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Guest Daniel42

Totally unable to capture V2 (or V2+10)

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Guest Daniel42

I'm practicing take-offs using the 747-400X PW, taking off from Runway 24 at Schiphol (EHAM). T=15 degreesHeadwind = 8 kts.ZFW = 245.000 kgFuel = 73.000 kgCG = 24%, Trim = 5.8Flaps = 10I've selected a Derated TO-1 at 56 degrees, which results in using up quite a lot of the runway.The moment I push the throttle I also start the chrono:25 seconds: 80 knots called out40 seconds: V1 called out (at 140 knots)44 seconds: Rotate called out (at 154 knots)49 seconds: V2 called out (at 168 knots)63 seconds: Main gear leaves ground, altitude increases (202 kts)68 seconds: Finally at +50 feet (212 kts)So, while it just takes 5 seconds from VR to V2, it takes 24 seconds from VR to the altitude at which I can pitch up to stop the acceleration.I've tried more than several times, some slightly better than above, some slightly worse. Maybe I'm not close enough to pitching up 8 degrees in 3 seconds at rotate... could that be the issue?Daniel

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Why the heavy hand on the derating?The initial pitch up of 8 deg applies to the rotation, not the initial climb out. Once the tail is clear of the pavement, continue to pitch up to maintain V2+10.Your problem is probably both pitch and power (old pilot adage: performance = pitch + power).


Dan Downs KCRP

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Correct! Use TOPCAT (Google) for derates, rotate, wait for tail clearance (LNAV green works well) and then PITCH for SPEED!Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 - FSGS System Unification | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Sony 40" Bravia XBR | Creative X-Fi Fatal1ty | Bose Companion 5 | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |


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Carl Avari-Cooper

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>> which results in using up quite a lot of the runway.Some 24 seconds between V2 and unstick? Either you're not rotating fast enough, or your V-Speeds are incorrect for the weight.I've found that heavy, she's off the mains dead on V2 (and it's a satisfying feeling to hear "V2" and watch the RA start to increase at the same time! :D ). You want to pitch at 3

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Sounds to me like your trim isn't set correctly. The PMDG seems to default to a nose down trim setting for takeoff, under most situations. By pressing the line select key next to 'CG' under your Vspeeds in the takeoff page of the FMC, this should give you the setting you need for that configuration. Try that as well.


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Chris Palmer

Founder/President

Angle of Attack

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Ditto to that. Set the pitch using the FMC's 'CG' recommendation on the 'TAKEOFF REF' page by pressing line select button R4 to get the value and then set this value on your throttle console. She'll cruise right up off the runway with far less effort, unless you're WAY too heavy.Kim


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I'm almost positive that's the issue. Even if you're too heavy, you should have the right Vspeeds (assuming setup was correct) to give you the correct lift to get off and up. However, if you're pitch is set incorrectly, your nose is going to stick to the runway. Pitch trim is a pilots best friend when handflying.


I can't be in all places at once. If you see someone is having an issue with an Angle of Attack product, or something that should be brought to my attention, please message me. I want everyone to have a stellar experience with AOA. Thanks so much!

Chris Palmer

Founder/President

Angle of Attack

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Guest Daniel42

Thank you all for your answers. Eventhough my answer to each suggestion was 'That's what I'm doing (Topcat, trim, ...)' they helped me establish that I probably was doing something very simple very wrong.For a moment I thought I had perhaphs set -6.0 degrees of trim, but actually the scale is from 0 to 12.So, I did the takeoff once more, but this time I switched to the Locked Spot view. At 'rotate' I pitched up as far as possible without a tail strike... and the plane did takeoff promptly. I paused, switched to the cockpit and noticed 10 degrees pitch.Hmm, 10 degrees as indicated by the line that has two labels '10' beside it. So far I had been so hard trying at the 8 degrees in 3 seconds pitch that I never noticed I pitched up just 4 degrees. I had assumed the first small line was 5 degrees and the slightly larger line above it 10. I was so convinced of this, that I even was blind to the purple FD line that is actually at 8 degrees in the TOGA phase.Daniel

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