The father and son team of Jim and Mark Matheson marked the advances in fleet support for the Twin Commander Aircraft, since their acquisition of the company last November 1. In that first year, the Mathesons have aimed to preserve or even increase value for Twin Commander owners.

“Serving out-of-production aircraft is a challenge,” said Jim Matheson at NBAA’06. “We want to maintain the level of owner satisfaction.”

The Matheson method began with a performance upgrade by conversion to the Dash 10T engine configuration, completed by Landmark Aviation for the Honeywell TPE331-10. Landmark Aviation’s Doug Clarke calculates that the TPE331-10 configuration costing $625,000 nets a “free” outlay as expressed in present value terms, after crunching the savings over a decade in executive time, lower fuel consumption, extended range for reduced fuel stops and lower maintenance. At least 168 Twin Commanders have completed the conversion. As many as half of the remaining 250 of the 690 A/B models and 135 JetProp models are eligible.

Clarke added a “Value Calculator” online at landmarkaviation.com to quantify the line items and justification for the conversion, and also made the case in the current Twin Commander magazine, Flight Levels.

Next, the Mathesons dramatically reduced the price of key replacement parts by up to 86 percent. Gull seals (a fuel transmitter gasket), which once listed for $1,265.48 now cost $172.70. Fuel caps dropped from $630 to $333. Twin Commander owners can also buy individual components such as premium rubber wiper blade refills fitting any model at $39.95 per side, as opposed to a previous need to purchase the entire blade assembly for $337.

“We are aggressively pursuing parts that are priced out of alignment,” said Jim Matheson. Matheson also named its 15th factory-authorized center to install such parts, Legacy Aviation Services at Clarence E. Page Municipal Airport in Yukon, Okla. Legacy can perform periodic inspections, maintenance and repair on all turboprop or piston Twin Commander models.

Twin Commander is studying further modifications under a concept it is introducing at its NBAA booth (No. 4636). Project Enterprise would measure fuel savings from the addition of winglets and aft underbody strakes to the 690A/B model, The winglets would add effective span, lowering the induced drag. The aft-body strakes would block airflow, which otherwise would induce drag through separation and the creation of a shed vortex.

The Twin Commander booth holds a model fitted with the Project Enterprise winglets and strakes, which in a computational fluid dynamics (CFD) simulation burned 5.1 percent less fuel from takeoff to touchdown.

Not only that, “The aircraft looks fast and contemporary,” said Matheson. “It has tremendous ramp appeal.”

A new digital LCD fuel quantity indicating system emerged from a partnership with Olympic Aero Services of Olympia, Wash.

The company is also pursuing a new method to stop leaks at the rear pressure bulkhead by applying a membrane-like seal with a special adhesive to the wing root area. Some 45,000 hours of testing to simulate 40,909 cycles are planned and if viable, the process will be considered for the control column and rudder pedal boots.