My trainer will launch either by hand or ground but i ran across this guy with a corsair telling me that he can only launch off the ground. Is that true with planes of that type? Why?

It may be more of a function of the pilot than the plane. Some people are simply not coordinated enough to throw the plane and get their hand back on the control stick before the plane crashes.

Some planes are simply too heavy to hand launch. Some need to be going faster than you can run/throw.

There are many reasons.

What kind of plane are we talking about? Many manufactureres make corsair models. Some can be hand launched and some probably can not.

While there is no hard fast rule I would say that the weight of the plane, the wing loading, the power of the motor and the strength of the launcher are the key factors.

For example, I believe the new Aerobird Xtreme is over 2 pounds and it hand launches just fine.

For most parkflyer type planes, say under 20 ounces, hand launching is fine. If the plane has a very high wing loading, say over 16 oz/sq foot, and a less powerful motor, it might launch better off the ground as it could be hard to get it up to flying speed fast enough by hand.

Many people make the mistake of throwing the plane UP on a hand launch. Many times that will cause a stall and the plane will crash. Hand launches should be strong throws going out level at full throttle. Some flying wings are launched by hand with the motor off and then the motor is turned on, but those planes glide very well.

If that is a GWS corsair, I am quite confident it can be hand launched.

Thank you for your responses. The main reason i asked is that the property i usually fly at does not have a runway. I didn't want to buy a plane that i couldn't get hand launched.

I fly in a grass field. Virtually every plane at our field is hand launched. We don't have a runway of any kind and most of the planes are in the parkflyer class which don't launch well off grass unless it is very short and the ground is very smooth and well groomed.

We ain't got none of dat!

Most park flyers can be hand launched. In fact some can only be hand launched and not rise of ground. I think most of the warbirds from GWS and Alpha can be hand launched.