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Guest alpha2003

Takoff procedure

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Well it seems the manual is a bit unclear as to the difference of opinion. The manual does not say why the put "(IAS/MACH window airspeed).1. They may mean that because it's OEM procedure to set V2 in the MCP window, that these two will always coincide.2. They may also mean that it commands either V2+10 (because it's set in the MCP windwo) or blah blah blah.This means that if the MCP value is set to another value, then indeed all other target speed vary.I have a question: In the MD-82 I flew, V2 is calculated by Air Data Computers. You can dial in 900 KTS if you want. The flight director just takes it's V2 source from something a bit more reliable than the pilot (the ADC's). At engine failure, the same rules apply as to the 747. Wouldn't it be more logical for the AFDS to get it's V2 data from something other than the MSP window? Sounds like you're asking for it in mountainous areas and an MCP wich is set improperly.Xander KooteATP


Xander Koote

All round aviation geek

1st Officer Boeing 777

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Guest benhoffman

Intersting discussion.@ Randy, at United V2 is set in the MCP window on all the Boeing fleets (not sure about the Airbus)@ Q, thanks for posting that manual page, but if you dont want the airline name to be known, you may want to sensor the customer ID number as well :)Basically at UAL the -422 takeoff profile using VNAV is this: - v2+10 until 800ft AFE - min. clean until 3,000ft - 250kts from 3,000ft until 10,000ft - ECON above 10,000ft

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Guest alpha2003

So thanks to everybody.So i think i can do now the correct takeoff.1. set the V2 in the MCp2. activate TOGA // The FD set the pitch to V2+10Then at 1500 AGL i will accelerate and activate FLCH , set clean speed, when i reach Flaps 5 i will set climb thrust.Later when i have set Flpas up i activate VNAV.Or the other mode is to set vnav on the ground.Greetings Markus

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Markus if you haven't done the PMDG 747 tutorials then I suggest you do this. It will make it a lot clearer as to the correct TO procedure. You are making a lot of hard work for yourself trying to takeoff in the manner you describe.LNAV and VNAV are normally armed prior to TO.CheersSteve


Cheers

Steve Hall

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"Well it seems the manual is a bit unclear as to the difference of opinion. The manual does not say why the put "(IAS/MACH window airspeed)."Seems clear to me, Xander... The manual says in B&W that the aircraft pitch is based on V2+10 speed which is based on the MCP (the FMC is not mentioned)."1. They may mean that because it's OEM procedure to set V2 in the MCP window, that these two will always coincide."It guess it helps because you don't get too many crazy things happening when the FMC takes over speed control from the autopilot at 400' AGL. At this point, your FMC's V2 entry is used. I get the impression that the FMC is not relied upon for any low altitude work (takeoff and landing)."I have a question: In the MD-82 I flew, V2 is calculated by Air Data Computers. You can dial in 900 KTS if you want. The flight director just takes it's V2 source from something a bit more reliable than the pilot (the ADC's)."What makes you think that computers are reliable? :( I wouldn't have a job if they were ;) How does the MD-82 ADC compute V2 without a pilot entry? Isn't V2 based on weight? Does the MD-82 have a weight and balance computer or does the PILOT make an entry for weight via the CDU?Thanks.Cheers.Q>

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Where did this whole V2+10 thing start? I've heard a few people talking about it, but have never seen it in black and white. I've seen four (4) AOM's that all state V2 should be entered. Where's V2+10 appear from?

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"Where's V2+10 appear from?"The entry of V2+10 speed is a United Airlines/customer procedure variation. So, AFAIK, the FD on United will give a pitch guidance of V2+20. Shallower climb, but more stall protection.Cheers.Q>

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Capt. Randazzo also wrote V2+10 into the TRCs as well, if I recall correctly.Oddly enough, and I know this isn't for the Queen, but I recall the CRJ normal procedure for Independence Air listed as V2+15.Regards,Kyle Rodgers


Kyle Rodgers

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Hi all,I think I pretty much understand this V2 and V2+10. In the first tutorial put out by Robert Randazzo, he stated that both of these are correct. I've tried entering both V2 and V2+10 into the FMC and here's what happens:When I enter V2+10 into the MCP, for expample 184 knots, and this is where the speed bug is placed, the speed tape will stop moving at 184 knots and the commaned pitch bars commands this speed of 184 knots. If I enter V2, which is 174, and this again is where the speed bug is set, the speed tape does not stop moving at 174 knots but continues until 184 knots is reached and then the speed tape stops moving and the command pitch bars commands the same speed of 184 knots, 174+10=184. I use V2. It looks like I get the same pitch command from the pitch bars rather I use V2 or V2+10. So either is correct like Robert said. It depends on the airline company you're flying for. Is this the results all of you get?Ken.

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Guest D17S

Hey Ken, Here's my take and how my test flights went. First off, I found it

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"I set the MCP to 250 knots and we launched. I wasn

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Oddly enough, they are entirely different aircraft ;)It is my particular belief that there are a lotta pilots out there to whom this discussion goes way beyond their needs and interests. To illustrate, I decided to start a similar V2 discussion with a friend who has been flying 777s as a capt for quite some time. Ultimately he didn't know what would really happen if he were to set 250kt on the MCP window. Would the 777 AFDS guide him as it would should the MCP be set properly to V2? Some might say that it's obvous he shouldn't know such a thing since he'd never try it for real or waste level-D time with this. Another question that came up was from where comes the command for the f/d to pitch to V2 + whichever speed. But who cares right? What matters is that the crew knows what will happen during normal and non-normal takeoffs. Well things got messy by then and we gave up on the matter. But the truth is that knowing such information shows in-depth knowledge of the aircraft and imho, that the pilot goes the extra-mile to understand some aspects of his aircraft which aren't necessary but are nonetheless precious. And this is the kind of professional that most people look up to. Not that I don't think that my friend is a great pilot. As a matter of fact I have trusted my life to his hands on numerous occasions and seen him flying like few people can. But this is my sincere congratulaitons to Steve and all other ATP in this forum who "waste" their time on such discussions here, which only add to their carrers.Best Regards,Victor LimaSBGLhttp://www.precisionmanuals.com/images/forum/800driver.jpg

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>Oddly enough, they are entirely different aircraft ;)I figured that was the reason, but still, V2 is V2... (don't read too much into that)>But the truth is that knowing such information shows in-depth>knowledge of the aircraft and imho, that the pilot goes the>extra-mile to understand some aspects of his aircraft which>aren't necessary but are nonetheless precious. And this is the>kind of professional that most people look up to.I agree. I really think it is very important to know what you're flying and how to work every aspect of what you're flying. You'll probably never need to use most of the things you learn, but I think you'd be better prepared for certain incidents and certainly better educated in very least.Regards,Kyle Rodgers


Kyle Rodgers

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Guest alpha2003

thanks all of you.i was flying the 737-700 the whole time and i thought i have to do or i can do the same takeoff procedure in 747 like in the 737.

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