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.
| Parameter | Williams Int. FJ44-3AP |
Pratt & Whitney JT15D-5 |
| Thrust (lbs) max T.O. | 3,050 | 2,965 |
| Weight (lbs) | 528 | 645 |
| 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 ** |
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* Williams International TAP Elite (Includes periodic inspection cost)
** Pratt & Whitney ESP Gold and periodic inspection costs |
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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.
