MTV-14 aircraft propeller offering

The MTV-14 from MT-Propeller is a four-blade, full-feathering, counter-weighted, constant-speed aircraft propeller for twin-engine piston aircraft, supplied as a supplemental type certificate kit. The version covered here, designated MTV-14-D-C-F/CF188-30g, is approved for the Cessna 340 and 340A, and also for the 335 under the EASA approval, including aircraft with RAM modifications.

The hub is a milled single-piece aluminium part, and the CF188-30g blades are a scimitar design in a light-weight natural composite with a bonded stainless-steel leading edge for erosion protection. Electro-thermal de-ice boots are fitted. The blades have an unlimited life and can be repaired after foreign object damage. The maximum diameter is 74.0 inches (188 cm) and the minimum diameter is 72.0 inches (183 cm), so the diameter can be trimmed within that range when the installation is set up.

For the airframe, the maker gives the weight of two installed propellers with de-ice as 145.5 lb (66.0 kg) and states that they weigh approximately 20 lb less than the original propellers. Compared with the three-blade McCauley or Hartzell propellers that it replaces, the maker quotes a takeoff distance shorter by approximately 3 percent, a climb improvement of approximately 5 to 8 percent and a cruise gain of approximately 3 to 5 knots, at maximum takeoff weight, sea level and ISA conditions. The maker also reports a clear reduction of vibration and of noise inside and outside the cabin.

Integration is defined by the kit and its approvals. The kit contains two propellers, two full-composite spinners (P-587-1-A), an airplane flight manual supplement, installation instructions, instructions for continued airworthiness and the operation and installation manual. The engines may be any approved piston engines with a maximum power of up to 335 HP at 2700 RPM. The approvals are the FAA STCs SA01284WI and SA02510NY and EASA STC 10014993, on the airframe TCDS 3A25 and the propeller TCDS P3BO / P.017; the maker's pages also list acceptance in other countries.

Typical applications are the upgrade of Cessna 335, 340 and 340A twin-engine aircraft for private, business and charter flying, where owners want a four-blade propeller to improve climb, cruise and comfort.