If flying with a 20kt crosswind requiring yaw input as well as roll input to maintain course, would the fuel indicators show different loads depending on the roll angle of the aircraft (in this case, an MH-53e)

Clarification: With a left bank angle of 15-20 degrees would it appear that the right side fuel cells were using fuel faster with a quantitative fuel quantity system?

Thank you sir. That is a better way of saying it.

  • 3
    $\begingroup$ Isn't the plane still flying straight and level even with a crosswind, even though course and heading are different? $\endgroup$
    – Steve
    Aug 4 '17 at 12:12
  • $\begingroup$ It depends, what indication are you looking at? I'm guessing on the MH-53 it is a fuel totalizer, not an actual gauge. If it were a physical gauge it may change, but more expensive military/commercial aircraft use totalizers. $\endgroup$
    – Ron Beyer
    Aug 4 '17 at 13:49
  • $\begingroup$ Crosswind requires a 20deg bank angle with yaw input to fly along a predetermined course. It's pretty windy and this is an actual pilot reported issue. $\endgroup$
    – Derek
    Aug 4 '17 at 19:33
  • $\begingroup$ 4 tanks and it is a totalizer system so each probe covers the tanks from top to bottom and you can transfer to and from all tanks $\endgroup$
    – Derek
    Aug 4 '17 at 19:36
  • 2
    $\begingroup$ Where did you get the idea that flying a predetermined course in a crosswind requires a constant nonzero bank angle? $\endgroup$ Aug 5 '17 at 5:15

I don't know what fuel quantity indicating system is installed on the MH-53, but most aircraft use a capacitive indicating system. Basically, there are multiple probes spaced throughout the fuel tank(s). During a turn or bank, the fuel will accumulate to one side of the tank, which increases the capacitance on the respective probes on that side of the tank. Meanwhile, the capacitance decreases on the probes that aren't covered as much. Total capacitance of all the probes is then summed and processed. Basically, no matter how the aircraft is oriented, in a properly operating system, there should be no detectable change in fuel quantity.

  • $\begingroup$ It is capacitance based but has a single probe per cell and bags out around 24k pounds split between 4 cells $\endgroup$
    – Derek
    Aug 6 '17 at 8:33
  • $\begingroup$ Each cell has its own indicator plus a total just to clarify $\endgroup$
    – Derek
    Aug 6 '17 at 8:34
  • $\begingroup$ Generally speaking, a capacitance based system will be designed so that all but the most extreme flight characteristics are accounted for. My guess is that there would be very little or zero change. That said, it's possible there is something in the flight manual or maintenance manual about extreme flight characteristics and the fuel qty reading. $\endgroup$
    – Frank
    Aug 15 '17 at 6:21
  • $\begingroup$ As the overall load decreases the appearance of a miscompare increases. Even though fuel is being used from each tank equally the stationary fuel probes show more fuel on the wing down side. $\endgroup$
    – Derek
    Aug 15 '17 at 6:31
  • $\begingroup$ Are you sure fuel is being used from each tank equally as the level decreases and these maneuvers are performed? $\endgroup$
    – Frank
    Aug 15 '17 at 6:41

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