Robinson Helicopter Company R44 Quick Start Manual

DATE: 03 July 2013
TO: R44 & R44 II owners, operators, and maintenance personnel

SUBJECT: Rotor RPM Sender Magnets

ROTORCRAFT AFFECTED: R44 helicopters S/N 0001 thru 2310, R44 II helicopters
S/N 10001 thru 13519, spare C006 main rotor gearbox assemblies, spare C908-1
yoke assemblies, and spare 102MG11 magnets (alternate P/N 102MG11BP). B570-1
magnets with black epoxy fillet are unaffected (see Figure 1).
TIME OF COMPLIANCE: Within next 100 flight-hours or by 31 October 2013.
BACKGROUND: RHC received a report that a MRGB yoke assembly's 102MG11 magnet
came out of its housing during flight and activated the low-rotor RPM warning system.
This bulletin requires applying additional adhesive to affected magnets.

COMPLIANCE PROCEDURE:

1. Refer to Figure 2. At C908-1 yoke assembly, if a yellow dot is painted on the outboard
surface of both 102MG11 magnet housings, the requirements of this bulletin have
been complied with. Proceed to step 8.
2. If gearbox is installed, remove tailcone cowling.
3. Refer to Figure 3. Rotate blades as necessary. Press in on magnet with finger to
ensure magnet is completely seated in magnet housing. Apply B270-10 adhesive to
create a continuous fillet between magnet and magnet housing. Repeat for second
magnet.
4. Allow adhesive to cure for a minimum of 4 hours.
5. Wipe off adhesive from magnet exterior (adhesive will be drawn into space between
magnet and housing and will be dry in this location, but wet on the exterior.)
6. Paint a yellow dot on outboard surface of both magnet housings.
7. If applicable, install tailcone cowling.
8. Make appropriate maintenance record entries.

R44 SERVICE BULLETIN SB-86

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