Aircraft Spares and Supplies
Pipeline and Hazardous Materials Safety Administration · Jun 24, 1991 · Reference No. 91-0004
Interprets: 49 CFR § 171.11
Reggie’s quick take
Someone asked whether aircraft spares and supplies on one air carrier can be sent on another contracted carrier to a final destination under an IATA exception. PHMSA says IATA rules have no official U.S. standing. The recognized alternative is the ICAO Technical Instructions, which allow air carriers and their contracted carriers to move spares in containers designed for that purpose, if the containers at least meet the ICAO packaging requirements. All other ICAO and 49 CFR Part 175 rules still apply. Packages without proper UN markings should not be accepted.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This is in response to your letter dated May 8, 1991 concerning whether aircraft spares and supplies on an air carrier can be offered for transport on another contracted air carrier to a final destination under the provisions of paragraph 1.7.1(b) and USG-33 of the International Air Transport Association (IATA) Dangerous Goods Regulations.
The IATA regulations do not have official standing within the U.S. The regulations recognized by the Department of Transportation and authorized in 49 CFR 171.11 as an alternative to compliance with 49 CFR requirements are the International Civil Aviation Organization's (ICAO) Technical Instructions) which have a similar provision in Part 1; 2.3.2(a). The exception permits air carriers and air carriers contracted by those air carriers, to transport aircraft spares and supplies in containers specifically designed for that purpose provided such containers are capable of at least meeting the requirements for packaging specified in the ICAO Technical Instructions. All other provisions in the ICAO Technical Instructions and Title 49 Code of Federal Regulations Part 175, must be met.
Your Second question concerns, how a carrier determines whether a package is capable of meeting performance standards in the ICAO Technical Instructions, if it has not been properly tested and marked with the required UN markings. Placing the UN mark on the packaging is certification that the packaging meets the required standards and performance tests that are required for the contents of the package. Therefore, if there is no marking or incomplete marking the package should not be accepted (see ICAO Part 4; Chapter 2 for package markings).
We trust this answers your questions. Let us know if we can be of further assistance.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.