Frustration with hard-to-understand regulations has led more than one pilot to interpret the words in a way that supports what they want or need to do. Live and work long enough in a tightly regulated environment and you will find yourself tempted to do this. None of us is immune. I've learned to be skeptical of attempts to broadly interpret a rule to fit one's own argument, especially when I hear the words coming out of my own mouth. Like it or not, we're all in a partnership with the FAA.
I heard an aviation insurance broker give a good technique for testing whether or not your interpretation of a regulation is any good: Simply try prefacing your argument with the words "Your Honor, ..." This is a remarkably effective approach to making a pilot think twice about the soundness of their reasoning.
Well, your honor, before the engine failure after takeoff, I asked three other people who were standing on the ramp if they thought the plane was okay to fly. They all said yes, so ...The regulations say that no person may operate an aircraft that is not in an airworthy condition. They also say that the pilot in command is responsible for determining if the aircraft is in a condition for safe flight. One of my favorite questions to ask a pilot during a flight review is "Just what is the difference between airworthy and in a condition for safe flight? Airworthiness is a legal concept while in a condition for safe flight is a practical concept. Here's what I mean.
To be airworthy, the aircraft must comply with its type certificate. This means that all airworthiness directives that affect the aircraft type have been complied with. It also means that all of the required inspections have been performed within the specified interval. This includes the annual inspection, 100 hour inspection (if applicable), altimeter/transponder/pitot-static system tests (every 24 calendar months), and the Emergency Locator Transmitter test (every 12 months). The ELT battery must also be within it's acceptable life limit. If the aircraft is going to be flown under instrument flight rules, the VOR receivers must have been tested within the last 30 days and the results logged.
To be airworthy, the required aircraft documents must be on board, too. Some people use the acronym AROW to remember what these documents are: Airworthiness certificate, Registration, Operating Limits, Weight and Balance data. And here's a bit of trivia: If the aircraft is operating with fuel tanks that are located inside the cockpit (such as ferry tanks), the Form 337 for that alteration must be on board, too. Note that an aircraft radio station license is not required unless you are flying outside the U.S.
An airworthiness consideration that pilots tend to overlook is whether or not an aircraft has been returned to service after maintenance was performed. 14 CFR 43 says that anytime maintenance is performed on an aircraft, the mechanic must log the date, the number of hours on the aircraft, a description of the work performed, their certificate number, their name, and their signature. This entry shows the aircraft was returned to service. Some mechanics will add the words "... returned to service only for the work performed." If a certificated mechanic performs maintenance, but does not make the logbook entry, the plane has not been returned to service and is not airworthy. And should you get into some sort of trouble, you can be sure the FAA will be looking at the aircraft logs.
A lot of aircraft owners don't realize that every time they update the database in their IFR-certified GPS, according to 14 CFR 43 appendix A, they must log it.
Updating self-contained, front instrument panel-mounted Air Traffic Control (ATC) navigational software data bases (excluding those of automatic flight control systems, transponders, and microwave frequency distance measuring equipment (DME)) provided no disassembly of the unit is required and pertinent instructions are provided. Prior to the unit's intended use, an operational check must be performed in accordance with applicable sections of part 91 of this chapter.
Inoperative equipment is one area where many pilots have a hard time facing facts. You're all set to go flying and everything looks good until you see the something is not working. What to do, what to do? One popular approach is to go flying anyway and if you run into the FAA, just claim that the beacon failed during flight. Then you find out that someone squawked the problem before your flight, your little lie is uncovered, and you might just be spending more time with the FAA before you get your flying privileges back.
You can find the required equipment for your type of operation (day or night VFR, or IFR) in 14 CFR 91.205. If something is not working, see if the thing that is broken is listed in 91.205. If it is, the aircraft ain't airworthy. Otherwise, the next step is to check the equipment list or limitations section in the aircraft's POH or approved flight manual. The older Cessna POH list equipment required for certification with an item number that ends with an R suffix. Other POH or AFM use a minimum equipment list format. If the thing that is broken on your plane appears in the POH or AFM as required, the aircraft ain't airworthy. If the thing that is broken isn't in any of those places, you can fly provided you placard the item as "INOPERATIVE" and either deactivate it or remove it. Removing the item is usually not an option unless you also hold an A&P certificate.
An aircraft can be airworthy, but still not be in a condition for safe flight. An aircraft's inspections and documents may all be in order, but there could be a mechanical discrepancy that would preclude safe flight. These discrepancies are usually related to things that wear out - what the FAA calls life-limited parts. During your preflight, you could find a pool of oil under the engine, or brake fluid leaking from a caliper, or a huge gouge in the propeller, or that a fuel truck backed into the horizontal stabilizer, or that one of the tires is so worn that chord is showing. The plane is technically airworthy, but you'd have to be crazy to fly a plane with one of these problems.
When I was flying freight, I had only a couple of occasions where I had to tell maintenance that something was a no-go item. It didn't make me very popular, so I took some advice from another captain: Anytime you suspect something might be amiss or about to become a problem, let maintenance know immediately. The sooner you let them know, the more time they have to prepare to work on the issue. You also have covered your butt since there will be a record that you reported an issue. Most 135 operators are pretty good at managing maintenance and their procedures for inoperative equipment are well-defined. I didn't have many problems in the Caravan, but heard plenty of stories about some 135 operations flying pretty ratty equipment. Even if you are renting aircraft, my advice is don't be bashful about bringing discrepancies to the attention of the operator.
Now if you got this far without throwing up your hands, giving up, and saying "Flying is too much damned trouble," here are my last thoughts. Life is full of risks and if you choose to go flying, you have increased the number of life-threatening risks you might face. All of these regulations and procedures are meant to reduce or mitigate most of the risks associated with flying. In short, following the regulations and best practices could just save your life, the lives of your passengers, the lives of people on the ground, and that shiny aircraft you're flying.
Follow the rules and you'll reduce your chances of having to stand in front of a judge and say, "Well, your honor ..."