When equipped with the original 108-hp engine, the airplane consumed 5.3 gph at 2500 feet and 64-percent cruise power
. Endurance at this altitude and power setting was 3.9 hours.
At max cruise power
, the XP140 mod has a still-air range of 825 miles at 12,000 feet while the OEM -114A it replaces will stretch to 900 miles.
At 7000,1 set cruise power
and settled back to enjoy the flight when I was handed over to Atlanta Approach.
The petrol engine is optimally sized to provide the cruise power
at its most efficient operating point, resulting in improved fuel efficiency overall.
Stein put his plane on high cruise power
and headed south as fast as he could.
Morgan claims it has cracked one of the technical problems inherent in other fuel cell engines by de-coupling cruise power
from acceleration allowing for a tiny 25kw cell rather than the usual 100kw.
Since pressurization is drawn from the engines, at cruise power
settings less air pressure is available, and the system is subject to pressure variations.
At cruise power
, the PC-21 reaches a speed of 300 knots (against the PC-9's 290) thanks to its five-blade propeller, "but our aim is to reach 330 knots", said Tyndall.
When the pump's pressure was adjusted, it passed the cruise power
flow test requirements.
Coupled with the smooth-running Rotax, it makes for a comfortable cabin environment during climb and cruise power