Loading GPS on ground

Turbine

Well-Known Member
What do you think about loading your flight plan into the GPS and saving it on the ground. Then after start loading it in and saving you some time.

This would all be done off the battery. Since you do not want to drain the battery you decide to pull a few breakers for the more consuming equipment, then reset them once you have finished.

Good practice or not?
 
I don't really see the need to pull any circuit breakers... I used to do this all the time in my Cherokee 140 with the KLN-94. Never hurt the battery... Just took about 5 minutes or less but it saves fuel though... Not really that much but it helps. That way your not doing it with the engine running... That just 2 cents. Hope it helps!!
 
That is basically what we do in the airlines. Of course, we don't pull breakers since we either are on ground power or APU. But, yeah, if I still flew small planes that is the way I would do it. No use wasting gas.
 
This is how I always did it in GA planes. Never really hurt the battery. I'd also pick up the atis/clearance before engine start as well. Less distractions and higher safety margins when you're single pilot and your prop isn't moving on a ramp.
 
Thanks, yes i guess it wouldn't hurt the battery to much it doesn't take that long anyhow. Appreciate it!
 
What type of plane and how many fixes (how much time) are we going to spend doing this? Is a GPU available/reasonable?

-mini
 
Yea i never have, that's why i asked.

The unit is a Garmin 430 and fixes would typically be no more then 5.
 
If you're only putting in 5 fixes, even in a plane with the worst battery shouldn't really be an isssue. Especially in a 430. If it's a battery issue, get a GPU. Don't pull breakers.

-mini
 
5 fixes will only take 2 minutes tops to put into a flight plan. So you won't be saving much fuel. But like somebody has mentioned you could go ahead and get the weather and maybe call up clearance.
 
It annoys me to no end to see pilots sitting on the ramp, engines running at 1500 RPM, twisting away on the knobs of their GNS 430. I realize you've got enough money to buy that fancy airplane, but damn, talk about throwing money down the drain.
 
My only comment is that I don't think it's a good habit to pull breakers.

If you weren't supposed to pull them, you wouldn't be able to. I pull the ACS breaker on the mitsi all the time, and sometimes the fuel pumps if it's cold out. They aren't doing a damn thing on the ground besides using up juice. "Breakers in" is on the checklist, and it's part of my before takeoff scan, too. Haven't broken the surly bonds yet without them in. That said, real men don't need no steenkin GPS. ;)
 
If you weren't supposed to pull them, you wouldn't be able to. I pull the ACS breaker on the mitsi all the time, and sometimes the fuel pumps if it's cold out. They aren't doing a damn thing on the ground besides using up juice. "Breakers in" is on the checklist, and it's part of my before takeoff scan, too. Haven't broken the surly bonds yet without them in. That said, real men don't need no steenkin GPS. ;)

I think the breakers are designed to be "pull-able" (is that even a word?) so that you can pull them in abnormal circumstances. I'm thinking like the resolution of an emergency, or an abnormal indication, operation, etc. In fact, in the KC-135, the T-37 and the T-6 there were abnormal ops/emergency checklists that called for pulling circuit breakers.

As for normal ops, however, I think if they wanted you to treat a circuit breaker like a switch, they would have installed a switch.

That said, I don't think you'll do any damage by pulling circuit breakers 99% of the time. But it wouldn't be my prefered habit unless I had a pretty good idea about the wiring of the aircraft. There may be multiple devices going through a circuit breaker where only the main device is listed for the breaker, or there may be devices on other breakers that take inputs from the device on the breaker in question. So... not my prefered habit.
 
In most aircraft, you'd have to leave the battery on for a signicant amount of time to drain it. A few minutes loading fixes into the GPS shouldn't hurt anything.

As far pulling breakers goes. There was a procedure for pulling the fuel boost pump breakers in the chieftan due to it draining the battery if left on for any significant time and also leaving an awfully big puddle of gas under the engines. It also caused flooded starts. I chock it up to lack of forethought by the piper folks!
 
I think the breakers are designed to be "pull-able" (is that even a word?) so that you can pull them in abnormal circumstances. I'm thinking like the resolution of an emergency, or an abnormal indication, operation, etc. In fact, in the KC-135, the T-37 and the T-6 there were abnormal ops/emergency checklists that called for pulling circuit breakers.

As for normal ops, however, I think if they wanted you to treat a circuit breaker like a switch, they would have installed a switch.

It's the simplest kind of system. If you even have the faintest recollection of the wiring diagram for your aircraft, you know what's powered by the particular circuit. It seems like there are two equally silly schools of thought abroad these days. Either you have to able to pull apart and fix everything within tolerances, or you kick the tires and light the fires unless an alarm goes off. What ever happened to having a basic understanding of how the systems work and using a little good sense in deploying that understanding? In the case of the misti, for example, the ACS just powers a huge-draw fan on the ground. The fuel pumps just try to pump fuel from the tips to the main (the tips aren't pressurized, so there's no fuel to be pumped). And yes, when it's -10 in Cleveland and you want to get the (#*$(#$ out of there and go south, this stuff can make the difference between warmer climes and a hung start.
 
In the KC-135 we pull breakers all the time. The TO tells us to, so instruments aren't powered needlessly on the ground.

I don't see a problem with it as long as you know exactly what happens when you pull it. For example, what happens when you pull the avionics CB, with the avionics master in the "OFF" position?
 
It's the simplest kind of system. If you even have the faintest recollection of the wiring diagram for your aircraft, you know what's powered by the particular circuit. It seems like there are two equally silly schools of thought abroad these days. Either you have to able to pull apart and fix everything within tolerances, or you kick the tires and light the fires unless an alarm goes off. What ever happened to having a basic understanding of how the systems work and using a little good sense in deploying that understanding? In the case of the misti, for example, the ACS just powers a huge-draw fan on the ground. The fuel pumps just try to pump fuel from the tips to the main (the tips aren't pressurized, so there's no fuel to be pumped). And yes, when it's -10 in Cleveland and you want to get the (#*$(#$ out of there and go south, this stuff can make the difference between warmer climes and a hung start.

Boris, that's why I said, "it isn't my preferred habit" rather than something stronger like, "you SHOULDN'T pull" or you should "NEVER except in an emergency pull", etc., etc. I don't really see anything wrong with it in a basic GA airplane, where it really is pretty simple. But what you wrote sort of implied that it is ok to pull any circuit breaker in any airplane at any time if you want to de-power a piece of equipment (that's probably a little stronger than the way you wrote it, but that's what I got from what you were saying). And the passage that I quoted above sort of implies that, too, but I think you were talking about small GA airplanes.

But I still think that in general, maybe 99% of the time, treating a circuit breaker like a switch is probably fine. But especially in more complicated airplanes (like the -135, e.g., with literally hundreds of circuit breakers and a wiring diagram that takes up multiple pages), as a general rule you probably shouldn't treat them like a switch. My personal habit is to pull circuit breakers when things aren't working right in an attempt to get them to work right, or in emergencies when a checklist tells me to, or maybe even once in a while in training to force a student into a scenario that I want him to work through. But that's all it is: my personal habit, or my personal "rule of thumb".
 
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