jeff guzzetti lubrication and end play inspection lubrication and end play inspection
TRANSCRIPT
Jeff GuzzettiJeff Guzzetti
Lubrication and
End Play Inspection
Lubrication and
End Play Inspection
Lubrication:The ProcedureLubrication:The Procedure
• Gain access to
the tail
• Remove access
panels
• Gain access to
the tail
• Remove access
panels
Lubrication:The ProcedureLubrication:The Procedure
• Apply grease to
acme nut fitting with
grease gun until
grease exits out top
of acme nut
• Apply grease to
acme nut fitting with
grease gun until
grease exits out top
of acme nut
FAIRING
ACCESS PANELS
GREASE GUN
Lubrication:The ProcedureLubrication:The Procedure
• Brush application of
“light coat of grease”
onto jackscrew threads
• Operate jackscrew
“through full range of
travel”
• Brush application of
“light coat of grease”
onto jackscrew threads
• Operate jackscrew
“through full range of
travel”BRUSHBRUSH
Lubrication:ObservationsLubrication:Observations
• Differences with method of application
• Small access panel
• Lube of nut fitting only is not adequate
• No inspection req’d
• Recommendations issued, and more proposed
• Differences with method of application
• Small access panel
• Lube of nut fitting only is not adequate
• No inspection req’d
• Recommendations issued, and more proposed
Jackscrew Lubrication:Alaska Airlines Interval ExtensionJackscrew Lubrication:Alaska Airlines Interval Extension
0 1000 2000 3000 4000FLIGHT HOURS
1996
1994
1991
1988
1987
YE
AR
0 1000 2000 3000 4000FLIGHT HOURS
1996
1994
1991
1988
1987
YE
AR
Manufacturer's Recommended IntervalAlaska Airlines Interval
Lubrication:Manufacturer’s Recommended Interval Lubrication:Manufacturer’s Recommended Interval
0 1000 2000 3000 4000FLIGHT HOURS
1996
1965
1964
YE
AR
0 1000 2000 3000 4000FLIGHT HOURS
1996
1965
1964
YE
AR
Maintenance Intervals:IssuesMaintenance Intervals:Issues
• Process is deficient
• Does not account for design assumptions
• Not supported by data
• Does not account for lack of task accomplishment
• Process is deficient
• Does not account for design assumptions
• Not supported by data
• Does not account for lack of task accomplishment
The End Play Check:BackgroundThe End Play Check:Background
• DC-9 jackscrew life: 30,000 hrs. - No Inspection
• 1965 Sampling program: Premature wear
found during bench checks
• Changes to acme screw & wear limits
• On-wing End Play Check developed in 1967
• DC-9 jackscrew life: 30,000 hrs. - No Inspection
• 1965 Sampling program: Premature wear
found during bench checks
• Changes to acme screw & wear limits
• On-wing End Play Check developed in 1967
The End Play Check:BackgroundThe End Play Check:Background
• Ad Hoc procedure developed using tools already available to airlines:• Horizontal Stabilizer Restraining
Fixture• Dial Indicator• Torque Wrench
• Purpose: To check amount of thread wear without jackscrew removal
• Ad Hoc procedure developed using tools already available to airlines:• Horizontal Stabilizer Restraining
Fixture• Dial Indicator• Torque Wrench
• Purpose: To check amount of thread wear without jackscrew removal
GAP
0.003 to 0.010
The End Play Check:The ProcedureThe End Play Check:The Procedure
• Move stabilizer to the 1
deg. ANU position
• Remove fairings
• Install restraining fixture
between horizontal and
vertical stabilizer• (Continued)
• Move stabilizer to the 1
deg. ANU position
• Remove fairings
• Install restraining fixture
between horizontal and
vertical stabilizer• (Continued)
The End Play Check:The Procedure (Continued)
The End Play Check:The Procedure (Continued)
• Clamp dial indicator to torque tube nut (below nut)
• Preload dial indicator• Apply 250 – 300 in-lbs
torque to shorten restraining fixture
• Record dial indicator reading (interpretation required)
• Clamp dial indicator to torque tube nut (below nut)
• Preload dial indicator• Apply 250 – 300 in-lbs
torque to shorten restraining fixture
• Record dial indicator reading (interpretation required)
The End Play Check:The Procedure (Continued)
The End Play Check:The Procedure (Continued)
• Relieve torque and ensure indicator returns to initial
• Repeat steps several times
• Check end play is “between 0.003 and 0.040 inch.”
• Relieve torque and ensure indicator returns to initial
• Repeat steps several times
• Check end play is “between 0.003 and 0.040 inch.”
End Play Check:Alaska Airlines Interval ExtensionEnd Play Check:Alaska Airlines Interval Extension
0 2000 4000 6000 8000 10000FLIGHT HOURS
1996
1988
1985
YE
AR
0 2000 4000 6000 8000 10000FLIGHT HOURS
1996
1988
1985
YE
AR
Manufacturer's Recommended Interval
The End Play Check:ObservationsThe End Play Check:Observations
• Installation of dial indicator can affect end play reading
• Installation of dial indicator can affect end play reading
The End Play Check:ObservationsThe End Play Check:Observations
• Dial indicator can be difficult to read
• Dial indicator can be difficult to read
The End Play Check:ObservationsThe End Play Check:Observations
• Working conditions can be adverse
• Working conditions can be adverse
The End Play Check:ObservationsThe End Play Check:Observations
• Restraining fixture condition, torque, and rotation direction can affect reading
• Jackscrew rotation during check can affect reading
• Restraining fixture condition, torque, and rotation direction can affect reading
• Jackscrew rotation during check can affect reading
The End Play Check:ObservationsThe End Play Check:Observations
• Differences w/ Alaska Airline fabricated restraining fixture
• Differences w/ Alaska Airline fabricated restraining fixture
BOEING TOOLBOEING TOOL ALASKA AIRLINES TOOL
ALASKA AIRLINES TOOL