POST-MAINTENANCE BEST PRACTICE ....

Acknowledgements: FLYING LESSONS by Thomas P Turner (Mastery Flight Training Inc.)

Ed. Note: The following was extracted from Tom’s offering on the NTSB’s preliminary accident report (CEN23FA079):
“On January 16, 2023, a Piper PA-32-301T was destroyed when it was involved in an accident near Kingfisher, Oklahoma .... According to witnesses, the airplane was seen trailing black smoke before it rolled over and dived into the ground .... The accident flight was the first flight after the airplane had undergone maintenance including the installation of a new autopilot system and an annual inspection .... From what the investigators think they know until they investigate further:

  • The airplane had just came out of annual, and an autopilot installation. Other work may also have been performed.

  • The accident flight was the first flight of the airplane after this maintenance event.

  • The flight was conducted with at least the intention of autopilot familiarisation, and under instruction ....

  • Black smoke more indicative of burning fuel or oil than suggestive of an electrical fire ....

  • .... the airplane rolled into a steep dive, and impacted vertically, suggesting .... an inflight loss of control.

.... One possible sequence is that a fire erupted in flight, probably an engine or fuel system fire but perhaps sparked by an electrical overheat; under the stress and perhaps physical impact of the fire the pilot(s) lost control of the aircraft .... In the spirit of FLYING LESSONS, where we try to draw inspiration for safe operating practices from the available details of accident reports, I offer these suggested best practices for a post-maintenance test flight:
First, do your homework

  • Be “up” on new equipment. You have time to read up on the changes and new equipment while the work is being performed.

  • Get familiar with any new Pilot’s Operating Handbook/Airplane Flight Manual (POH/AFM) Supplements.

  • Do your “playing” with systems simulators when they’re available ....

  • If possible, get some flight experience with similar devices in another airplane so you are familiar with its operation.

  • This first flight is to confirm that the equipment works the way it’s supposed to, not for you to try to figure out how to work it.

  • Create a test profile, a checklist of your specific goals for the flight. Ensure you test everything you want to test .... you don’t want to land and remember something you wanted to check but forgot. Plan your test flight, and then fly your test plan.

  • Be current and proficient. Don’t show up as a “rusty pilot” to conduct a test flight .... you might have to be a peak performance. You won’t know until the flight is complete, so be ready before it begins. 

  • Be very familiar with emergency procedures. This is a test flight to determine whether the inspection/maintenance/repair/modification event has accidently introduced trouble. Include all the power loss and fire checklists, and any emergency procedures contained in POH/AFM Supplements for installed equipment including anything that’s new.

Make the first flight after inspection, maintenance, repair or upgrade entirely a test flight

  • Spend extra time reviewing aircraft documents: “What was done?”, “Was everything that was supposed to be done completed?”, “Are all required logbook entries complete?”, “Does the documentation match the physical appearance of the aircraft?”.

  • Conduct a detailed, sceptical pre-flight inspection. Now’s the time to be especially picky. Don’t rationalise away imperfections .... Inspect the aircraft as if you’re expecting to find problems ....

  • Go through the motions of emergencies before you take off .... rejected take-offs, partial or total power loss immediately after take-off, engine anomalies and failures at higher altitudes, engine and electrical fires, autopilot malfunctions and trim runaways - things that require an immediate response and allow referencing a checklist only after your initial actions .... sit in the pilot’s seat, engine off, and physically move your hands through the motions of each emergency’s response. You’re more likely to need one of these procedures on a test flight, and you won’t have time to think about your response if you do ....

  • Don’t detract from the mission of this test flight by trying to accomplish other goals ....

  • Wait for good, daylight, visual conditions without challenging surface winds or inflight turbulence ....

  • Make the flight under Visual Flight Rules to reduce workload and maximize flexibility ....

  • Don’t let record-keeping be an additional workload and distraction .... Managing video is a good use for a second pilot, but not a good idea when solo, so bring another pilot along to help with data collection, traffic avoidance, or pilot chores if you wish, but otherwise limit the flight to essential crew only. 

Be prepared, be methodical, and be flexible

  • If you see something you don’t expect, quickly document what you can and land right away to investigate it on the ground. Don’t try to troubleshoot or fix it in the air. 

  • Figure it out at one G and zero airspeed. Then make a new test profile after you’ve come up with a plan of action on the ground. That’s what the test pilots do.    


You are not doubting the shop’s ability or its employees’ expertise:

·       You are simply confirming as far as possible that they had not succumbed to the same human factors that affect pilots!

·       You are upholding your PiC responsibility as the person ultimately responsible for determining the airworthiness of the aircraft .... 

·       If you don’t feel up to all this, just hire someone who is current, qualified and proficient to do the flight for you. After it’s done, hire an instructor to get you up to speed”.

 

FLY SAFE!

Tony Birth