FAA Orders Inspections of Diamond DA40 Aircraft
An airworthiness directive targets passenger door separations on about 987 U.S.-registered Diamond DA40 airplanes.
Updated on Nov. 2, 2026 in Air Travel
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The Federal Aviation Administration issued an airworthiness directive covering all Diamond DA40, DA40 F, and DA40 NG aircraft after multiple in-flight passenger door separations. The directive affects an estimated 987 U.S.-registered airplanes and takes effect Dec. 7.
Why it matters
A separating door could damage the aircraft's structure and potentially lead to loss of control in flight. The FAA determined that the secondary safety latch does not resolve the unsafe condition and rejected requests to exclude newer aircraft from the directive.
The directive covers an estimated 987 U.S.-registered airplanes, with the 2010 FAA action following 31 earlier door separations on DA40 models. Initial inspections cost about $331 per aircraft, plus $85 for flight manual revisions, and the root cause remains under investigation by Diamond Aircraft.
The players
Federal Aviation Administration
The U.S. federal agency responsible for regulating civil aviation, including issuing airworthiness directives that require corrective action on aircraft types found to be unsafe.
Diamond Aircraft
The Austrian-headquartered manufacturer of the DA40 single-engine aircraft, which is investigating the door separation problem and attributed some incidents to improperly secured doors.
Transport Canada
Canada's federal transportation regulator, which worked with the FAA on the determination that the secondary safety latch does not resolve the unsafe condition.
The details
The directive requires operators to revise aircraft flight manuals and complete initial inspections within 100 flight hours or 100 days, whichever comes first. Required checks cover door latches, safety hooks, hinges, springs, and related components, and Diamond Aircraft attributed some incidents to passenger doors being improperly secured or latched in flight.
Timeline
2010: FAA took action following 31 reported door separations on earlier DA40 models.
Nov. 2, 2026: The FAA published the airworthiness directive.
Dec. 7, 2026: The directive takes effect.
Within 100 flight hours or 100 days: Operators must complete initial inspections.
Seasonal Patterns
The 2026 directive follows the FAA's 2010 action after 31 door separations on earlier DA40 models, showing the problem has recurred across successive generations of the aircraft. The FAA's rejection of requests to exclude newer aircraft indicates the agency sees the issue as unresolved rather than confined to older designs.
Owners and operators of DA40, DA40 F, and DA40 NG aircraft must revise flight manuals and complete door latch, hook, hinge, and spring inspections on a set schedule. Passengers flying these aircraft should expect possible temporary groundings while inspections are completed.
The takeaway
Aircraft owners should not assume newer models are exempt from door-related safety directives, and should schedule the required inspections before the Dec. 7 effective date. The directive shows that even a secondary latch may not fully prevent in-flight door separations.
What happens next
Operators must complete initial inspections within 100 flight hours or 100 days, and the directive takes effect Dec. 7, 2026.
Further reading
For more on aircraft safety rules affecting U.S. travelers, browse our Air Travel coverage.
Source note: This article includes information reported by AVweb.
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