Germany-based MT-Propeller has received STC approval for the Quiet Fan Jet composite five-blade propeller on the Cessna 441 powered by two Honeywell TPE-331 turbines. The FAA STC is in progress.

The installation features bonded-on wide chord nickel alloy leading edges for superior erosion protection of the blades. It also offers a smaller diameter of up to four inches compared to the original propeller, which gives a greater ground clearance of about two inches for less FOD and also more clearance to the fuselage, therefore less cabin noise from the prop tips. Take off is improved by up to four per cent and, compared to the original AFM, there is greater safety for the calculated take off run. There are no propeller ADs, and maintenance costs are lower thanks to TBO 4,000 hours or six years, whatever comes first. No intermediate inspections are needed between the TBO, which requires the propeller removal, and costs are reduced for spare parts and overhaul of the complete propeller assembly.

There is no rpm restriction for the complete operational range and the natural composite blades provide significant inside and outside noise reduction. There is no life limitation and repairable in case of an FOD, and all models comply with the strict German Landeplatz Lärmschutz Verordnung noise regulations 2010 for unrestricted airport operations in Germany and other European countries. The MT-Propeller natural composite blades provide best vibration damping characteristics for almost vibration free propeller operation.

MT-Propeller is a natural composite propeller manufacturer with 30 propeller models from two blade to seven lade hydraulically controlled variable pitch propellers for engines producing up to 5,000hp, and two blade to four blade electrically controlled variable pitch propellers for engines producing up to 350hp as well as two blade fixed pitch propellers.

The high performance, light weight and durable MT-Propellers can be used on aircraft with piston engines and propeller turbines, as well as on airships, wind tunnels or hovercraft. They can be developed for nearly every aircraft type from motor gliders to regional airliners.

Fulfilling the highest certifications requirements, the company is also supplemental type certified on Part 25 aircraft.

MT-Propeller is the holder of over 210 STCs worldwide and the OEM supplier for more than 90 per cent of the European aircraft industry as well as 30 per cent of the US aircraft industry. 25,000 propeller systems with more than 75,000 blades are in service.

150 million fleet hours have already been performed on MT-Propellers. The first was shipped 37 years ago and a factory certified network of 62 service centres provides service and maintenance all over the world.