When air traffic controllers gave pilots the wrong orders, a jet carrying 180 people came within six feet of crashing into a field near Paris, it has been discovered.
On May 23, the Norwegian Air Sweden flight from Stockholm to Charles de Gaulle airport experienced an incident while the pilots were attempting to land in dense cloud using only their cockpit instruments.
When they set up the instruments, a French tower worker who spoke to them in English gave them the wrong reading, which meant that the plane was actually 280 feet closer to the ground than the on-board computer had indicated.
Fortunately, pilots chose to abort the landing when they couldn’t see the runway’s lights.
They were only 6 feet off the ground at the moment, something they were unaware of.
The incident happened on May 23 at around 11.40 a.m. local time, according to BEA, the French air accident investigator.
The Airbus A320 carrying Flight NSZ4311, from Stockholm Arlanda to Paris Charles de Gaulle, was coming in for a landing when the near-miss occurred.
They received landing instructions from a French-speaking air traffic controller speaking to the pilots in English around 11.30am, when they were about 5,000 feet above the ground.
However, the controller unintentionally gave them the wrong reading for “QNH” while they were reading the instructions.
The on-board altimeter can determine the plane’s height above the ground thanks to the QNH, which provides information about where sea level is.
The controller informed the pilots of a reading of 1011 rather than the accurate reading, which was 1001.
It meant that the plane was actually flying 280 feet below the altimeter’s reading from that point forward.
Then, when they couldn’t see the ground and had to rely on instruments to guide them, pilots tried to land in dense fog and pouring rain.
The pilots believed they were 300 feet above the ground ten minutes after the incorrect reading was reported, but they were still unable to see the runway’s landing lights.
They were only a few feet above the ground, but the runway was a mile ahead of them, and they couldn’t see the lights.
The pilots chose to execute a go-around after abandoning the landing because they felt something was wrong.
The tower radioed at the same time to report that an altitude warning signal had activated and to inquire as to whether they were in danger.
The pilots replied that they did not receive a warning signal but yet chose to forego the landing.
Equipment revealed that the aircraft was just 6 feet off the ground when the captain pulled it out of the landing, not the 286 feet that the pilots had been told it was.
Amazingly, the mistake from the initial landing wasn’t fixed, so the altimeter was still off as the plane circled for a second attempt.
Fortunately, during the second landing, the mist parted just enough for the pilots to see the runway; they then altered course and landed safely.
Air investigators discovered that the same tower controller—who was also speaking in English—had provided an inaccurate reading to an incoming EasyJet flight at roughly the same time as the Norwegian flight.
However, in that instance, the pilot misheard the reading and returned the right one, which the tower was unaware of.
A third plane received the right QNH reading from the same controller, who was this time speaking in French.
The recommendations made by the investigators were for the air traffic services to “immediately ensure that controllers are aware of the importance” of providing the proper altimeter values.
Additionally, they advised airlines to enhance their processes for verifying the readings that are provided.