starting APU while climbing up to 10000 ft

[davidngr]

Just a question ouf of sheer curiosity: Should we start the APU after takeoff while climbing up to 10000 ft?

[philipp]

Normally not.

It is usually not done unless you have an engine failure and want a backup for the bleed air.

If you are critically short on bleed air (engine+wing anti ice with 14th stage bleed, not modelled in our CRJ though) you could also use the APU for backup.

Philipp

[Carlos Garcia]

For general Planes : I dont know the CRJ procedures.

No... You have to shut down the APU as soon as the engines are running. It is started again after landing, ( is at the discretion of the flight crew) and shut down when ground power is on line. External power is preferable! APU usage cost a lot of money (burn fuel)

Carlos

Edited January 11, 2012 by Carlos Garcia

[davidngr]

Many thanx:-) BTW hope the CRJ200 will simulate also the 14th stage bleed one day:-)

[deltapilot90]

APU ON 10th Stage OFF. After Takeoff (Pressurized meaning Packs ON): at 1500 ft or so you perform an "Overs" non verbal checklist which is APU START/STOP pressed (to Stop APU), L 10th Stage OFF, ISOL OFF, R 10th Stage OFF, LCV OFF then once your APU RPM drops below 50% you can then press PWR/FUEL. As Philip mentioned its also used in Cold/Moist Conditons where Bleed Air is a factor.

Note: Its ALWAYS used during UnPressurized takeoffs (Packs Off) due to short field departures etc. I would suggest learning the APU and 10th Stage first so when the 14th is modelled its much easier to learn. Any more questions feel free to send me a PM.

Tristan.

[davidngr]

APU ON 10th Stage OFF. After Takeoff (Pressurized meaning Packs ON): at 1500 ft or so you perform an "Overs" non verbal checklist which is APU START/STOP pressed (to Stop APU), L 10th Stage OFF, ISOL OFF, R 10th Stage OFF, LCV OFF then once your APU RPM drops below 50% you can then press PWR/FUEL. As Philip mentioned its also used in Cold/Moist Conditons where Bleed Air is a factor.

Note: Its ALWAYS used during UnPressurized takeoffs (Packs Off) due to short field departures etc. I would suggest learning the APU and 10th Stage first so when the 14th is modelled its much easier to learn. Any more questions feel free to send me a PM.

Tristan.

Thanx for your reply!Could you please better explain to me this above-mentioned concept: "then once your APU RPM drops below 50% you can then press PWR/FUEL." Do you usually leave the APU doors open during the ascent phase?

Davide

Edited January 15, 2012 by davidngr

[deltapilot90]

APU is started during approach because 10th stage and 14th stage can't be on at the same time. You need 14th for Thrust Reversers and de-icing. Checked.

I made an error in my last post where I said L/R 10th Stage "OFF"..I meant "ON" hence changing over from APU to 10th Stage.

You close the doors when you press the PWR/FUEL switch but only do so when the motor is running below 50% rpm.

Tristan.

[davidngr]

APU is started during approach because 10th stage and 14th stage can't be on at the same time. You need 14th for Thrust Reversers and de-icing. Checked.

I made an error in my last post where I said L/R 10th Stage "OFF"..I meant "ON" hence changing over from APU to 10th Stage.

You close the doors when you press the PWR/FUEL switch but only do so when the motor is running below 50% rpm.

Tristan.

Thanx Tristan:-) Are u a real CRJ pilot?

Davide

[deltapilot90]

No Davide not quite....yet. I not too long finished RJ Training out in Phoenix which was awesome So I have extensive knowledge of the aircraft along with its "slang" such as the Altitude Range Arc is known as the "banana" as I mentioned in one of my posts

-Tristan.