When to start and stop the APU

[@Sim737Pilot]

Another informative video with realistic scenarios of when we can't or can start the APU and why. Thanks!

[@countryflyboy8255]

Well.. I guess im gonna hafta buy and learn the airbus now.. 😀 It's gonna be a big change for me. And regarding this video that is exactly how my APU routine was for the 737. I check my fuel usage after each flight and I usually end up saving a few hundred pounds difference from what the OFP said I would.

[@rnavdlrey]

You brought up a good topic in this video. Not sure if you've done this before, but could you do a video on single engine taxi procedures? As in when it is implemented on both Boeing and Airbus aircraft. Thanks!

[@Sim737Pilot]

It's primarily operator dependent, but the engines do need to be running a minimum of 3 minutes before takeoff for warmup and 3 min at idle after landing before shutdown. Ryanair afaik doesn't allow single engine taxi for takeoff. United does allow single engine for takeoff and landing.

[@davey6693]

Based on IRL observation in Brisbane, if the wheels are on the ground the APU is either on or about to be started :)

[@juliashenandoah3965]

You can pull out the magnetic standby compass and see the compass wander 60° to the east in the Fenix because the relais is drawing so much power from the battery when starting the APU in cold and dark with no ground power. It generates a magnetic field disturbing the compass.

[@AndyWhite]

One thing I love about the Fenix is that the APU fuel flow decreases and increases if you turn on or off EXT power with the APU running. Great detail

[@A330Driver]

Nice detail indeed! Now if only the engines did the same when you turn the packs on/off ;-)

[@AndyWhite]

@@A330Driver typical pilot mentality Emi; only perfection is almost good enough . . . !

[@owenklein1917]

I think the regulations are completely different in the US. Every pilot I’ve talked to, they said they started the APU before boarding even started and they sometimes leave it on during a turnaround

[@iamra_n3189]

Great video, and very nice to see some genuine emphasis on fuel efficiency!

[@tomstravels520]

There is a SETWA (Single Engine Taxi Without APU) mod available for A320 both NEO and CEO. Don't know if Fenix has it though as not sure how to test for it.

[@My320Sim]

Interesting video! I find it really cool to see different SOPs relating to certain systems/procedures! I'm currently in my A320 Type Rating and our SOP says to leave the APU start normally until "shortly before engine start" and that we should keep APU bleed off and packs off until "immediately before engine start", likewise after landing we delay the APU start also but leave the APU bleed off completely until the next engine start (providing we have a comfortable cabin environment), also on the taxi in we take pack 2 off, then on stand switch pack 1 off in the shutdown :)

[@A330Driver]

Thanks for the insights! In theory we also have such an approach, in practical terms it prooved not to hold up however so the video was influenced more by what we actually do rather than what's in the SOPs. The "good mix" of what we actually do on the line. Especially when it's rather hot or rather cold (so most of the time... in winter one way, in summer the other) we need the air conditioning. So the APU comes on. The last thing you want is a cabin crew constantly nagging because they don't feel comfortable (and honestly... it's their workspace, why should I make them feel uncomfy only for the airline CEO to earn another two bucks?).

[@My320Sim]

@@A330Driver That's interesting, I agree about the cabin crew, I would also like a comfortable temperature so I think it really is discretionary as you say but I also think there is a balance to try and meet the book also, that said I recently had a flight where the crew were flying by the book completely and left the Packs both off in Madrid - it was so hot and uncomfortable in the cabin until after takeoff, would have been nice to have cooled the cabin. I really like what you said about setting the cabin temps really far down before shutting off the APU to keep the cabin cool

[@mefjuldz]

Oh man ! That was my quiet wish that one day you would do Airbus stuff. Keep it up !

[@gregoryl.4872]

More very informative nuggets. Thanks

[@Micg51]

My airline has us turn the APU on when doing our after landing flow. We keep it on until the ground air is plugged in unless it’s hot/cold or a quick turn. I guess fuel cost doesn’t matter that much cause the airline doesn’t really care about us turning it off, more of a PIC discretion thing.

[@iamra_n3189]

That's a shame, bit of an old way of doing things.

[@Micg51]

@C H I have never seen it any airport, from JFK and ORD to the smallest outstation

[@iamra_n3189]

@C H Commonplace here in EU. Saves noise and emissions...undeniably so!

[@Groveish]

I thought that the rules for the APU was due to emissions regulations primarily. They can indeed be loud but I guess most ramp agents have hearing protection available? If it's for the residents living near the airport, do the APUs matter when you have departing aircraft at near full thrust drowning out the sound of everything else?

