Hi there all,

I've been flying my plane for more than 1 1/2 years, Im gonna buy my 3rd airplane, I ain't gonna ask which should be the best third plane, probably, it would be a warbird or something like Venus kinda stuff. I love fast planes with good speed, though my high wing trainer used to fly at good speed with ASP .46. and I love to take low passes a lot, I'd take the low pass take the plane up almost vertical upto a good height then make a circuit then go for another low pass. I mostly fly in that manner alongwith some maneuvers.

Now my question is while taking a nose dive from a good height lets say 1,000 feet, what should be the position of the throttle, is it should a full throttle? or should it be at idle postion to take a nose dive? as I was told by some flyers that taking a vertical nose dive with full throttle flooded the engine and it would stall it, is it true? So what should be the position of the throttle while taking a nose down, then as it reaches to 20 feet above the ground so level the plane and move the throttle up to full and fly away.

I hope it is not a silly question as I used to think about it a lot and my practice was lowering down the throttle 25% and take nose dive. Please advise.

Thanks

Mody

To avoid overspeed you normally want to lower the throttle when the plane enters a dive.


A vertical dive will only "flood" the engine if you do not have it properly tuned.

The idea is to set the engine so that when you point the nose up and it leans out, that it doesn't lean out TOO much.
Likewise when it goes nose down, the engine will richen, but it must not richen so much that the engine cuts out.

Thanks opjose,

I got the idea, its a good answer and I understood it.

Thanks

Mody

Armody, Opjose answer is very good so I will leave it at that. I set my engines to run at idle on vertical
downlines so the propeller will add a brake effect.

Another thing to consider about your nosedive not related to engines, you said 1000 feet to 20 feet.
The plane will carry alot of speed from this height and your airframe (wing setup) may not be able to
handle the loads applied to it. Also if you really plan to do dives to this degree you will want metal geared
high torque servos on the elevator that can handle the loads that will be placed on them. at the
speed the plane is travelling and the force applied to the elevator at pull up, there will be a certain amount
of blowback on the control surface. this will cause the plane to pull up alot slower than usual. And
it may actually meet the ground before it has a chance to level out.

Most of our trainers and sport planes with exposed mufflers, thick wings, tricycle landing gear without wheelpants, and boxy fusilages are so aerodynamically dirty that they probably couldn't reach VNE even in a verticle dive at full throttle. The exception is fun fly/3-D planes which have a very low VNE because of how lightly they are built and sailplanes because they are so clean.

Thanks overbored and B.L.E. for your reply, I understood it, it really depends upon those factors which you mentioned, I would have to learn alot about it. By the way, what is VNE?

Mody

Much to the surprise of the pilot, who will promptly exclaim that there was no response from the plane when it went in!

Velocity Never Exeed. All full scale airplanes have a VNE rating. Sorry about assuming that modlers are familiar with the term.

A full throttle vertical (or near vertical) dive from 1000 feet could be self limiting because the fuel will drop to the front of the tank leaving the clunk sucking air. At full throttle it doesn't take long for the engine to use up what fuel is in a few inches of fuel line .

true, but a 100+ mph it doesn't take long to travel 1000 ft. And balsa and lite ply will break all the same whether or not the engine is running at impact.