STANAG 3368 internal aircraft engine starting systems

What it is

What STANAG 3368 covers

STANAG 3368 is the NATO standardization agreement on internal aircraft engine starting systems. Most STANAGs are a cover: the agreement by which NATO nations commit to implement a separate Allied Publication that carries the technical detail. This one is different. Its "STANDARD" field is answered "N.A.", and the requirement sits directly in the agreement clause itself: "The design of aircraft shall incorporate an engine starting system independent of ground facilities, to allow at least two (2) starts when ground starting equipment is not available." The document adds one clarification: "The internal engine starting capability may or may not be the normal means of starting the engine" - the requirement is for an independent fallback to exist, not for it to be how the aircraft starts day to day.

This is Edition 4, promulgated 7 November 2014, and it supersedes STANAG 3368, Edition 3 (reference MAS(AIR)403-ASP/3368).

Who ratifies it, and what it means for a design team

A STANAG binds a nation, not a design team directly. STANAG 3368 "is considered implemented when the provisions specified therein have been included in the national documentation concerned with reference to STANAG 3368," with national and partner-nation decisions recorded in the NATO Standardization Document Database (NSDD). Nations "are invited to report on their effective implementation of the STANAG using the form in Annex H to AAP-03(J)," and partner nations report adoption "using the form in Annex G to AAP-03(J)."

In practice, the requirement reaches a design team only where a contract or a tender names STANAG

1. Because it governs the aircraft's starting architecture (the starter, the onboard power

source and how they integrate), it is a decision that belongs at the design stage: retrofitting an independent starting path into a finished airframe is a different, harder problem than designing one in from the outset.

Review and related documents

This STANAG "is to be reviewed at least once every three years," with the result recorded in the NSDD. Its own "OTHER RELATED DOCUMENTS" field reads "None." The only other publication it names is AAP-03, cited solely for the Annex G and Annex H forms nations use to report implementation and adoption, not as a technical requirement the design clause must meet.

How it's evaluated

The document names no certification, audit or inspection scheme, and no accredited or notified body appears anywhere in it. What it describes is a national ratification, implementation and review cycle run through NATO's own machinery. Whether a given aircraft's starting architecture actually delivers the required independent starts is a question for whatever airworthiness or acceptance process a procuring nation applies; this document does not describe that mechanism.