JPI EDM800 frustration

[drgwentzel]

Flyers,

I have the EDM800 and there is one very frustrating thing that I hope will be fixed or maybe has already been fixed with a firmware update that I don't yet have. BTW, I have no idea what firmware I am using, but the unit is about a year old.

Here's an example situation:

1) a pilot is in a flying club with 23 other pilots
2) The club plane holds 40 gallons of fuel and has an EDM800
3) The tanks are not full when he arrives to fly, so he sticks the tanks and determines he has 33 gallons of fuel on board
4) He boots up the EDM800 and it asks the cryptic question: "FUEL ?N"
5) He assumes the complete question is, "Did you in anyway change the amount of fuel onboard since the last time you shut me down?"

Ok, that's a legit question. So, before he can answer that, he has some questions of his own:

1) What the *&^% does the "N" stand for and how is it helpful in answering the question?

2) How can he properly answer the question, when he has NO IDEA how much fuel the unit "thinks" he has. He can ONLY answer the question if he just filled the tanks and knows they're full right now. Any other fuel state, and he has NO IDEA how to answer or correct the unit because the EDM800 is mum on how much fuel it "thinks" he has.

Look, these units are not just in airplanes with one owner. They could be in a partnership or a flying club with anywhere between 2 and 50 pilots. It could be a school plane with hundreds of pilots! We have NO IDEA how the last pilot left the fuel state in the airplane and more importantly we have no idea whether or not they programmed the proper fuel status into the unit in the first place.

The unit should ask the question, BUT provide more information, (AND DROP THE "N"!). The question should read, "FUEL ? 33". Meaning, "When I was shutdown last, there were 33 gallons of fuel that I calculated remaining in the airplane. Do you still have 33 gallons onboard, or is the fuel state different then that?"

NOW, we can answer the question and properly add or subtract whatever fuel is required to bring the unit to an accurate fuel accounting.

Does this make sense? Is there a problem with the screen display that would prohibit such a fix in the firmware? The programming seems simple. The display I can't answer to.

Gene - 1971 Cardinal RG

 

[ElPaso Pilot]

Flyers,

I have the EDM800 and there is one very frustrating thing that I hope will be fixed or maybe has already been fixed with a firmware update that I don't yet have. BTW, I have no idea what firmware I am using, but the unit is about a year old.

Here's an example situation:

1) a pilot is in a flying club with 23 other pilots
2) The club plane holds 40 gallons of fuel and has an EDM800
3) The tanks are not full when he arrives to fly, so he sticks the tanks and determines he has 33 gallons of fuel on board


4) He boots up the EDM800 and it asks the cryptic question: "FUEL ?N"

While not entirely intuitive, the actual sequence is in the manual, but the clarity is limited to the 8 or so character text display and two button interface. This ain't an iPad, and they didn't pull their MMI folks from Apple.

5) He assumes the complete question is, "Did you in anyway change the amount of fuel onboard since the last time you shut me down?"

That would be pretty close. Now restate it in 8 characters.

Ok, that's a legit question. So, before he can answer that, he has some questions of his own:

1) What does the *&^% does the "N" stand for and how is it helpful in answering the question?

2) How can he properly answer the question, when he has NO IDEA how much fuel the unit "thinks" he has. He can ONLY answer the question if he just filled the tanks and knows they're full right now. Any other fuel state, and he has NO IDEA how to answer or correct the unit because the EDM800 is mum on how much fuel it "thinks" he has.

Have him try this. If he doesn't know how much fuel is in the unit, immediately exit out of the fill screen.

Then, check what the unit thinks is in the tanks.

If correct, then done.

If incorrect, then per the manual,

"Enter the pilot program mode by simultaneously holding the STEP and LF buttons until the display changes, about 5 seconds"​

which immediately goes back to the fuel fill screen and the delta can be entered to correct the unit.

Look, these units are not just in airplanes with one owner. They could be in a partnership or a flying club with anywhere between 2 and 50 pilots. It could be a school plane with hundreds of pilots! We have NO IDEA how the last pilot left the fuel state in the airplane or even whether or not they programmed the proper fuel status in the first place.

That will be a problem with any flow meter system. It is not a fuel gauge. It only accurately measures how much fuel has passed through meter as it is being used, and can be very accurate at that task if calibrated properly.

Resetting the totalizer by sticking the tanks could be terribly inaccurate. Do the sticks accurately represent the contour of the tanks? Is the plane perfectly level?

If you're lucky, the sticks are accurate to +/- a few gallons. The meter is accurate to +/- a few tenths.

If someone is improperly using the flow meter / totalizer and setting it to the sticks before flights, you've lost that accuracy.

The unit should ask the question, BUT provide more information, (AND DROP THE "N"!). The question should read, "FUEL ? 33". Meaning, "When I was shutdown last, there were 33 gallons of fuel that I calculated remaining in the airplane. Do you still have 33 gallons onboard, or is the fuel state different then that?"
NOW, we can answer the question and properly add or subtract whatever fuel is required to bring the unit to an accurate fuel accounting.

While it might have been nice to see what the unit thinks is in the tanks, JPI didn't set it up that way, I pointed out the alternate method that only involves a few button presses.

Does this make sense? Is there a problem with the screen display that would prohibit such a fix in the firmware? The programming seems simple. The display I can't answer to.

Gene - 1971 Cardinal RG

Feel free to contact JPI, but I doubt they'd go through the effort to change the sequence on a certified unit that has been in the field for years.

Again, you are in a bit of a pickle because you want this to be a fuel gauge and it isn't -- it only measures fuel used from a known point. Per the manual:

Your known points are full or tabs, plus or minus any gallons added or removed from the tanks.

Sticks aren't necessarily reliable known points, nor is expecting a flow meter/totalizer to be a fuel gauge in a rental the appropriate usage of the tool.

 

[drgwentzel]

Yes, I have the flow chart in my checklist book. I have to refer to it everytime, because, as you stated, "It's not very intuitive."

I understand that it's not a fuel gauge and have never looked at it that way. I get the "garbage in, garbage out" philosphy of this unit.

All my whining and moaning could be mitigated by simply having the unit display the last calculated fuel state while it's asking for the information. It's asking you to confirm the fuel state without showing it to you. That is just poor programming.

Yes, you have provided a workaround and that is exactly what I have been doing, except that I didn't know the Step and LF buttons held for 5 seconds would bring me back to the Fuel State question. I just shut the unit off with the Avionics Master and then turn it back on and wait for the boot up sequence to complete. Your advice might be quicker. Still, it was a stupid mistake and it's a simple 5 minute fix for any programmer and a ten minute fix to update the online manual.

I get your point about it being a certified unit. Not sure how that affects things. This would be an improvement/correction of an error and not effect performance in any way.

Gene

 

[flyingron]

The sad part when they put the fancy display on the 800 is they didn't add a few more buttons. Trying to invoke functions on an instrument as complex as the 700/800 with only two buttons is a bit tedious.

I just live with the two step basic (FULL MAIN, FULL AUX) I've got mine set up for. Yes, it's not right if I fill ALL the auxes, but I can deal with it.