Mandatory Bulletins and Service Bulletins vs. ADs, Limitations, and TCDs

A current controversy over the scope of mandatory service bulletins has been caused by a decision of the NTSB involving the field overhaul of a Lycoming engine.


The Board said in the case that a manufacturer may legitimately include service bulletins by reference into their manuals. Most of us don't believe this is accurate. If so they could replace the whole manual with the simple statement "… incorporated by reference"... Any changes or additions to manuals have to be approved by the FAA. Where is the approval for these service bulletins and instructions? (Unless included in ADs.)

Even if they do simply incorporate by reference there is no requirement under the current law to follow them. They would be strictly voluntary and optional for compliance because they are not referenced as an approved airworthiness limitation. Unless the FAA approves and concurs in a mandatory bulletin, service instruction, or information letter, they need not be followed.

The Legal Significance

You might think that this case is of little significance. But it is a huge subject when it comes to the litigation of an aviation tort case. You can bet your money on the plaintiff's bar grabbing this case and using it to maintain that you have been negligent and in fact violating the law by failing to comply with manufacturers' service bulletins, service instructions, and letters pertaining to the maintenance of an aircraft. It becomes very easy to argue liability for damages when there is proof of violation of regulation, law, or statute. Where are the insurance companies when you need them?

Further Appeal

It is likely that this case will be appealed further by the mechanic. A Federal Circuit Court of Appeals either in Washington, D.C., or the airman's home circuit may hear this case and open up the issues for further examination. We'll have to wait and see.

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