AAMedP-1.3 aircraft oxygen equipment and pressure suits

What it is

What AAMedP-1.3 covers

AAMedP-1.3 is NATO's Allied Aeromedical Publication setting the minimum functional requirements an aircraft's oxygen equipment and pressure suits must meet to protect aircrew and passengers against hypoxia and against the effects of a rapid loss of cabin pressure. It sits between NATO's aerospace medicine doctrine and general aircraft engineering: it is not a medical procedure document and not a general airworthiness code, but a requirements publication for the life-support equipment fitted to military aircraft. Edition B, Version 1 was promulgated in January 2025, superseding Edition A, Version 1, which affected nations were told to destroy under local document-destruction procedure.

The document addresses each NATO nation directly, not a supplier by name. Its own words are that "it shall be the responsibility of each nation to ensure that its aircraft are fitted with appropriate oxygen equipment" giving aircrew adequate protection throughout the aircraft's operational envelope. An organisation that designs, builds or maintains this kind of equipment meets AAMedP-1.3 because a nation's procurement specification, or a contract for an aircraft oxygen system or pressure suit, calls it up, not because the publication reaches a company directly.

Hypoxia protection and the aircraft it covers

Chapter 1 sets out the underlying obligation and distinguishes the aircraft categories the rest of the document treats differently. Unpressurized aircraft need an oxygen system once flight altitude passes a defined threshold, with narrowly bounded exceptions for brief excursions above it under operational necessity. Pressurized aircraft split into two further categories: high-differential- pressure, transport-type aircraft, and low-differential-pressure, fighter-type aircraft. For transport-type aircraft, the requirements differ by who is aboard: personnel flying the aircraft, other operational crew, and transported personnel (passengers), each a defined term in Annex A, with different requirements for how quickly and how easily equipment must be donned and how it must avoid interfering with other protective gear or assigned tasks. Fighter-type aircraft crew need an oronasal mask providing supplemental oxygen, ordinarily worn through all phases of flight.

Minimum functional requirements for oxygen equipment

Chapter 2 is the technical core, and it is genuinely a functional-requirements document: almost every clause sets a threshold equipment has to meet, verified, in the document's own words, through "assessment using a breathing simulator and during human trials." This page names what each part covers rather than reproducing the thresholds themselves, because those thresholds are exactly the kind of figure a reader could work to as a specification, and that is not what this page is for.

The chapter works through: the oxygen sources an aircraft may use, including a molecular-sieve on-board generating system as an alternative to a stored pure-oxygen supply, plus a separate, automatically activated oxygen source tied to the ejection system; purity and composition requirements for pure oxygen and the lower purity an on-board generating system produces; the minimum oxygen concentration the inspired gas must maintain, including a step adjustment the document calls the "Ernsting notch," whose size is "dependent on system design including cabin pressurization schedule"; the physiological response required following a rapid cabin decompression and the descent action the aircraft must then take; a ceiling on maximum oxygen concentration to manage the risk of atelectasis and barotrauma; limits on the work of breathing; a positive safety pressure requirement, selectable by the crew; detailed mask-cavity pressure limits for standard and high-performance aircraft applications; positive-pressure-breathing requirements at high altitude and how mask-cavity pressure must behave without counter-pressure equipment; a limit on oscillatory pressure activity; and a requirement for an alarm warning the crew when part of the oxygen system is defective or inoperative. Peak, average and safety pressures are determined using methods the document points to in ISO 16900-12.

A notable exclusion: the document puts CBRN (chemical, biological, radiological and nuclear) protection of inhaled gas outside its own scope, stating plainly that it "is the subject of a separate agreement." A reader looking for CBRN filtration requirements will not find them here.

Counter-pressure suits

The same chapter sets requirements for counter-pressure suits, distinguishing a full pressure suit, which pneumatically pressurizes the whole body including the head, from a partial pressure suit, made of separate garments each mechanically pressurizing part of the body, such as "a chest counter-pressure garment for respiratory protection used in combination with an anti-G garment." It sets altitude bands at which a partial suit becomes recommended and then mandatory, and at which a full suit becomes recommended, without this page repeating those bands, and modes of operation for respiratory, lower-body and full-body counter-pressure, each tied to the mask-cavity pressure the crew member is already receiving. Prolonged use of a full pressure suit is explicitly outside the scope of this agreement. Whatever counter-pressure garment is used, it must not compromise the wearer's vision, hearing, speech, mobility, thermal comfort or ability to escape in an emergency.

How it binds, and where reservations come in

AAMedP-1.3 binds a nation through STANAG 3198, the NATO agreement recording "the agreement of nations to use this publication." That ratification is a national commitment, not a certification or a law reaching a company on its own, and a nation can attach a reservation against specific clauses or specific aircraft types at the point it adopts an edition. Several nations, including Belgium, Bulgaria, Finland, France, Croatia, Slovakia and the United States, recorded reservations against this edition, so what a supplier actually has to meet turns on which nation's implementation and which contract apply, not on the publication alone.

How you are evaluated

No organisation can hold a certificate against AAMedP-1.3. The document names no accredited certification body, notified body or other scheme, and what it describes instead is equipment checked against functional requirements using the engineering assessment methods it names, principally a breathing simulator and human trials. A national authority, not NATO, decides how and against which aircraft types the requirements are actually applied to a piece of equipment, and one nation's own reservation notes that a manufacturer's qualification approval and quality assurance can form the basis on which that nation accepts equipment. None of that is a certificate a company holds: it is a national procurement and airworthiness decision, taken clause by clause and aircraft type by aircraft type.

Standards it references

• STANAG 3198 - the NATO agreement recording nations' commitment to use this publication, and

the cover that gives AAMedP-1.3 its force. We hold the record for it but have not yet written a page: see the standards explorer.

• Civil aviation oxygen-equipment standards, named in the document's own footnotes as the baseline

it builds on: International Civil Aviation Organisation International Standards and Recommended Practices (Annex 6, Part 1), United States Federal Aviation Regulations, and European Aviation Safety Agency certification specifications. These are outside our catalogue; AAMedP-1.3 cites them by name, adding requirements on top for the additional cognitive, night-vision and ventilatory demands of military aviation.

• ISO 16900-12 - cited for the methods used to determine peak, average and safety pressures in

respiratory equipment. Outside our catalogue; named here as the document names it.