SAE International and EUROCAE jointly announced the publication of “Hydrogen Fueling Stations for Airports, in Both Gaseous and Liquid Form.” These documents serve as the first worldwide hydrogen station guidelines for the aerospace industry.

SAE AIR8466, developed in collaboration with EUROCAE’s ER034, provides the first step in defining performance targets and safety limits to enable hydrogen as an accessible fuel for various commercial aircrafts. Considering the wide range of aircraft with hydrogen storage sizes, SAE AIR8466 and EUROCAE ER034 also define fueling categories for hydrogen eVTOLs, Regional, Narrow body and Widebody (including Lighter than Air).

Hydrogen fueling process limits (including the fuel temperature, the maximum flow rate, time required, etc.) are affected by factors such as ambient temperature, fuel delivery temperature, and initial pressure in the hydrogen storage system. The further goal is to establish basic fueling protocols within these limits as a starting point while evaluating minimum criteria, including evaluation of fueling with or without communications. AIR8466 establishes the protocol and process limits for hydrogen fueling of aircraft and plans to establish fueling protocols starting with small aircraft. Optionally, communications may be used, and a general description will be included.

—SAE AIR8466

SAE AIR8466 sets the stage for hydrogen fueling at airports by closing a major aerospace industry gap. There are plenty of airport standards for fueling jet A-1 fuel, but there haven’t been any standardization efforts yet for hydrogen stations.

It was quite a coordination between international aircraft OEMs, Tier 1 suppliers, regulators and hydrogen companies to find consensus on an airport hydrogen fueling station guideline, but we did it. This is a guidebook for hydrogen safety and fueling station definitions. The SAE AIR8466/ EUROCAE ER034 gives the industry a starting point for fueling stations for hydrogen aircraft in gaseous and liquid form.

—Jesse Schneider (ZEV Station) chair of the SAE AE-5CH Hydrogen Airport Taskgroup

Key highlights of this guideline document include:

• Range of estimated hydrogen storage onboard based per aircraft type and use case.

• Categorization of hydrogen fueling speeds (flow rates in kg/minute), based on airline turnaround time, which gives a first definition of coupling size categories.

• Fueling Process Parameter definitions for gaseous hydrogen and liquid hydrogen fueling of aircraft at airports and mobile and stationary station use cases.

• High-level hydrogen properties including safety definitions.