Being a Better Aviator: Is Your Airplane Airworthy?

The responsibilities of being pilot in command are great — and some are not so obvious.

Regulation 91.3(a): “The pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.” Also not to be overlooked, regulation 91.7 tells us that the PIC is responsible to determine that the aircraft is airworthy before flight.

Here’s what that means: whether you’re a renter pilot, a flying club member, a partner in owning an airplane, student pilot or owner … It really doesn’t matter: if you’re flying it and you’re responsible for the flight, then you’re the PIC and if there’s a problem, it’s yours — no matter what “it” is.

Something of at least passing interest here: the reg’s make no distinctions between what kind of pilot certificate you might hold as long as you’re qualified to fly whatever aircraft you’ll be in. If you’re legal, and you’re PIC, the same requirements apply to recreational pilots and airline transport pilots.


As PIC, you must determine if your airplane is “airworthy” before flight. So, what does “airworthy” mean?

Well, the reg’s say that for an aircraft to be airworthy, two conditions must be satisfied:

  1. it meets the design standards of its Type Certificate, and
  2. it’s in a condition for safe flight.

Easy enough, right? Careful … the easy questions are always the hardest to answer.


An aircraft manufacturer earns a “Type Certificate” for a particular aircraft when it’s proposed design standards meet the regulations for airworthiness certification — sort of an approval to go ahead and manufacture the aircraft. Then, when you look at an Airworthiness Certificate (one of those “AROW” pieces of paper in the airplane) it means that the aircraft met those design standards at the time it was made, not unlike a birth certificate.

Unfortunately, most of the airplanes we fly are 20 or more years old (mine is 25 years old right now.) How can we know whether it meets those design criteria, 20 (or more) years after the fact?


All aircraft must have regular inspections (remember those annual inspections and 100 hour things you learned about for the knowledge test?) and undergo maintenance to correct deficiencies. Once the inspections and maintenance are finished, there must be an entry in the aircraft maintenance records (airframe and engine logs, etc., more on that later) to document the work that was done.

In addition to the AROW documents — Airworthiness certificate, Registration, Operations limitations (contained in an aircraft flight manual, on placards, etc.), and Weight and balance data — a pilot needs to know about six things (which must also be present in the aircraft’s maintenance records):

  1. Aircraft annual inspection [91.409(a)(1)];
  2. ELT battery date [91.207(c)];
  3. ELT “annual” inspection [91.207(d)];
  4. Altimeter/Mode C test within 24 months [91.411] (if the airplane is flown IFR; if it’s a VFR-only airplane, then a “correlation test” [91.217] between the Mode C and the altimeter must have been done at some point, with no maintenance on that system done in the between times);
  5. Transponder test within 24 months [91.413]; and —
  6. Some record of compliance with all applicable Airworthiness Directives [91.403(a)]. Usually, this is a list showing all ADs that apply to the aircraft type, which ADs apply to that particular airframe, engine, propeller, or appliance (by serial number) and whether it is a “one-time” or a “recurring” AD.

On ADs: when one generates an AD listing for a particular aircraft, the list will be fairly long. Most will not apply. Be prepared to spend a good amount of time and frustration figuring out which ones do. Still, putting a little effort into keeping up with ADs will make the process a lot easier and go a long way toward giving you intimate knowledge of the aircraft you fly — another good reason to stay on top of ADs.

Special notes: if the aircraft has no electrical system, which is to say it came from the factory (certified) that way, then no transponder or mode C tests are necessary. In fact, the aircraft doesn’t even have to have a transponder, or an encoder, or a radio, or a VOR receiver. Just please stay out of the B, C, and D airspace areas to keep everyone happy—yes, it is possible to enter those, but only with prior coordination with ATC.

The Log Book:

Generally, for items 1-6 above, part 43 requires that the date of the work, what was done, how it was done, and the signature of the person (with a certificate number) who did the work be included in a logbook entry. Incidentally, even the ADs that do not apply should be shown as not applicable [“N/A”] and the reason why should be entered.

Example: equipment not installed, serial number of the installed equipment is outside the range of applicable numbers… The entries for maintenance work [43.9] and inspections [43.11] are slightly different — take a look at the reg’s so you’ll know what to look for. Make sure that the maintenance logs include all the inspections and that they are properly recorded — then take a look at some of the other entries. Are all the entries complete? Were all the parts FAA approved? See all those yellow, green, and white tags in there? That’s how you’ll know. Checking the logs is a laborious process, especially the first time and especially if you do it right — but it’s your responsibility. Enough said.


With type certificate requirements attended to, “condition for safe flight” hinges largely on the preflight inspection. When you do that walk-around, you determine that the aircraft is safe. You look at the tires, make sure there’s oil inside the engine (and not too much outside), brakes aren’t leaking, and generally that all the big pieces are still attached, right? If you fly a “new” Cessna 172, do you get all those fuel drains … 13 of ’em, isn’t it? If you fly a Citabria, do you remember to check the drain under the belly?

Trouble Spots:

What repairs have been done? If the fairings are cracked, how were they fixed? Stop drilled? Duct tape? How about the windshield: is it cracked and stop drilled? Ever give any thought about what might happen if you hit a bird? (I’ve hit three in my career.)

Dents, ripples, and small holes in the skin of an airplane are a problem. Remember back in ground school you learned something about “monocoque” or “semi-monocoque” construction? This means “stressed skin — which means the aluminum skin carries most of the aerodynamic loads. Any dent or hole in the skin could compromise the structure (read: create a stress point where it can fail) — not a good thing.

Even in fabric airplanes, you don’t want tears or holes since the fabric can vibrate and tear away — yet another bad thing. Cracked fairings can come apart in flight with the risk of jamming flight controls or changing the control characteristics of the aircraft, essentially making you a test pilot.

Repairs and maintenance must be done, and materials used must be of such quality, that the original certification standards for the aircraft are kept intact. If you want to be a test pilot, go to school for it.


It should go without saying, I suppose, that if the maintenance log entries are made, then the work was actually done. However, experience has taught me that it is prudent to check!

For renter pilots, ask to see the logs on the airplanes you fly. If you get a run-around (“we don’t keep them here”, “they’re in the shop”, “the owner has them”), it just might be time to take your business elsewhere. It’s your pilot certificate, after all. Even more important, it’s your life! In these matters, the responsibility falls on the pilot, not the owner, not the mechanic.

Relevant CFR Summary

14 CFR 91.3 — the PIC is responsible for, and is the final authority as to, the operation of that aircraft, and 14 CFR 91.7 — tells us that the PIC is responsible to determine that the aircraft is airworthy before flight.

14 CFR 91.403 — the owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with part 39 (Airworthiness Directives.)

14 CFR 43 — an A&P mechanic both must do the work and make the maintenance log entries.

Note: Part 43, Appendix A, does have a list of 30 (or so) things a pilot may do. However, if it’s anything other than very simple preventive maintenance items (for example, changing light bulbs, changing the oil, replacing spark plugs), an A&P must at least assure that the work was properly done and make the log entry.


    • 14 CFR 43: Maintenance, Preventive Maintenance, Repairs, and Alterations


    • 14 CFR 91: General Operating and Flight Rules


    • Practical Test Standards


    • Advisory Circular 43-9C: Maintenance Records


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