# What degree of elevator deflection is required to takeoff?

I've always wondered how much the elevator actually needs to deflect in order to cause rotation on takeoff for a large airliner. On videos I can rarely see the elevator moving at all.

I'd really like to know what the degree required is for a 777, but if someone can provide this for another airliner that would be ok. I presume that it depends on takeoff speed, which is of course variable, but let's see what you can come up with.

• Degree measured from what? The elevatot doesn't have to deflect much because the whole stabilizer is already turned to an optimal setting for take-off. Even the angle of attack for the stabilizer would be hard to say since it depends on speed, weight and center of gravity.
– Sami
Jul 3 '15 at 14:47
• @Sami The stabilator AoA might not be hard to see. On the EMB-145, e.g., it is almost always +8 degrees for takeoff and if you look closely (on ours at least) there is a scale painted on the tail to visually read the stabilator AoA. Jul 3 '15 at 17:17
• There's a scale on the tail of E190 also. I'm pretty sure it's not degrees though. Even if it was, I would still find it difficult to determine the elevator angle during takeoff.
– Sami
Jul 4 '15 at 11:55
• Stabilator settings vary by CG, takeoff weight, and power setting. In Boeing 747 manuals they're in section 1-06-001. You can look at an example at terryliittschwager.com/WB/manuals/… starting at the 71st page of the pdf. I don't know how to convert from the stab units to degrees. Jul 4 '15 at 17:19
• @casey Sorry, I was wrong. They are degrees. Just checked..
– Sami
Jul 5 '15 at 13:38

The Boeing 777 has a computer based weight and balance system, called Accuload, which will compute the proper take-off trim setting, therefore, no discrete values can be given. With the recommended trim setting, the pilot will apply forward pressure on the control column until roatation speed ($v_R$), relaxing control forces to neutral for smooth rotation.