an engine failure the FD will command an appropriate speed to fly.Most airlines use VNAV for TO. This is set in the FMC and armed prior to departure. You can set what you like dependant on noise abatement etc. My company uses 1500 ft AGL as the climb thrust setting and occasionally Flap 5.If you wish to do a non-VNAV departure then you would climb at V2 to V2+10 until the thrust cutback altitude (as said we use 1500 ft). You then select FLCH and set the desired speed you would like (probably 250 kts or min clean if close in terrain or a steep departure gradient is required). If the thrust has not come out of TO thrust then push the Thrust button on the MCP. This should select the armed climb thrust limit.V/S is not normally used in this situation although there is nothing to stop you using it. The only point to remember is that there is no alpha protection in this mode.CheersSteve


Cheers

Steve Hall

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>Some airlines use V2 +10 (UNITED is the only one I know of) but not >others like Virgin etc. As with the 737, you set V2. The F/D >already gives you the margin after liftoff. >>Boeing says to set V2 - this should really settle the issue unless >one is replicating UNITED..>>Best,>Randy J. SmithSorry for my single-track mind and lack of signature.I regressed and forgot just about every other SOP in the world besides United and what I was taught.Apologies,Kyle Rodgers


Kyle Rodgers

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Guest D17S

(My turn?)Hey Markus, You are working with a pretty manual mode, but it's great for practice. Generally, a crew might at least have the AT engaged, but it

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Don't think you are going to get anyone to agree on this, Alpha:-lol As a real world 747-400 engineer... here is my response...MOST airlines use V2 in the MCP window. The Autopilot/Flight Director system uses this MCP value in it's airpeed calculations.In TOGA mode, at rotation, the autopilot/FD system computes an initial climb airspeed of rotation airspeed plus 10kts (or MCP speed plus 10knots, whichever is greater). If airspeed exceeds this speed for 5 second, the reference speed becomes the lesser of current airspeed or V2+25kts. If you dial in a higher MCP value, your targets will also increase accordingly.The process is actually a bit more complicated than that, as V/S is also monitored shortly after takeoff. V/S is critical, because you want the aircraft clear of the runway as soon as possible (for windshear protection).Until VNAV becomes active at 400', the speed is controlled by the autopilot (****IT IS NOT CONTROLLED BY THE FMC UNTIL VNAV BECOMES ACTIVE***** Your FMC computer could be sitting on the tarmac and it would not make any difference to your FD indications).Although the MCP window speed remains at V2 until VNAV engagement, the FD will be giving you commands to maintain the +10~+25 speed. According to the manufacturer of the 744 A/P system, in theory, you could engage the A/P as soon as you lift off the runway, but it's NOT recommended. This critical phase is left to the pilot.V/S Mode is not normally used for takeoff because there is no full speed (underspeed/overspeed) protection in this mode."3. And why does the Fd director always show me the correct pitch when i dont selecting the AT. I am using the manual thrust setting."Hmmmm.... because it is designed that way? :) Hope this helps you to figure out reality from fantasyCheers.Q>

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Guest D17S

That's an entirety different ops scenario than is modeled in this sim . . . or the new Level D 744 sim that just got bolted into the last bay in our flight ops crew training facility. Maybe you're describing a beta version! It's sure not the RTM we got.I've always been interested in this phase of flight so I was sure to check it out. I dialed in 250 knots into the MCP for TO and the sim operator said "Hey, what ya doin'?" I said. "Just checking how good that PMDG sim is." Pretty darn good, actually. So, it's just like I said. In TOGA, pitch command is driven independantly of the MCP airspeed setting.Try it in whatever sim you have available. Dial in 250 and take off in Vnav-less, TOGA mode. Stop the acceleration with pitch ASAP. The flight director will command pitch to the FMC's V2, the lift speed, or an averaged speed (which ever is greater) as long as pitch remains in TOGA. The MCP airspeed setting is not involved. Now, what box does these calculations? I expect it

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"That's an entirety different ops scenario than is modeled in this sim . . . or the new Level D 744 sim that just got bolted into the last bay in our flight ops crew training facility. Maybe you're describing a beta version! It's sure not the RTM we got."Sam, I'm talking about the real aircraft."Now, what box does these calculations? I expect it

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Guest D17S

That Level D sim I spoke of is not a PC with the LVLD 767 video game running on it. It's a "real deal" Level D, full motion, 3 tonne sim that we are training real pilots on. (I understand they had to take a section of roof off and lower it in with a crane!) The Feds are a bit sticky about there things reflecting real aircraft system ops. So I really have to trust that it IS reflecting the ops of a real airplane. Same with the MD11. That one was at a Boeing/Alteron (Flight Safety) crew training facility.The ops manual can be a little fuzzy when it comes down to this level of detail. Virtually all 74/75/76 pilots actually believe that the MCP airspeed setting is generating their pitch guidance during the TOGA pitch phase. As long as they always dial in a V2-ish speed, how would they know any different? Would they see it? It's very rare that they just sit on any kind of V2 for any legnth of time at all. Even at max weight, acceleration altitude comes along very quickly. It gives me a real warm fuzzy to actually know what that vertival guidance command bar is actualy telling me during that critical phase of fight. This is a detail that is generally not understood, but it should be.In any case, a very careful look (and indepth discussion) of the V2 concept is always a very good thing. It's the real core of Markus' very good question.

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Sorry, but I remain unconvinced. A Tech Pilot specifically ran several tests in a Level D sim a few years ago for me in relation to this, using all his skills to nail the rotation speed.Your description is a radical departure from what the AOM says. If AOM's were as fuzzy as this, they wouldn't be legal documents.For the moment, I'm putting my faith in my manuals and real 744 pilots.Steve? Alexei? Any comments?Cheers.Q>

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Guest D17S

I've long lost my religion about manuals . . . and of the omniscient operator. Fuzz is a way of life. I consistently see aircraft related "legal documents" that are complete gibberish . . . and had been so for 20 years. Ops procedures that are wickedly dangerous, but have been used for years. "If the manual says so it's gotta be?" That's where we all started. I did too.We're making ya think here, Markus. Fly the sim. What do you SEE. Play with it. The PMDG model is plenty close enough to see how a real 744 operates. 1/2 speed is the trick.

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Whoah! This outside the bounds of normal line aircraft operation. We takeoff with VNAV everytime and I cannot see any reason for not doing so. I have always been of the view that the MCP speed setting is just positioning the speed bug on the ASI. However having said that we always have V speeds entered and use VNAV. Sam I assume you entered the V spds on the TO page?What happens if this page is left entirely blank? No Flap accel height, and just the small fonts left for the others?Our manuals are next to useless when it comes to things outside the norm....actually they are not much better within the norm either!!!!Will have to muck around and see. As there is a high degree of systems integration I suspect that there is also a degree of redundancy here (should one integrated component fail or provide out of tolerance data input) and that under normal ops the FMC will provide the FD cues but if the TO page "crashes" (like it used to do sometimes with a power transfer prior to load 16 I think it was) then the FD may default to the MCP.CheersSteve


Cheers

Steve Hall

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