Engine Manual Start and Ignition Panel is part of A320 overhead panel
Engine Manual Start Switches #
ON – When an ENG MAN START switch is selected to ON, the engine start valve opens, if the ENG MODE selector is in CRANK or IGN/START and N2 is less than 15%. The ON light illuminates blue to confirm switch is selected to ON.
OFF – When OFF is selected, the associated engine start valve is closed unless an automatic start cycle is in progress. No illumination indicates the switch is selected to OFF.
MANUAL STARTS – Manual starts are only performed on the ground. During start, the FADEC controls the igniters (A and B), the high pressure fuel valve, and the closure of the start valve. The FADEC monitors N1, N2, and EGT when N2 is below 50%. ECAM start fault detection is available, however, automatic abort and crank capabilities are not available.
Engine N1 Mode Switch #
ALTERNATE CONTROL MODE – If any of the inputs required for normal control mode are lost, the FADEC automatically reverts to its alternate control mode, which uses N1 as the controlling engine parameter (EPR mode inoperative). The alternate control mode consist of an N1 Rated Mode or N1 Unrated Mode. All auto thrust functions, including alpha floor, are lost. Depending upon which specific inputs are lost, the engine may revert to either of two N1 modes; N1 rated mode, or N1 unrated mode. Additionally, the N1 mode can be manually selected by pressing the N1 MODE switch on the overhead panel.
OFF – When an ENG N1 MODE switch is selected to OFF (no light illumination), the normal (EPR) control mode is selected, if available.
ON – When an ENG N1 MODE switch is selected to ON, associated thrust control reverts from the normal (EPR) control mode to the alternate (N1) control mode. When an automatic reversion to the N1 rated or unrated mode occurs, selecting the switch ON confirms the mode. The ON light illuminates blue to confirm the switch is selected to ON.
Engine N1 Mode / Rated / Unrated #
N1 RATED MODE – In the N1 rated mode, the FADEC controls engine N1 as a function of thrust lever position, temperature, and altitude while preventing the engine from exceeding operating limits. Thrust is controlled in the same manner as in the normal mode without auto thrust. Place the thrust lever in the TO/GA detent to obtain TO/GA thrust, the MCT detent to obtain MCT thrust, and the CL detent to obtain climb thrust.
N1 UNRATED MODE – In the N1 unrated mode (N1 DEGRADED mode on ECAM) the FADEC controls engine N1 as a function of thrust lever position only.
The thrust lever detents do not provide limit protections; over boost is possible. With one engine in the N1 rated mode, the N1 of the unrated engine should be matched with the N1 of the rated engine (the thrust levers may not be aligned). If both engines degrade to the N1 unrated mode, N1 limit values in the Takeoff Performance, Climb Performance, and Landing Performance chapters must be used.
