View Full Version : Selecting Standby Power to OFF


EW73
7th May 2012, 06:58
For any guys flying the B737NG, does anyone have this item in their Secure Checklist.
Of course, the FOs preflight prep will also have the line item to select the standby power back to AUTO.
Has this habit been dropped over recent years, or do some companies still heed the 'dangers' of leaving it selected at AUTO.

EW73 :confused:



Denti
7th May 2012, 07:12
Never had that in our checklists or procedures, neither on the classic nor on the NG.

captjns
7th May 2012, 08:05
Some 30 years experience on the the 737 from the 100s up to the -900... no reference to the "STANDBY POWER" Switch on any normal check list item. Although there used to be a STANDBY POWER check way back when.

EW73
7th May 2012, 08:54
Yeah...I'm guessing this is only done by the long hauler aircraft, as it was quite common in the B747 Classics, as they spent longer on the ground between flights.

sudden Winds
15th Jun 2012, 03:47
selecting stby power to off is neither required nor desired, if it was, boeing would have put it somewhere in the secure checklist. Everytime I do my preflight checks and find something unusual (just like the stby power in off) I check with maintenance before continuing, even with the maintenance logs already checked. Someone might have been doing some work. These kind of non standard actions can lead to mistakes and delays.

Yeelep
15th Jun 2012, 20:11
A standby power control unit-operational check is performed by maintenance every 15 days on the NG, 5 days on the Classic. Its a little more involved than just selecting standby power to off, takes about 5-10 minutes. So with that being done there probably isn't any reason for flight crews to do a check.

EW73
16th Jun 2012, 10:40
Ya missed the point, Yeelep...

Think about this for a moment....in an NG you arrive normally at the gate, external power is plugged in and the engines are shut down!
All normal checklists are completed and you depart the airplane, looking forward to going home for the day!
The airplane is scheduled for another couple of legs in a couple of hours...
Some time after you leave the airplane, the external power fails or gets accidentally pulled from the receptacle...
With the AC power failure inside the airplane, the Standby Power system immediately kicks in and powers all those good things you expect it to do.
Now it sits there at the gate with all this stuff powered (won't be everything that's normally powered though, since the #1 IRS, engine R IGN and the lighting will all be switched off at this time), until the next crew turns up to start their preflight prep.
By this time, depending whether this airplane has a single or dual battery system, the standby system will be almost or completely dead.
This will mean one/both batteries will need to be changed, since there's not enough time to get them fully recharged before the upcoming flight.
Have fun....I'd rather simply select standby power to OFF between flights.

STBYRUD
16th Jun 2012, 11:14
If you leave the airplane unattended what you should really do is secure the airplane, hit the ground service switch if you need it and turn off the battery - In my airline if no one takes over the airplane (be it the next crew or tech) you put it to sleep completely.

Denti
16th Jun 2012, 13:34
If one completes the secure checklist there is no need to switch the standby power off. No battery depletion will take place. Simply operate the plane according to boeing checklists and everything is fine.

oceancrosser
16th Jun 2012, 22:17
Agreed, leave the STBY PWR SW in AUTO where it belongs.
Switch off the battery power, case closed if the GND PWR dies.
On 737NGs/757/767s switching the STBY PWR off and on will create electrical system problems.
This was something done in older types and is not found in Boeing checklists or normal procedures for these airplanes.
Leave it.

sudden Winds
18th Jun 2012, 19:29
There's a little button in the flight attendant panel called Ground Service, that will solve all the problems, just do the secure checklist and do not create procedures on your own.