The pilot reported that, after departing from David Wayne Hooks Memorial Airport (KDWH) in Spring, Texas, he noticed that the Pitts S-1T’s engine power was not responding to throttle movements.
He turned back toward KDWH and entered a left downwind leg to Runway 35L.
During the base turn and after turning off the engine ignition switch, he executed a forced landing.
Due to a higher-than-anticipated headwind, he misjudged the flight profile, and the airplane landed before reaching Runway 35L.
It hit instrument landing system structures, which substantially damaged both wings, the fuselage, and the empennage. The pilot was seriously injured in the crash.
Post-accident examination revealed that the throttle cable was disconnected from the throttle lever arm at the fuel injector/control, and a loose washer was found at the bottom of the engine cowling.
Throttle lever arm with throttle cable disconnected.
Proper installation of the throttle lever included a bolt, two washers, a castellated nut, and a cotter pin. The bolt, castellated nut, and cotter pin were not located.
During the airplane’s last annual inspection, the engine fuel nozzles, fuel injector, and flow divider were removed for overhaul and were then reinstalled. During this maintenance, the throttle cable would have been disconnected, and it should have been reconnected once the maintenance was completed.
After the annual inspection, no maintenance actions were recorded or reported that would have required the throttle cable to be disconnected.
Probable Cause: The failure of maintenance personnel to properly connect the throttle cable, which led to the pilot’s inability to control engine power during the initial climb. Contributing to the accident was the pilot’s misjudgment of the headwind during the forced landing, which resulted in the airplane’s touchdown short of the runway and its impact with airport structures.
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This February 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.
There are a lot of folks that have the A-P license. But smart enough to pass the test but have no mechanical back ground. I say all who go for the license should pass an aptitude test. It should be an FAA inspector administer the tests, both written and practical! I used to do the work on my plane and the IA would back me and do the final inspection. I’ve had the A-P from Sparten school of aeronautics but I have 40+ years as a hydraulic specialist in the US Air Force. They started a program called grow your own mechanic!! In my opinion it was and is a total failure. The ones that worked around me couldn’t read a techorder or understand what was printed. I’m 81 now and keep all of my farm machinery in working order including my D8K caterpillar. Ask around your FBO they will inform who you can trust!!!
Turned downwind and base? Sorry to say and some might object but if I am having problems I’m coming straight in and announcing an emergency coming in straight in with engine problems.
I don’t object to your points at all. In fact, this case is a perfect example of why folks should read the entire NTSB Form 6120.1, especially the “Narrative History of the Flight”, written by the pilot, before they ‘comment’.
Landing that Pitts with the power ‘fixed’ due to a disconnected throttle cable, should have been a non-event. The stuck throttle didn’t wreck his airplane; the way he flew the plane and managed his energy, did.
I have no doubt that he would do things differently if given the chance, including not letting the tower controller influence his decisions.
T/O may have been the first time the cable was at full extension and unable to retract.
Coming in short might make you think to turn the ignition back on to use the engine as neccessary.
Is that mechanic still employed there? I recommend suspension of his/her certificate and criminal prosecution for dereliction of due professional care. Has the pilot died I’d recommend a charge of manslaughter. SOMETHING MUST BE DONE to change the culture of GA owners and shops from the Wild Wild West to modern western civilization. Chargers of malfeasance are common among the professions (e.g., law, medicine, accounting, etc) and so should it be in the GA industry. If you can’t trust your airplane mechanic, who can you trust?
Regards/J
James, If you read the FAA Inspectors report on this accident; you will find that the owner of the aircraft, who is also an A & P mechanic, performed the work himself. Killing the power on base leg doesn’t seem like the wisest thing to do; but I cam empathize with the pilot in this high powered little airplane with a runaway engine which was probably over red-line RPM’s at the time. Too bad the darned ILS antennas got in the way.
For you ESPECIALLY, I would ask your mechanic if he would allow you to assist him during your annual inspections. Two sets of eyes on the job is much better AND you will LEARN MUCH about your aircraft’s systems. Besides, getting dirty is FUN.
Recognize that even with you help, his inspection process will likely take a bit longer (from answering your questions) and he may need to be compensated for the extra time spent. BUT, it will be the best money that you have ever spent on your airplane.
BTW, during my travels, I have not encountered ANY licensed A &P rogue mechanics. I have met a few unlicensed mechanics doing work on their OWN aircraft, trying to save money. For THEM, I always offer my advice of finding a relationship with a good licensed A&P to at least INSPECT their work.
Note that in most cases it is completely legal for YOU to do the work yourself under the close supervision of a licensed A&P mechanic; after which he will perform a final inspection and sign off the work as completed and airworthy.
HAVE FUN
I was in a crash a very serious one. The A and P didn’t instal a PRC clip in the Marvel Shebbler carb the plane worked fine till it didn’t. Fuel starvation was the actual cause. Crash at about 1000 ft on climb out
So how did the pilot get from the hangar to the runway, do a proper run up, and take off with no positive throttle control?
I’m wondering the same thing. A hand-tightened bolt, pre-tightening & pre-cotter pinning, vibrated loose after takeoff?
I was wondering the same thing, if the engine was over running you’d know or if you ran it up for magneto check I think your would know if the throttle was not connected/working.
My first thought, how did he get that far with no throttle?
I suspect that the screw and nut were installed, loosely, and not tightened and didn’t have a cotter pin installed.
So, the engine vibration slowly loosened the nut until it fell off and the screw fell out at some point after take off…
JimH, I suspect that you are very correct. EVERYBODY MAKES MISTAKES; and the only thing we can do is work to minimize them.
Whenever it is necessary for me to leave work partially completed (hand tightened / cotter pin not installed / not safety wired, etc.), I add the uncompleted item on my DO list / checklist to insure that the work is properly completed. This is especially important if the job extends overnight or more.
I also recommend OWNER ASSISTED ANNUAL INSPECTIONS, if your mechanic allows – More eyes on the job is great and it gives you a good chance to LEARN your aircraft’s systems.