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SECTION 3
EMERGENCY PROCEDURES
MOTOR FAILURE
o
Operation is possible with one motor/ESC/propeller failure
The two adjacent motors/ESCs will be increased in thrust automatically by the flight
controller to overcome the loss
In cases where the airframe is highly loaded the maximum rating of 40 amps may be
exceeded by these two motors/ESCs
Operation should be terminated as soon as possible to reduce the possibility of damage
to the remaining motors
COMMUNICATION FAILURE
o
Video link failure
5.8 Ghz being the shortest wavelength in general AV use has the least ability to
penetrate. This link should be the first to be lost.
It is best to lose video first! It is the least likely to cause a crash when it fails.
5.8 Ghz can lose link with little warning.
Ensure that the GCS station antennas are perpendicular to the AV. Do not point the
antenna at the AV.
Yaw the AV to change the antenna position
Other links should still be good. Return back to the GCS until link is restored.
Transmitters produce heat when in operation. When overheated they may have
thermal protection which interrupts use temporarily. Use of a heat sink or fan may be
required especially with high ambient temperatures.
Higher gain antennas may be used, but do so with caution. High gain antennas are
directional.
Multiple antennas using “diversity” can be used. Diversity is a device which
determines the best signal, and uses that.
5.8 Ghz even at high wattages theoretically has less range than lower frequencies.
Changing to 1.3 Ghz is an option, though there are other issues to be considered.
o
RC link failure
2.4 Ghz antennas can lose link with little warning.
Anything in between the two antennas can cause temporary signal loss especially a
person.
Hold the transmitter up in the air and walk in the general direction of the AV (aerial
vehicle).
Ensure that the antenna is vertical. Do not point the antenna at the AV.
The failsafes on the RC link should be set so that the AV returns to home. Should this
require a heading change, the antenna may move into a more desirable position and
link will be restored.
The onboard equipment may block the signal. Yaw the AV so that the antennas point
towards the GCS.
A LRS (long range system) can be used as a permanent solution. This is higher in
wattage and usually on 433 Mhz.
o
Data Link Failure
900 Mhz do not lose link without some warning. When drop outs are noticed to
increase in frequency that is the limit of the range.
