TM 1-6625-724-13&P
0075 00
0075 00-3
The CH-47 Flight Plans are listed below with a brief description of their purpose. The selectable Flight Plans (see
table 1) are listed in order of appearance in the menu of the CADU and not in the order in which they are to be
performed.
50HOUR
The CH-47 50-hour vibration survey is performed on the combining and aft transmission oil cooler fans, see task 5.
This procedure measures vibration levels of the components only, and does not offer corrective actions for out of
tolerance conditions.
AFTVIB
The aft vibration survey is performed whenever an unusual vibration is suspected in the aft part of the synchronizing
drive shaft or cross shaft area, see task 5. This procedure measures vibration at hanger bearings 4, 5, 6, 7, cross
shaft No. 1 and cross shaft No. 2. This procedure measures the vibration levels of the components only, and does
not offer corrective action.
FLIGHT
This test, see task 4, is designed to reduce rotor system lateral and vertical vibration to specified levels, using pitch
change links, tabs and tracking weights. It is to be used after GROUND and HOVER or for “tuning up” an aircraft that
is already in service.
FWDVIB
The forward vibration survey is performed whenever an unusual vibration is suspected in the forward transmission or
synchronizing drive shaft area, see task 5. This procedure measures vibration at the forward transmission oil cooler
and at hanger bearings 1 through 3. This procedure measures the vibration levels of the components only, and does
not offer corrective action.
GROUND
This Flight Plan is designed to track the rotors prior to hover balancing, using pitch change links only. It is the first
step to be performed after any component change or major rework on the rotor.
HOVER
This Flight Plan is designed to be used after GROUND has been completed. It is designed to reduce the rotor
system’s lateral vibrations to specified levels, using pitch change links and spanwise balance weights.
PROBES
This Flight Plan is designed to use data from up to 8 accelerometers to assist in isolating irregular or unusual
vibrations. It will measure data one channel at a time on DAU ACC1 through ACC4 and the multi-channel cable
connected to the track and balance accelerometer blocks. All accelerometers will measure a 0 to 500 Hz spectrum (0
to 30,000 RPM).
