FAA Approved Installation Manual for the Report No 908
EDM-900 and EDM-930 Page 37 of 56 Rev I
Primary Engine Data Management System Date 1-18-2013
38. Fine tuning the K Factor
The K factor shown on the fuel flow transducer does not take into account your aircraft’s particular installation. Fuel
hose diameters and lengths, elbows, fittings and routing can cause the true K factor to be different from that shown on
the fuel flow transducer.
You must use the following procedure to fine tune the K factor.
1. Make at least three flights of about two to three hours each. Note the actual fuel used (as determined by topping
the tanks) and the EDM-900 calculation of the fuel used for each flight USD.
Flight
Fuel USED shown by EDM
(total tank - REM) Actual fuel used by topping tanks
1
2
3
Total
2. Total the EDM-900 calculated fuel used and the actual fuel used.
3. Record the current K factor here ____________________ and in the table below.
4. Calculate the New K factor as follows:
New K factor = (EDM fuel used) x (Current K factor)
(actual fuel used)
New K factor = ( ) x ( )
( )
Every time you fine tune the K factor, change it by only half of the amount calculated above, and record the
measurements here:
Date
EDM
fuel used
actual
fuel used
Current
K factor
New K factor
=
x
/
Pilot’s
initials