Will the plane take off?

Jonn

New member
Hello, I am almost finished with my v-tail pusher plane, but now I am wondering if it will take off with wing that has negative AoA when on ground.
1701187567952.png
 

quorneng

Master member
If the AoA is such that the wing produces no lift it will not take off unless the nose wheel hits a bump or the elevator elevator becomes effective enough to lift the nose causing the wing AoA to create sufficient lift to keep the plane at a flying attitude.
Many full size aircraft will not take off in a practical distance unless the nose is positively raised once sufficient speed has been achieved.
 

RossFPV

Well-known member
Hello, I am almost finished with my v-tail pusher plane, but now I am wondering if it will take off with wing that has negative AoA when on ground.
View attachment 241104
Probably not but if it does it will need a lot of speed, you could move the main landing gear forward and put a tail skid on the back or you could make the front landing gear taller to get a positive AoA.
 

JFC24

New member
RC airplanes are subject to the same laws of physics as their larger cousins but they fly differently. Ask Samuel Langley.

Yes, it will fly if you get enough speed to give yourself elevator authority but that a big if.

One of the jets I fly has a negative AOA on the ground and in cruise of about -3°. Because of that my ADI shows us nose low, even at FL400.

Taking on in a transport category aircraft isn’t like taking off in a small Cessna or an RC plane.

We have several speeds on the ground to pay attention to:
Vmcg (minimum control to give the flight controls authority on the ground)

V1 (Takeoff safety speed). When we give a takeoff briefing it usually says something like: “Anything after V1 is an inflight emergency. We will take it in the air and run the appropriate checklist….”

Vr (rotate). At that speed we increase pressure on the elevator and set a deck angle for initial climb. This lifts the nose off the runway and you ride a wheelie until the airplane flies away from the runway.

Your aircraft will have to perform that way and not jump into the air like a normal RC plane.

It can be done, it is done with large RC planes, and is a viable technique but it’s up to you to decide if you want to adjust your design a bit for a more traditional skillset. As long as you don’t get a prop strike on takeoff, the worst thing that happens is you build a new plane.

Go for it, have fun, and learn something new you can share with others.