How does a Mooney fly if the prop comes off?

[Bob]

I found this link and started thinking about it in more detail.

http://www.wbtv.com/story/15196616/report-propeller-separat

ed-from-plane-in-deadly-crash-killing-doctor

Does anybody know what happens if a prop comes apart? If one blade is lost or the whole thing comes off? Do the parts exit to the sides or is their a risk of wing or fuselage damage?

If it comes off "clean", and the plane noses up, would it be controlable or is it past the control limits?

Just curious, don't think I saw this discussion yet?

[Chimpanzee]

Hi Bob

was at a flight training outfit years ago when on of their Piper Warriors lost about 3 " of the prop blade on night flight from LAX to Vegas. I was not flying it, but I saw the wreckage when it was brought in. Both Pilots survived with light bruises, as they put the plane down next to the interstate in the desert. However, only because they immediately shut the engine down before the vibration (extremely heavy I was told) broke the engine mounts, which would then have been loss of engine and with that weight gone the plane would have been lost. In this case they kept it under control and crashlanded very well, all thing considered.

I have to look at my weight and balance, but I think a clean separation of the whole prop would leave the plane still controllable, but the loss of the whole engine certainly not.

The main thing that I learned from the accident is that I would shut down the engine immideatley if it suddenly started to vibrate extremely. After all, with a windmiling, or better, stopped prop, the Mooney is quite an efficient glider.

Cheers

Norbert

[Marauder]

I found this link and started thinking about it in more detail.

http://www.wbtv.com/story/15196616/report-propeller-separat

ed-from-plane-in-deadly-crash-killing-doctor

Does anybody know what happens if a prop comes apart? If one blade is lost or the whole thing comes off? Do the parts exit to the sides or is their a risk of wing or fuselage damage?

If it comes off "clean", and the plane noses up, would it be controlable or is it past the control limits?

Just curious, don't think I saw this discussion yet?

I do. I have a friend who survived a prop break that resulted in losing 23 inches on one blade. He said that the E model he was flying went into an extreme vibration. He actually saw the prop piece depart the plane. He was not able to shut the plane down by pulling the mixture because he said the vibration was so bad that he could only slide his hand down his leg and turn off the mags. By then the engine had come loose from its mounts but remained in the cowling.

He landed in a hilly area. Would have been fine had it not been for the field he selected was uphill and he pancaked it. Both he and his passenger suffered back injuries.

He claimed and this was ithe accident report, that he actually saw the blade come up over the windshield. I suspect if it departed in another part if the rotation it could have hit anything on the plane upfront.

[AndyFromCB]

Q: How does a Mooney fly if the prop comes off?

A: Gravity

But yes, I have also heard of the engine coming off the mounts and the cowling holding it in place. All of the sudden the million quarter turns needed to be taken off to take a peak at the engine don't sound so terrible.

[DaV8or]

I do. I have a friend who survived a prop break that resulted in losing 23 inches on one blade. He said that the E model he was flying went into an extreme vibration. He actually saw the prop piece depart the plane. He was not able to shut the plane down by pulling the mixture because he said the vibration was so bad that he could only slide his hand down his leg and turn off the mags. By then the engine had come loose from its mounts but remained in the cowling.

He landed in a hilly area. Would have been fine had it not been for the field he selected was uphill and he pancaked it. Both he and his passenger suffered back injuries.

He claimed and this was ithe accident report, that he actually saw the blade come up over the windshield. I suspect if it departed in another part if the rotation it could have hit anything on the plane upfront.

Just had a thought after reading this story. Maybe they need a safety switch with some sort of accelerometer mounted on the motor so that if the engine shakes violently at the normal engine frequencies, it automatically kills the mags. Sort of triggered by a bad shaking back and forth over a short period of time so as not to fooled by turbulence, or other normal flight spasms.

[scottfromiowa]

Just had a thought after reading this story. Maybe they need a safety switch with some sort of accelerometer mounted on the motor so that if the engine shakes violently at the normal engine frequencies, it automatically kills the mags. Sort of triggered by a bad shaking back and forth over a short period of time so as not to fooled by turbulence, or other normal flight spasms.

No thanks. I will just maintain my prop. Having a prop blade/portion of a blade depart is pretty low on my list of concerns...

How many of these occur/year?

In Iowa they have installed cable barriers on four lanes to "prevent a car from losing control going accross median and striking a vehicle coming the other way"...How many times does this occur/year? I know that after active snow events I count over 100 cars/trucks etc. in center median. Now instead of getting towed out they will smash into the barrier damaging the barrier/car/occupants?...and potentially go back into traffic as they are only five feet in from a 1/4 shoulder here. Last year we had no snow. Looking forward to seeing the carnage in Iowa this winter.

You can't engineer out everything. If this happens a lot then I am just ignorant to it. Another reason not to put a three blade prop on your plane

[fantom]

If my prop breaks up and/or comes off in flight, I better have a:

[Parker_Woodruff]

If my prop breaks up and/or comes off in flight, I better have a:

And that picture actually resembles a Mooney...

