DAIR 100^® engine to the world. Formed just over two years ago, the company is proud to

have designed, built and tested (for over 1000 hours) several prototypes.

The 100 h.p. engine is the first in a family of engines, using the same constructional

techniques to cover the range from 100 h.p. to 600 h.p. This first engine resembles a flat four

or ‘boxer’ engine, but only two cylinders, each with two pistons. The engine has two

outboard crankshafts connected by gears to the propeller-drive and accessories. This ‘flat

plane’ layout ensures the engine can be easily retrofitted in place of the popular

Continental^® or Lycoming^® engines, using the same mounting points in many cases.

Key Design features are:-

• Consumes 1 gall. Diesel less per hr. than typical gasoline engine at 75 h.p. cruise
• (less than 3.7 Imp. Gal/hour at 75 h.p.) and substantially lower fuel cost.

• Two-cycle operation for simplicity and low weight.

• Liquid-cooling for duability and the avoidance of ‘shock-cooling’.

• Single-lever control, (fuel mixture and carburettor-heat controls eliminated).

• Starting by integrated electric starter.

Work continues to refine the engine’s performance and bring it to a production status

prior to flight trials in the company’s aircraft and subsequent release of a small batch of

engines under PFA regulations for customer evaluation.

The first customer is AIRSHIP TECHNOLOGIES Ltd. ^® , who are using the engine in a

Vectored Thrust Propulsion Unit to be used on the airships. This programe is

currently the subject of a Research & Development award under the UK Governments’s

CARAD scheme.

Two Diesel Air 100 h.p. engines will be displayed at the Cranfield PFA Ralley from the

2^nd – 4^th July this year, and directors of the company will be on hand to welcome all enquiries.

Speaking of the engine, David Soul (Managing Director of Diesel Air ltd.) said:-

"We have been working for two years to provide the next generation of engines for

light aircraftof the 21^st century. The diesel engine offers the best specific fuel

consumption of any prime mover with the two-stroke cycle giving the best efficiency

in that class. It also allows us to achievethe required power density from a diesel

for aircraft use. An operator using Avtur would see a fuel cost saving over the

life of the engine in the UK of around £15,000 compared with avgas. The tax

differential helps of course; using off-road (red) diesel, the saving could be

nearly £30,000."