Safety Recommendation
The Australian Transport Safety Bureau recommends that National
Jet Express Pty Ltd implement a periodic inspection routine, based
on BFG SL 1714, of all main landing gear wheels that have undergone
a hub bushing repair.
Safety Recommendation
The Australian Transport Safety Bureau recommends that National
Jet Express Pty Ltd implement a periodic inspection routine, based
on BFG SL 1714, of all main landing gear wheels that have undergone
a hub bushing repair.
We have looked at the recommendations of AWB 32-004 and the BF
Goodrich SL 1714 with regard to the failure of the Main Wheel and
the following are the decisions taken in consultation with the
Maintenance Controller of the B727 fleet.
1.) We currently comply with the requirements of the BF
Goodrich CMM for these wheels which have the subject area inspected
at each overhaul which occurs at the third tyre change. The
inspection of the suspect area when it has been repaired by
sleeving is called up as part of the overhaul procedures in the CMM
by visual NDT procedures using penetrant inspection, this requires
that the repair sleeve is removed for the inspection and then
replaced.
2.) BF Goodrich SL 1714 gives an alternate method using
Ultrasonic inspection methods which do not require the sleeve to be
removed but it is an alternate not a replacement method, should the
inspection be required at each tyre change then the repeated
removal of the sleeve would very quickly cause the hub to become
oversize and thus this ultrasonic inspection would be the preferred
method in that case.
3.) We ... interviewed ... Vintage Overhaul who currently do
these wheels for JetExpress and Looking at his records back for 15
months he has had no other failures of this type (and in his
recollection cannot recall another failure of this type). I also
contacted the Reliability Manager of FedEx in the United States who
replied on the 9th of January who also operate these aircraft and
they carry out inspections of this area at the overhaul periods (in
fact they have extended the overhaul period to the fourth tyre
change). Similarly the Delta Airlines staff who are now working for
FedEx stated that Delta also did them at each overhaul period when
they operated B727 aircraft.
From this the conclusion is that based on the above evidence
that NJS will continue to carry out the inspection of the B727 Main
Wheel hubs at the periods specified in the BF Goodrich CMM, that is
inspection of the area where the repair sleeve is fitted by removal
of the repair sleeve at each overhaul period (3rd tyre change) for
inspection of the machined area in accordance with the approved
procedures of the CMM.
The ATSB considers that the action proposed by National Jet
Systems Pty Ltd in section-1 of their response to ATSB safety
recommendation R20050008, is satisfactory and meets the intent of
the recommendation to implement a periodic inspection routine of
repaired B727 main landing gear wheel hubs.