The RV-10 pilot stated that shortly after takeoff from the airport in Palatka, Florida, the engine sputtered then lost total power.
He was unable to return to the airport and made a forced landing to heavily wooded terrain, resulting in substantial damage to the fuselage, both wings, and the tail section. The pilot was seriously injured in the crash.
Post-accident examination of the engine revealed that the cannon plug type circular connector that connected the electronic ignition wiring harness to the firewall was not locked and the connector was partially engaged.
The connector provided the connection between the wiring harness and the two electronic control units located on the cockpit side of the firewall.
According to a representative of the manufacturer of the ignition system, if the firewall connector was not secure “…this would result in a single point failure of the entire ignition system.”
A review of the airplane’s maintenance records revealed that the electronic ignition system was installed in October 2020. There were no subsequent entries that discussed maintenance of the ignition system since that date.
Probable Cause: Total loss of engine power due to the improper installation of an electronic ignition system connector plug.
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This July 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.
Amateurs. After decades working as a mechanic in Part 121 what I see in Part 91 scares the bejesus out of me. I’ve met lots of 60 day wonders that think they know it all.
True: “improperly installed part”
A properly designed redundant system would call for two cannon plugs, one for each system.
The typical key switch is also a potential single failure point for two otherwise independent ignition sources. Whatever type is used. Two toggle switches eliminate that possibility.
Same for any ignition driven by the accessory case that can shed parts into your engine.
Redundant external position sensing eliminates that possibility also.
Safety Wire (.020) works wonders. Many Cannon plugs have the holes
In my many tears in working with Cannon plugs both in the USAF as well as civilian aviation – ALL critical cannon plugs (like this one !!) had a provision for additional securing via SAFETY WIRE !! (usually .20 diameter depending on the location). Sure would have helped in this situation !!!
Cannon connectors (named after the inventor and need a capital ‘C’) are used extensively in military and heavy-duty commercial broadcast and communicatons equipment. I have supervised intern techs attempting to install the Cannon plug without understanding the need to rotate the conector to align the key so as to engage the pins, then the need to rotate the locking ring into position. Some of those connectors have a million pins offering significant friction to insertion and may result in only partial insertion in which case the locking ring will not rotate. I speculate this might have been the case in this incident. I can see the mechanic giving up after several tries, shrugging shoulders then walking away from it saying, ‘Oh well, it’s tight enough.’ Nope. Vibration will back it out, as it apparently did. I don’t own an airplane, but if I did, I would stand and watch the mechanic’s work to ensure all necessary steps are taken. Way too many stories featured on this service pointing to incompetent mechanics failing to do proper jobs as noted in the other post below. Heck, it’s only a life-and-death matter, right? The mechanic who failed to secure that connector should be identified, fired for cause and have his certification revoked permanently. Bad enough the pilot was seriously injured and not killed. That mechanic can go work in an oil change joint or car wash. One man’s opinion…
Regards/J
This being an experimental aircraft, the pilot or others may do work on the aircraft, without any A&P supervision.
An A&P does the annual condition inspection, and may not be familiar with other experimental equipment.
So, the ‘freedom’ of not having an A&P do work and sign it off, has this type if risk of improper/ incomplete work.
In my engineering work I don’t remember using Cannon plugs. It was mostly Molex or Ampex connectors.
Any work done on an aircraft, if done improperly or incompletely has the potential for failure.
Failing to torque a nut, install a cotter pin, leave out a lock washer, fail to safety wire an attachment, has the same potential for failure.
In this case it took 200 hours and 5 years, [ and 5 condition inspection failures to notice ], for the connector to loosen and disconnect the electrics….
A very sad sequence, and an injured pilot and severly damaged aircraft.
Upgrades have their own perils.