The flight departed Myrtle Beach International Airport (KMYR) in South Carolina and was en route to Columbus County Municipal Airport (KCPC) in Whiteville, North Carolina.
Shortly after departure from KMYR, the pilot reported to air traffic control (ATC) that he was having problems with the compass, which resulted in difficulty maintaining assigned headings. He stated that he wanted to return to the airport and was not declaring an emergency.
About 30 seconds later, he reported a loss of engine power. He informed ATC that he was unable to make it back to KMYR and had identified an off-field landing area near Conway, South Carolina.
Surveillance video captured the Piper PA-28R-201 as it flew low near trees but did not capture the accident due to a power surge when the airplane hit a powerline.
The plane first hit an estimated 40-foot-tall pine tree and then a powerline and came to rest against a berm along a gravel road. The right wing and vertical stabilizer separated during the accident. A post-crash fire ensued that consumed much of the wreckage.
The pilot and a passenger died in the crash.
A post-accident examination of the engine revealed that the Nos. 2, 3, and 4 connecting rods were separated from the crankshaft. The left engine crankcase half was fractured inboard of the No. 4 cylinder mounting pad. The Nos. 3 and 4 connecting rods were separated from their crankshaft rod journals and the damaged rod ends were visible through the crankcase fracture.
During disassembly of the engine, a vacuum pump cover was removed from the vacuum pump drive pad but no gasket, or remnants of a gasket, were found. Other engine components were removed, and all had remnants of a gasket despite the thermal damage.
The plane had been at a shop in Myrtle Beach for several months for an avionics upgrade.
As part of the work being accomplished, the vacuum system was removed and replaced with electronic instrumentation.
The Garmin G5 Electronic Flight Instrument Installation Manual states, in part: “The vacuum system and associated parts may be removed if there is no remaining need for vacuum. See the airplane specific maintenance manual and AC 43.13-2B for guidance when removing the vacuum system. If the vacuum pump is removed, the engine accessory port must be properly covered.”
A review of the work order revealed that although a vacuum pump plate was ordered, there was no reference to the required vacuum pump drive pad gasket being ordered.
A review of the aircraft maintenance records revealed that after one certificated airframe and powerplant mechanic had completed the work on the airplane, the Director of Maintenance, an airframe and powerplant mechanic with inspection authorization, signed off to return the airplane back to service. The return to service logbook entry stated that the vacuum pump had been removed but did not address the installation of the drive pad gasket or vacuum pump cover. Additionally, there was no mention of an engine run-up following completion of the work.
In an interview, the mechanic who completed the removal of the vacuum pump and installation of the vacuum pump cover stated that when he removed the vacuum pump, the gasket was still attached to it. He cleaned the mating surface of the cover and drive pad with Scotch-Brite and then installed the cover. He stated that he thought he had replaced the gasket.
When asked about the performance of an engine run-up, he stated that he ran the engine for about 30 minutes after the installation of the avionics modification. He did not recall seeing any oil leaks following the run-up and said that before the run-up there were about 7.5 quarts of oil in the engine and a “few days later” checked it again and the level was still above 7 quarts.
When asked if there was more than one mechanic working on the modification, he said that other mechanics would come in and help complete some tasks while he concentrated on the wiring.
The Director of Maintenance was asked how he reviewed completed work before returning the airplane to service, to which he replied, “I look at it all.” He stated that on larger jobs he would conduct his inspection in stages by reviewing one area when the mechanic completed an area such as the cockpit or engine and moves to another area.
Probable Cause: The mechanic’s failure to install the required gasket on the vacuum pump drive pad in accordance with the maintenance manual, which resulted in oil exhaustion and the subsequent loss of engine power. Contributing to the accident was the Director of Maintenance’s failure to verify the installation of the vacuum pump gasket before returning the airplane to service.
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This September 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.
Paul W is correct. The engines I use all have the option for use of a wet vacuum pump. I also use the paper gaskets he talks about. Not certain how long term a leak would take to rid the engine of oil, but undoubtedly there could exist a pressurized leak.
To those folks who are ready to punish these 2 mx troops, and send them to Sing-Sing prison for life, based solely on this article:
NTSB reports provide details about the accident, analysis of the factual data, conclusions and the probable cause of the accident, and the related safety recommendations.
But sometimes (fortunately, not often), they might get it wrong.
That’s why the term is “probable cause”, and not “absolutely, positively, guaranteed, without-a-doubt cause”.
Regardless, their conclusions are not a legally-binding “guilty-as-charged” verdict.
So, how about we just use a good, old-fashioned PRC torture: Rip their fingernails out with a pair of pliers.
That way, in case they DO end up being exonerated, maybe they can still earn a living using their hands.
I’ve rebuilt a few thousand automotive engines. My guess is the main bearing was on it’s way out. Because the engine continued to be run at higher RPM, being an aircraft with the noise level and trying to maintain flight instead of a car, it exasperated the condition and threw rods.
Of all the engines I’ve dismantled due to oil starvation or overheat, 95% of the vehicles had gauges, not “idiot lights”.
Looking at the pics of the crankshaft, from the docket, the #1 rod and nose bearing look ok, no discolor.
But, #3 and #4 rod bearing and #3 main are black from excess heat, most likely from spun bearing on main #3 causing oil loss to #3 and #4 rod bearing.
#2 main journal is somewhat discolored.
The NTSB should review any engine work that was done recently, like replacing a cylinder.
Doing this incorrectly, moving the crank, can dislodge a main bearing and cause it to eventually spin and cut off the oil to the affected bearings.
