TAXES, LAWS, AND FINANCE: Defining “airworthy”

The word’s meaning is important but difficult to pin down.

There’s an old saw in business aviation that there’s no definition of “airworthy,” and thus no decisive way to establish an aircraft’s “airworthiness.”

At one point, the U.S. Federal Aviation Administration seemed to agree. Years ago, in an Order now suspended, the agency observed that the term “is not defined in the Federal Aviation (FA) Act or the regulations.” Over time, though, the FAA changed its tune. A subsequent Order sought to clarify the meaning of “airworthy” by “a review of case law.” Eventually, the FAA bit the bullet and defined the term itself in a section of an Order entitled (to leave little room for doubt) “Definition of the Term ‘Airworthy’ for U.S. Type-Certificated Aircraft.”

Despite all this waffling, however, the FAA’s position on “airworthy” has remained basically the same over the years. To be worthy of flying, an aircraft must meet two basic requirements, according to the agency’s definition: it must conform to its type certificate and it must be “in a condition for safe operation.”

Note that these requirements pertain only to airworthiness, not registration. To register an aircraft in the U.S., you have to comply with FAA registration prerequisites, such as satisfying the citizenship tests. Whether you can actually fly in the airplane is an entirely separate matter. Indeed, at the time they’re registered in the U.S., many foreign-registered aircraft must be modified to satisfy U.S. “airworthiness” requirements.

The first of the FAA’s conditions is relatively simple. An aircraft’s type certificate is the blueprint that the FAA approved for building the model. When it comes off the production line, the aircraft is certified as complying with the type certificate so it can receive an airworthiness certificate. Subsequent modifications to the airplane may require compliance with supplemental type certificates (so-called STCs).

To obtain a U.S. airworthiness certificate, an aircraft built in a foreign country and initially registered outside the U.S. may need a certification from the country of manufacture that it complied with U.S. type design when delivered. This sets a baseline for evaluating subsequent modifications, repairs, and maintenance, which will also need to comply with U.S. standards.

The second of the FAA’s stipulations is that the aircraft must be safe, or rather, in a condition for safe operation. That’s the kind of aircraft I want to fly on, but how do you know? The FAA’s order offers a strangely one-sided explanation of this rule; it says it “refers to the condition of the aircraft relative to wear and deterioration, for example, skin corrosion, window delamination/crazing, fluid leaks, tire wear.” This makes it seem as though—assuming the aircraft satisfied type design when manufactured—the only airworthy issue to worry about is “wear and tear” over time. That’s obviously important, but what about the status of required maintenance, compliance with airworthiness directives and service bulletins, compliance with regulations regarding newly required equipment, repair of damage, and so on?

Trying to prove an aircraft is safe is like trying to prove there are no purple sheep in the world. All the sheep you find—millions of them—may be white, brown, or black, but that doesn’t mean there isn’t a stealthy purple one skulking around somewhere. FAA regulations require that when a technician approves an aircraft’s return to service following an inspection, he must certify in its records that it “was deemed to be in airworthy condition.” Thus, the FAA seems to require the technician to certify something he can’t possibly know: that no “unairworthy” condition exists.

Before concluding that no aircraft can ever be returned to service, however, consider the sign-off required by the FAA if the technician concludes that the airplane isn’t airworthy: in that case, he certifies that it was inspected “and a list of discrepancies and unairworthy items dated (date) has been provided for the aircraft owner or operator.” Since there is apparently no third option and because, if the aircraft is deemed unairworthy, the technician is required to say why, the FAA must think the technician is within his rights to return an aircraft to service as airworthy as long as he isn’t aware of any condition that would render it unsafe.

A lawyer might add “after due inquiry,” but what does that mean? The amount of checking you can do on an aircraft is virtually endless, and the checking itself can cause problems. No wonder maintenance technicians and repair stations focus on the tasks at hand, like the inspection they’ve been hired to accomplish. This doesn’t mean that if you’re just servicing the aft lavatory you’re supposed to ignore the giant crevasse you notice on a leading edge. Technicians are expected to follow up on observed defects, but not to disassemble the aircraft looking for them.

Purposeful checking for airworthiness issues not related to an inspection coming due is the province of the “prepurchase evaluation” that buyers perform. Terms like “evaluation” and “survey” are deliberately used to avoid the word “inspection,” because the prebuy may not include any inspection that takes the aircraft out of service and that would require the sign-offs just discussed to return it to service.

Still, sellers are quick to say in purchase contracts that they will repair only “airworthy discrepancies” (or, depending on whom you’re talking to, “unairworthy discrepancies”), because this language eliminates the obligation to fix all sorts of things that buyers will (and should) want repaired. No technician will ground an aircraft because a window shade is stuck. Items like this are frequently referred to as “cosmetic,” as though the inability to pull down a shade were an aesthetic problem. The same can’t be said if the DVD player doesn’t work, yet in the end that too is unlikely to ground the aircraft. In a retail transaction, the aircraft should certainly be airworthy at delivery, but the buyer will also want everything on it to work properly, regardless of whether or not it affects safe operation.

Determining that an aircraft is “airworthy” may be an impossible task, like proving there are no purple sheep, but a thorough prepurchase evaluation should uncover the most obvious airworthiness issues.    

Jeff Wieand  is a senior vice president at Boston JetSearch and a member of the National Business Aviation Association’s Tax Committee.