efiscompmon
...
- Joined
- Jun 24, 2002
- Posts
- 198
-3A1 and -3B1 differences are limited to -3B1 "improvements in compressor and turbine construction which has resulted in a reducton in total fuel consumption and improvements in flat-rated power capability." (Bombardier PTM, 20-1)
From the Bombardier FCOM vol.1 (the big silver one from the manufacturer), p18-10-1
"When at high thrust settings, the engine is controlled by an electronic control unit (ECU) which works in tandemwith a fuel control unit (FCU). The ECU monitors sensors (T2C and P3, etc), sets up the appropriate fuel, acceleration and temperature schedules, and relays appropriate operating data to the flight crew through data concentrator units (DCU) to the flight compartment displays (EICAS)."
p18-10-6
"Speed control is as follows:
--At low thrust settings, the FCU meters fuel to the injectors to control N2 speed. In N2 mode, matched movements of the thrust leversproduces matched N2 speeds but N1 speeds and thrust may be mismatched between engines. A mechanical thrust lever setting and N2 speed schedule is contained in the fuel control unit.
--At take-off, climb, and cruise power settingsthe engine is N1 speed controlled. In N1 mode, the FCU responds to N1 speed references. Matched movements of the thrust levers produces matched N1 speed and nearly matched thrust between engines. An electrical thrust lever setting and N1 speed schedule is contained in the fuel control unit and controlled by the ECU. Switch over from N2 to N1 control can occur at speeds above 79% N1 by switching N1 control on.
--If N1 mode is selected off, the engine speed control reverts to N2 mode (mechanical)."
See? Everyone is right! Now let's go have a beer in memory of our friends.
From the Bombardier FCOM vol.1 (the big silver one from the manufacturer), p18-10-1
"When at high thrust settings, the engine is controlled by an electronic control unit (ECU) which works in tandemwith a fuel control unit (FCU). The ECU monitors sensors (T2C and P3, etc), sets up the appropriate fuel, acceleration and temperature schedules, and relays appropriate operating data to the flight crew through data concentrator units (DCU) to the flight compartment displays (EICAS)."
p18-10-6
"Speed control is as follows:
--At low thrust settings, the FCU meters fuel to the injectors to control N2 speed. In N2 mode, matched movements of the thrust leversproduces matched N2 speeds but N1 speeds and thrust may be mismatched between engines. A mechanical thrust lever setting and N2 speed schedule is contained in the fuel control unit.
--At take-off, climb, and cruise power settingsthe engine is N1 speed controlled. In N1 mode, the FCU responds to N1 speed references. Matched movements of the thrust levers produces matched N1 speed and nearly matched thrust between engines. An electrical thrust lever setting and N1 speed schedule is contained in the fuel control unit and controlled by the ECU. Switch over from N2 to N1 control can occur at speeds above 79% N1 by switching N1 control on.
--If N1 mode is selected off, the engine speed control reverts to N2 mode (mechanical)."
See? Everyone is right! Now let's go have a beer in memory of our friends.
