Aviation safety issues and actions
Recommendation issued to: National Jet Express Pty Ltd
|Date issued:||09 December 2005|
|Safety action status:|
|Background:||Why this Recommendation was developed|
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.
|Date issued:||16 May 2006|
|Response from:||National Jet Express Pty Ltd|
|Action status:||Closed - Accepted|
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.