There has been much discussion in these forums about RC aircraft and near misses with commercial airliners and questioning of how much damage could a 60 sized RC airplane cause to an airliner. For this poll let’s consider an airliner at approach speed on final about 7 miles out at 2500ft. A typical, 60 size airplane at approximately 4 lbs. is ingested in one of the turbofan engines. Would there be:

A: No damage
B: Minor damage not causing a loss of power
C: Major damage causing loss of power and/or possible engine shut down.

Brad

D: Hell to pay.

I dont think it would be no damage, But it could either B or C but I don't think many 60 size models are flown at 2500 ft but with FPV technology I guess anything is possible.

Aircraft - Beechcraft D-18S. RC airplane - Alpha 60 ARF. B-18 was at 50 feet conducting a go - around at about 120 knots when it met head on with the rc aircraft. The rc impacted the propeller blade and entered the front of the 985 P&W destroying several pushrods resulting in a partial power loss and massive oil loss. The engine was immediately feathered and the airplane successfully landed. Damage was over 33,000 dollars. A 10 pound airplane could easily cause a airplane to crash. Any engine damage to oil, fuel and other exposed engine components will likely result in a fire and powerplant failure. A cockpit hit would be devastating. Any damage to the primary control system would be lethal. Wouldn't matter if it was a rc helicopter, drone or quad.

I voted minor damage, but actually I believe it would be moderate to heavy with partial loss of power.

Brad: I voted for major damage , and yes the engine will shut down. When an object is induced into the impeller blades, it will fracture a few blades, then those blades compound the problem fracturing more blades. You end up with with an implosion in the engine.

Engines are tested with 8 pound birds so I doubt it. Most of the fan blades may go through the bypass and not damage the power turbine so likely only a loss of power from vibration of main fan blade and no damage to compressor blades. Though your scenario is possible (random odds on this), even the turbine can injest a few blades and keep running, but then the power would be real low.

Thanks for the real life account. There is so much to learn from just that one post. I hope people take heed and quit all the silliness that seems so prevalent nowadays.

Yes, especially for the smaller planes a hit could be devastating or a non event. But the odds are that it would be devastating. But this poll was about an airliner, and a head exercise not a safety warning.

One thing is exceedingly clear, nothing good can come from putting our models in front of full scale aircraft.

No one can say for sure what would happen in every case but i'm sure the engine would need some repair to the tune of thousands of dollars even if it did not lose power at all.

What is the message here? "See and Avoid" for whatever kind of RC model: airplane, glider, helicopter, multi-rotor, turbine, EDF and whatever way you control it, conventional Visual Line of Sight, or FPV is the solution......................

Those that are trying to make model to full scale collisions a quad-copter only issue are ignorant.

See and Avoid, See and Avoid, See and avoid.......................
'see

Another point, we talk about airliners, but the most likely scenario is a small plane or helicopter flying low over the flying field. Doesn't matter if they are breaking the rules. GET OUT OF THE WAY.

I voted there will be major damage causing loss of power and/or possible shut down. But actually I'd like to comment further and say that a 60 sized airplane would be ripped to shreds if it went through a turbofan. I don't see how it could survive. The .60 sized engine would not only shut down, it would be damaged beyond repair. I certainly wouldn't buy it even if someone did repair it ... No matter how much JB Weld was used to glue it together!!

Nor would I buy the servos, or the plane! All the glue used to repair the plane would make it too heavy to fly again ... even with a .90 engine.

Brad: it is a real possibility for a quad copter to come in contact with a full scale aircraft. Some of these people do not know of the 3 mile rule, and are new people to this hobby. They are the people that are dangerous, because they don't know the AMA even exists, much less FAA Regs. It has not happened yet, and I hope it never doe's.

Back in about 1984 I was in a Citabria and we hit a falcon 56.. it caved in 4 feet of the leading edge all the way back to the spar just outboard of strut attachment. We were at 1000ft agl and the model pilot didn't think we were anywhere close to hitting.

Two fast points:
1) The FAA/AMA set the 400ft ceiling for one simple reason, full sized helicopters are required to maintain a minimum altitude of 500 feet, a fixed wing aircraft 1000. The 100ft difference is a buffer to prevent the a collision like 2walla just described. If 2walla is correct in how high the Citabria was flying, the Falcon was at fault for being 600ft above where he should have been and, therefore, the Falcon's pilot should have been required to at least pay for all repairs to the Citabria.
2) The clearance between the fan tips and shroud on a turbine engine is only A FEW THOUSANTHS OF AN INCH. If one blade is broken, the fan is unbalanced and will start hitting the shroud. This will cause the remaining blades to break, destroying the engine. If the engine is a twin spool, the interior compressor blades COULD be fine and keep running while the fan disintegrates which could, under the right conditions, give no indication of engine damage in the cockpit.

Yet another real life account of a model airplane hitting a full scale...thanks for sharing! Glad you made it back to the ground OK.

Hard to imagine someone flying a model in any way that might interfere with full scale but it does happen and unfortunately it will continue to happen. I hope the idiot flying the model airplane was held fully accountable...Maybe he was an AMA member and only had to worry whether our insurance would cover him financially or not... Hmmm....

So you were missing 4 foot of wing to the spar? Or do you mean the width of the model back 4 feet which was to the spar?

My guess would be that he meant to say 4 inches vice feet. I believe Citabria cords run 56", 63" and 66" depending on year/model. Pictured is a Citabria wing after conversion to a metal spar wing.



Frank