Forum: F-16 Procedures

Happy Gilmore, I now agree with you about the float switch in the vent box being tied in with the external tank transfer switch. Looking at the schematic, it looks as though the power is taken away from the float switch in the vent box when wings first is selected. I imagine they have this design just incase the float switch in the vent box gets stuck in the up position, none of the tanks will transfer, so, if you put it in wings first, the tanks will tranfer just fine with a stuck float switch. That still leaves the internal v&p to discuss.

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My disagreements are... you say the internal v&p doesn't work with power off, i say it does. You say the float switch in the vent box does not work when the external tank transfer switch is in wings first, i say it does. Please point on these issues. Thank you!

Bealio, good answers and a good point, you should be an Instructor dude. The vent tank float valve however only stops external fuel transfer if the External Fuel Transfer Switch is in the NORM position. Which ever external tanks are installed the tanks shutoff valves are energized to the closed position. when fuel enters the vent tank, de-energizing them by placing the switch to WINGS FIRST makes them open and transfer continues.
I also said, or at least meant to say the internal V&P valve doesn't work during ground refuel (That is power off) the RSPRV always takes over in case of the internal V&P valve failure, which is during ground refuel.
I don't want to get into a meaningless argument here, it's like fighting with a girlfriend via e-mail.
Can't we all just get along, where's the love?

Happy Gilmore, now that we are all getting along...I was wondering if you could explain why the internal v&p does not work during ground refuel. This is interesting if it is true. The schematics for the v&p's aren't very detailed and is hard to see how they actually work inside the components themselves. If you could explain to me why the remote sensing pressure relief valve vents pressure during ground refuel instead of the internal v&p, that would be a big help to me. The way i see it is, if the internal v&p vents pressure in flight, why wouldn't it vent pressure during ground refuel. On that note, are you saying the internal v&p only comes in effect when power is on? Possibly because the air ejectors are open with no power, possible robbing air from both v&p's so they both don't function? Holy crap, this is bringing up a million questions. Let me know ASAP if you could. I guess i, the crazy instructor dude, need to schedule to go back to fuel systems school. I appreciate you making me get my head in the books, knowledge is power my friend!

Happy Gilmore, because of your quick response, i had to go out and ask someother oldtimers. From my understanding, the internal v&p and toilet bowl both work during ground refuel because of the rappid increase in pressure due to fuel entering so quickly. The air pressure will rise quickly causing a jump in pressure and allowing the internal v&p and toilet bowl to open. Normally, when applying ground air or bleed air, the internal v&p will pressurize the system slowly, especially when there is no gas in the tanks, there will be more space to fill. In that situation, the internal v&p doesn't need any help from his back up remote sensing pressure relief valve. Air will come from a small fitting while fuel will come from a rather large manifold. Do you agree? Again, thank you for your quick response!!!

I can break this down for you all............... Thumb

i'm listening........

To answer the original question - No, the internal system cannot cause the external tanks to overfill. During refuel, the internal and external tanks refuel simultaneously (not externals last), and the externals fill and shut off completely independently of the internal system and each other.

Do i hear an echo in this forum?

wow............did anyone learn anything in the three pages of this thread?

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Question #1. IFR switch is place into the "OPEN" position. 3,000 psi hydraulic pressure from system B opens the IFR door. Internal and external v&p are energized. Internal pressure drops to 1-3psi. External pressure drops to zero. The ready light comes on, the indicator is to the right of the HUD. External IFR lights come on as well as some lights in the IFR bay. If you want me to be more specific, let me know.

not to be a d!ck bealio but IFR door opens using A sys Hyd. A sys operates IFR door and secondary flight controls. i had to make up for my self because i confused somethings around in my earlier post.

yeah, i'm gonna have to go ahead and disagree with you there... B system opens the door!

CajunMaintainer wrote:

for the fellow fuel shoppers out [Link pending approval]

[Link pending approval] man, isn't that the truth! Shocked

Happy Gilmore, I've been waiting for a response for 7 years. I'm amazing now, so no need to respond you piece of sh*t! I mean that in the most respective way.

Adam, you are crazy! Hats off to you, Homie!

Active Member Joined: Apr 08, 2004 - 10:40 PM Posts: 203

this thread is funny

Forum: F-16 Procedures

External fuel tank over filling