FAA Mandates Inspections and Fixes for Diamond Aircraft Fuel Tanks
Published Date: 3/26/2026
Rule
Summary
If you own or fly a Diamond Aircraft DA 40, DA 40 F, or DA 40 NG, listen up! The FAA updated safety rules to fix fuel tank issues by requiring inspections, part replacements, and using new service instructions for the DA 40 NG. These changes kick in April 30, 2026, and help keep your flight safe without breaking the bank.
Analyzed Economic Effects
3 provisions identified: 1 benefits, 2 costs, 0 mixed.
Mandatory Fuel-Hose Inspections and Replacements
If you own or operate a Diamond Aircraft Model DA 40, DA 40 F, or DA 40 NG, you must replace affected fuel tank connection hoses, inspect the main fuel tank chambers, and remove any detached rubber material. Do the work within 100 hours time-in-service or within 2 months, whichever comes first, after April 30, 2026. The FAA estimates this AD affects 987 U.S.-registered airplanes and gives cost examples: inspection $85 per airplane, removing detached rubber $425 per airplane, and replacing the hose $1,233 per airplane.
Ban on Installing Affected Hoses
As of April 30, 2026, you may not install an "affected part" fuel tank connection hose (as defined in the AD) on any airplane. The AD defines affected parts by part number, purchase dates (between July 13, 2017 and February 26, 2019), serial-number lists, or replacement-installation date criteria.
Updated Service Instructions Required for DA 40 NG
For Model DA 40 NG airplanes the AD requires using Diamond Aircraft Industries Mandatory Service Bulletin MSB 40NG-064 Rev. 3, dated January 23, 2025. The Director of the Federal Register approved incorporation by reference of that service bulletin as of April 30, 2026.
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