FAA proposes tougher fuselage rules for Honda HA-480 at high altitude

The Federal Aviation Administration has put forward extra certification requirements for the Honda HA-480, a derivative of the HondaJet HA-420 that Honda Aircraft intends to certify for operations up to 47,000 feet.

The proposal, published Monday, deals with the aircraft's pressurised fuselage and the loads it would face at those altitudes. Existing Part 23 rules do not cover every aspect of designs flying above 45,000 feet, according to the agency.

For the HA-480, the FAA wants Honda to demonstrate that the pressure vessel can handle the maximum cabin pressure differential using a safety factor of 1.67 instead of the customary 1.33. That higher margin would apply to the fuselage and to other parts of the pressure vessel, including doors and windows. The agency said the extra allowance is necessary because of the greater pressure differential involved in high-altitude flight.

The FAA also looked at whether occupants would need further protection after a loss of cabin pressure. It concluded that separate special conditions are unnecessary, since updated Part 23 rules already address depressurisation for aircraft operating above 45,000 feet.

Honda Aircraft first applied in 2019 to amend the HA-420 type certificate to include the HA-480. The aircraft has two engines, seats up to 11 people and has a maximum takeoff weight of 17,550 pounds, and it falls in the normal category.

Comments on the proposed special conditions are open until Nov. 19, 2026. The FAA said it could change the requirements in light of the feedback it receives.