The Weekly Reflektion Week 38 / 2020

High workload for the operating staff can be a major issue that can lead to incidents and accidents. People are often determined to do a good job and satisfy the customers; however, if they feel they are under pressure, they may start to improvise and find ways of doing the work quicker. Shortcuts became common place and the safety margins start to be eroded. A serious near miss may focus the organization’s attention on what is important before someone is hurt. Unfortunately, it may not be a near miss, and someone gets killed.

When your organization is under time pressure, do you or the people working for you improvise and/or take short cuts? What do you do when you find out that your safety margins have been reduced when you cut the corner?

XL Airways Germany Flight 888T was an Airbus A320 which crashed into the Mediterranean Sea, 7 kilometres off Canet-en-Roussillon on the French coast on 27 November 2008. All seven people on board were killed.

The aircraft was owned by Air New Zealand and had been leased to XL German Airlines in 2006 for a 2-year period. The aircraft was due to be delivered back and before New Zealand Airways accepted the aircraft it had to be repainted in the New Zealand Airways colours. Following this work the aircraft was to be subjected to a flight test to ensure all the systems were working satisfactorily.

On the Airbus 320 there are three Angle of Attack (AoA) vanes. These vanes measure the pitch of the aircraft and provide information on the aerodynamic lift to the flight control computer. During the painting and water washing of the aircraft the AoA vanes were not protected from ingress of water. The maintenance manual required that these vanes be fitted with protection caps during any washing.

The flight tests started 3 days after the painting and were to be carried out in congested airspace. The schedule for the tests was tight and the crew were under pressure to complete on time. One of the tests is to verify that the stall protection on the Airbus 320 was working. The crew raised the nose of the aircraft and reduced speed. The flight control system would normally register conditions approaching a stall and automatically take action to compensate. However, two of the AoA vanes registered that the aircraft had a level pitch and sufficient aerodynamic lift. The third AoA vane registered the correct pitch and the potential stalling condition. The computer was designed to select two of three signals in the event of any discrepancy and disregarded the correct signal. The computer did not take any action and the aircraft crashed.

The crew had carried out some tests at high altitude and the low temperature had frozen the water in two of the AoA vanes and locked them in position. The crew was not granted sufficient air space to complete the tests and they were on their way back to the base. They decided to improvise and carry out the tests anyway. Unfortunately, they were flying at only 3000 feet while the test procedure stated it should have been carried out at least 10000 feet. When the flight control computer failed to react to the stall the crew did not have enough time to recover the situation as they would most likely have done if they had been flying at 10000 ft.

The XL Airways German captain and first officer and the Air New Zealand captain on board witnessing the tests all had extensive experience with the Airbus A320. This may have made them overconfident about the aircraft’s automatic stall control and hence their willingness to take a shortcut in the test procedure. They expected the test to be OK.

A test flight that replicated the XL Airways Germany Flight 888T conditions was carried out as part of the accident investigation. The AoA vanes froze and the flight control computer did not respond to the imminent stall when the stall test was initiated. The test was carried out at 10000 feet and the crew recovered the situation and landed safely. During the replication, an alarm appeared on the flight control panel that indicated the flight control computer was receiving conflicting information. The alarm was requesting the pilot to take over control of the aircraft and sort out the problems manually. This alarm was not covered in training and flight simulations. The crew of XL Airways Germany Flight 888T did not react to the alarm and even if they had they may not have known how to respond.

Don’t take short cuts when working with hazardous materials in hazardous conditions. Take the time you need to plan and carry out the job safely and effectively. If something unexpected happens, you are uncertain or there is a dangerous condition, then Stop the Job.

Reflekt AS