# Takeoff problem

Hello. Recently I have been having trouble taking off. I do not crash but what happens is when I pull up to take off, the plane shifts to one side when it really should go straight up.

I pull up at about 100kts and with flaps at like 30.

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What plane are you using and you should usually takeoff with flaps from 20 degrees to 10 degrees

737-800. Will the 20 flaps fix it alone or what else is happening here?

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It could be there is to much wind and your plane is flipping. If its not that make sure synchronization is on on the weight settings. In a 737-800 I pull back at around 145 knots to 135 nots with 15 degree flaps when i have a heavy load. If i have a medium load the flaps are at 10 degrees. If i have a light load the flaps are at five and i rotate at 135 knots.

Sounds like the issue may be wind. :)

@stevetheipadâ€¦ Steve, suggest you consult the Tutorials and review the free FAA publication â€śPilots Handbook of Aeronautical Knowledgeâ€ť and do a Google search on your aircraft of choices characteristic. Vâ€™s flap settings, angle of attach etc are readally available utilizing any search engine. Hope this helpâ€¦ Max Sends

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Although I suppose theoretically you can use flaps 30 for take off on a 737-800 it really isnâ€™t used in the real world. Flaps 15 take off is pretty much the most flaps you would use, and typically Flaps 5 is used. Even a very lightly loaded 737-800 with Flaps 15 would have a VR of around 120 kts, and Flaps 5 would be 128-150 kts. Tbh I would suggest use a rule of thumb of Flaps 5, VR 145, and V2 160 kts and see where that gets you.

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Well if youâ€™re flying a 738,

100 kts. is too slow take off with a 737-800 under normal conditions.

30 degree flaps is wayy too much flap for takeoff. 10-15 degrees is what I use.

If the wings change from level flight to at a severe angle to the ground, then the plane is stalling, which can be solved with more airspeed.

And if you really want to calculate exact V speeds try this spreadsheet:

https://docs.zoho.com/sheet/published.do?rid=mr778a62fed16a6b0406794fdd3d94be61001&mode=html

In real life after putting the data in to the FMS the V speeds are calculated for you depending on what takeoff flap configuration you use.

Try and maintain V2 speed as you climb (pitch around 15-20 degrees) until you get around 1500ft above ground level (acceleration height) where you drop the nose a few degrees and start to gradually accelerate whislt still climbing. Start bringing your flaps up once you go past V2 +15 kts, and generally you should be at Flaps UP beyond 200 kts.

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For a 737-800 at near max take off weight (around 174,000 lbs, 79 tons) Flaps 5 V speeds would be V1 153 kts, VR 156 kts, V2 161 kts, V2 +15 176 kts. All from the speadsheet I posted a link to.

EDIT: this is for fairly benign conditions and near sea level, obviously if temperature/wind/runway altitude are very different this can alters the speeds.

Hmm. You need to have the flaps at 5*, and you also need to be going at about 130 kts. The reason it tips over is probably because:

1. you stall
or 2), the wind velocity and direction is effecting your aircraft.

I use flaps 5, and start pulling up after 140kts

You dont have a 737 takeoff at 160 knots with 5 degree flaps I use ten degree flaps and lift off at 145

Ok. I guess you know better. As I say, the figures come from the spreadsheet and seem to be in keeping with my own experience so I have no reason to doubt them. Seems pointless to ask the question if you think you already know the answer.

Do you have autopilot on when you takeoff? I found out that when you take off with autopilot controlling the speed, you always shift to one side.

Okay this may seem silly but check that you are calibrating your device correctly by watching your artificial yoke.

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Hi Samuel! @samuel_mashil
Could your actual airspeed that the AutoPilot is maintaining be the issue? If the
Speed is too low, then you aircraft could well be stalling as you rotate and ascend, which would subsequently cause the wings to drop(The Plane banking to one side)

So maybe try going a little faster, with perhaps a little less weight. Also check the weather,wind may be an issue.

And as @Louis_Cochran Said, ensure your device is properly calibrated!

Hope this helps! :) ;)

No, I donâ€™t do that normally but I just tried it to see what happened. I took off at 180 knts while autopilot made my speed go up to 240 knts.

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