Saturday, 21 May 2005, Barbara and I took her two grandchildren to do a little touring in South Jersey and to take in the Millville Air Show. If you missed this show, too bad for you. It's a must-see. If you're close enough to tour South Jersey and have not, I'm sorry for your loss on that account too. But I was born there, so I'm prejudiced.
We began our return flight to Connecticut: VFR, because the weather was suitable and I like to give my passengers something to look at if I can. The plane is a Grumman Tiger, known for its excellent visibility.
We took off before sunset because part of the route is over New Jersey's Pine Barrens, home of the Jersey Devil. I don't like to fly over that area at night. There are suitable landing sites, but they are few and far between. Also, it would take a long time for any kind of help to reach a pilot who was forced to land there and needed assistance afterward.
Just after we had cleared the worrisome terrain, the engine started making a ticking noise, similar to an exhaust leak. We lost about 15 knots of airspeed, but everything else seemed normal. Oil temperature was a little on the high side, but well within the green. Oil pressure was normal.
A few minutes later, the mystery wasn't solved but the course of action was clear. With a definitive POW! the engine stopped making power and flames appeared over the nose (sorry, no picture).
This was my lucky day. We were a couple of miles southeast of RJ Miller Air Park, which has a very long runway. Essentially, we were on the downwind leg to runway 24, so I just practiced what I preach and made a standard power-off approach and landing, securing the engine in the process. The fire did not go out until shortly after we were stopped and had evacuated the airplane (quickly).
That's when my traveller's knowledge of that airport was reinforced. There's not much around there, it's painfully difficult to find a hotel room on Saturday night, and it's just about impossible to rent a car on Sunday morning. The Ocean County sheriff and the Berkeley Township police did an outstanding job of getting us settled in for the night, and we got lucky with Avis for the rental car.
I went back the next morning to inspect the damage by daylight. Apparently
the fuel for the fire was engine oil. Some of it obscured my view of the
runway on short final, but not completely. The windscreen stayed clean until
I decelerated and flared, by which time there was enough to see out the side
for a normal landing.
The scorched fiberglass of the nose bowl smelled a little bit like straw, so
my first thought (while still airborne) was that I had missed a bird's nest
on pre-flight inspection. This is a problem with the Grumman because
birds like to build nests between the forward bulkhead and the nose bowl,
where they are just about impossible to see.
The right side of the engine looked normal.
Imagine my wonder when I opened the left cowl and found the mess you see
here. That's part of the #2 cylinder's connecting rod lying on top
of the cooling fins, exactly where I found it. Just above it in the photos,
you'll see a little piece of "sheet metal" butted up against the base of the
cylinder. That's part of the piston skirt.
Viewed from a slightly higher angle, it's easy to see the piston and how the
connecting rod tore part of it away. There's also a dimple in the crankshaft
(not the oil hole)
that I don't think Lycoming put there. These photos also show a hole on the
bottom of the crankcase on the other side of the engine.
Here's the view into the right-side engine cowl, showing a tear on the bottom
behind the exhaust pipe. Also, the worm's eye view of the right cowl flap
area. It looks like the fire wasn't just on top of the engine.
As you can see, the piston's connecting rod bent a little before it snapped.
One end of it got kind of hot, too.
When I fly VFR, if I'm not using radar advisory service I usually monitor the appropriate radar facility anyway, in case I hear them point out traffic to another airplane, and the traffic sounds like it's me. So I was already on the McGuire freq when trouble struck, and I had time to make a mayday call with a position report. As they must, they asked me about fuel and souls on board. I always figured they asked about fuel so they'd know how much time they had to help a lost pilot before he would be forced to land. So it felt kind of funny answering that question just after I'd told them I was landing right now. Why call at all? This airport closes up early, and I correctly assumed that everyone had already left for the day. In case the landing or its aftermath went sour, I wanted ambulances on the way.
There has been a 24/7 sheriff patrol at this airport since September 2001, so we had company within seconds after the forced landing. The sheriff's officer is on the lookout for terrorists, and he has watched hundreds or thousands of planes land at this airport. All the other ones taxi toward the buildings after they land. We stopped on the runway, shut our lights off, and ran away from the airplane PDQ. I can only imagine what he thought we were up to. He monitors the CTAF, but I had not used that frequency (preoccupied).
This is where I got another major dose of good luck, and a humbling lesson in human nature. Where I live, I would expect the police to take their information and leave us where they found us. We spent a couple of hours in the company of the Ocean County Sheriff's Department and the Berkeley Township Police, all of whom deserve high praise for their action. They went far beyond the call of duty, unasked, to make sure that we four strangers were taken care of that night (by the time they got done with their police business, it was dark and fairly chilly). They not only called several hotels until they found us a place to stay, they also drove us there. The Sheriff's Officer told us he was "risking his reputation," but he raided his troop's icebox to make us some sandwiches because he knew it had been a long time since lunch. Two little kids learned that not every ride in a troop car leads to a jail cell, as the men in uniform generally did all the things that we don't learn about by watching "Cops" on TV. They really are in it "to protect and serve." To all the police who read this, Thank You for the side of law enforcement that we usually never know about.
