This is for not using APU at the gate - The SHUTDOWN checklist says APU BLEED AIR SWITCH 'ON'. The SECURE checklist thereafter says PACKS 'OFF' so nothing is mentioned about switching the APU BLEED AIR SWITCH off. So you could leave it ON with APU shutdown and not using the APU at the gate (FCOM) normal procedures.

 

Anyone know actually the procedure for the APU bleed SW? I have looked everywhere and only found the APU bleed valve closes automatically during shutdown.

 

 

So you could leave it ON with APU shutdown and not using the APU at the gate (FCOM) normal procedures.

 

Yes.

 

 

 

Anyone know actually the procedure for the APU bleed SW?

 

What the Boeing procedure says in the FCOM. If it doesn't say anything, leave it where it is.

Roger that

Oh what is the procedure for the recirc fans? It just says in the FCOM as desired!

 

So i've been doiny research and seems some pilots turn the left recirc fan off below 100 to reduce noise!

 

Again, like the APU any idea on what to do with these during shutdown and secure? Leave them in AUTO?

 

 

Again, like the APU any idea on what to do with these during shutdown and secure? Leave them in AUTO?

 

I just shut them off on the 600/700 once the external air is plugged in. On the 800/900, I turn the right side off only. Again, it's really only a noise thing. The only part that's a maintenance issue is that the fans receive extra wear if you don't turn them off.

 

Hint for the future: as desired means "do what you want." Sometimes that's okay in aviation. Not everything has a procedure.

Turn the APU bleed off if you're not using the packs; to leave the apu bleed on without the packs on is to burn more fuel. There are other reasons to switch it off... But that would be the primary one.

 

As for the recirc fans, as Kyle puts it, set them 'as required' hahaha

 

Brian Nellis

The only FCOM note I've seen regarding recirc fans on the ground is a recommendation to turn them off on the ground in hot conditions to aid cabin cooling (as when they are on they will be recirculating hot air).

 

Otherwise do as you wish!

 

 

On the 800/900, I turn the right side off only.

 

The left recirc fan is the one that makes the most noise on the flight deck.

On the NGX if you turn the right recir fan off the noise stops?

On the NGX if you turn the right recir fan off the noise stops?

 

Both fans cause airflow noise in the cockpit but the noise from the left fan is noticeably greater.  It's not uncommon to turn off the left fan to keep the noise down while leaving the right fan on to provide airflow to the cabin.

This is for not using APU at the gate - The SHUTDOWN checklist says APU BLEED AIR SWITCH 'ON'. The SECURE checklist thereafter says PACKS 'OFF' so nothing is mentioned about switching the APU BLEED AIR SWITCH off. So you could leave it ON with APU shutdown and not using the APU at the gate (FCOM) normal procedures.

 

 Problem is the APU Bleed SW has to hold the time of 30 seconds after the APU is started prior to be used. So, after the APU is OFF, you shall also turned the APU bleed by the fact the SW shall be OFF after the first 30 seconds of APU is started.

 

 

Source: FCOM and GOL SOP.

 

Galeno Garbe

Roger that

Oh what is the procedure for the recirc fans? It just says in the FCOM as desired!

 

So i've been doiny research and seems some pilots turn the left recirc fan off below 100 to reduce noise!

 

Again, like the APU any idea on what to do with these during shutdown and secure? Leave them in AUTO?

 

For the recycle fan, you have first to understand their function, that's basic collect the cabin air, filter and re-inject in the cabin. At the end this will save some pneumatic energy by recycling it instead to use the engine bleed air. If we use less eng bleed air, we will drain less energy from the engines and keep these energy to generate trust. So is important and also recommended to use the rec. fans during all the flight phases. This will colaborate for a better fuel consumption during the flight. the rec. fans also helps the packs system for pressurization... so is all about saving pneumatic power from the engines.

 

Galeno Garbe

Found this on recirc fans

 

http://www.pprune.org/tech-log/560953-boeing-737-ground-operations-question.html