August 1, 2003
I was a low-time pilot with 188 hours total, 135 of those in a 1972 Piper Arrow I had purchased at a fair price from a business that might be called "Smilin' Jack's Pre-Owned Planes and Air Drayage." The Arrow was represented as having a recent major overhaul by Jack's A&P. The A&P at my FBO did a prepurchase inspection and gave the Arrow his OK, although he asked about the orange RTV (room-temperature vulcanizing, otherwise known as silicone sealer) beaded around the middle of the crankcase and cylinder bases. Jack's A&P said he had put the RTV on the engine because he was looking for a mystery oil leak that turned out to be the prop seal, and he just didn't bother to scrape it off.
The first hint of trouble with the Arrow was a rough engine at start-up early one morning at Quad City International Airport, in Moline, Illinois, where I'd stopped for the night, headed for Chicago on a business flight. This was my first flight east of Denver from my home field, the Missoula International airport in Montana, so I was a little nervous. The first A&P to show up for work that morning helped me pop off the cowling and run up the engine. At full rich, we heard a "jick, jick, jick" sound. Once we leaned the mixture, it ran smooth as an old Wankel rotary.
"I think one jug is running rich ... probably just a fouled plug," the A&P said. "I'll set your injection pump to the lean stop, but be sure to get it in the shop when you get home. It could be something else." He ran his finger over the rubbery orange RTV on top of the engine. "Any idea what all this RTV is about?"
"The guy I bought it from told us they were looking for an oil leak. Turned out to be the prop seal. My A&P signed off on it on the prepurchase. He was suspicious, though."
The A&P shrugged. I taxied to the run-up area and took off for Merrill C. Meigs Field in Chicago with the mixture leaned back more than an inch. Nothing unusual showed on the gauges en route and I landed relieved and ready to go to work on a new educational software publishing project on Michigan Avenue.
On Friday afternoon, business done, I took a taxi back to Meigs and checked the weather at Moline, Illinois. It was 5,000 feet broken, 8,000 scattered. It was 4:45 p.m. on an August afternoon, with plenty of daylight left. I planned to overnight in the Quad Cities (what the locals call Davenport and Bettendorf, Iowa, and Moline and Rock Island, Illinois).
"Clear prop!" The engine jumped to life but no miraculous cures had occurred: "jick, jick, jick." I took the foam plug out of my right ear to listen closely, and when I put it on the right seat it rolled off onto the floor. Never mind, it would be a short flight. I ran up the engine and leaned aggressively. The "jick, jick, jick" stopped.
This jicking sound was making me nervous no matter what the A&P said about running a little rich. But there were no maintenance facilities at Meigs so I decided to get to the Moline airport and take care of this problem, even if it meant waiting until Monday and tearing the injector pump down or even having to take a commercial flight home.
On takeoff the lightly loaded Arrow surged through the thick lake air and leaped off the runway. Out under the Class B, I cut across to Interstate 80 cruising at 2,500 feet, setting the prop and throttle at 2,300 rpm and 23 inches. It seemed like there was more vibration than usual, and there seemed to be a lot of cockpit noise too, but my earplug was on the floor.
Maybe this is normal, I thought. Maybe I'm just spooking myself. I switched between digital cylinder head temperature (CHT) and exhaust gas temperature (EGT), which read 1,300 and 370 degrees Fahrenheit, respectively, all green. The Quad Cities were just a few minutes out I-80 West. More vibration.
The Ottawa, Illinois, airport (Skydive Chicago) slid by underneath; I thought about landing but it was only a few more minutes to the Quad Cities. Traffic was heavy on I-80 below. Semis looked like an elephant parade in the slow lane. A dead-stick landing would be an accordion trick.
The cockpit noise level seemed to be getting louder. Something definite was jiggling up through the yoke. A resonance frequency? The prop and throttle fighting each other? The EGT was now up to 1,360 degrees F. I advanced the mixture a little, and the EGT came down, but the vibration got worse. The gauges were still green. The yoke was making small circles in my left hand like a power sander. The engine noise was deafening. I needed to turn back to Ottawa and land quickly!
I entered a left 180-degree turn and the vibration was shaking my eyeballs. I throttled back and advanced the mixture to full rich, which caused a loud explosion.
The left-front cylinder head was popping in and out of the engine cowl. Acrid blue oil smoke poured into the cockpit through the air vent in the left wing root. The nose of the Arrow was thrashing back and forth like a shark shaking a fish with every revolution of the engine. I yanked the mixture to idle cutoff and the engine shuddered to a stop.
