(d) Except for operations conducted in accordance with paragraph (a) or (c) of this section, a person may takeoff an aircraft in operations conducted under this part with inoperative instruments and equipment without an approved Minimum Equipment List provided—
(1) The flight operation is conducted in a—
(i) Rotorcraft, non-turbine-powered airplane, glider, lighter-than-air aircraft, powered parachute, or weight-shift-control aircraft, for which a master minimum equipment list has not been developed; or
(ii) Small rotorcraft, nonturbine-powered small airplane, glider, or lighter-than-air aircraft for which a Master Minimum Equipment List has been developed; and
(2) The inoperative instruments and equipment are not—
(i) Part of the VFR-day type certification instruments and equipment prescribed in the applicable airworthiness regulations under which the aircraft was type certificated;This is generally Part 23 or CAR 3 for light airplanes. It MAY go back to Aeronautical Bulletin 7A if your airplane is old enough.
(ii) Indicated as required on the aircraft's equipment list This document is generally in your AFM/POH, and lists components that are required for flight...for example, on my Maule, it says the generator is required, or on the Kinds of Operations Equipment List for the kind of flight operation being conducted The KOEL is another list that MAY be included in the AFM/POH...not all airplanes have it. This one generally has columns for Day, Night, VFR, and IFR next to each item that will be checked if the item is required for that particular type of operation;
(iii) Required by §91.205 or any other rule of this part for the specific kind of flight operation being conducted 91.205 is the "basic instruments and equipment" regulation...other regulations in Part 91 require certain pieces of equipment...landing lights if the flight is "for hire", anticollision lights, ELT, oxygen, etc. Technically, this is probably where you'd also determine whether your flight manual supplements require specific equipment; or
(iv) Required to be operational by an airworthiness directive This can be a toughie...you have to know what ADs apply to your airplane.; and
(3) The inoperative instruments and equipment are—
(i) Removed from the aircraft, the cockpit control placarded, and the maintenance recorded in accordance with §43.9 of this chapter; or a lot of people miss this "or".
(ii) Deactivated and placarded “Inoperative.” If deactivation of the inoperative instrument or equipment involves maintenance, it must be accomplished and recorded in accordance with part 43 of this chapter; and
(4) A determination is made by a pilot, who is certificated and appropriately rated under part 61 of this chapter, or by a person, who is certificated and appropriately rated to perform maintenance on the aircraft, that the inoperative instrument or equipment does not constitute a hazard to the aircraft. This is a "catchall"...kind of like the "careless or reckless" reg.
An aircraft with inoperative instruments or equipment as provided in paragraph (d) of this section is considered to be in a properly altered condition acceptable to the Administrator.