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basa

737-800 Avoiding a tailstrike

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My dear friends,After more than 3 years flying the NG-700, my airline has recently started to operate the '800 (winglet equipped of course).Things are quite similar between the 700 and the 800. Perhaps one of the main differences is the tailstrike risk at take off: low in the 700 and high in the 800. Some test flights have showed me that is more difficult to avoid a tailstrike in the 800 than in the 747.I normally load my NG-800 with 170 pax, wing tanks full and 1000 kg of fuel in the centre tank. That makes a typical TOW of 67.000 kg. I use flaps 5, trim is 4.8, TO-1=95%, V1=141, Vr=142 and V2=147.So, I've stablished the following take off technique:1.- Initial rotation to a max of 7.5 degrees of pitch angle2.- Mantain 7.5

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Just read a post over at airliners.net on the forum, and a 738 pilot over there states 11

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My dear friends,After more than 3 years flying the NG-700, my airline has recently started to operate the '800 (winglet equipped of course).Things are quite similar between the 700 and the 800. Perhaps one of the main differences is the tailstrike risk at take off: low in the 700 and high in the 800. Some test flights have showed me that is more difficult to avoid a tailstrike in the 800 than in the 747.I normally load my NG-800 with 170 pax, wing tanks full and 1000 kg of fuel in the centre tank. That makes a typical TOW of 67.000 kg. I use flaps 5, trim is 4.8, TO-1=95%, V1=141, Vr=142 and V2=147.So, I've stablished the following take off technique:1.- Initial rotation to a max of 7.5 degrees of pitch angle2.- Mantain 7.5

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My dear friends,After more than 3 years flying the NG-700, my airline has recently started to operate the '800 (winglet equipped of course).Things are quite similar between the 700 and the 800. Perhaps one of the main differences is the tailstrike risk at take off: low in the 700 and high in the 800. Some test flights have showed me that is more difficult to avoid a tailstrike in the 800 than in the 747.I normally load my NG-800 with 170 pax, wing tanks full and 1000 kg of fuel in the centre tank. That makes a typical TOW of 67.000 kg. I use flaps 5, trim is 4.8, TO-1=95%, V1=141, Vr=142 and V2=147.So, I've stablished the following take off technique:1.- Initial rotation to a max of 7.5 degrees of pitch angle2.- Mantain 7.5

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See FLIGHT TECHNIQUES manual pg 10-4.As noted, tail strike for -800 is 11 degrees.

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Also, you do not make slow rotations instead you make fluent firm ones most of the time about 3degr. per sec of rotation:so pull back the stick, gently but firmly (needs practise - maybe see some vids on youtube), rotate to 10degr. pitch - hold there,then at 50 - 100 ft AGL continue rotation to 15degr.And last, are you sure you have the numbers right : for a NG -800 with a V1=141 and V2=142 seems to close to each other butnot sure there
My handbook says 2-3deg/sec, with 3 for the shorter (-4,-7) and 2 for the longer planes (-8,-9). I didn't realize this, but the FMC actually incorporates tailstrike into its V-speed calculations.Of course, the book also says not to pause the rotation, but online, most pilots do wait. When I've jumpseated on NWA 757-300s, they call out an initial target pitch at Vr (10 degrees, I think).

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And last, are you sure you have the numbers right : for a NG -800 with a V1=141 and V2=142 seems too close to each other butnot sure there
Well, the guys at PMDG have been so kind to build a FMC that automatically calculates V1, Vr and V2 for us...so any complaint should be adressed to them :(
See FLIGHT TECHNIQUES manual pg 10-4.As noted, tail strike for -800 is 11 degrees.
Thanks a lot, here is what the manual says:<<< A proper rate of rotation for the 737 is 2.5

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