The prop was not windmilling because the engine had seized. There was a long cornfield about half a mile ahead, and I had about 800 feet of altitude to get there. Trouble is, there's just one chance when the only sound in the cockpit is the rush of wind over the airframe.
I pushed the nose over to pick up airspeed. At 300 feet agl, the cornfield was dead ahead with a ravine at the near end and power lines and a road at the other. No way to set up on the road without a low and slow 90-degree turn to final.
Thwackity-thump! Cornstalks banged against the leading edges, then the emergency gear horn erupted — I forgot to lock out the low-speed automatic Arrow gear-down release when I left the gear up for the cornfield landing.
There were starbursts of light and enormous deceleration. The Arrow yawed sideways in a fast ground slide, then flipped up on the left wing. My head broke out through the pilot's side window. The Arrow balanced like a Tilt-A-Whirl, then slammed back down right side up on one descended gear leg.
Wisps of smoke curled up around the bent prop; the gear warning horn sounded like a fire siren. I switched off the master rocker to postpone explosion, having missed turning it off on the emergency checklist.
I discovered an ominous problem. Blood was dripping onto the jumbo ear of feed corn in my lap. Probably coming from my carotid artery, which a piece of broken windshield had severed. I touched my neck and face, though I felt faint, and found a divot of flesh hanging down from a flap of skin on my cheek. I pressed it back in place like a plug with my finger. The bleeding stopped. Corn must have punched back through the windshield as the seized prop sheered off ears on the way in.
I remembered that an explosion and fire could happen at any second and I unbuckled my seat belt and leaped out of the door onto the wing, which was slimy with cornstalk juice. I walked around the Arrow and lifted the broken cowling to look at the engine. A chunk of crankcase was gone where the left-front cylinder blew off its station; engine oil was cooked onto the cooling fins back to the firewall. That was where all the blue smoke came from. I paced off a swath of flat corn, where I went from 90 mph to a dead stop in about 30 yards. Because I forgot to override the automatic gear-down mechanism, the right gear had started automatically dropping at 80 mph, yawing the Arrow sideways as it flew through the forest of stalks.
In its final report, the NTSB determined that the cause of the accident was "improper engine maintenance, mechanical component failure." What the report did not mention was that at teardown the investigators found that the RTV silicone sealer had been beaded between the crankcase parting surfaces so thickly it hung down in orange stalactites inside the engine. It had also been used to make a gasket between the cylinder stations and the crankcase. This is strictly forbidden by Lycoming's overhaul manual and was probably done because the engine was leaking large amounts of oil. I did a little detective work and discovered that my crankcase came from a Texas aircraft junkyard with no overhaul documentation because it was run out. Always take care of any mechanical problems on the ground before taking chances with your passengers' lives, not to mention your own. If anything seems amiss in flight — rough running, excessive cockpit noise, any of your gauges abnormal — land immediately at the nearest airport and get the problem diagnosed and fixed, even if you have to take a commercial flight home. And if a recently overhauled airplane is advertised with a price below market value for quick sale, there probably is a good reason for this — which is an excellent reason not to buy it.
Richard Cummins, AOPA 833717, lives in San Diego, where he owns a computer-related business serving the medical transcription industry. He has more than 600 hours in his logbook, with 276 hours in a Rutan VariEze experimental.
Additional information on engine failures and maintenance is also available via these links:
Return to the "Never Again Online" main page.
FAA Information and Services,
Aircraft Power and Fuel,
Takeoffs and Landings,
Safety and Education
Internet giant Google will acquire Titan Aerospace, the New Mexico-based developer of high-altitude unmanned aerial vehicles.
The FAA proposes to supersede an airworthiness directive requiring modification of the aft main spar of some Diamond Aircraft DA40 and DA40F airplanes.
The National Aeronautic Association has awarded the Collier Trophy for “the first unmanned, autonomous air system operating from an aircraft carrier.”
VOLUNTEER AT AN AOPA FLY-IN NEAR YOU!
SHARE YOUR PASSION. VOLUNTEER AT AN AOPA FLY-IN.CLICK TO LEARN MORE >>>
VOLUNTEER LOCALLY AT AOPA FLY-IN!
BE A PART OF THE FLY-IN VOLUNTEER CREW!CLICK TO LEARN MORE >>>