FAA proposes high-altitude certification requirements for Honda HA-480

The FAA is proposing additional certification requirements for Honda Aircraft's HA-480, a derivative of the HondaJet HA-420 designed to operate at altitudes up to 47,000 feet, AVweb reported on Tuesday.

The proposed special conditions, published Monday, focus on the airplane's pressurised fuselage and the structural loads created by high-altitude operations. For owners and operators, these requirements do not change the aircraft's capability — Honda designed the HA-480 to reach 47,000 feet and the FAA is now setting the safety margins it must meet to do so. The FAA is accepting comments on the proposed requirements through 19 November 2026.

Current Part 23 certification rules do not fully address aircraft designed to operate above 45,000 feet. For the HA-480, the FAA is proposing that Honda use a 1.67 safety factor when demonstrating that the airplane's pressure vessel can withstand the maximum cabin pressure differential, rather than the standard 1.33 factor. The higher factor applies to the fuselage and other parts of the pressure vessel, including doors and windows. According to the FAA, the additional margin is necessary because of the higher pressure differential associated with the HA-480's high-altitude operations.

The FAA also considered whether additional requirements would be needed to protect occupants following a loss of cabin pressure. It determined that separate special conditions are not necessary because updated Part 23 rules already address depressurisation for airplanes operating above 45,000 feet.

The HA-480 is a twin-engine, normal-category aircraft with seating for up to 11 people and a maximum takeoff weight of 17,550 pounds. Honda Aircraft originally applied to amend the HA-420 type certificate to add the HA-480 in 2019. The FAA could modify the requirements based on feedback received during the comment period.

For operators and buyers, the certification process does not affect the aircraft's intended high-altitude capability; it establishes the structural safety margins required to operate there. The reporting does not say whether the HA-480 has been ordered by customers or when Honda expects to complete certification.