MT-Propeller Entwicklung GmbH announced it has received STC approval from both the FAA and European Union Aviation Safety Agency for installation of its 7-blade Silent Seven Propeller on the Beech King Air models 300, 300LW, B300, B300C series aircraft powered by two Pratt & Whitney PT6A-60A and for the same aircraft models powered by the PT6A-67A engines.

The Blackhawk XP67 conversion is also covered by this STC. The propeller was first introduced to the GA market in 2020 with its certification on the Pilatus PC-12 and currently there are over 130 PC-12s flying with the Silent Seven prop.
MT-Propeller began flight testing to get the STC certified for the Silent 7 prop system on the King Air 300 series aircraft.
Martin Albrecht, Vice President of MT-Propeller said the installation provides these advantages:
- General performance improvement (8% take-off & climb)
- No propeller speed restrictions on ground while operating in low idle
- Lower ITTs at high altitude; allowing a top speed increase up to 6 KTAS or longer engine life.
- Unbeatable esthetic ramp appeal
- Significant cabin noise and vibration reduction
- All models comply with the strict German noise regulations 2010– Landeplatz Lärmschutz Verordnung (Landing Site Noise Protection Regulations) for unrestricted airport operations in Germany and other European Countries.
The smaller diameter of the Silent 7 propeller gives better ground clearance on the King Air 300 series. This reduces blade tip erosion and FOD damage, and most FOD damage can be repaired. In addition, the bonded nickel alloy leading edges give further protection from erosion and FOD. Their composite construction and vibration damping characteristics reduce the noise level both outside and inside the aircraft.
FMI: www.mt-propeller.com