Letter of Authorization (LOA)

A Letter of Authorization is the mechanism by which the FAA grants a non-air-carrier operator specific operational authority that exceeds the standard privileges of the operator's pilot certificates or aircraft type certificates. LOAs are issued under 14 CFR Part 91 authorities and are the functional counterpart of Operations Specifications (OpsSpecs) issued to Part 119 certificate holders (Part 121, 125, and 135 operators). Where OpsSpecs are provisions within an air carrier operating certificate, LOAs are standalone documents issued to operators who do not hold an air carrier certificate.

LOAs are identified by alphanumeric codes in the FAA Air Transportation Oversight System (ATOS), and the most operationally significant types are as follows.

LOA C055 — RVSM Authorization. Reduced Vertical Separation Minima (RVSM) airspace exists from FL290 to FL410 in domestic US and ICAO-designated oceanic areas. Aircraft operating in RVSM airspace must be RVSM-compliant (meeting the altimetry system performance standards of ICAO Doc 9574 and FAA AC 91-85B): two independent altitude-measurement systems, an automatic altitude control system, and an altitude alerting system. The operator must have an approved RVSM monitoring program — typically satisfied by enrollment in the Global RVSM Monitoring Agency (GRMA) altimetry data collection program — and submit an RVSM maintenance program covering altimeter system checks every 24 calendar months. C055 is operator-specific and aircraft-specific; adding a new aircraft to the RVSM authorization requires an amendment to the existing LOA.

LOA C063 — RNP Authorization Required (RNP AR). RNP AR approaches (RNAV (GPS) approaches with RF legs and/or approach minimums requiring RNP less than 0.3 NM) require both aircraft equipment and operational authorization. The aircraft must have an FAA-approved RNP AR avionics installation per AC 90-101A, and the operator must demonstrate training programs, crew qualification procedures, and a maintenance program for the navigation system. Curved RNP AR approaches — such as those serving mountain airports including Juneau International (PAJN) and Queenstown (NZQN) — are operationally significant and require C063.

LOA C384 — Cat II/III ILS Approach Authorization. Category II (DH 100–200 ft, RVR 1,200 ft) and Category III (DH below 100 ft or no DH, RVR below 700 ft) ILS approach operations require not only an ILS-equipped aircraft with approved autoland or heads-up display systems but also an operational authorization covering crew training and qualification, maintenance programs, and dispatch/flight-planning minimums. C384A covers Cat II and Cat III with DH; C384B covers Cat III with no DH (autoland required).

LOA A056 — Authorization for Special Flight in Class B Airspace. Some flight activities in Class B airspace (parachute jumping, aerobatics) require specific authorization.

LOA B045 — Polar Operations. Transpolar routes over the Arctic via FAA polar track system require authorization covering equipment (backup navigation, additional communications, ELT requirements for remote operations), cold-weather operations training, and diversion planning for remote airports.

The LOA issuance process begins with the operator submitting an application to their local Flight Standards District Office (FSDO) or, for corporate operators, their Principal Operations Inspector (POI) within the Certificate Management Office (CMO). The application package must include: a description of the proposed operation, applicable aircraft equipment documentation, training program for flight crew, maintenance program for affected systems, and a statement of operating procedures. The POI reviews the package, may conduct a proving flight or records review, and issues or denies the LOA. Some LOAs (RVSM, RNP AR) have standardized application kits published in the applicable Advisory Circular.

EASA equivalent authorizations are called Specific Approvals (SPA) under Commission Regulation (EU) 965/2012, Annex V (Part-SPA). The EASA SPA catalog includes SPA.RVSM (equivalent to C055), SPA.LVO (Low-Visibility Operations, equivalent to C384 Cat II/III), SPA.PBN (Performance-Based Navigation, covering RNP AR equivalent to C063), SPA.HEMS (Helicopter Emergency Medical Service), SPA.HOFO (Offshore helicopter operations), SPA.NVIS (Night Vision Imaging System operations), SPA.HHO (Helicopter Hoist Operations), and SPA.DG (Dangerous Goods). EASA SPAs are issued by the competent authority (e.g., CAA UK, LBA Germany, DGAC France) in the member state where the operator holds its AOC, as an amendment to the operator's OpsSpecs under Part-ORO.

LOA management for corporate flight departments operating complex aircraft (Gulfstream, Bombardier, Dassault, Embraer business jet fleets) can involve holding ten to twenty active LOAs simultaneously — RVSM, multiple RNP AR authorizations for specific airport approaches, Cat III, polar operations, MNPS (Minimum Navigation Performance Specifications for North Atlantic), and potentially data link communications authorizations. Each LOA references underlying maintenance and training requirements that must remain current for the LOA to remain valid; expiration of the underlying altimetry check, navigation system certification, or crew training event may implicitly invalidate the LOA even without a formal revocation by the FSDO.

For flight schools operating technically advanced aircraft or turbine aircraft in training programs that include instrument approaches, RVSM navigation, or Cat II approaches in the training syllabus, LOA currency is a compliance obligation that overlaps with training record management. An ATO whose training program includes RNP AR approaches must ensure that every flight crew member conducting those approaches under the training program is authorized — either through an operator LOA or through a specific student training authorization from the POI.

Aviatize's compliance and auditing module maintains a registry of all active LOAs for the operator, tracking each authorization's issuance date, the underlying maintenance and training prerequisites, and any aircraft-specific restrictions. When an underlying requirement approaches its due date — the 24-month RVSM altimetry check, the crew proficiency check tied to a Cat III authorization, or the navigation system software compliance verification — the platform generates an advance alert to the Accountable Manager or Director of Operations, preventing inadvertent operation under an implicitly lapsed LOA.

For training organizations conducting type-specific programs that include special operations (RVSM navigation training, RNP AR approach training), the compliance module links each LOA prerequisite to the relevant training records for the specific instructors and students authorized under that program. This creates the documented compliance chain — from LOA through training program approval to individual crew qualification — that satisfies both the FSDO during LOA renewal review and the operator's insurance underwriter during annual coverage renewal.