Missing red arc in fuel level indicators

[MariuszXC]

In a document titled 1959 Cessna 172 Manual.pdf I found on the net, in section IV - Operating limitations, there is a statement on page 4-2:

Fuel Quantity Indicators. Empty (2-1/2 gallons unusable each tank) ... E (red line) Not recommended for take-off ... E to 1/4 (red arc).

The descriptions clearly reference a red line and red arc on the fuel gauge scale.

Similar reference is made on page 1-4 under "Fuel Quantity Indicators" section.

I don't know if these markings were carried over to later years models, but I don't see a reason why not, so maybe this missing bit should be added to fuel gauges model?

The firt page of the PDF I referenced is titled 1959 Cessna 172 Owners Manual N7084T

[wlbragg]

Thank you MariuszXC, I'll try to take a look at this potential addition in the next few days.

[MariuszXC]

Thank you for taking a note. I would love to send a pull request instead, but I am afraid I do not have necessary blender skills, and that is the area I think is needed in this case..

[wlbragg]

@dany93

I'm planning on trying to clean up some of the outstanding issues. Please don't feel obligated to participate in reviewing my work, but if you don't mind, it would be nice to continue forward as we have been.

1439 is ready to merge upon review.

[dany93]

@wlbragg OK for the red line. Do you you intend trying to add a red arc (E to 1/4) or is it enough?

[wlbragg]

Empty (2-1/2 gallons unusable each tank) ... E (red line) Not recommended for take-off ... E to 1/4 (red arc).

I searched google images for c172p fuel gauge. I couldn't find one with a red arc. Also, "arc" depicts a different type of fuel gauge, a gauge with a semicircle or arc scale where the red arc is part of the line with the tick marks (bottom image). I like the idea of the "red arc" for safety reasons. Our gauge is a straight scale. I decided on the current one because it is similar to our original one but it contains more information, including the red "line". it is from a picture of what looks like a real aircraft that is very close to our model.

So I guess a compromise?

[dany93]

I agree on your red "arc" considerations (a gauge with a semicircle or arc scale). Your gauge is exactly as your picture. It's OK.

[MariuszXC]

Yes, 'arc' was a bad choice of wording on my part. OTOH I quoted the POH.. Probably a low fuel warning 'zone' would have ben more fitting.

Anyway, thanks for following up on this.

[wlbragg]

Thank you for reading the POH and reporting it to us. That original fuel gauge as far as I know was from the very start of this project. No telling what data might have been available and used at the time. We've a much larger pool of resources now to draw from.