phlpsfrnk

There has been much discussion in these forums about quad copters and near misses with commercial airliners and questioning of how much damage could a quad 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, well equipped Quad copter at approximately 2 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.

Frank

ramboamt

My Feedback: (36)

You should also have one answer stating ALL THREE OF THE ABOVE. It all depends on where it strikes the engine: on the blades, nose cone or inlet lip.

littlecrankshaf

My Feedback: (58)

Yep...and its fairly likely the pilots would never even know...but it possible that the damage could cause an imbalance so great the wing rips off...causing the plane to crash into a bus full of Nuns at the orphanage, starting a fire that kills everyone including a future President that would have finally found ways and laws to meter the air we breath and the water we drink.

Hossfly

Frank, your question fails to state what kind of "airliner". There are many of the 2-engine airliners and also many of the 3 and 4 engine airliners.

As ramboamt states it could be, "All of the above." Turbo fans compress the air which will compress much-much more as it flows over the compressor section for more compression. Things do get hot there.
The turbo fan itself is fairly well heavy duty. The compressor section is not so well enhanced.

init4fun

I attended "East Coast Aero Tech" a zillion years ago to earn an FAA A&P mechanic's license . We were shown films of tests whereupon turbine engines were "destructively tested" as to what they could injest with and without suffering major damage . Things as large as big seagulls wouldn't even cause a change in the sound's pitch , whereas something as small as a 5/8" box wrench was enough to cause enough damage to flame out the engine . It truly is "the luck of the draw" anytime something gets into a turbine's intake , and bird bones being softer than brushless outrunners I can easily see where a quad in the intake possibly COULD result in engine destruction as did the 5/8" wrench .

Is it a certainty that an engine would grenade after swallowing a quad ? Of course not ! Is it a possibility ? Hell yea ! could even be a probability .

Best thing would be for ANY model aircraft to stay out of the way of something that has more "right" to the skies than any unmanned craft has !

littlecrankshaf

My Feedback: (58)

Spot on! The argument against quads is getting old.

ira d

Anything weighing two pounds has the potential to cause major damage to a aircraft be a prop strike or being ingested in the engine. It may not cause the
engine to be shut down but I bet at some point there would need to be some repair done as a result of the strike.

littlecrankshaf

My Feedback: (58)

.
True but if we keep asking questions about "how bad are those quad copters???" everything else will seem to be benign...I guess that's the theory anyways...

init4fun

I think that we as a flying community should be encouraging proper use of quads , rather then advocating "banning" them , so LCS and I are on the same page here .

The "quad Genie" is out of the bottle , and ain't goin back in ! Just as every new technology before it there are folks who will abuse that technology to great notoriety . The rest , guys like Rob 1260 and others , will go on using that technology properly , and get great enjoyment out of it . Now , due to the few "bad apples" , regulations will end up being enacted to punish improper use just as happened in the "barnstorming" days of early full scale aviation . There ya had it , a new technology , a few abusing it , and a bunch calling for banning ALL airplanes , just about a hundred years ago . And yet full scale survived . Got a few regulations slapped on their butts and likely ruined the "fun" for a few , but the majority of the public went on to enjoy full scale aviation just fine in the relative safety of having a few common sense guidelines to fly by . Whats common sense for a quad ? The same common sense as for any remotely piloted craft , to ensure it hits nothing and causes no harm . Stay the Hell outta the way of the full scale . So long as someone can enjoy their quad or any other RC toy without endangering others lives (as in the extreme example of a quad in a Turbine's intake) , a ban is just too drastic .