[@A330Driver]

In the papers it's usually noise, but emissions usually play a role as well of course. It all goes hand in hand. There's a huge difference between aircraft taking off and landing and APU usage however: Runways are usually much further away from terminals and resident houses. We can approximate that the percieved volume of something reduces linearly with distance. An aircraft with a running APU might therefore be percieved louder than an aircraft taking off on a runway that's a kilometer away. Also keep in mind that aircraft taking off and landing will only make noise for a short moment while the aircraft at the gate would do it for a long time.

[@Groveish]

@@A330Driver Interesting. It seems like APU regulations are way more common in Europe than North America. Like how trains in Germany never blow their horns unless there's a clear imminent danger but in the US it's horns for everything imaginable

[@Ficon]

Also start the APU if you just hit a flock of geese and you are going to put it in the Hudson.

[@madhavmenon2545]

In fenix, the load sheet takes a lot of time to come up even I set the loading time to 9 mins

[@andreasolsen5174]

I guess there is a lot of different SOPs.. Where i work we just plug in the GPU while the engines are running. So no APU on arrival. (737 and A320)

[@Sim737Pilot]

Are you allowed to say what airport you work at? That way we can simulate the same procedures there?

[@andreasolsen5174]

@@Sim737Pilot Somewhere in Norway. But i think its standard procedure in all of Norway. SAS, Norwegian, Widerøe. Its up to the airline. All of the charters we get start their APU on arrival.

[@Islandsoundzz]

I have a video suggestion for you. Would you mind creating a video on how to use the Maddog Performance Management System (PMS) during climb, cruise and descent?

[@bangalykouyate4706]

Hello Emanuel Thank you for your videos. Please I want to know if you did any video about CLIMB GRADIENT or MISSED APPROACH GRADIENT. If so, please share the video link.

[@lincolnhawk3934]

He has made hundreds of videos by now and if you can operate an aircraft even in a sim, you are capable of searching the video by yourself on youtube. you can do it i believe in you

[@paulhadley9047]

Don't forget, if you lose both engines start the APU!

[@abumari1955]

Like the one took off LaGuardia AP and struck by birds.🤣

[@valmirsallahu4209]

So I saw you turned off pack 2 when you arrived at gate. Can you explain why you do that?

[@WilliamArnauts]

Excellent insight on how to correctly operate the APU! Appreciate it! Is there a limitation on when you're allowed to turn on/off the APU bleed after turning on/off the APU? And How long would that be? I remember a B737 would take around 3 minutes if I'm not wrong.

[@A330Driver]

Thanks William! In the 737NG according to Boeing it's one minute, according to my airline it's two minutes.

[@jirivnuk6303]

Also, when I am at airport where GPU is not available for some reason, I leave the APU ON for whole time during turnaround, right?

[@FalconX88]

so when do I stop it? did I miss it in the video?

[@skylineswithoutskies5072]

Is it possible to go straight to ground power and shut the engines down after arriving or is the APU always required?

[@Sim737Pilot]

Yes, if the APU is not needed for cabin air conditioning (warm or cold). Ground power will obviously only provide power, not heating/cooling.

[@skylineswithoutskies5072]

@@Sim737Pilot Thanks! 👍

[@Dave60ist]

Very interesting

[@elbapino6531]

Now what will be your stream name sir ? AIRBUS DRIVER or A320 DRIVER or AXXX DRIVER ? Good question !!!

[@mercurybullet6043]

Depends on where in the world you are. In my country apu's are never shutdown while the engines are off.

[@leonolink6738]

So then when do pilots use PCA?

[@A330Driver]

When the airport has it (most don’t) and uses it (many times even those that have it just don’t use it).

[@leonolink6738]

@@A330Driver Thanks!

[@77flyer]

Are u changing to airbus pilot name on KZbin? Hehe 🙃

[@Cool737pilot]

So in extreme temps, let’s say -10/-20 C or 30/40 C OAT without A/C unit you will still turn/keep the APU off?

[@Micg51]

At my airline in those temps the APU is running anytime crew or pax are on board.

[@iamra_n3189]

He did say that even at +5*C, they can run it at own discretion to warm the cabin. I've done it myself, run the APU when we arrive for cold & dark power-on, warm the cabin just for 5 mins or so until it hits +15*C, then shut it down. During boarding, the passengers stir the temp up to +20*C, sometimes more. Then restart it again a couple minutes before push, unless we use external power. This was a large turboprop, so electrical starters rather than bleed air.

[@Daveodaddeo101]

1st 🤣