B

Question 1

Bearing Monitor System Fault Isolation

Answer 1

The bearing monitor panel (BMP) shows bearing monitor system (BMS) fault indications to the aircrew. If a fault indication shows more than a maintenance condition, the pilots have to know immediately. This is normally done by the BEARING VIB LIMIT, BEARING TEMP DETECT, or BEARING TEMP LIMIT lights on the caution/advisory panel. If the aircrew sees a system, WOW, or bearing fault condition on the BMP:

*1. Land as soon as practical if a system fault occurs which precludes monitoring of swashplate
vibrations/temperatures as indicated by any of the following conditions:
a. Illumination of a TEMP or VIB system status light, and SP1 and SP2 fault indications appearing in the BMP alphanumeric display.
b. Illumination of the PANEL system status light and PNL NG fault indication appearing in the BMP
alphanumeric display.
c. Failure of the BMP display or loss of system power.

WARNING
(ON AIRCRAFT NOTMODIFIED by AFC 491 PT3) Because the threshold for attenuation induced vibration sensor failure is below the TEMP DET limitation, the first indication of swashplate thermal imbalance may be the VIB SYSTEM status light accompanied by SP1 or SP2 fault indications
appearing on the alphanumeric display.

NOTE
• (ON AIRCRAFT MODIFIED by AFC 491 PT3) A swashplate thermal imbalance may be indicated by a VIB system status light, accompanied by
SP1 OR SP2 fault indication appearing on the alphanumeric display.
• Failure of both the SP1 and SP2 sensors or failure of the bearing monitor panel (BMP) will result in loss of swashplate monitoring capabilities.

Question 2

BEARING VIB LIMIT Caution Light

Answer 2

If the BEARING VIB LIMIT caution light comes on:

1. Aircrew — Alert.
2. Land as soon as practical.

Question 3

BEARING TEMP DETECT Caution Light

Answer 3

If the BEARING TEMP DETECT caution light comes on:

1. Aircrew — Alert.
   * 2. Land as soon as possible.

Question 4

BEARING TEMP LIMIT Caution Light

Answer 4

If the BEARING TEMP LIMIT caution light comes on:

1. Aircrew — Alert.
   * 2. Land immediately.

Question 5

BIM Caution Light

In Flight

Answer 5

If BIM®caution light goes on, have a crewmember check if BIM®circuit breaker is in (on right cabin circuit breaker panel). Due to the sensitivity of the system, the caution light may go on due to Electromagnetic Interference (EMI),
giving the pilot a false indication of impending spar failure. If the caution light remains on with the circuit breaker in, and EMI is not verified:

• 1. Airspeed — 80 KIAS, minimize maneuvering.
• 2. Altitude — Minimum safe.
     
     3. No. 3 primary AC BIM® circuit breaker — Check in.
     4. Land as soon as practical. Do not exceed 1.5 flight hours unless necessary to reach a safe landing site.
        a. If flying with an external load that cannot be safely transported at 80 KIAS, consideration should be given to load jettison. Hover flight should be minimized.

WARNING
Flight operations outside a level cruise flight regime of 80 ±5 KIAS and operations in a hover produce blade flight loads that will increase potential crack stresses and accelerate crack propagation rates. Continuous flight outside this recommend flight profile will compromise the safety margin incorporated into the maximum prescribed flight duration and lower the allotted 1.5 hour interval.

Question 6

BIM Caution Light

On The Ground

Answer 6

If all spar indicators arewhite, but the BIM®caution light remains on or the IBIS BIT is unsatisfactory, a malfunction in the radiation detector or signal processor is indicated. The helicopter may be flown for 1.5 hours at 80 KIAS at minimum safe altitude (minimizing maneuvering). The helicopter must then be landed and reinspected before continuing on additional 1.5-hour legs. If a spar indicator shows black at any time, further flight shall not be attempted until qualified maintenance personnel check the integrity of the spar.

Question 7

BEARING MONITOR PANEL VIB/Detect Status Light (SP-1 and/or SP-2, DISC)

Answer 7

A VIB status light on the BMP indicates that the BMS has sensed bearing vibration levels which are higher than

normal. If the VIB DETECT bearing status light illuminates:
1. Aircrew — Alert.
a. Record sensor location and time of occurrence.
2. Perform BMS reset procedure.
3. If VIB DETECT bearing status light returns during the same flight — Land as soon as practical.
4. If light does not come on again, resume routine monitoring.

NOTE
• Should a VIB Detect occur on SP-1 and/or SP-2 and the system is reset, a Subsequent VIB Detect on DISC is unrelated and another system reset may
be performed. The same applies to an initial VIB Detect on DISC with a subsequent VIB Detect on SP-1 and/or SP-2. Do not reset the BMP if a
second VIB Detect occurs at the same location (swashplate or disconnect).
• For purposes of this procedure, a flight is defined as the period between rotor engagement and rotor shutdown.