Mach Jump
10th Jan 2024, 18:59
JP3, with Viper 101 engine.
On initial spool up for takeoff the engine, rather than overswinging to 102%, and then settling at 100%, as normal, slows, and stops on 100% exactly, without overswing.
During acceleration on the ground, maintains 100%.
Once airborne, and accelerating, slowly rolls back to 98%.
Increase in speed causes further roll back to 97%.
Reduction in speed causes RPM to increase.
The HP fuel pump, and BCU have both been changed. Fuel filter has been checked and clean. LP 'FUEL' caption is out.
The JP3 has not much thrust to start with, and so 2% makes a big difference to performance, esp in warm weather.
Anyone any ideas what might be the problem?
I'd be very grateful for any help with this.
Thanks
MJ:ok:
On initial spool up for takeoff the engine, rather than overswinging to 102%, and then settling at 100%, as normal, slows, and stops on 100% exactly, without overswing.
During acceleration on the ground, maintains 100%.
Once airborne, and accelerating, slowly rolls back to 98%.
Increase in speed causes further roll back to 97%.
Reduction in speed causes RPM to increase.
The HP fuel pump, and BCU have both been changed. Fuel filter has been checked and clean. LP 'FUEL' caption is out.
The JP3 has not much thrust to start with, and so 2% makes a big difference to performance, esp in warm weather.
Anyone any ideas what might be the problem?
I'd be very grateful for any help with this.
Thanks
MJ:ok: