ENG747 - Undercarriage handle inspections

Initial Report

I believe that in [month], base maintenance discovered their [Airbus Fleet] Landing Gear safety locking device for the cockpit lever was defective. The hook that protrudes from the item into the Landing Gear lever was missing. No one knew how long it had been missing, therefore not knowing how many Landing Gear levers it had been used on or if it was lost in an A/C or elsewhere. A work order was raised to inspect the Landing Gear lever of all the company [Two Airbus Types] on the line at [Base].  The initial thought was to remove the Landing Gear lever unit and shake it for sounds of the hook (FOD) in the unit. It was decided this was not suitable for certification reasons.

The next proposal was to examine the lever internally with a camera for signs of the hook. This entailed first inspecting with the lever in the down selection position then, if nothing seen, to proceed and move the handle to the gear up position after first putting the A/C in the “Air” to be able to move the lever. This involved fully pinning the landing gear, then pulling over 50 CBs [on one type] to enable the A/C to simulate being in a weight-off situation before the baulk is removed to enable the lever to be moved up. Then a second camera inspection is carried out.

We were assuming the hook was coated RED and would be easy to spot. These fleet-wide inspections were expected to be carried out during normal turnaround times on the line, with no extra manpower or time, and with all the normal routine and non-routine maintenance continuing. Also, with all other agencies carrying out their tasks, cleaners, caterers, fuelling etc. Towards the end of the task, we had aircrew in the flight deck and all the usual “noise” of A/C departure preparations. (This quite normal).

I understand the broken hook has not been found. The first inspection [on a second type] took 6 hours, again on a normal turnaround. As the engineers carrying out these inspections, we asked for the aircraft to be moved to Base for the inspections. We asked for dedicated teams of engineers separate to the routine work to be used. We suggested overtime to be called to facilitate this. We asked for longer turnarounds. None of these questions were answered or acted on.

I personally voiced my objection to all of the above and especially to how they were allowed to keep flying the A/C with this potential FOD hazard. All fell on deaf ears. There is a lot of speculation as to how we ended up carrying out this maintenance on the line and that the fleets were allowed to continue flying. I believe the maintenance should have been much better planned and organised, and possibly not carried out on the line. If an A/C had ended up on its nose, we as engineers would have carried the FULL weight of blame immediately for sure, my main concern is how the A/C were allowed to continue to operate. What were the processes that justified this decision?

CHIRP Comment

The operator was contacted with the reporter’s consent. After considerable time, during which a number of attempts to receive feedback were made, no response was received. Did the last user of the tool notice it was missing a part? If so, presumably it should have had an unserviceable tag attached on return to tool stores. The staff member in tool stores should have inspected the tool before placing it in its store location. One or both of these protections obviously failed. Should the maintenance record not have the tool serial number recorded in the same way a torque wrench is recorded for follow up if it does not perform as per the calibrated standard?

One can understand that once a decision was made to check both fleets of aircraft then it should be carried out as soon as possible. However, the risks should have been assessed and would likely have required more manpower and/or staff seconded from Base to assist or carry out the work, leaving the Line staff to continue their normal duties. The dangers of time pressure and also distraction by the procedures carried out by various others prior to departure are well understood. Planning was obviously less than helpful to say the least. From a Human Factors perspective, we are looking at examples of Complacency, Communication, Pressure, Resources, and Distraction.