Selection on IGN

[Driver170 42]

Ignition select switch ...................................................................................IGN L or R

Select IGN R when operating through manned maintenance stations.

 

Can some explain what this means?

[Houghton11 12]

That's a little different, I think it means use the R IGN when you're at an airport where you have company maintenance facilities available.

 

Generally one just switches it between L and R on alternating legs.

[Driver170 42]

doesn't IGN R let you know the AC STBY  system is working fine?

[Houghton11 12]

I guess you could.

 

The normal power source of the AC standby bus is the AC transfer bus number 1 anyways. You're not really checking much with normal AC applied on the aircraft.

 

The electrical metering panel can tell ya if the standby inverter is working correctly.

[scandinavian13 5,192]

Can some explain what this means?

 

It's probably just a different way of ensuring even wear. If the outstations are not manned, and you're operating hub and spoke (not SWA-style), then the maintenance through flight would (usually) be through the hub.

 

Hub departure - IGN R

Oustation - IGN L

Back at Hub - IGN R

Back at Out - IGN L

 

Other airlines use "Select IGN L for odd numbered flights; IGN R for even numbered flights." That works for airlines that use some sort of out/back flight numbering system, but for operators like CJC who used the same flight number out and back on occasion, this wouldn't work. SWA also does this to a certain degree (SWA982 is BWI to MDW, and then MDW to TPA). My bet is that it's simply a different way of skinning the "even wear" cat.

[JoeDiamond 67]

 

Ignition select switch ...................................................................................IGN L or R

Select IGN R when operating through manned maintenance stations.

 

Can some explain what this means?

 

 

If I had to guess it's for schedule reliability.

 

translated as "do not select ignition R at stations where maintenance personnel are not available and a significant delay will occur when you discover the R ignition system is not working"

 

The flight crew can defer the left ignition system per the MEL, the right system can only be deferred by maintenance as there is a maintenance procedure involved.

[scandinavian13 5,192]

If I had to guess it's for schedule reliability.

 

translated as "do not select ignition R at stations where maintenance personnel are not available and a significant delay will occur when you discover the R ignition system is not working"

 

The flight crew can defer the left ignition system per the MEL, the right system can only be deferred by maintenance as there is a maintenance procedure involved.

 

Interesting. Didn't know that. Makes sense.

[PHXMD-11 86]

It's probably just a different way of ensuring even wear. If the outstations are not manned, and you're operating hub and spoke (not SWA-style), then the maintenance through flight would (usually) be through the hub.

 

Hub departure - IGN R

Oustation - IGN L

Back at Hub - IGN R

Back at Out - IGN L

 

Other airlines use "Select IGN L for odd numbered flights; IGN R for even numbered flights." That works for airlines that use some sort of out/back flight numbering system, but for operators like CJC who used the same flight number out and back on occasion, this wouldn't work. SWA also does this to a certain degree (SWA982 is BWI to MDW, and then MDW to TPA). My bet is that it's simply a different way of skinning the "even wear" cat.

 

Delta's policy is the ignition switch is set to L for the captain's leg and R for the first officer's leg. Also the ignition switch is set to R for the first flight of the day (after midnight local time) to ensure the ignition is powered by standby power.

[JoeDiamond 67]

Interesting. Didn't know that. Makes sense.

 

When they defer the right ignition system they have to switch the power source for the L system to the AC standby bus.