Engine Replacement Details
The existing Pratt & Whitney JT15D-5 engines will be removed from the aircraft and replaced with the modern fuel efficient Williams International FJ44-3AP dual FADEC high bypass turbofans. The general specifications of both engines are listed in the table below.
|Pratt & Whitney
|Thrust (lbs) max T.O.||3,050||2,965|
|Fuel Consumption (lbs/hr) @ 447 KTAS||790||1,160|
|Overhaul Interval (hrs)||4,000||3,600|
|Engine Maintenance - Program Cost - Per Hr.||$246.34 *||$335.70 **|
* Williams International TAP Elite (Includes periodic inspection cost)
** Pratt & Whitney ESP Gold and periodic inspection costs
The major advantages of the Williams FJ44-3AP include:
- Higher Thrust To Weight Ratio
The Williams engine weighs 117 lbs. less than the Pratt & Whitney while producing 85 lbs. more takeoff thrust. The thrust to weight ratio of the Williams engine is over 20% better than the Pratt & Whitney.
- Lower Specific Fuel Consumption
With the advent of the dual Full Authority Engine Control (FADEC) along with the state of the art design of the FJ44-3AP the fuel consumption is improved as much as 30% to 40% depending on operating parameter.
- Reduced Maintenance Cost
The total cost per hour to maintain the Williams Engine is 27% less per flight hour and the overhaul interval is 11% greater as the Williams engine will operate 400 hours longer between overhaul intervals. The engine maintenance savings is published to be $79.36 per hour or $317,440 over the engine overhaul period.