The pilot, seated in the left seat, said that the instructor pilot, seated in the right seat, asked her to perform a magneto check inflight.
During the magneto check, she inadvertently turned the ignition key to the off position, resulting in a total loss of engine power to the Cessna 172.
As she turned the key to restart the engine, the head of the ignition key broke off.
The instructor pilot attempted to move the ignition key, but was also unsuccessful.
The instructor pilot took the controls and performed an emergency landing onto a school football field near Gates Mills, Ohio.
The airplane landed hard and sustained substantial damage to the firewall, both wings, engine mount and fuselage. Both pilots sustained injuries in the crash.
Probable Cause: The instructor pilot’s decision to perform an inflight magneto check with no suitable area to land. Contributing to the accident was the pilot’s failure to correctly perform a magneto check that resulted in a total loss of engine power.
To download the final report. Click here. This will trigger a PDF download to your device.
This August 2022 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Just yank the wires out of the back of the switch in this kind of an emergency. Breaking the wires results in the mags being HOT.
Technical comment on post. The first picture cannot be the plane that landed on a football field.
Yes, the photo is taken from the NTSB docket on the accident.
Looking at the pic in the docket and google maps of the stadium, it looks like they landed east of the stadium on a long section of grass, with a roadway on the west edge.
It looks like an ok length, but they rolled to the end and into the bushes..
And, the lat/long listed is the grass strip east of the FB field.
Too bad they couldn’t get it stopped in the about 1,200 ft of grass.
When I fly in a new to me aircraft I perform a static check during the run up to be sure the engine can make static before flying.
An experienced CFI or pilot /Mechanic make do these checks for you……Simple and it gives peace of mind……Engine problems or weak mags will show up.
Tell your shop to do these tests, if they say why?……get a different shop!!!
Great comments, all. Remember, GA airplanes are basically consumer appliances, not military jets. Even though GA manufacturers charge 1/4 million $$ and up for their airborne appliances, they still have investors to reward and seek to shave costs wherever the can. Consider replacing two toggle switches for the magnetos: two holes in the dashboard, and a separate wiring harness for each. Now, with a cheap key-operated switch, one dashboard hole and one harness. See the beauty of it? Saves the cost of one switch and perhaps 20 minutes of assembly labor. Approximate net savings: $7.49. Goes right to the bottom line, folks! So what some pilot and passenger face death mid-air checking their magnetos. We sold another airplane! There’s more safety and beef in a Ford 150 than in a Cessna 172.
/J
That might be a good solution, BUT, for a certified aircraft, like the C172, no changes can be made to any system without FAA approval using a form 337 or an STC.
I’m not sure that such a modification to the mag system would be approved.
Experimental aircraft owners are free to make such a modification, and some have.
James Brian Potter would not know that.
GA aircraft have much more in common with an F-16 than an appliance, like a Kenmore refrigerator..!!
Have you ever been close to a GA aircraft..? I’m sure you’re familiar with a refrigerator,!!
An inflight mag check is a maintnenance procedure done by an experienced individual. As an A&P I perform this inflight and after an annual/ 100hr, to be sure both mags will operate under load.
rwyerosk
Real life scenario back in the 90’s. A neighboring maint shop spent hours unable to nail down a “transient” rough runner. The shop owner told the pilot that next time the roughness appeared to cycle the mags and try to see if a mag, under load, was the issue. As the pilot and his wife started their climb out in their Beech Sierra after this diagnosis the roughness returned. The pilot quickly turned the mag switch one notch. When the key wouldn’t allow him to go back to both he “ jiggled” it, ( high stress 200’ up) …eventually to off. And there it was when the FAA investigator got to it. He operated the switch normally two or three times and was going to move on to the next item when one more try locked the switch in off…. The whole issue was a failing switch. Neither the pilot nor his wife were injured in the gear up landing/flop in the shallow snow in only semi clear field for miles…. about half a mile from the runway but both jammed their knee trying to step down from the wing already at ground level …. Do NOT “try stuff” without considering the options first. Murphy is a flaming optimist!
In addition to that scenario, some very worn key switches can allow the key to be removed in other than the ‘off’ position.
So, it would be possible to be doing a inflight mag check and inadvertently pull on the key,
and partly pull the key out, jamming it…
When on the ground, without the engine running, I do pull on the key, to be sure that it will not pull out in the other 3 positions, just the ‘off’ position.
Turning the mags. off in flight is a very dangerous thing to do, it is not recommended at all under any circumstance, there is a chance of blowing the top out of one of the pistons among many other bad things that can happen by doing that. Ignore anyone that tells you to do that, would you turn off the fuel selector valve to check it ?? for any reason ??? than why in the world would you want to turn off the magnetos ??? What ever reason or alleged reason you are told that its ok to do that, don’t do it, it is very unsafe and detrimental to the longevity of the engine. It is the same as accelerating the engine then turn off the ignition switch, see what happens when you do that, you’ll hear a loud bang and smoke then the tach. will go down to zero, I wonder why ???
“Turning the mags. off in flight is a very dangerous thing to do, it is not recommended at all under any circumstance.” ?
Not trying to be a wise guy, but:
Source: Cessna 172M POH, Section 3, EMERGENCY PROCEDURES; page 3-14.
