JET-A DIESELS - NOW A MATURE TECHNOLOGY

As Avgas prices head for R40/ litre the need for an alternative to Avgas powered planes becomes ever more pressing. The good news is that, for the past 16 years, Jet-A diesel piston engine technology has been quietly maturing. It has now become a well-developed aero engine that is a serious contender to compete in the piston market.

FLIGHT REVIEW: CONTINENTAL CD-100 JET-A DIESEL CESSNA 172

MOST C172S ARE POWERED by the clunky and antiquated Avgas burning Lycoming 0-320, or the even older six-cylinder Continental 0-300. The question this flight test asks is whether the Jet-A burning 155hp Continental CD-100 powered Cessna 172 is a real alternative.

Mogas Power?

The threat to Avgas supplies has been around for twenty years. A major step towards freeing the General Aviation industry from Avgas happened in 2006 when an enlightened SACAA allowed South African flight schools to train on non-type certified aircraft. However, Mogas is prone to vaporisation and many piston singles, particularly low-winged types, proved unsuitable for a Mogas STC.

Despite a much hoped for revolution in training aircraft and a reduction in costs as schools embraced Mogas-burning trainers such as the Sling 2, (which will run on car petrol; so-called Mogas), there has also been a huge shift back to legacy Cessna C172s. The demand has been so great that nowadays you can hardly find a clapped-out 60-year-old C172 for less than R1 million.

At the time SA Flyer noted that; "Non-ACSA airfields, managed by property speculators rather than intrinsic service providers, have shown little enthusiasm in encouraging aviation by installing Mogas pumping facilities. However, the provision for supplying Jet A1, the motive fuel upon which our entire global transport infrastructure exists is an entirely different matter. Big jets mean big hangars and big maintenance facilities and big volumes of fuel = big profits.

With problems with both the availability and quality of Mogas, running a piston engine on Jet A1 is a logical alternative, but it was a solution which was surprisingly slow to develop.