What it is
STANAG 7191 is the NATO Standardization Agreement covering the boom-receptacle interface requirements for air-to-air (aerial) refuelling equipment used by tanker and receiver aircraft of NATO forces. This is Edition 2, promulgated 16 June 2022, superseding STANAG 7191 Edition 1, dated 3 June 2013.
A STANAG is not the specification
A STANAG is the agreement by which NATO nations commit to implement a standard, not the technical specification itself. STANAG 7191's own text is short and administrative: an aim, a single interoperability requirement, and the ratification, implementation and review machinery. The boom-receptacle interface requirements named in its title are specified in a separate publication, ATP-3.3.4.5 Edition B, which the STANAG names as the standard participating nations "agree to implement". Anyone actually designing, building or checking a boom-receptacle refuelling interface needs ATP-3.3.4.5's own text, not this cover agreement.
What it commits nations to
The single interoperability requirement reads in full: "To achieve and maintain the required compatibility among the interfaces required to engage in boom-receptacle refuelling operations, to facilitate air-to-air refuelling between aircraft of NATO forces." The document also names a set of related technical documents that sit alongside ATP-3.3.4.5: STANAG 3971 (covering the air-to-air refuelling publication ATP-3.3.4.2), STANAG 3447 (covering the probe-drogue interface publication ATP-3.3.4.6), the Joint Service Specification Guide JSSG-2009 for air vehicle subsystems, Military Standard MS-27604 for the universal aerial refuelling tanker boom nozzle, and an Aerial Refueling Systems Advisory Group document on aerial refuelling pressures.
Who it binds, and how
STANAG 7191 binds nations, not suppliers. A nation is considered to have implemented it "when a nation agrees to conform to the requirements of this standard and has issued instructions that future equipment developed or services contracted will be in accordance with the requirements detailed in the covered standard" - so a supplier meets it only where a contract or tender invokes ATP-3.3.4.5, not because the STANAG exists. The document also carries an exception for aircraft and refuelling equipment already in service, or already being procured or modified, before promulgation: a nation in that position must instead "identify the exceptions to the requirements detailed in the covered standard for these aircraft", rather than retrofit them. Reporting is not symmetric: Allies and NATO bodies "shall provide implementation details through the electronic reporting tool", a standing obligation, while partner nations "are invited to provide their implementation details through the electronic reporting tool", a lighter invitation for nations outside NATO membership. No NATO effective date is set (the document records it as "Not applicable").
How it's evaluated
STANAG 7191 describes no certification scheme and no audit. What it describes is nations reporting their ratification and implementation decisions to the NATO Standardization Office for the record, using its electronic reporting tool; nobody is "STANAG 7191 certified", and the document never uses that language. Where a supplier's actual boom-receptacle hardware does get checked against ATP-3.3.4.5's interface requirements - test reports, drawings, acceptance records - the assessor and the evidence required are set by the contract's own quality clause, not by this STANAG.
Standards it references
STANAG 7191 covers ATP-3.3.4.5, the Allied Tactical Publication that carries the actual boom-receptacle interface requirements. Its "Other Related Documents" also list STANAG 3971 (covering ATP-3.3.4.2, air-to-air refuelling) and STANAG 3447 (covering ATP-3.3.4.6, probe-drogue interface characteristics), plus the Joint Service Specification Guide JSSG-2009 for air vehicle subsystems, Military Standard MS-27604 for the universal aerial refuelling tanker boom nozzle, and an Aerial Refueling Systems Advisory Group document on aerial refuelling pressures, none of which sit in our catalogue. Nations report the review of this STANAG in accordance with AAP-03.