FES Maintenance manual, v1.16 May 2020
Page 21 of 24
5.4 Annual inspection
It is necessary to check the sailplane every 12 months following the 100 flight
hours inspection.
Additionally, please check if we published any updates to FES manuals on the FES
website under the download section!
5.5 Inspection after a rough landing or ground loop
After a rough landing or ground loop, please do the following:
−
check battery packs for visible damage,
−
check the FCU instrument for proper operation,
−
check if there is any damage on the propeller blades,
−
check motor mounting points and spinner.
5.6 Inspection at the end of flight season
Remove the FES battery packs from the glider and store them in a dry place at
room temperature. The capacity of the batteries is best preserved when you keep them at
50% for storage, which is about 3.7 V per cell, ca. 52 V per pack, or ca. 104 V total
voltage displayed in the FCU instrument.
6. Parts with limited service life
The following FES system parts have a limited service life:
−
12 V Pb battery should be replaced every 5 years (if installed in a glider)
Replace other components of the FES system based on their condition.
7. Placards
Sailplanes equipped with the FES system require additional placards in the cockpit:
−
Ventilation open and ventilation closed placards
−
Maximum speed to fly with a motor running placard
8. Balancing of rotating parts
We balance the complete assembly of motor, spinner, and propeller blades to
achieve vibration-free smooth operation of the FES. We use specialized equipment to
reduce the oscillation of the rotating components to less than 0,1 IPS before installation.
During assembly, we mark the components with alignment dots, such that they
match on all linked parts. These marks must be taken into account when assembling the
spinner or propeller blades so that they oriented the same as before. If these marks are
ignored, excessive vibration can occur during the motor run!