SPARK PLUG FOULING
A slight engine roughness in flight may be caused by one or more spark plugs becoming fouled by carbon or lead deposits. This may be verified by turning the ignition switch momentarily from BOTH to either L or R position. An obvious power loss in single ignition operation is evidence of spark plug or magneto trouble. Assuming that spark plugs are the more likely cause, lean the mixture to the recommended lean setting for cruising flight. If the problem does not clear up in several minutes, determine if a richer mixture setting will produce better operation. If not, proceed to the nearest airport for repairs using the BOTH position of the ignition switch unless extreme roughness dictates the use of a single ignition position.
MAGNETO MALFUNCTION
A sudden engine roughness or misfiring is usually evidence of magneto problems. Switching from BOTH to either L or R ignition switch position will identify which magneto is malfunctioning. Select different power settings and enrichen the mixture to determine if continued operation on BOTH magnetos is practicable. If not, switch to the good magneto and proceed to the nearest airport for repairs.
Sorry…I guess you meant shutting them both “OFF”…completely, as they did here, by accident…not cyling through them one at a time.
Curran
Actually, turning off the mags allows fuel/air mix to be pumped into the exhaust system.
So, turning the mags back on will ignite the fuel in the engine and it will resume running ok, no problems.
BUT, the unburned fuel in the exhaust can cause damage to the mufflers and flame arrester cones…. [ mufflers are expensive.!!]
NTSB: “….no suitable place to land.”
What’s missing, of course, in this “discussion”…is context:
Why did the CFI want to do a mag check at that particular time, location, and altitude, in the first place?
Just for fun? That would’ve been silly & ill-advised.
OTOH, as noted previously, if they had indications of a “rough running engine”, then the C-172 POH explicitly directs a “magneto check” to help isolate the cause.
Maybe with his extensive, seat-of-the-pants experience, the 79-year-old CFI picked up on something that the 27-year-old Private Pilot did not?
Too bad the CFI hasn’t told his side of the story.
60+ years ago when I started flying , we didn’t have to worry about keys breaking. Each magneto was operated by a toggle switch – basic , reliable and no chance of getting an internal short as in a combination key operated mag switch ( which , fortunately , is rare). I still have the old basic toggle switch system in my aircraft and can attest to its reliability. Paul.
I have always thought that using the key switch to only operate the master relay, and , as you mentioned, use separate toggle switches for each mag.
That’s a more reliable setup.!
No in-flight mag check? Pure silliness. When a throttle cable breaks or disconnects during flight, do we conclude that the throttle should not be adjusted in Flight? Of course not. We rightly are suspicious that proper maintenance was ignored. A magneto switch is no different.
So in my opinion 1/3 of all engine failures are do to a bad mag miss firing and if left alone will destroy the engine and put you in a field. This could’ve been stopped by checking the mag in flight and staying on the mag that lets the engine run smooth. A miss firing mag can burn a hole in the piston in minutes. This happened to me because I didn’t think to check the mags in flight. No one should be afraid to check the mags in flight. The point here is don’t turn the mags off. I luckily made an airport with my problem.
An inflight mag check will absolutely help diagnose a weak mag that checks fine on the ground. But, it should be a very infrequent test to diagnose a problem, not an every flight procedure.
IN-FLIGHT MAG CHECKS are very useful for troubleshooting an elusive ignition problem.
HOWEVER, I would suggest that they be performed HIGH above a friendly airport in order to give yourself TIME to THINK. If it’s a controlled field, advise controller of your intentions beforehand.
The problem here is the instructor. Turning off the mags in flight causes big problems, especially that the aircraft was over, obviously a congested area
I routinely perform a in flight mag check during maintenance, to check the condition of each mag and wether or not each mag is capable of running the engine. Under load and at full RPM that can not be tested on the ground. It should be done by an experienced pilot…..not a student, who obviously shut the mags off……Dumb and the instructor in this case is responsible……
rwyerosk is technically correct in his assessment of why inflight magneto checks are a good idea. What remains unsaid is that heat-sensitive devices internal to a magneto, like ignition coils and condensers, will deteriorate with exposure to altitude and heat. This repetitive cycle, over time, can stress these components beyond the ability to perform as single systems. Of these components, the point condenser has a far greater potential for failure than the coil. When it does, it causes erratic ignition performance, including misfire, point arcing, and variable electrical bounce in the secondary circuit.
But the real problem is found in the fact that carburetors and fuel injection systems don’t know the magnetos are off and will still deliver fuel and air to the cylinders. This raw combustible mixture then collects throughout the exhaust system and will ignite if given the opportunity. When it does so, it’s with a bang that’s a bit more tolerable on the ground than in the air. Blowing holes in mufflers and pushing overboard stacks out of stainless steel clamps is not what you want in flight.
An in-flight mag check is useful in testing the mags under a high stress condition; high power and lean mixture. An excess rpm drop will indicate a weak coil, or internal arcing.
Just don’t turn the mag switch to ‘off’…!!
Mike Bush has a lot to say about operating an aircraft engine in one of his books, ‘Engines’.
I’ve never heard of a key breaking off in a switch.!
You shouldn’t do a mag check midflight just like you shouldn’t do a walk-around midflight.
Rubbish!
Inflight mag check? Why? If you suspect a problem …..land! It makes absolutely no sense.
Troubleshoot on the ground. The fact that a flight instructor ask for and did this is disturbing.
An inflight mag check??
I’ve heard of a similar story, where the instructor wanted to simulate an inflight engine failure by turning the mags off. After they had picked a landing site, he went to restart the engine, but the key would not turn no matter what he did. The simulation turned into a real emergency landing. (I can’t recall if their was damage or not as this was many years ago). He said he never did that again.
Their – there
The best time to evaluate magneto performance is before a flight and after a flight.