For all you B777 Experts...
"What is the system that if you
turn the switch to OFF,
that you will actually
turn something in the aircraft ON?"
Enjoy the Journey!
XOX Karlene
An aviator's journey continues ... Changing the world one word at a time.
When you turn the center tank pumps OFF...you turn ON the scavenge pumps?
ReplyDeleteGreat Guess! That was not what I was thinking of and I had to go look this up....because I was not sure.
DeleteWhat I learned is that technically when you turn off the center pumps (leaving fuel in the system) the mains take over to supply fuel to the engines.
The main tanks have to use enough fuel to create room for the center tank scavenge fuel, before fuel can move into those tanks.
The scavenge pumps are on and ready to go as long as the main pumps are on. But... they don't do anything until main tanks decrease for room for that extra fuel.
Thanks for this great comment. I really had no idea how that scavenge system technically worked. I learned something new today. Thank you!!
When you turn the Fasten Belts sign OFF, you turn the line for the bathroom ON, (although I don’t think that’s specifically a B777 thing.)
ReplyDeleteGood answer. But not the specific one. So... speaking of the LAV... What is the mathematical term for light in the flight deck that indicates the forward lav is in use?
DeleteWait... does your plane have that light? The 747 did. Will have to investigate the 777.
Wouldn’t turning off some electric driven hydraulic pumps make the air driven demand pumps come on? The other guess would be alternate flaps.
ReplyDeleteKristopher, excellent guess. Alternate flaps you actually turn the Alternate flaps to on due to another failure.
DeleteNow... the pumps, let me think about this. The ADPs actually run during high demand, or anticipated high demand. Not really because you turned off other pumps.
Actually, if you were sitting on the ground and turned off electric pumps the ADPs wouldn't run, especially if there was no air.
Keep the guesses coming!
OK, Karlene. I am no subject matter expert on the 777, but I will take a crack at it and say that one of my guesses would be if the ADIRU were to deactivate or experience interruption in flight, it would initiate the SAARU providing the flight data backup.
ReplyDeleteIt was worth a try!
Happy Holidays,
-Jeremy
Jeremy, That's not it... but great guess. There are lots of back up systems that automatically start when something fails. But this is specifically turning switch and system off, which actually turns something else on, in the process.
DeleteI'll give the answer next week. I have another question ready to go the following week. I'm thinking I'll have to give a free book those who can guess them all. :)
Keep the guesses coming. And... Thank you for the trivia idea too. My best part is learning from the guesses.
Happy Holidays!!!
If you turn off both engines in the air, the apu will turn on automatically and the RAT deploys.
ReplyDelete-Rohan
Rohan, that is a good guess. But, pilots don't turn off engines, we shut them down. Keep thinking! GREAT guess!
DeleteRadio navaid updating can be activated by selecting the RAD NAV INHIBIT toggle to OFF on the REF NAV DATA page in the CDU.
ReplyDeleteRohan, Thanks for the great comment. You are really thinking about this. So, this is not the answer to my question. I will have it posted on Tuesday.
DeleteTechnically anything in the CDU is not toggled. Just selected. It's also not a switch. You are not turning a switch off, but selecting the disabled Rad NAV to off. I had no idea that this was a process and found found an interesting article.
Here you go: http://www.flight.org/gps-failure-and-subsequent-navigation
Thanks for the comment!!
The fly-by-wire system turns on when the wheel weight switch turns off, which happens when the airplane lifts off from the ground.
ReplyDeleteLol... I love it!! Wait... that's an interesting fact. There is nothing fly by wire until airborne? I suspect not, or it would be ground by wire.
DeleteOkay... this is an excellent guess. But... the switch action I'm looking for is accomplished with your finger on the overhead panel. Answer on Tuesday with another question....
Thanks for your comment!