DIAMOND AIRCRAFT IND GMBH DA 42 NG

The DA42 NG is a four-seat composite twin with two Austro diesel engines burning Jet-A. It cruises at 160 knots on about 11 gallons an hour total, which is roughly half what a comparable avgas twin uses, and each engine has a single power lever instead of throttle, propeller and mixture controls. The NG of 2009 replaced the Thielert-engined DA42 with Diamond's own 168 hp AE 300 engines, and the registry string covers one further step: the DA42-VI of 2012, which the type certificate treats as a DA 42 NG with a modification package rather than a new model. The VI has new engine nacelles and propellers, flush-mounted ice-protection panels, a reshaped rudder that lowered the minimum control speed by five knots, and a reduction in empty weight of nearly 90 lb; it is about 15 knots faster on the same engines. So a 2010 or 2011 aircraft is an NG and a 2012 or later one is, in practice, a VI, with the better numbers.

That fuel figure is the entire argument, and outside North America — where avgas is expensive or unavailable — it is decisive. It is also the standard modern multi-engine trainer at many schools for exactly that reason. Two qualifications: the AE 300 has a gearbox and fixed replacement lives on major components, so there is a scheduled overhaul cost that arrives whether or not anything has worn out, and diesel support is thinner than Lycoming or Continental support, particularly in the United States. Single-engine performance is good for the class and the composite airframe is well regarded.