Shortly after takeoff from Santa Monica Municipal Airport in Southern California, the pilot advised the air traffic control tower controller that the Ryan’s engine had lost power, and he requested an immediate return to the airport.
He initiated a left turn toward the airport, however during the approach, he realized that the airplane was unable to reach the runway.
Subsequently, the airplane struck the top of a tree and then hit the ground in an open area of a golf course
A post-accident examination of the engine revealed that the carburetor’s main metering jet was unscrewed from its seat and rotated 90°. The unseated jet would have allowed an increased fuel flow through the main metering orifice, producing an extremely rich fuel-to-air ratio, which would have resulted in the loss of engine power. It is likely that, over time, the jet gradually loosened from its seat, which allowed it to eventually rotate 90°.
A review of the airplane’s maintenance records indicated that the carburetor was rebuilt during the airplane’s restoration about 17 years before the accident.
The carburetor maintenance instruction manual contained no pertinent instructions for the installation of the jet assemblies.
Further, no maintenance entries in the engine logbook regarding carburetor maintenance were found.
Had the carburetor maintenance instruction manual identified a means to ensure the security of the main metering jet, it is unlikely that the jet would have become unseated.
There was no record of maintenance personnel inspecting the carburetor jets during the previous 17 years nor was there a requirement to do so.
The front and rear seats of the airplane were equipped with non-factory-installed shoulder harnesses. The pilot’s shoulder harness was installed by mounting the end of the restraint to the lower portion of the seatback assembly, which was made of thin aluminum. No reinforcement material or doublers were installed at or around the attachment bolt hole in the seatback.
The lack of reinforcement allowed the attachment bolt, washers, and stop nut to be pulled upward and through the seatback structure during the crash, which resulted in the pilot’s loss of shoulder harness restraint.
It is likely that the improperly installed shoulder harness contributed to the severity of the pilot’s injuries.
As a result of this investigation, the NTSB is working with the pilot community to inform them of the lessons learned from this accident: The security of the carburetor’s main metering jet and the security of the shoulder harness are both critical aspects of aviation safety.
Probable cause: A total loss of engine power during initial climb when the carburetor main metering jet became unseated, which led to an extremely rich fuel-to-air ratio. Contributing to the accident was the lack of adequate carburetor maintenance instructions. Contributing to the severity of the pilot’s injuries was the improperly installed shoulder harness.
NTSB Identification: WPR15FA121
This March 2015 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.
Ford did a credible job of making the best of a very bad situation. Kudos to his piloting skills but he should have known better than to have himself so poorly secured with that weak shoulder harness installation. You can bet he’s paying closer attention to that now or maybe not if his ticket is pulled by the FAA over his blunder recently at Orange County John Wayne International.
This sounds like the Harrison Ford accident a few months back.
Was Harrison Ford the pilot involved?
It would sound as if who ever came up with that shoulder harness installation did not give it much thought beyond just attaching it to the seat, no regard at all for whether it could actually perform its intended function. I would say it is worthwhile to go back and see just what approval process was followed to add them to the airframe, somehow this one got through without any common sense being applied to it. Bottom line is that restraints only work when they stay attached to the airframe/seat in a collision, they are not there for decoration.
Finally, a complete analysis by the NTSB of the defects that caused the engine to stop running, along with the reason for the pilot injuries.
This type of complete report allows us aircraft owners and pilots to inspect our aircraft and correct any issues.
Thanks to the NTSB.!
The report says nothing about the cause of the accident…
Accidents don’t occur until touchdown. The flight control following the loss of power is what leads to an accident.
With a Ryan, if the pilot makes an off airport engine out landing (crash) and lives, he did a great job.
It’s not a spam can.
Robert: Take a look at the docket. There’s a report of what was found in the engine post mortem. The pilot descended wings level after turning toward the airport, and was on speed. It appears he lacked KE to clear a tree in the golf course. Note that KSMO is otherwise surrounded by development. I think the pilot did an outstanding job from the moment the engine quit until the airframe was at rest.
Well said John. This is just part of the inherent risk in operating aircraft out of airports that have become surrounded by civilization. As with this incident when things go wrong the pilot usually does not have many choices about where the aircraft will end up so they have to make the best of what is available. In this case the golf course was a very good option with open spaces but as noted the aircraft just did not have the altitude / airspeed to make it all the way. Just a little more KE and it would have been a minor incident that just annoyed a bunch of golfers until the aircraft could be removed.
The docket says HF’s aircraft had aftermarket shoulder harnesses. The harnesses were installed without doublers or other structure to prevent failure resulting from impact forces. Consequently they pulled loose and (according to one of the images in the docket) and his helmet clad head impacted the panel in front of him. The message in the docket is to follow installation instructions and good practices when adding essential safety equipment, like shoulder harnesses. The images also show that the aircraft was under control all the way down, though the flight path was disturbed when one wing struck a tree just before impact. The pilot made the very best of the cards he was dealt.
1) Carburetor must have come loose after the last annual inspection – assuming it was done. I guess the A&P didn’t think to check the mounting screws.
2) Inadequate shoulder harness mount – is this why FAA is so fussy about modifications?
3) NTSB withholds names of accident pilots to protect their privacy 😉
1, 2, 3… upon all we agree. 🙂
The metering jet inside the carb came loose, not the carb itself. How often does your aircraft have the carb disassembled to check the security of the metering jet??? I’d venture to say never. As the report states, there was no record of it ever being checked, nor was there a requirement to do so.