May 17 2021

MAINTENANCE MYTHS Posted 3 years 224 days ago ago by Admin

A myth is generally defined in this context as a widely held but false belief or idea. And when it comes to aircraft maintenance, a majority of aircraft owners and a smaller number of mechanics seem to thrive in that mythical maintenance world.

So pop in your copy of Magic Carpet Ride and let’s take a journey down the yellow brick flight line to unlock some of those long-held maintenance myths. 

MYTH: The mechanic is responsible for maintaining the aircraft.

No. While a mechanic is responsible for the specific work they perform, in reality, it is the owner who is held responsible overall by the FAA for maintaining the aircraft in airworthy condition. The feds even conveniently stated that in black and white in FAR Part 91.403(a). 

So if you think you get a pass on all regulatory maintenance infractions, you may want to think again and be more involved in the maintenance processes that take place on your aircraft.  

And just when you think you have that myth resolved, the owner is also responsible for compliance with the requirements of Part 39, Airworthiness Directives. This is also stated in Part 91.403(a). So while your APIA may check for the actual AD compliance during every Annual inspection, the owner is the one who is accountable to the Man.

Now in all honesty, there is a cross responsibility on Airworthiness Directives that holds a mechanic accountable for ensuring that all applicable ADs are complied with, but only when they perform certain inspections. So if a new AD is received in the mail by the owner, it falls to the owner to ensure compliance with the new AD until the mechanic performs a required inspection per Part 91 or 125 or §135.411(a)(1) and also assumes responsibility for the new AD compliance.

MYTH: The mechanic handles all the maintenance records.

Nope. Granted, a mechanic is required per Part 43.9(a) and 43.11(a) to make an entry in the maintenance record for most of the work they perform. However, it falls to the owner to ensure the mechanics make those appropriate entries in the aircraft maintenance records that indicate the aircraft has been approved for return to service per Part 91.405(b). It also falls to the owner to ensure those maintenance records are kept in accordance with Part 91.417(a). 

Once again, it’s the owner who is the responsible party and not the mechanic. Additionally, the owner is required to retain a number of records in the course of normal operations and maintenance, including certain records that must be kept indefinitely and transferred when the aircraft is sold. Part 91.417(b) is the go-to reference on that topic.    

MYTH: The mechanic selects the aircraft inspection program and corrects all discrepancies.

This one always seems to get the most traction in the FBO Saturday morning coffee shop discussions. So let’s split it out into two parts. 
First, the inspection program selection. Part 91.405(a) gets us right into the action...“Each owner or operator of an aircraft – (a) Shall have that aircraft inspected as prescribed in subpart E of this part...” Nothing mythical about that statement. So where does the confusion come from?

It’s a given that most owners and mechanics know that with some exceptions, any aircraft operated in the National Airspace System (NAS) must have an Annual inspection performed in the preceding 12 months. And in keeping with the references, that would fall under Part 91.409(a). 

But most owners and some mechanics do not know that when it comes to certain types of inspections or aircraft, the owner must select the inspection program. Sure, it’s always prudent for an owner to consult with a mechanic when looking at maintenance procedures. But unfortunately, a lot of owners view that consultation process as a delegation process as well. No go, say the FARs.

If you want a Progressive inspection program per Part 91.409(d), the owner – not the mechanic – must submit a written request to the local FSDO for approval to include all the necessary details. 

Now, if you are the owner of certain large airplanes, turbojet multi-engine airplanes, turbo-propeller-powered multi-engine airplanes, or turbine-powered rotorcraft as listed in Part 91.409(e), the owner is again required to make that inspection program selection, and to identify that program selection in the aircraft maintenance records as directed in Part 91.409(f).

But as a side note, thankfully for you turbine-powered rotorcraft owners, there is an exemption in Part 91.409(e) that allows you to  use one of the previous inspection programs listed in Part 91.409(a), (b), (c), or (d), instead of selecting from paragraph (f).  

Moving on to the discrepancy side of this myth... 

Nowhere is it stated in the FARs that a mechanic can arbitrarily walk up to an aircraft and fix something without the owner’s involvement. A mechanic simply doesn’t have that regulatory stroke. Only the owner can make that call.

Ironically, it starts in the same regulation that puts the onus on the owner to have the aircraft inspected, Part 91.405(a). Specifically it states, “Each owner or operator of an aircraft – [...] shall between required inspections, except as provided in paragraph (c) of this section, have discrepancies repaired as prescribed in part 43 of this chapter...” Once again, only the owner is mentioned.

A little factoid: notice how it states just “discrepancies” and not “airworthy discrepancies?” But I digress. We’ll leave that topic for another time.

As for where the mechanic does fit into the discrepancy topic, we need only look to Part 43.11(b) for one example. Rather than simply state that the mechanic repairs those discrepancies, it says the mechanic “must give the owner or lessee a signed and dated list of those discrepancies.” So even in the mechanics’ own Part 43, the owner is still the head honcho.   

MYTH: Only a mechanic can return an aircraft to service.

Gong. Not quite. While a mechanic does play a part in returning an aircraft to service, the final return to service falls to the pilot, who also is the owner of most small GA aircraft.

The funny thing about this myth is that, out of all those listed here, this one actually has the makings of a good myth because the “return to service” is not well defined within the FARs. 

Let’s start at the mechanic end on this one. Per the FARs, Part 43.9(a)(4) to be precise, when it comes to an aircraft a mechanic can only “approve for” return to service. The key words are “approve for.” This is different than “return to service.” So why no corresponding regulation in Part 91 for aircraft return to service?

I don’t know. But it is implied in Part 91.407 as follows, “(a) No person may operate any aircraft that has undergone maintenance, preventive maintenance, rebuilding, or alteration unless – (1) It has been approved for return to service by a person authorized under §43.7 of this chapter; and (2) The maintenance record entry required by §43.9 or §43.11, as applicable, of this chapter has been made.”

Part 91.407 does state that the aircraft needs a signed approval for return to service, as we mentioned earlier, and it goes on to require certain aircraft checks including a record entry if the aircraft is flown after maintenance. But nowhere do those three words “return to service” get used separately. 

So how do you know I’m not just making this up or simply expressing my opinion? Well, I just so happen to have found the location of one of those obscure FAA references to this subject. Unfortunately that reference has since been cancelled, but it works in this context. Plus I’ve been told there are other similar references that I haven’t uncovered yet. 

Buried in the former FAA AC 91-67, Minimum Equipment Requirements for General Aviation Operations Under FAR Part 91, in Section 6, Definitions, Item (x), is this dandy short paragraph: 

“Return to Service: Return to service has two applications. An appropriately certificated person approves an aircraft for return to service after an inspection or after maintenance. A certificated pilot, in fact, returns the aircraft to service after the pilot conducts an appropriate preflight and accepts the aircraft for an intended flight.”

So there you have it: signed, sealed, and returned to service!

Whew! Sure is a lot of “owner this,” “owner that” in those “maintenance” regulations. Well, I hope your Magic Carpet Ride through the myths of aircraft maintenance was a smooth one. It was for me, and it sure beats the hell out of trying to figure out the myth of Pandora's Box.

About the author: Scott Skola can be contacted at [email protected].