EAAer Lands Safely on Interstate in New Mexico
The cause revealed
By Patrick Panzera, EAA 555743, firstname.lastname@example.org
Jon Finley with Subar-Sonic, his Quickie Q-2 that won the COPPERSTATE 2008 Best Alternative Engine award.
The following article was published in the March 12, 2010, issue of EAA e-Hotline, and at the time of that writing, the cause of the engine failure was inconclusive. We now know the reason, so the ending has been revised. ~Pat
A Quickie Q-2, owned and piloted by Jonathan (Jon) Finley (EAA 394580), made an emergency landing Saturday morning, March 6, on Interstate Highway 25, parallel to Mid Valley Air Park (E98) in Los Lunas, New Mexico. Jon’s plane is powered with a direct-drive, Subaru automobile conversion and was featured in the March 2009 issue of Experimenter, EAA’s homebuilder e-newsletter.
After having flown hundreds of uneventful hours in Subar-Sonic (its nickname), Jon’s morning departure for breakfast with fellow EAAers was quite routine. Climbing north for 2-3 miles and over the village of Los Lunas, the engine suddenly stopped without warning. The tachometer read 270 rpm from the windmilling propeller, but switching systems from stand-by made no difference. Jon said his only option at that point was the interstate.
The southbound lanes of I-25 seemed more appealing due to reduced traffic flow, so Jon lined up. “There was one truck on the road right below me, and I am fairly sure that I just barely cleared him—I bet he had nightmares last night about that UFO dropping out of the sky right in front of him!” Jon told us. “The landing was pretty normal, and I let her roll for quite a while so the automotive traffic behind me had a chance to figure out what had just happened and could slow down.”
Stopping in the middle of the two lanes, Jon jumped out and pulled his plane safely to the side, allowing traffic to continue flowing. Jon commented that the Interstate is really smooth; he wishes his home field was that nice.
It didn’t take long for emergency crews to show. State police, Los Lunas police, fire, ambulance, tow truck, and the media seemed to all converge at once. Jon managed to get a radio call out to his flying companions before he landed, letting them know that he was going to be late for breakfast, and it was a welcome relief to see friendly faces show up at the scene as a result of that call.
With the textbook landing, there were no injuries to Jon or his plane, but it was reassuring that the response team would have been there for him had he needed it. The authorities called the FAA in spite of the fact that there was no damage and no injuries, so Jon had to wait until they showed up before they could start loading the plane. During the wait, Jon’s friends were able to bring his truck and trailer, along with lots of manpower from Mid Valley Air Park, to help load the plane. The state police were kind enough to escort them back to Mid Valley, so the plane didn’t have to be disassembled; the load was 17 feet wide. The plane made it home without a scratch.
By noon, Subar-Sonic was back in the hangar and still not willing to start. Initial troubleshooting indicates that the problem may be due to a single nut coming loose and getting into some electronics. “The problem appears to have been a nut in the cockpit—no, not this nut,” he joked. “Last time I looked at it was some 300 hours ago. Somewhere in that timeframe it worked its way off the bolt and fell onto a printed circuit board which seems to have defeated all of my built-in redundancy.
“At least that is the theory at the moment, and I can’t find anything else wrong. I won’t know for sure for at least several days but will let ya’ll know when I know.”
This is not Jon’s first interstate landing in an experimental aircraft. I-15 (near Helena, Montana) was his auxiliary runway in the early 1990s when his Quickie (Q-1) misbehaved.
Jon is scheduled to be a guest speaker at the Alternative Engine Round-Up fly-in at the JeanSportAviationCenter, Jean, Nevada, on March 27,2009. For more information, visit www.ContactMagazine.com/roundup.html.
Addendum: The cause of the engine failure has been determined to be exactly as suspected. In order to mount his electronic fuel injection controller (a computer in a metal box, also known as an electronic control unit [ECU]), Jon elected to mount two bolts (studs) on the underside of his header tank that is located inside the cockpit. Two corresponding holes were drilled into the metal ECU box. The box was then secured to the studs using nylon insert locknuts, which would be the fasteners of choice for this application.
These nuts (as with any aviation-threaded assembly) require at least two threads to be proud of the nut after being torqued to specification. If there aren’t enough threads in contact with the nylon, the nut(s) can vibrate free, and Jon knows all this. The problem came when Jon installed the nuts but failed to verify that the lengths of studs, as they protrude into the box, were sufficient to allow for the surplus threads when assembled with washers. The difficulty in getting the visual verification within the tight constraints of working behind the instrument panel from the underside was a contributing factor that would have been alleviated by the simple use of a mirror or whatever object would have been required for visual confirmation.
Sometime during the 300 hours of flight time since its installation, one of the nuts and its accompanying washer came off, landing on the printed circuit board. Speculation is that they bounced around until finding the ideal location to cause a short that killed the circuit and shut off fuel to the engine.
With a new ECU in hand, Jon has now installed nutplates with the proper length studs and has resumed committing aviation.
Jon offers this experience to his fellow EAA members as an example of what not to do and reminds us to “learn from others’ mistakes, ‘cause you don’t have enough time to make them all yourself!”