Alps crash calls attention to Airbus safety history

The crash of the Germanwings flight in the Alps on Tuesday has focused attention on the safety record of the French aviation company Airbus, which manufactured the A320 plane.

Experts have pointed out similarities between the crash that killed 150 people and another incident involving an Airbus flight last November.

On that occasion, data from malfunctioning sensors triggered a sudden plunge by an Airbus plane shortly after it had taken off from Bilbao, in northern Spain.

The A320 plane, operated by German airline Lufthansa, unexpectedly lost height after its automated systems misinterpreted data. In that case, the plane had been flying on autopilot when the pilot noticed one of the displays was “increasing unusually rapidly”, according to the German Federal Bureau of Aircraft Accident Investigation.

The display was reporting the plane’s “angle of attack” information, which concerns the alignment of the wing line and flight path. But the sensors were giving incorrect data. That faulty data triggered the activation of the aircraft’s ‘Alpha Protection’ system, which usually prevents stalling and the effects of wind shear.

When this was combined with other technical information, the plane responded by automatically ordering “a nose-down pitch rate”, which meant that in effect it went into a dive. “The nose of the airplane dropped further and the copilot counteracted this movement with the sidestick,” noted the report. “The copilot stated the airplane did not respond as expected and continued to descend.”

Frozen sensors
For at least 45 seconds, the pilot battled to stop the plane from dropping any further, as it plunged about 1200m. Only when the controlling sidestick was pushed as far back as possible were the plane’s systems overridden to allow it to fly horizontally again. It subsequently emerged that some of the plane’s sensors had frozen shortly after take-off and only defrosted as the plane came into Munich to land.

At the time, Airbus issued an “operational engineering bulletin”, which is a rapid-response temporary notice sent out by the manufacturer to the users of an aircraft. On December 14 2014, the European Aviation Safety Agency also sent out an emergency directive for overriding the “undue activation of Alpha Protection” for Airbus planes. The directive warned pilots to switch off sensors if they malfunction.

Some aviation experts believe that as plane operation systems have become more sophisticated, pilots have become increasingly dependant on them.

This can lead to serious difficulties if the systems develop a fault, as was the case with a 2009 Air France crash. In that case, an Airbus A330 crashed after leaving Brazil for an overnight flight to France. Frozen sensors led pilots to misinterpret the situation and crash the plane into the Atlantic. All 228 people on board were killed.

In October 2005, a British Airways Airbus A319 had a “major electrical failure” as it was leaving Heathrow on its way to Budapest. “This resulted in the loss or degradation of a number of important aircraft systems,” noted the subsequent Air Accidents Investigation Branch report.

Radio lost power
According to the report the pilot tried to transmit a mayday call to air traffic control but it was not received because the radio had also lost power. In this case, the pilots were able to reboot the systems and the plane continued its journey.

Airbus is responsible for manufacturing some of the most popular aircraft in the world, which log millions of incident-free hours in the air every year. It has delivered about 6 200 short-haul and medium-haul jets in the A320 group.

The Germanwings plane that crashed this week had been delivered to Lufthansa in 1991, three years after the first A320 entered service. The plane was transferred to Germanwings, and had flown about 58 300 flight hours in about 46 700 flights in the past 24 years. – © Guardian News & Media 2015

Subscribe to the M&G

These are unprecedented times, and the role of media to tell and record the story of South Africa as it develops is more important than ever.

The Mail & Guardian is a proud news publisher with roots stretching back 35 years, and we’ve survived right from day one thanks to the support of readers who value fiercely independent journalism that is beholden to no-one. To help us continue for another 35 future years with the same proud values, please consider taking out a subscription.

Related stories

‘SAA 2.0’: New deal provides a lifeline

Airline brought back from the brink as rescue practitioners and Gordhan agree to work on a rescue plan by the end of June

A French revolution in the making

France gave the world the word entrepreneur – and now it is giving the world entrepreneurs

Global investors are launching a climate plan to pressure gas emitters

The plan will focus on: improving governance on climate change, curbing emissions and strengthening climate-related financial disclosures"

SAA Airbus swap deal goes Nene’s way

Former finance minister Nhlanhla Nene left a bit of sanity behind as South African Airways retains financial stability.

Myeni fought SAA deal to bitter end

The chairperson of the airline apparently resisted until the 11th hour, but treasury put its foot down.

Treasury rejects SAA’s proposed aircraft leasing deal

The national treasury has officially rejected the controversial alternative Airbus deal proposed by the SAA board and its chair, Dudu Myeni.

Vaccine trial results due in December

If successful, it will then have to be manufactured and distributed

White men still rule and earn more

Women and black people occupy only a few seats at the JSE table, the latest PwC report has found

The PPE scandal that the Treasury hasn’t touched

Many government officials have been talking tough about dealing with rampant corruption in PPE procurement but the majority won't even release names of who has benefited from the R10-billion spend

ANC still at odds over how to tackle leaders facing...

The ANC’s top six has been mandated to work closely with its integrity committee to tackle claims of corruption against senior party members

press releases

Loading latest Press Releases…

The best local and international journalism

handpicked and in your inbox every weekday