Couldn't we just ban reckless Morons from using em , and BAM , "problem" solved ????

init4fun

Last sentence said in jest

FMRR

Ihttp://www.jetlegend.com/null.gifn itsfun,
I'm current A&P, you remember your instruction well. ANY thing like a quad motor ingested into the N1 N2 cold section compressor section can destroy the engine. Good call.

loopdeeloop

My Feedback: (4)

There is not enough data here to make a reasonable response. Unless the quad is in FPV flight the operator would not even see it if it is actually at 2500 ft. A video on web a couple of years ago showed a collision between a hovering scale airplane and full scale biplane at a private airstrip in Colorado. Airspeed of the full scale was far below that of a jet at 2500 feet and the collision nearly took out the biplane. Yes, the model was heavier than a quad but hovering so it's speed was zero. Does "Miracle on the Hudson" ring a bell? If a flock of birds can take down an airliner, a quad could as well but it would depend on circumstances.. Would it cause a turbine failure if ingested? Hard to say but I would venture the resulting damage would set the owner of the quad back a few coin if it did. We just saw a turbine failure at a critical time on a Taiwan commuter plane and it went down. So your poll, although interesting is rather nebulous since the scenario is not very well defined.

JohnShe

I spent some time in the Navy working on an aircraft carrier as regular crew. Often, after or during, a hard days work, I would have the opportunity to look down on the flight deck from high up on the island. From there I could see the Airedales preparing for aircraft launch and recovery operations. It was amusing to watch a long line of them walking abreast from one end of the ship to the other stooped low in sort of a duck walk. What they were doing was excruciatingly important. They were looking for any object that could cause foreign object damage to the engines or airframes of the aircraft. I would see one of them pause every now and then to pick up an object that was too small for me to make out. It might have been a screw or some other fasterner. It may have been tiny but it was significant enough to pick up.

Let's make it clear, no object of any size or hardness belongs in the flight path of any airplane. There are plenty of federal regulations that apply to these situations. I expect the FAA and local law enforcement to enforce them brutally.

By the way, my answer is: all of the above.

FMRR

Johnshe,
Your 100% spot on.

Hossfly

Very nice stuff above. The main theme, as i think, is the quads need to be significantly commanded to be kept out of the way of full scale airplanes.
Now that is the same problem that is big time around the Highways and even lesser roads. Every day the highways and roads are down because of dumb-butted people driving at break-neck speeds and damage from fender-benders to ultra bad wrecks with multiple deaths. Personally I despise speeders, text-messaging while driving, and drinking alcohol drinks before and during driving. It will happen. So what is the answer? IMO, not just a "fine" but a minimum of 6 months in the slammer!
My bet is that there are 1000% more quad fliers than AMA RCers. How can it be controlled? No Frigging idea, except that learned RC fliers should be aware of those problems and do their best to assist anyone doing the wrong things to give significant thought to what danger they could develop especially in the vicinity of full scale.

Explaining the difference between knowing and not knowing or not caring can be helpful to those that do care but do not know. One of my days was returning to Laredo AFB after a 3 day cross country. Decided to stop at Randolph AFB (San Antonio) for some lunch and fuel. VFR approach, on the downwind leg (1500 ft. above ground), BOOM, airplane into a heavy shudder, EGT went to max, declared emergency, shut the 0ne & only engine down (T-33) rolled into a steep bank and a dive turning to runway end, had enough hydraulic pressure to drop the gear and some flaps down, then rolled out on a short final and landed. Got towed into the maintenance area. There were several holes in the airplane from the turbine blades behind the OLD Centrifugal Flow engine. The CF Compressor stood a lot of hard use. OTOH the turbine could sling a few blades now and then. When anyone becomes a "Book of Knowledge" ref. the actions of a jet engine, my bet is there will be a few surprises just waiting.
Knowledge is the main thing, but you ain't gonna' find it in the Hobby World other than those that do it frequently and WISH to remain safe.

loopdeeloop

My Feedback: (4)

