Is it a bad idea to......
 

I've been flying for several years and have always thought or it was alluded to that it is "bad" to run the engine with the wings stab or canopy/hatch removed.
so as I sit here in the man cave looking at my 40% Sukhoi I wonder if this is true the canopy is plastic the wings and stab bolt to the fuselage. So they don't add to the structure strength. What do ya all think

I think it's bad BC the oil residue will seep in open areas. IMO

More parts attached to absorb the vibration of the engine and not just the fuselage.

I have run the engine without wings, etc. many times without any problems. I do get concerned about getting trash inside the fuselage, but that is about all. As long as I can secure the fuselage so that it can't run away I don't see a problem.

Some planes will visually shake so bad its obvious its harmful. That doesn't mean yours will..but if you have ever seen a plane that does shake !!!! you won't soon forget it ! hahaha

OK let me first report on what I know from running for three years, two races a year what I called the 'Wingless Trainer' races. These were anything up to around .60 size that could taxi without a wing and included conventional trainers, all manner of sticks and all types of landing gear. These were very popular races and well attended and yes I know they are smaller airplanes and not giant scale.

Most of the racers, raced open with no added covering over the wing saddles. I and a few others did fabricate some fairings simply because it looked cooler.

Oil seepage was never an added problem and I do not recall any having coated their electronics etc with oil. Structural liabilitys was never a problem at all.

Lets move on now to the giant scale and first what I have actually experienced with my only giant scale airplanes of that type. I have static ran both my 50cc sized Katana and my Yak 54 both without wings and without canopys for considerable periods of time with no apparent problems other than the possibility of kicking up dirt from the ground and that why this was done on our new concrete runup pads with removable restraint yokes. I might add I could discern no more or less vibration with or without the canopy.

Now for my own uneducated speculation: I seriously doubt that structural integrity is affected only marginally if at all without the wings even for taxi work. I also do not believe with the poor structural design and fitting of most canopys that they provide much structural rigidity at all and also for the same reasons its doubtful that they contribute much to vibration damping.

There I said it! Free at last, Free at last:p

John

I have no experience with anything over 6' WS but up to that size, I never had a problem. I am sure the vibration nodes are different but the test stand soaks some of that up. I use cling film to close off the fuse.

Take the time to bolt the wings on they will absorb a great deal of vibration. Your Sukhoi has a very lightly built fuse and will take a pounding from the 150 mounted on the nose. You just can't compare the vibration of a 150 to glow powered airplanes.

I was always afraid that the torque might flip the fuselage on a wingless taxi test so I always put the wing on. I guess if some guys make ground racers out of them my fear is "groundless". (pun intended)

Not really, I have had both small and large planes try to flip over when running them up without the wing attached. Vibration is why most people assemble the plane before run up but the flip over is why I always attach the wings. I don't always have the cowl or canopy on, never really had any problems with dirt or oil getting into the plane.