How to Track ADs and Service Bulletins on an Experimental Aircraft

Few subjects generate more confusion among experimental aircraft owners than airworthiness directives (ADs) and service bulletins (SBs). The legal question of whether they apply is genuinely unsettled at the edges, and reasonable, well-informed people disagree. What follows is a map of the terrain - not a ruling. Treat it as a starting point for your own reading, and weigh the safety question separately from the legal one.

What an AD is, and where its authority comes from

Airworthiness directives are issued under 14 CFR Part 39 to correct an unsafe condition in a type-certificated product - an aircraft, engine, propeller, or appliance that has a type design. 39.1 frames applicability around products with a type certificate, and FAA guidance (Advisory Circular AC 39-7, on AD compliance) reflects the same scope.

Why the airframe of a homebuilt is different

An experimental amateur-built airframe is not type-certificated - it has no type design. On the most widely stated reading, that means airframe ADs do not legally attach to the homebuilt airframe itself, because there is no type certificate for the AD to act on. This is the part most observers, including the EAA, broadly agree on.

The genuinely debated part: installed certificated components

The hard question is what happens to an AD against a type-certificated engine, propeller, or applianceonce that component is installed on an experimental aircraft. One view is that the AD follows the product - it was issued against that engine or propeller by make, model, and serial, and installing it on a homebuilt does not erase the unsafe condition or the directive. Another view holds that once the component is operated on an experimental aircraft it is itself considered "experimental" and no longer conforms to its type design, which complicates whether the Part 39 obligation still runs. FAA legal interpretations and community guidance have been read both ways over the years. This article does not resolve that question, and neither should you take it as resolved.Read your operating limitations, the specific AD, and current FAA guidance, and ask your A&P or FSDO if it matters to a decision you are making.

The safety hook everyone agrees on

Underneath the legal debate is a standard that is not debated: an E-AB aircraft must be in a condition for safe operation to be inspected and flown. It is entirely reasonable - and a position the EAA has expressed - to regard an aircraft as not in a condition for safe operation if the owner has ignored a known unsafe condition that an AD identifies on a component installed on it. In that light, complying with ADs against your installed components is a defensible safety practice regardless of how the applicability technicality is ultimately read. Separately, applicable ADs on the certificated engine and propeller generally must be addressed at initial certification, during Phase I flight testing, to establish a condition for safe operation.

Service bulletins are not mandatory

A service bulletin is a manufacturer's notice - a product improvement, an inspection, or a safety alert. SBs are not mandatory on their own, even for type-certificated aircraft, unless they are made mandatory by an AD or by an operating limitation. They are, however, often the earliest and most specific warning of a real problem. Alert service bulletins in particular flag conditions the manufacturer considers safety-related. Many experimental owners treat relevant SBs as recommended best practice and comply with them for the same reason they comply with ADs: flight safety, not legal compulsion.

A practical approach

The approach this app takes - and the one we would suggest - is to track everything, decide deliberately, and document the decision:

• Record every AD and SB that could relate to your airframe kit, engine, propeller, and appliances.
• Treat compliance as the default for anything safety-related, especially alert SBs and ADs on installed certificated components.
• If you defer an item, do it deliberately and write down why - the app lets you mark an item deferred, at your own discretion and risk.
• Re-check recurring items by date or hours so nothing quietly goes overdue.

The app encourages compliance for safety and surfaces due items, but it does not assert what is legally required of you. That judgment is yours, made against the primary sources and your own mechanic's advice.

How this app tracks ADs and SBs

Each aircraft has a single ADs & Service Bulletins list. You can add items by hand or import a service bulletin from a web URL (with a Van's model selector for RV builders). Items can be marked recurring on a calendar-month or hour interval; the app records the last-complied and next-due values and flags an item for review when it comes due - on the dashboard, in the list, and during the AD/SB phase of an inspection. Reviewing an item as complied, deferred, or N/A updates its status everywhere and writes a maintenance log entry so the decision is part of the permanent record.