Urban Aeronautics has manufactured new propeller blades that will be fitted to its unmanned AirMule ducted fan vertical take-off and landing aircraft.
Using in-house capabilities, the company has manufactured 12 composite rotor blades for the two new six-bladed rotors that it plans to install on the aircraft next month. These will replace the four-bladed rotors that have been used since the beginning of 2010.
The new rotors have the same diameter and RPM as the original sets, but are expected to increase the AirMule's payload capacity by approximately 200kg (440lb). They are also much closer to the final production version planned for the system.
Company president Rafi Yoeli says the design of the blades and the construction of their associated tooling, rotor hubs, variable pitch mechanism, retention systems and other associated hardware have been carried out by Urban Aeronautics staff. The blade design complies with the loads specified for the US Federal Aviation Administration's FAR 35 standard for propellers, he adds.
The first test flight of a Turbomeca Arriel 1-engined AirMule equipped with the new rotor blades is scheduled for mid-February.
Meanwhile, Urban Aeronautics is also accelerating the assembly of a second AirMule prototype in preparation for a series of demonstration flights requested by potential customers. The aircraft is intended primarily as a reserve, to ensure uninterrupted flight testing once mission demonstrations to customers are underway: a milestone currently planned for mid-2014.
The first prototype of the AirMule internal rotor vehicle has recently been fitted with a double redundant hydraulic system to enable continued rotor pitch control in case of a failure in one of the pressure supply lines or any hydraulic control system hardware.
The Israeli company is planning to complete an automatic precision landing demonstration in the next few months, with a Controp-produced D-STAMP stabilised eletro-optical payload having already been installed. The sensor forms part of a system that will enable the aircraft to guide itself to touch down over any high contrast marker, or alternatively at a laser spot placed in a combat zone.
The company says the auto-landing feature will be the final step towards enabling fully autonomous take-off to landing flight paths using pre-programmed routes. Accurate positioning will be maintained en-route by an on-board inertial navigation system, used in conjunction with GPS or, alternatively, a Doppler navigation unit.