Some variables are: 1. How level the wings are during refueling. 2. The effects of any crossover tubes. 3.
The ability of the line attendant to fill the tank to the same mark. The shape of the tank and the dihedral of the
wing can aggravate the situation.
Note:
K Factor settings below 580 will cause the display resolution to increase above .1 Gal/Hr. when used
with a Display Update Time setting of "UP2." K Factors below 180 will cause the display resolution to
increase above .1 Gal/Hr. when used with a Display Update Time setting of "UP1." The FT-90 Flow Trans-
ducer has a K Factor around 198.
Filter -
There are two filters used by the FP-5 to remove fluctuation or jump in the fuel flow readings. Select-
ing either filter will not affect the accuracy of the FP-5. Use filter F 1 for most fuel-injected engines. This
filter has the fastest response time (eight times faster than other flow gauges). Use filter
F 2 for most carbureted engines. This filter has a slightly slower response time than F1 (still faster than
other flow gauges) but will take out any fluctuation or jump you may have seen using the F1 filter.
Display Update Time -
The Display Update Time may be set to "UP2" or "UP1". A "UP2" setting causes
the display to update two times per second and a .1 Gal/Hr. resolution can be maintained for K Factors from
580 to 999. A "UP1" setting causes the display to update once per second and a .1 Gal/Hr. resolution can be
maintained for K Factors from 180 to 999. When using the FT-60 Flow Transducer use the "UP2" setting.
When using the FT-90 Flow Transducer use the "UP1" setting if .1 Gal/Hr. resolution is required, otherwise a
"UP2" setting would be preferred.
Loran/GPS Interface (FP-5L only) -
The Loran/GPS Interface may be set to "L 1" or "L 2". A "L 1"
setting is used to interface the FP-5L to any of the following units that have a moving map output: King,
ARNAV, Garmin, Trimble, II Morrow or Foster. A "L 2" setting is used to interface the FP-5L to any
Northstar unit with a moving map output.
To program the Full Fuel Level, K Factor, Filter Display Update Time and Loran/GPS Interface,
perform the following steps:
A. Turn the aircraft electrical power off, push both Prg Buttons, and hold them in.
B. Turn the aircraft electrical power on, wait two seconds, then release the Prg Buttons. At this point,
the far left digit should be blinking and there should be a Gal or Lbs annunciator in the right
corner of the display. All the green display mode LEDs should be off. If this is not the case, start
over with step A. The Full Fuel Level is being displayed and you are now ready to program the Full
Fuel Level, K Factor, Filter, Display Update Time and Loran/GPS Interface using the following
procedure:
a) Select a Digit - The Right and Left Prg Buttons move the blinking digit to the right or to the
10
Blinking Digit