[aviatoreb]

No thanks. I will just maintain my prop. Having a prop blade/portion of a blade depart is pretty low on my list of concerns...

How many of these occur/year?

In Iowa they have installed cable barriers on four lanes to "prevent a car from losing control going accross median and striking a vehicle coming the other way"...How many times does this occur/year? I know that after active snow events I count over 100 cars/trucks etc. in center median. Now instead of getting towed out they will smash into the barrier damaging the barrier/car/occupants?...and potentially go back into traffic as they are only five feet in from a 1/4 shoulder here. Last year we had no snow. Looking forward to seeing the carnage in Iowa this winter.

You can't engineer out everything. If this happens a lot then I am just ignorant to it. Another reason not to put a three blade prop on your plane

Good story about over engineering the highways and trying to engineer out danger leading to unintended consequences.

What does three blades vs 2 blades have to do with it - 3 blades makes 3/2 times as likely to loose one blade?

In the story of the M20K he lost a two blade prop - but the whole prop and more than likely that incident had something to do with a jimmy-rigged fix as this was immediately following a prop replacement following a prop strike for a ferry flight.

OMG I sure hope my prop stays on - surely if the airplane is still controllable with all that missing weight it would require a very large and unusual amount of forward pressure to maintain level flight to prevent the airplane from going nose up and trying to stall.

I am guessing that without an engine, if an engine shook away and fell off, that no amount of forward pressure could be enough to keep the airplane from rising up and stalling.

[DaV8or]

I am guessing that without an engine, if an engine shook away and fell off, that no amount of forward pressure could be enough to keep the airplane from rising up and stalling.

Yes. You are on a one way trip to oblivion unless... a higher power loves you so much that you land on top of a pillow factory.

[Marauder]

And for those who are interested in the specifics of the accident: http://www.ntsb.gov/aviationquery/brief2.aspx?ev_id=20001212X19629&ntsbno=NYC99LA202&akey=1

[scottfromiowa]

Good story about over engineering the highways and trying to engineer out danger leading to unintended consequences.

What does three blades vs 2 blades have to do with it - 3 blades makes 3/2 times as likely to loose one blade?

In the story of the M20K he lost a two blade prop - but the whole prop and more than likely that incident had something to do with a jimmy-rigged fix as this was immediately following a prop replacement following a prop strike for a ferry flight.

OMG I sure hope my prop stays on - surely if the airplane is still controllable with all that missing weight it would require a very large and unusual amount of forward pressure to maintain level flight to prevent the airplane from going nose up and trying to stall.

I am guessing that without an engine, if an engine shook away and fell off, that no amount of forward pressure could be enough to keep the airplane from rising up and stalling.

I think the two blade was replaced with a three-blade. The three blade prop failed...I have a three blade prop on my plane. Just a 1 more blade to fail...A little sarcasm in first go-around...

[Bob]

I agree that the chance of this happening is so, so, low. But just came accross it and wanted to hear about experiences and thoughts from others. I figure that every part of knowledge may help out some day.

I remember reading a post in the past of a guy just last year that had a inflight breakup in another aircraft (not a Mooney) and it did not end good. The thread talked about weather and turbulence that tore the plane apart. I listened and shoved it in the back of my hear. A few months later I had a real "wild Ride". It was the roughest flight I had in 250hrs. I pulled the throttle and nosed up to slow it down fast. It was information from that thread that helped me keep my cool and respond quickly. Thanks for sharing thoughts on this!

[WardHolbrook]

Thirty years ago I was flying a friend's ultralight when it threw a blade. The resulting vibration tore the engine from the mounts. I don't imagine that the mounts on a Mooney (or any other airplane) would be able to stand up to that intense vibration either. A few years ago there was a Malibu that lost the entire propeller on climb out out of Aspen (KASE). That guy was able to return to the airport and land safely.

[DaV8or]

Thirty years ago I was flying a friend's ultralight when it threw a blade. The resulting vibration tore the engine from the mounts. I don't imagine that the mounts on a Mooney (or any other airplane) would be able to stand up to that intense vibration either.

Just curious, was the engine completely separated from the airplane and was the design a pusher and therefore it didn't effect CG as much as it would in a tractor design? I have always heard that the engine leaving any airplane that is a conventional tractor design, was a death sentence.

[Marauder]

I believe that many Formula One racers (that often run very high RPM) have straps attaching their engines to the airframes just for this reason. To at least keep the engine attached and hanging in the event of a prop failure. I wonder how many racers have been saved this way?

I also fly RC airplanes and have had two motor mount failures with my electric-powered planes. Fortunately on both occasions the motor and prop have remained attached to the aircraft and hanging by the three electric power wires. On one occasion the wires were twisted around each other so badly that the motor was not economically repairable. On the other occasion I figured out what was going on a little bit quicker and was able to pull the power in time to avoid damage.

It would be a wild and very violent ride, to say the least, to have this happen in your Formla One or any other plane.