Responsibility is a characteristic that does not exist with some people. Two summers ago I received a call from a friend who asked if people should be flying RC airplanes in the parking lot of our water park; Any reasonable person in a heartbeat would answer no. As the club president at the time I went to the park and sure enough -- two adults in their late 20's - early 30's were flying 40 size nitro airplanes. Kids were riding bikes in the parking lot, houses across the street, and the water park itself adjacent to the parking lot. See anything wrong with this picture even though there is no picture? These dudes didn't have a clue that anything could possibly go wrong. They didn't even blink when I told them they were in the flight path to the airport and were less then a mile from the end of the runway. They didn't know what the AMA was or what the AMA safety recommendations were. This is the category of person we are dealing with whether its airplanes, helis, cars, or quads. At a swap meet last fall I heard a noise above me. Here was an 8-motor unit with a GoPro taking pictures of the event. I could have stuck a broom handle in the air and taken this thing out. At probably 4 - 5 pounds, this thing would have hurt someone or damaged a lot of stuff being sold. The fellow in the trailer next to me said "where is a shotgun when you need one". It seems you simply can't cure stupid.

cloudancer03

My Feedback: (22)

Ever see what a rock dropped off a overpass does to a windshield on a moving car..it likely injures the driver and causes a a life threatening situation.so what if a metal or plastic object is ingested into a passenger plane jet motors do you really believe it won't cause a potential catastrophic event.think again.

FLAPHappy

My Feedback: (209)

John, you are correct. A jet engine is designed for intake of air through the Impellers, Air ONLY. not screws, bolts nuts, or anything else. If a hard metal,plastic, or foreign material enters the impellers, it will fracture then shatter the others, which causes a rapid stop to the function of the impellers. The engine will shut down or implode. Nothing but AIR is to be ingested into any jet engine. I have worked on B-52's and KC-135's, and I believe this to be a true statement. Look at prop driven aircraft. Throw a bolt in the propeller , what happens?
Damage to the prop, which creates unbalance, which creates damage to the crankshaft, bearings, valves etc. That also will cause shutdown in certain cases. Birds, are also a problem near Airports, and have caused many aircraft to make emergency landings as you are aware of. To many uneducated wanna be pilots are buying these "Drone" Quad Copters without knowing the responsibility they are undertaking. This has become a very serious problem for the FAA and the AMA, but it continues. Once a serious accident happens, LOOK OUT!

Sport_Pilot

I agree it could be all of the above. But I think a single 2 pound sUAV would more often have minor damage with no loss in power. They will ingest a single 5 pound bird with no loss in power and I cannot see a 2 pound sUAV causing more damage than a 5 pound bird. Now a bizjet, or older airline, or military plane depending on the plane may cause loss of power, but airliners are built to different standards.

ramboamt

My Feedback: (36)

The bird is flesh and bone whereas the sUAV is plastic, aluminum, steel and the Lithium battery. Which one is the softer in materials of the two? If you say the sUAV well I'm sorry it is NOT!!!

littlecrankshaf

My Feedback: (58)

Here is a good video about getting sucked into a jet engine. https://www.youtube.com/watch?v=vHtgXsIxA8A

ramboamt

My Feedback: (36)

Yes this is a good video of what happens when a foreign object is ingested into a jet engine. Did you noticed the, at the end of the video, sailor sitting to the left of the other sailors had only bandages and all of his appendages, the engine was "FOD" by his head set i.e. plastic and steel and some small rubber bits, and his body blocking the air flow into the inlet causing a compressor stall, the flames out the tail pipe. This goes to show that Plastic, Steel and Rubber can destroy an engine.

Sport_Pilot

Softness doesn't matter, a pound of mud in a bag would do as much damage as a pound of lead, maybe more because it is larger. At high velocity mass matters most, it's like jumping in a lake of water from a tall bridge, it will kill you just as fast as jumping on a concrete road.

Sport_Pilot

A sailor is a lot lager than any sUAV. Also military aircraft do not undergo the same design and testing as an airliner engine.

FMRR

Gentleman, I am only posting a comment because I have seen this question a few times now. So I hope I am perfectly clear. A small screw or nut can destroy turbine engine. You are putting the flight crew and passengers in extreme jeopardy. I am beside myself why anybody would think it's ok to fly anything in the flight path of a passenger or miltary aircraft. .