The Federal Aviation Administration has temporarily exempted Gulfstream’s in-testing G700 and G800 business jets from certain fuel-icing airworthiness rules, seemingly bringing the company one step closer to achieving the jets’ certification.

A three-year exemption issued by the FAA on 17 January means the agency can certificate both the G700 and G800 – and Gulfstream can start delivering them, and customers can start operating them – despite the jets not complying initially with some fuel-icing rules.

The FAA insists the move will not impinge safety, saying G700 and G800 fuel systems, as they are now, have a level of safety equivalent with regulatory standards.

Gulfstream G700 first flight

Source: Gulfstream

The exemption clears a hurdle to Gulfstream achieving the long-delayed certification of its G700

Other aircraft manufacturers sometimes request exemptions ahead of certification, and the FAA sometimes approves such measures. But the practice gained attention and criticism in recent weeks after Boeing, struggling to address safety concerns, applied for an exemption for its 737 Max 7.

Gulfstream requested its exemption last October, asking for the time to conduct newly required fuel-icing tests.

The FAA’s approval requires Gulfstream to conduct those tests, and send the results to the FAA, in time for the agency to confirm compliance before the exemption expires at end-2026.

“[Gulfstream] states that the scope of this activity, which requires extensive rig building and testing, has yet to be fully established and that it will take many months before testing is completed,” says the FAA’s exemption. The move will “allow Gulfstream additional time to demonstrate full compliance with the regulations”.

Gulfstream did not respond to a request for comment.

The exemption would seem to put Gulfstream closer to completing what has been a long-delayed certification programme for its 7,750nm (14,353km)-range G700 and 8,000nm-range G800, both powered by Rolls-Royce Pearl 700 turbofans.

Gulfstream has previously attributed delays to increased scrutiny by the FAA following the Boeing 737 Max crisis. Most recently, it aimed to have the G700 cleared last year, but that never happened. The G800’s certification is to come after the G700’s.

In its exemption request, Savannah-based Gulfstream said the FAA previously allowed it to use analysis to demonstrate compliance with fuel-icing rules.

No longer.

“Following dialogue with the FAA and other civil aviation authorities, it has been determined that compliance requires the conduct of a full-scale test of the fuel system,” said Gulfstream.

The fuel-icing rules require engines and auxiliary power units (APUs) to be capable of operating in cold temperatures with fuel containing a tiny amount of water. Gulfstream says fuel-icing concerns gained attention in 2008 when a British Airways Boeing 777 lost power and crashed on approach to London.

To keep fuel from getting too cold, Gulfstream engineers gave G700s and G800s a “heated fuel return system” that uses “spray bars” in the fuel tanks to distribute heated fuel.

Gulfstream asked for the 36-month exemption after learning it now faced the lengthy process of designing and conducting tests. It expects to complete the tests in 24 months but sought an extra year in case it must, for example, make design changes.

Gulfstream told the FAA the exemption would “expedite” the G700’s and G800’s service entry and promote US economic interests.

The company insists G700s and G800s are safe in the interim, citing tests conducted by it, R-R and APU maker Honeywell. Gulfstream notes its other in-service business jets – G400s, G500s, G600s and G650s – have similar fuel systems that have been proven safe.

Gulfstream now has three years to demonstrate “full compliance”. That means the FAA can continue “certification activities after type certification,’ the agency says. If Gulfstream makes design changes it must incorporate those changes into jets already in service.