So, I don’t think the loss of oil was from the block off plate.!
There’s little point on drawing too fine a point here, but the photos of the crankshaft are showing precisely what happens to a Lycoming four-cylinder engine when it is progressively starved of oil. In spite of how the lubrication schematic is drawn, #1 main bearing and rod journal are first in line for pressure oil. #4 is last. Last in line, first to burn.
Also, the photo of the vacuum pump drive is actually showing the oil screen mounting pad. The vac pump drive pad is upper, right or center. The small hole in the lower left of that pad is where pressure oil for a wet pump is sourced.
If you look at the oil lube diagram, the oil moves from the rear, from the oil pump, to the front.
So, the oil gets to #3 main first, then #2 and finally #1.
But the left side oil header also feeds the #1 main bearing.
So, my SWAG is that the #3 bearing spun, cutting off the oil to the #3 and #4 rod bearings,
The #2 main is a bit discolored from heat ,but the #1 main looks ok.!
The NTSB took the ‘easy’ fault. But I’m sure it was a latent defect in te #3 main bearing…cause ???
So easy to armchair blame the mechanic. I agree there is no way that much oil can blow by the cover with, or without a gasket. Even with the plate missing it would take some time to disperse that much oil. The location of the accessory would cause oil to blow on the underside of the cowl and show up on the windscreen. Usually an oil starved engine would weld the rods to the crankshaft before breaking off. Sounds like something else was going on.
I work in another ‘industry’ where gaskets aren’t used by choice,they seep over time. We’ll machined surfaces with proper sealants work well and don’t ‘blow out’.
This was a bad engine to start with.
That many connecting rods don’t fail at once. If the ‘operater’ monitored oil pressure properly there would have been more time to re act.
Don’t be so hasty to blame a poor hard working mechanic.
Somewhere in the universe beyond the clouds there is a solution to problems of this recurring nature — incompetence in GA shop work. Of course, the few bad apples spoil the whole basket unfairly.
Some of these incidents are comparable to taking your car into the shop for a brake job, and the mechanic gets interrupted, loses his train of thought and fails to tighten the air bleed screw on one of the wheel cylinders, and after a few braking strokes by the driver the system runs out of fluid and the car crashes with potential loss of life. It’s bad enough on the ground, but in the air it’s literally unforgiveable. Now… what punishment will be meted out to this shop and responsible personnel? I never read of such follow-ups to these stories. How about involuntary manslaughter, revocation of certs and bankruptcy of the shop for starters?
Regards/J
I fail to see how a missing vacuum pump blank-off plate gasket could allow 8 quarts of oil to be barfed overboard on a 30+ minute flight! The plate and the accessory case mounting pad are flat, and a a torqued blank-off plate couldn’t possibly permit such a leak. Plus, the existing vacuum pump driveshaft has an oil seal installed on it. This engine obviously came apart in flight, but it sure wasn’t because of this missing gasket!
I would. here be 7 quarts. Of oil on the wind screen when the propeller was cycled during the run up.
There is an oil pressure port in the vacuum pump pad for use with a wet type vacuum pump. Shop I worked at had a leak from a vacuum pump replacement. We stopped using the cork gasket supplied with a new vacuum pump. Used the MS paper type after that. This is back in the early 90’s.
I’m kinda dubious too, the blanking plate would have covered the small oil galley that exists I’m guessing, from the days of the wet vacuum pumps. Unless that plate was left loose in addition to the missing gasket, maybe, but the machined surfaces could have allowed no more than a possible seep; no way is it pumping out 7 quarts of oil in 30 minutes from that area. My guess is that this is more of a case of “sh** happens” and the engine decided to let go on that day, it just so happened to coincide with the return to service. I’ve seen cylinders crack off at the mounting flange and the only warning was when it blew through the cowling door, that was on a Baron, that again was a case of “huh, well sh** happens”. This seems like a case of, “missing gasket, that must be the cause”.
I agree with Henry…..There must have been another cause. Maybe FAA is coming to conclusions while looking for answers.
The vacuum pump pad is pressure fed for old style wet vacuum pumps. Without a gasket, a block-off plate could easily puke out enough oil to get below minimum oil level requirements and starve a rod bearing. I’ve seen it happen in a IO-360 just like this but in a Mooney. Mechanic didn’t install the proper oil governor gasket and special adapter plate and on the ground it leak checked fine- but when the engine heated up, oil thinned out, it puked all the oil out and threw a rod in less than 30 minutes. Fortunately the pilot was circling over the field as it was an initial test flight of a new engine installation and was able to put it down on the runway.
Wow, to me it seems that money and time was more important than correct work. Even if an old gasket was on the vacuum cover plate, to even think of reusing it again is just unbelievable.
The so called Maintenance Director, never did his job, it seems he was only interested in turning work around as fast as he could. To not even do an engine run after all that work again is cutting corners because they wanted to move the aircraft out to get more work in.
This sloppy work caused the life of people that trusted the ship to perform the work correctly.
Such a shame, so much for dedicated maintenance staff.
What has happened to instrument scan ? ? ? Try looking at pilot practice. A lot of excuses here. The impending loss of a sump full would become clear before the engine expired – I know as I experienced a system failure during which a full sump of oil was being pumped out. The problem became immediately obvious by oil on the windscreen and a falling oil pressure. It seems that the
investigation report is lacking in depth. Paul.
As a former aviation mechanic and pilot, I agree that important details are missing. What caused the opening that permitted engine oil to escape?