Jim

Sorry, can't resist asking this question. Did the little plastic RC pilot survive? on a serious note, my friend who experienced the prop break said the vibration was so intense that he felt he was absolutely lucky to be able to react at all, let alone quickly enough to shut down the motor before it departed the plane. He said if he hadn't actually seen the piece depart, the confusion about the immediate vibration was very disorienting even with the visual clue.

[carusoam]

How fast and what order can you pull the power out?

Red knob, blue knob, black knob?

Or blue knob, red knob, black?

Or pray first, then adjust knobs?

Or it just doesn't matter. Fly whatever you have left to the ground.

Or pray first, then go flying.

I go with maintain what you have to the highest level possible, then recycle through the above list as many times as you have time on your hands...

Who's idea was this one anyway?

What's my chance of having an MI while flying?

Or hitting a falling meteorite or Cessna 150?

Best regards,

-a-

[WardHolbrook]

Just curious, was the engine completely separated from the airplane and was the design a pusher and therefore it didn't effect CG as much as it would in a tractor design? I have always heard that the engine leaving any airplane that is a conventional tractor design, was a death sentence.

It was in a pusher design. It belonged to my friend who to this day is involved in the production of several designs. He sews the wing covers and has a couple two or three of his covers on aircraft on display at the Smithsonian Air & Space Museum and Museum Annex. One of the well-known UL propeller builders have him the prototype propeller to test on his UL. It was a composite, ground adjustable design that worked very well up until the point that it threw the blade from the hub. The engine was torn from the mounts but some how ended up tangled up in the aircraft structure so there was really no major change to the center of gravity. I didn't have too long to worry about it though, it had amphibious floats and I was over a cornfield on downwind to a farm pond at 400' agl. It was right before harvest time and the corn was pretty tall. I remember going into the tops of the corn and the next thing I know, I was upside-down and rolled up into a big ball - me, that UL and a bunch of corn. Luckily, I wasn't hurt. Did I mention that was my last UL flight?

[PTK]

"Ask not what your prop can do for you; ask what you can do for your prop!"

Be nice to your prop and it won't leave you!

If my prop decides to leave me during flight, I must've been really, really, bad! Kind of like the bride not showing up at the wedding leaving the guy standing there! Or showing up but refusing to say the I do part!

"Do you...bla bla bla...." "Oh no I don't! No No No...!!". Ok not quite!

[WardHolbrook]

No thanks. I will just maintain my prop...

Proper maintenance is the correct answer for an lot of questions having to do with airplanes. One thing that a lot of guys don't realize is that propellers have recommended times between overhaul just like engines do. Some folks tend to turn a blind eye towards propeller maintenance.

To answer the OP's question, if the entire propeller comes off, the airplane would turn itself into a glider with about the same L/D as an old Schweitzer 2-22 and would fly just fine. (The Mooney Rocket conversion uses engines and propellers from Cessna 340s. I've seen pictures of a Mooney Rocket in-flight with its prop feathered.)

If the entire prop didn't leave the airplane then you're survivability likely would depend upon how much of the prop you lost. If it's just a piece and you can shut the engine down fast enough then you'll end up with a "glider with about the same L/D as an old Schweitzer 2-22" assuming that you can stop the prop from windmilling. If you throw an entire blade, then you ain't going to be able to react fast enough... That engine is going to tear itself from the mounts and unless you're incredibly lucky your last few minutes of life will be as a passenger in an aerodynamically unstable, out of control, airplane fluttering to the ground. (A couple of years back I did read in one of the flying magazines about some crew in a Metroliner commuter that threw a blade and somehow the cowling kept the engine with the airplane. They manged to get the airplane safely back to the airport.)

Scott has the best answer, just maintain your propeller properly then you'll be able to spend your time worrying about other stuff.

[Alan Fox]

Generally when a prop fails , people die.... The guy surviving with the broken prop is the luckiest man in the world.....the centrifugel force of the one blade against the mounts is measured in tons , maybe tens of tons.....they instantly break the mounts ....and usually the engine departs the airframe...... Continental had a problem with the crankshafts failing at the flange and the props departing the aircraft in whole , most of these emergency landed safely....This is the VAR crankshaft AD ....The crash in question probably lost a blade...

[Piloto]

Q: How does a Mooney fly if the prop comes off?

A: It quietly glides down.

[garytex]

Actually I think the issue is germane for the A1A engines. As uncounterweighted engines they evidently are more stressful to props, and generate the highest incidence of prop tip breakage (3-4" off the tip) of any engine per The Avaition Consumer. Shutting down quick is important, and should be occasionally mentally practiced.

[Hank]

Q: How does a Mooney fly if the prop comes off?

A: It quietly glides down.

IF the loading isn't so far aft that the loss of nose weight puts you too tail heavy.

IF there is no significant other damage to the nose.

IF the engine isn't torn loose from vibration.

IF you shut the engine down immediately.

I would say, when the prop comes off in flight, all single-engine aircraft will fly poorly if at all.

[DaV8or]

IF the loading isn't so far aft that the loss of nose weight puts you too tail heavy.

Climbing out when the prop is at it's highest stress, at gross weight, the prop comes off. It does make you wonder how fast would you go to stall and could you recover?