Just a side note, the 737 series ETOPS aircraft must run the APU throughout the entire flight to serve as an alternate source of generator. Obviously, to run an APU for an entire LAX-Hawaii flight would require above standard parts.

I find it really hard to believe that a APU is running the entire flight. A. Most APU operation is limited to FL240 and below. B. That is quite a lot of money to operate. C. A RAT is usually your backup for emergency power.-Eric Toll

Turning ETOPS ON in our options also enables the dual battery and extra cargo fire suppression systems to on as those are required for ETOPS certification.

I find it really hard to believe that a APU is running the entire flight. A. Most APU operation is limited to FL240 and below. B. That is quite a lot of money to operate. C. A RAT is usually your backup for emergency power.-Eric Toll

Crack the books, and get back to us. You're 1 for 3. ;)

ETOPS is such a broad specification the main premise of ETOPS is to make sure that any aircraft that has one ore more engines is capable of flying extended distances on one engine. there are several ways a carrier can achieve this and how they achieve it depends on the certificate they apply for there is ETOPS-75, ETOPS-90 ETOPS-120/138 ect.The most basic requirement is what PMDG included the duel battery and the extra fire suppression, ETOPS aircraft also carries a separate MEL which sets forth the minimum equipment needed to conduct the flight under ETOPS rules.

So much fussing! could of used google =)http://en.wikipedia.org/wiki/ETOPSOr this really good PDF by Boeing!http://www.boeing.com/commercial/airports/faqs/etopseropsenroutealt.pdf

I find it really hard to believe that a APU is running the entire flight. A. Most APU operation is limited to FL240 and below. B. That is quite a lot of money to operate. C. A RAT is usually your backup for emergency power.-Eric Toll

As had been said, you're 1 for 3.A. In the 737NG, the APU can be started and operated up to FL410, the max certified altitude. At first I thought you were talking about the classics when you mentioned FL240, but they can be started up to 25000 ft, and operated up to max certified altitude(37000 ft, if I remember correctly). These numbers are for the electrics only.The APU is not able to give you the full electric load at altitude. Bleed and electrics can be used up to 10000 ft, bleed only up to 17000 ft.B. Yes, it does cost quite a bit of money extra to do so, about 50kg of fuel per hour + maintenance costs.C. Did you ever see a RAT on a 737?

Turning ETOPS ON in our options also enables the dual battery and extra cargo fire suppression systems to on as those are required for ETOPS certification.

Fun fact: dual battery is required on all JAA/EASA certified Boeings (European registered, then) - this is from Boeing document.

As had been said, you're 1 for 3.A. In the 737NG, the APU can be started and operated up to FL410, the max certified altitude. At first I thought you were talking about the classics when you mentioned FL240, but they can be started up to 25000 ft, and operated up to max certified altitude(37000 ft, if I remember correctly). These numbers are for the electrics only.The APU is not able to give you the full electric load at altitude. Bleed and electrics can be used up to 10000 ft, bleed only up to 17000 ft.B. Yes, it does cost quite a bit of money extra to do so, about 50kg of fuel per hour + maintenance costs.C. Did you ever see a RAT on a 737?

A: Many a different APU are used on 737s. Maybe this is valid on SOME NGs?

Something worth mentioning is that a 737 with an inop APU can still fly normally, but it can not be used on a route with an ETOPS leg because the APU is mandatory equipment for ETOPS flight but not for normal flight.

To the OP, it means Southwest can fly to the Caribbean and Hawaii..

Fabo,The NG is ONLY equipped with the Allied Signal APU, which fulfills every requirement I mentioned above.The other APU's are used in Classics and Jurassics.