The Anonymous Widower

Rolls-Royce And Gulfstream Give Wings To Sustainable Business Aviation

The title of this post, is the same as that of this press release from Rolls-Royce.

These are the first two paragraphs of the press release.

Rolls-Royce and Gulfstream Aerospace Corp. are leading the way towards sustainable business aviation by conducting the first original equipment manufacturer test flight of an ultralong-range business jet powered by 100% Sustainable Aviation Fuel (SAF). The test took place on the BR725-powered Gulfstream G650 twin-jet over Gulfstream’s headquarters in Savannah, Georgia.

Demonstrating that current Rolls-Royce engines for business jet and large civil applications can operate with 100% SAF as a full “drop-in” option, this test lays the groundwork for moving this type of fuel towards certification. At present, SAF is only certified for blends of up to 50% with conventional jet fuel and can be used on all current Rolls-Royce engines.


  1. The BR725 is described in this Wikipedia entry.
  2. The Gulfstream G650 is described in this Wikipedia entry.
  3. All current Rolls-Royce engines can run with blends of up to 50 % SAF and conventional jet fuel.

The BR725 or other engines in the family have other applications.

I can certainly see, the owners of business jets being very interested in operating a sustainable business jet.

But would the USAF be interested in running a seventy-year-old bomber on 100% Sustainable Aviation Fuel?

The Fuel Used In The Test

This paragraph of the press release describes the fuel.

The SAF that was used in the test consists of two components: HEFA (Hydroprocessed Esters and Fatty Acids), produced from waste fat and waste plant oils by low-carbon fuel specialist World Energy in Paramount, California, and (SAK) Synthesised Aromatic Kerosene made from waste plant-based sugars by Wisconsin-based Virent Inc. This innovative and fully sustainable fuel in development eliminates the need for the addition of further petroleum-based components and enables a 100% drop-in SAF that can be used in existing jet engines and infrastructure without any modifications. This sustainable fuel has the potential to reduce net CO2 lifecycle emissions by about 80% compared to conventional jet fuel, with the possibility of further reductions in future.

That sounds impressive.

A Sustainable Airliner

The Boeing 717 is a hundred seat airliner, with about a hundred still in service. They appear to have a good safety record.

One of the operators is Hawaiian Airlines and might be the sort of airline, that would like to decarbonise their flights.

So might we see some airlines using the Boeing 717 on SAF to attract passengers?

I wouldn’t rule it out and after certifying the engine on the Gulfstream, certification on another type wouldn’t be the most demanding of certifications.

I also think, it is quite likely, that an aircraft manufacturer could use engines in the BR 725 family to create a hundred seat sustainable airliner.


December 20, 2022 - Posted by | Transport/Travel | , , , , , ,

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