Aviation is regulated by the statutes and regulations, but certain technical aspects are so specific and intricate that it’s hard to determine what the law exactly says in those cases. When in doubt, pilot and aviation professionals have been requesting the FAA to pronounce themselves on legal questions. The response is a Letter of Interpretation (LoI).
Letters of Interpretation clarify what the FAA believes that the law says about a variety of questions.
LoIs are typically useful to:
- aviation professionals, and
- typically flight instructor candidates, during an oral exam, when asked to offer what is the source of law on a specific legal opinion.
The typical private pilot student has little or no use for LoIs.
A curated collection of useful Letters of Interpretation within this context follows.
DISCLAIMER: the regulatory landscape changes constantly. LoIs are published and rescinded constantly. While we make all efforts to keep this list updated, we make no representation that they are. It is your responsibility to verify the validity of any LoI, using authoritative sources, before citing it.
Listed alphabetically.
- Bennett, 2016 – on whether someone holding a pilot certificate (and therefore no longer a student pilot) undergoing training in a different category or class of aircraft, and holding a solo endorsement must also have a valid flight review.
Disposition: the pilot must have a valid flight review. - Carty, 2002 Memorandum – on what kinds of approaches satisfy the “three different kinds of approaches” requirement of 14 CFR 61.65(d)(2)(ii)(C). Holds that “different kinds of approach” does not necessarily mean “different types of navigational systems. Considers PAR and ASR acceptable navigation systems. Rescinds the Glaser and the Platte interpretations, previously held valid.
Disposition: flying different published approaches satisfies the requirement, even if they don’t all use distinct navigational systems. - Coleal, 2009 – on whether a pilot can perform a tire pressure check on an aircraft operated under Part 91.
Finding: pilots are allowed to perform tire pressure checks.
Rationale: pilots are already permitted by 14 CFR 43.3(g) to perform an operation (changing tires) that is more complex, and a strict superset of the one requested (checking pressure). Therefore, they must be considered authorized to perform simpler tasks that are subtasks of those explicitly enumerated. - Griffith, 2008 – on whether a CFII is needed to conduct an Instrument Proficiency check, or just a CFI suffices (among other questions). The letter of the law (14 CFR 61.57(d)) merely talks about “an authorized instructor”.
Finding: a CFII is required; a mere CFI is not sufficient. - Herman, 2009 – on whether it is necessary to hold a high-performance endorsement in order to be able to log PIC time when being the sole manipulators of the controls in a high-performance airplane.
Finding: the endorsement is not required to log PIC time. - Kortokrax, 2006 (superceded) – on whether a CFI instructing a pilot is considered a passenger for the purposes of passenger-carrying currency of 14 CFR 61.57 (a) and (b) and, consequently, whether the pilot can carry their CFI if the pilot is not current.
Finding: the CFI is not considered a passenger. A pilot can carry their CFI without being current.
Status: this LoI is rescinded and superceded by the regulatory changes below. - Mangiamele, 2009 – on whether a private pilot may act as PIC in furtherance of business activities as an employee and/or seek compensation or reimbursement for the flight.
Findings: the pilot may perform a flight while compensated and/or seek employer reimbursement, but the flight must be incidental to the business, and they may not carry property or passengers. - NPRM (88 FR 41194) – one of the Kortokrax findings has been codified in the 14 CFR 61.57(e)(5) “exceptions”: a pilot receiving flight instruction with their CFI does not need to be passenger-carrying current, as long as no other occupants are in the aircraft.
- Rohlfing, 2016 – on whether the 3h simulated instrument training time that a student pilot received to satisfy their private pilot certificate experience requirements also count toward instrument rating requirements, specifically, the 40h of total instrument time and the 15h of instrument time with a CFII, of 61.65(d)(2).
Findings: those 3 hours do count toward the 40h total instrument time requirement, but not toward the 15h instrument time with a CFII requirement. - Speranza, 2009 – on whether a pilot (B) that is not instrument rated can log PIC time while being the sole manipulator of the controls, under IFR rules, and flying with another pilot (A) who is instrument rated.
Findings:- again, acting as PIC and logging PIC time are separate things
- pilot A must act as PIC because – are the only legally authorized pilot to do so
- pilot A can log PIC time for the time they are the sole manipulators of the controls, as long as they are airplane certified and rated; that does not include an instrument rating
- pilot B can not log PIC time for the time in which pilot A is logging PIC time. No double logging.
- Trussell, 2012 – on who can log PIC time when performing simulated IMC flights with a safety pilot.