SB750-55-10
Page 6
Revision 4 - April 7, 2016
Citation
SERVICE BULLETIN
SB750-55-10
9.
Remove maintenance warning tags to the batteries and external power receptacle that have
"DO NOT
CONNECT ELECTRICAL POWER - MAINTENANCE IN PROGRESS"
written on them.
A.
Connect the batteries.
B.
Connect external electrical power.
WARNING:
Make sure personnel and equipment are clear of the horizontal stabilizer to
avoid injury to personnel or damage to the airplane or equipment.
10.
Do a check of the horizontal stab trim system.
A.
Do the stabilizer trim, primary and secondary split trim switch functional test.
(1)
Make sure the secondary trim control switch (SC017) on the upper left portion of the center
pedestal is in the OFF position and switch guard is down.
(2)
Make sure the PRI STAB TRIM CONT and PRI STAB TRIM PWR circuit breakers on left
circuit breaker panel are engaged.
(3)
Apply external power to the airplane and place the external power switch to EXT PWR.
(4)
Put the AVIONICS and EICAS switch in the ON position.
(5)
Do a check of the pilot's split trim switch.
(a)
Move the left half of the pilot’s split trim switch for NOSE UP and then NOSE DOWN
momentarily (at least three seconds), make sure the horizontal stabilizer does not move.
(b)
Move the right half of the pilot’s split trim switch for NOSE UP and then NOSE DOWN
momentarily (at least three seconds), make sure the horizontal stabilizer does not move.
(c)
Momentarily move both halves of the pilot’s split trim switch together for NOSE UP and
then NOSE DOWN and make sure the horizontal stabilizer follows the trim command.
(6)
Do a check of the copilot's split trim switch.
(a)
Move the left half of the copilot’s split trim switch for NOSE UP and then NOSE DOWN
momentarily (at least three seconds), make sure the horizontal stabilizer does not move.
(b)
Move the right half of the copilot’s split trim switch for NOSE UP and then NOSE DOWN
momentarily (at least three seconds), make sure the horizontal stabilizer does not move.
(c)
Move both halves of the pilot’s split trim switch together for NOSE UP and then NOSE
DOWN momentarily and make sure the horizontal stabilizer follows the trim command.
