Cover Story: Recip Technology: An Alternative

Reciprocating engine technology as an alternative to similar horsepower rated turbine aircraft engines


The engine currently has a time between overhaul (TBO) rating of 1,500 hours, but this TBO can be extended to 1,800 hours by working with the factory on an acceptable engine monitoring program including cylinder compression tests and a Spectrometric Oil Analysis Program (SOAP). Eventually, by use of field service, reliability, and maintenance data, TRACE hopes to have a program to extend the TBO to 2,000 hours.

The OE600A is designed to develop 600 takeoff horsepower at 4,400 rpm and 46 to 48 inches of manifold pressure (Hg) and a maximum continuous horsepower rating of 500 at 4,200 rpm and 39 to 41 inches of manifold pressure. The propeller drive gearbox has a reduction ratio of .4675 to 1. This means that at takeoff power with the engine running at 4,400 rpm, the gearbox output shaft for the propeller is turning at 2,057 rpm. The weight of the OE600A engine is approximately 730 pounds which includes engine-supplied/engine-mounted components, the fuel servo, the turbocharger, and related components.

Maintenance and training
Routine service and unscheduled maintenance can be easily accomplished in the field. For overhaul, TRACE recommends the engines be returned to the factory. So far only one engine has gone through the factory for repair/overhaul, along with two of the predecessor Orenda engines. This has provided the factory with valuable insight into the operation of the engine and the overall wear patterns so they can continually implement design improvements. At overhaul, the cylinders can be ground oversize by .010, .020, and .030, instead of replacing the steel sleeve inserts. TRACE provides a two-week training course for engine owners and service providers to teach the basic in-service maintenance program. So far four technicians have attended this training.

There isn’t a lot of operation history to provide yet for this engine. Currently there are OE600A engines on two Air Tractor AT401 agricultural aircraft being operated by Miccar Aerial of Yorkton, SK, Canada. Together they have approximately 1,300 hours of flying time.

AMT spoke with Allan Denesowych of Yorkton Aircraft Services the maintenance provider for these aircraft, regarding their experiences with the engines. Denesowych says, ”I feel the engine is very well built. The engine is still young and so far the maintenance has been simple, easy, and not much of it.”

Denesowych went on to say that routine maintenance tasks such as 50-hour oil changes and filter changes are easily accomplished with no access problems due to the remote location of the oil reservoir and filter. He commented there have been no maintenance issues with any of the cooling system components, and went on to say the engine analysis system in the aircraft provides the pilot with good information to assist with any troubleshooting.

Room for expansion
The TRACE facility is located on 22 acres with ample room for expansion. TRACE is planning for a capability of producing 120 engines per year and operating three engine test cells. TRACE is looking toward high-cycle utility aircraft as a potential market for this engine.

Czarnecki says, “This engine is not limited by the cycle time requirements that a typical turbine engine may be subject to, providing an advantage for operators of utility aircraft that have a high number of takeoff and landing cycles yet low hours of flight time.”

TRACE feels that new installations will be additional single engine aircraft having gross weights up to 6,000 pounds, and twin engine aircraft with gross weights up to 12,500 pounds.
In January 2010, TRACE successfully tested a production engine to more than 750 hp in its factory test cell. The engine had an experimental new-design camshaft.

According to Czarnecki, “The increased horsepower on our new engine will open doors to general aviation applications that are currently powered by 750-hp turbines.”

The TE750 will have electronic ignition and fuel injection systems. TRACE Engines plans to eventually offer its TE750 with enhancements to its current production certified OE600 model. The electronic engine management system will also be applied to the OE600 engine as a performance enhancement kit for engines in service, and will ultimately become stock on all engines from the factory once FAA certification is complete. Development and validation testing will continue through 2010, with full certification expected early next year.

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