The startswitches in 737
 

Hello!

The start switches in 737 is solenoid held to GROUND and spring-loaded to OFF. To change its position, is it nessecary to hold the button inwards before switching the button? I know it is nessecary to get it to GRD position but from GRD to OFF? From OFF to CONT and to FLT? Anyone?

Hi there

Push in and turn to ground when starting eng automatically goes to off at starter cutout. If need on cont push in turn to cont and manually have to turn off. Push in and turn to flight, believe you have to manually turn to off

Hope this helps

Ali1

All true - the only position spring loaded back to the off position is from GND following starter cutout. The other two positions, CONT and FLT have to be manually placed back to OFF - the difference with these positions being the number of igniters used, cont 1 and flt 2. Bon!

Push?
 

When you manually have to swith buttom from GRD to OFF you have to push? When you switch from OFF to CONT or FLT? Push?

It's a rotatable knob - much like my own! To move it from the OFF position you have to push it in and then turn (to GND, FLT or CONT).

Not exactly. Startswitch going to OFF causes the startvalve to closes. The signal for the Switch to go to OFF comes from the N2-Indicator at 46% (737CL) or from the DEU at 55% (737NG).