What Aviation Accident Reports Teach Us About Technical Documentation
In January 2024, a door plug blew out of a nearly new Boeing 737-9 climbing out of Portland. The cause wasn’t a design flaw or a pilot error. Four bolts had never been reinstalled at the factory, and, as the NTSB found, the work that removed them was never properly documented.
We usually think of aviation accidents as failures of metal, weather or pilots. But read enough accident reports and another factor keeps appearing: the documentation. Procedures that were unclear, incomplete, not followed, or never written down at all. The lesson for anyone who writes procedures or draws technical illustrations is uncomfortable but important: documentation is safety equipment.
What the Research Says
Recent research shows the problem hasn’t gone away:
| Source | Finding |
| NTSB final report on Alaska Airlines 1282, 2025 | Probable cause: Boeing’s failure to provide adequate training, guidance and oversight. Without proper documentation of the door plug work, no quality inspection took place |
| Lehman, Maki, Mamun and Veinott, Michigan Tech, 2025 | In 333 NASA ASRS maintenance reports from 2010–2020, procedural errors were still the most common type, at 56% |
| Mendonca and Zimmermann, Embry-Riddle, 2021 | 12 U.S. airline and commuter accidents from 2003–2017 involved maintenance-instruction errors as a contributing or causal factor |
There is good news in the Michigan Tech study: compared with the 1990s, more maintenance errors are now caught before the aircraft leaves the gate. But the most common error type hasn’t changed in 30 years. People still deviate from procedures, and procedures that are hard to use make that more likely.
A Case in Point: Alaska Airlines Flight 1282
On January 5, 2024, the left mid-exit door plug on a Boeing 737-9 separated as the airplane climbed out of Portland, Oregon. The cabin depressurized. Eight people had minor injuries, and the crew landed safely.
The NTSB traced it back to September 2023 at Boeing’s Renton factory. The door plug was opened so workers could repair damaged rivets, then closed the next day without its four retaining bolts. Because the opening wasn’t properly documented, nothing triggered a quality inspection, and no work instructions were followed when it was closed. In its July 2025 final report, the NTSB named Boeing’s failure to provide adequate training, guidance and oversight as the probable cause, with inadequate FAA oversight contributing.
It’s not a new lesson. In 2003, Air Midwest Flight 5481 crashed in Charlotte, killing 21 people, after a mechanic performed only some steps of an elevator rigging procedure. The NTSB found that procedure “did not include provisions for adjusting cable tension as an isolated task.” Two decades apart, the same gap: what the documentation covered, and what the people doing the work actually needed.
Where Documents Go Wrong
Different eras, different aircraft, but the same weak points keep showing up in investigations and in technicians’ own reports.
Put the research together and a few failure modes stand out:
- Undocumented work. If a task isn’t recorded, nobody knows to inspect it. That’s what happened on Flight 1282.
- Missing scope. The procedure doesn’t say what to do when only part of the task is needed, so people decide for themselves. That’s what happened on Flight 5481.
- Ambiguous wording. Steps that make sense to the engineer who wrote them, but not to a technician on a ramp at 2 a.m.
- Illustrations that don’t match the job. A figure drawn from the wrong angle, missing a callout, or out of date after a design change forces the reader to interpret. Interpretation is where errors creep in.
- No built-in verification. Procedures that end without a functional check leave no second chance to catch a mistake.
What Engineers and Technical Writers Can Do
- Write for partial tasks. If a procedure might be performed in pieces, say which steps are required for each case, or state plainly that the full procedure must be completed.
- Test procedures with the people who use them. Watch a technician follow your procedure before you publish it. Where they hesitate is where the document needs work.
- Make the illustration do the work. Show the part from the angle the technician sees it. Call out the dimension, direction or torque value right on the figure, not three paragraphs away.
- Keep drawings editable and current. When a design changes, the figure has to change with it. Vector illustrations with real geometry and organized layers are far easier to update accurately than flattened images.
- End with a check. Close critical procedures with a verification step, such as a functional test, a measurement or a sign-off, so mistakes are caught on the ground.
The Bottom Line
Accident reports rarely blame a single sentence or a single drawing. But again and again, they show that when documentation is unclear, incomplete or hard to use, people fill the gaps with their own judgment, and sometimes that judgment is wrong. Clear procedures and precise illustrations are one of the best defenses we have.
At Vector GFX, that’s what canvasxdraw was built for: accurate, editable vector illustrations that engineers and technical writers can trust and keep up to date. Watch for more practical tips in our How-To video series, including new episodes from retired Boeing Technical Fellow Paul Dufour.
Haven’t tried canvasxdraw yet?
See what precision without compromise feels like. Start your free trial