CESSNA®
MODEL 525B
MAINTENANCE MANUAL
Letter
Note
K
Average starting current.
L
Skid control hydraulic pump. System powered only when landing gear is
extended.
M
Power on only when battery is offline.
N
Items not included in the maximum current total due to mutually exclusive
condition. These items are: COMM 1 Receive, COMM 2 Receive, XPDR 1
Receive, TCAS, TAWS 8000, HF Radio Receive, and 500 Watt Inverter.
O
Ground Operation of Pitot/Static Heaters Limited to 2 Minutes on, 2 Minutes Off.
P
For the purpose of calculation, 1 minute of transmission for every 10 minutes of
flight, 3 minutes of transmission for every 10 minutes of flight during takeoff/land
and emergency.
Q
For the purpose of calculation, 95% of the time the transponder is in the receive
mode.
R
Only on transponder can be on at any one time.
S
The start PCB is powered from the Battery Bus Also.
T
RH Generator assumed off for single generator operation. (Analysis of
generator off versus Engine off found worst case electrical load to be with
generator off).
U
Pitch trim is operated either manually, or automatically from the autopilot.
During T/O or Landing phases, Trim is in use 10% of the time, and 5% in other
phases of flight.
V
Wing A/I Relays draw power from the Hot Battery Bus. During emergency
operation, relays are activated by Bleed Air O'TEMP Switch and therefore,
assumed off.
W
In Taxi Mode for calculation purposes, Hydraulic system Test/Operation for 3
minutes, speed brake extend and retract (1 minute), flaps extend and retract,
extend to take-off position (2 minutes).
X
PFD and MDF Heaters operate only when cockpit temperature is below -35
Degrees Celsius.
Y
FADEC Channel A is considered Channel in control.
Z
FADEC Channel B is on Standby.
AA
Each FADEC Channel has its own engine driven permanent magnet alternator.
The FADEC draws power from the airframe only during engine starts or failure
of the engine driven PMA.
BB
Emergency battery pack will charge only when input voltage is greater than 24
volts. Fully discharged battery pack will charge at Fast Rate 0.8 to 1.5 Amp for
60 minutes, then toggle between fast and slow rate for the next 60 minutes.,
then after 120 minutes will charge at the slow rate, 0.1 to 0.15 amps. For load
analysis purposes, the standby battery pack is considered fully charged at the
beginning of the flight.
CC
Circuit breaker for power distribution, protection for bus, no direct individual
system tied to this breaker.
DD
STBY Flight display has 3 circuit breakers in series; HC020, HT002, and
HC035. HC020 shows average battery charge current only. HT002 and HC035
in series, supply current to the standby display.
24-55-01
Page 23
© TEXTRON AVIATION INC.
Feb 23/2022
ICA-525B-34-00004
Form 2261 Rev 1