The airplane was not available for its scheduled activity on Monday – the annual inspection. I hope we find out what caused the engine to blow up, because if I did something bad I never want to do it again. It has been 1200 hours since major overhaul by Pine Mountain Aviation, a highly respected engine shop nearby in Danbury. (Recommended schedule is 2000 hours between overhauls.) Our flying club has tens of thousands of hours on about a dozen overhauls from this shop, with no problems at all. Including the accident engine, we have done all of these overhauls with new Millennium cylinders. We have had enough history with these engines to know that they make it to TBO with no significant intermediate attention required. This engine will be thoroughly inspected and I will report whatever I learn about the cause of its recent problem. The overhauler is at least as interested in the problem as I am, and I am very interested in the problem.
Passengers: The kids were great. Per my intention, they didn't know how serious the situation could have been until we were stopped on the ground and I told them this was a Real Emergency and they had to get far away from the airplane NOW. After the airplane didn't turn into a ball of flame, it just became a Great Adventure for them and they got a kick out of spending a night in a hotel and driving home in a brand-new car. The only psychological scar seems to be with Barbara's grandson, who was upset that we had to complete the trip in a car (takes too long). He'll get over it.
Big lesson learned: One of my mentors, Bob Martens (FAA), says that if you have not practiced a forced landing in the past month you will blow it. I practice them every week, and now I truly know why I'm glad I do that.
In the weeks since this story started, one of the many gratifying things that has happened is the large number of emails and personal comments I've had from pilots who say that they will now practice power-off landings more frequently because they have read or heard about this story. That is the very best thing that could happen. You just never know when it will be your turn. When it is, you will revert to habit, so it will be best if your habits are good ones.
Almost immediately after posting this page, I heard from some knowledgeable friends who were able to draw some tentative conclusions from looking at the photos above. Obviously, the #2 journal was not being lubricated. Possible causes include
Between the crankshaft and the connecting rod, there is a bearing made of soft
Babbitt metal. Part of its purpose is to trap tiny particles so they
don't scratch the crankshaft or connecting rod, sort of like an ink blotter.
This bearing isn't supposed to move. If it does, it can block the oil flow
from inside the crank. The resulting lack of lubrication will produce a lot
of heat almost immediately – enough to melt the Babbitt metal. When that
happens, a gap opens up between the crank and the connecting rod. This is
enough to produce a ticking noise like the one I heard before the engine
failed. It doesn't take long before there's enough heat and friction to make
the connecting rod jam against the crankshaft. In a case like that, something
obviously has to give. If that's what happened to this engine, the connecting
rod is what quit next, snapping at the middle. It apparently thrashed around
inside the engine for a short while before being flung out the side of the
crankcase.
The FAA did send an inspector to look at the plane. He tagged the engine, requiring that an FAA inspector had to be present when any inspection or teardown was done. Since that time, the engine has been removed and transported to the shop that overhauled it. Under the Fed's watchful eye, the overhaul mechanic removed some parts which the FAA will have analyzed. I hope I get to see the results of that analysis. Meanwhile, I have spoken with the inspector.
He told me that the FAA isn't drawing any conclusions yet, which is absolutely understandable. But there is evidence that the locating tang on the rod bearing failed, allowing it to spin and cause the kind of damage I just described above.
We now know that the oil hole was not blocked from inside the crank.
The inspector confirmed that this kind of failure is extremely rare in aircraft engines. He also confirmed that a virtually identical failure appears to be responsible for the downing of another Lycoming-powered airplane (different engine) just three days after my problem happened. What are the odds on that?
The other pilot was not so lucky as I was. He and his wife died that day.
Let me digress a little, now that I've read the NTSB's
accident report about the other pilot who lost his engine that week.
Unlike me, that pilot was on an
IFR flight plan. So he was
already communicating with an air traffic controller when he noticed engine
trouble. The controller advised him that the nearest airport was Danbury,
ten miles south. Based on information in the accident report, this was
apparently incorrect.
The pilot received an instruction (fly heading 180) that indicates he was
10 miles north of Danbury airport. This position is also three miles
west of
Candlelight Farms,
a public-use airport that happens to be unpaved. The airport is shown on the
VFR
sectional chart, but not on the IFR enroute chart. Its turf runway is
almost 3000 feet long, with a long overrun at one end. It would have
been an excellent choice for a forced landing, if either the controller or
the pilot had known about it. It's on the chart, but probably not on the
radar scope.
The other pilot didn't make it to Danbury, but he was able to fly five miles after trouble started. Too bad for him that he didn't try the three-mile run to the turf runway.
The foregoing is pure speculation on my part, because I don't know exactly where the other pilot was when his trouble started. I simply plotted it, using facts that were published in the accident report. It's food for thought, though. If we're willing to try landing in a baseball field in an emergency, it's also worth keeping track of all those little airports we don't normally use. One of them might just save your life one day.
There is a dark side to the Lessons Learned. We drove around in New Jersey, where the law requires kids to use booster seats. So I used them in the airplane, too. A booster seat is just a gadget to put the child a little higher up, so the car's (or airplane's) own seat belt will secure him properly. In a Tiger, this arrangement puts the buckle in a place where the child cannot release it. This was also true in the car. I get a creepy feeling thinking about a scenario where the adults in front are incapacitated in a crash, and the kids survive OK but can't get out of the flaming wreck because they're strapped in.
Last modified 28 august 2024
format only; no text changed since 2005
Link to accident report