ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
Rev.
5
MM-4-64
Nov
5/13
C. Overspeeds exceeding 420 rpm. Perform the following:
(1) Remove the main rotor hub and inspect by liquid penetrant inspection and in
accordance with the inspection tables in para. 9-1, D, or return to Enstrom
Helicopter Corporation for inspection and overhaul/replacement.
4-62. Main Rotor or Tail Rotor Transmission Chip Indication – Special Instruction
NOTE
New or recently overhauled transmissions will often make a magnetic "fuzz"
which will collect on the magnetic plug as gray sludge. This is normal and
may be cleaned off the plug. The plug may then be reinstalled and the
helicopter returned to service. If any main rotor transmission chips are found
which are larger than .065 inch/1.65 mm in cross-section or if any tail rotor
transmission chips are found which are larger than .035 inch/.9 mm in cross-
section, contact Enstrom Customer Service Department and discontinue use
until further instructions are received from Enstrom Customer Service
Department.
A. Main rotor transmission chip indication. Perform the following:
(1) Inspect the chip detector for accumulation of metal particles as follows:
a.
Main rotor transmission metal particles, flakes, or slivers exceeding .065
inch/1.65 mm: Contact Enstrom Customer Service Department and discontinue
use until further instructions are received from Enstrom Customer Service
Department.
NOTE
Sludge normally will not cause a chip indication by itself. There is normally a
small particle, flake, or sliver on the detector also.
b.
Sludge (a mixture of oil and fine metal particles resulting from normal gear
operation): Clean the detector and return the transmission to service.
(2) If the indication was caused by sludge or a particle, flake, or sliver not exceeding
the maximum size, return the transmission to service and annotate the chip
indication and results in the aircraft maintenance records.
B. Tail rotor transmission chip indication. Perform the following:
(1) Remove the tail rotor assembly and remove the flex pack.
(2) Turn the gearbox by hand.
(3) Inspect the chip detector for accumulation of metal particles as follows:
UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED
Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.