Language
of air travel: How traffic control keeps you safe
Nine instances of "pilot error" in Hong
Kong last year are being investigated, but they rarely impact
safety.STORY HIGHLIGHTSHong Kong Civil
Aviation Department reports pilots disobeying traffic control
ordersTraffic controller admits errors occur on "daily basis,"
often due to language barrierTechnology helps avert errors, but
most important is trust between pilots and controllers(CNN) --
Events in Hong Kong in 2013 served as a reminder that pilots are human,
too.Hong Kong Airlines was involved in nine incidents in which pilots
apparently disregarded instructions from air traffic controllers (ATCs),
including a plane taxiing onto a runway without permission and failure to follow
instructions about altitude and direction.
Hong
Kong's Civil Aviation Department is still investigating those
incidents.
Other recent cases of miscommunication between pilots and ground
controllers include:
*
July 2010: The captain of an Air Blue flight disregards instructions from
traffic control and crashes into mountains near Islamabad, killing 152.
*
June 2013: Two Boeing 747s narrowly miss colliding over Scotland when one plane
turns right and the other left -- effectively doing the opposite of ATC
instructions.
* December 2013: A British Airways jumbo jet crashes into a
building at Johannesburg airport when the pilot goes down the wrong
taxiway.
According
to Ady Dolan, an air traffic controller at London Heathrow Airport who spoke
with CNN for this story, human errors between pilots and air traffic controllers
occur on "a daily basis."
But while common, most errors go unnoticed and are
of no threat to safety, thanks to established systems of communication and
technology.
English
... but whose English?
English is the language of the skies.
According
to Dolan, controllers at Heathrow deal with 85 airlines and 1,350 flights a
day.
Controllers need to be able to communicate with pilots of many different
nationalities, he says.
English is the language of aviation and vital for
pilot-controller communication.
"We're
lucky that English is the language of the air," says Dolan. "If English is not
the pilot's first language and they only come to Heathrow occasionally, we need
to afford extra care to that pilot.
"We can't speak with speed and
abbreviation as we would to someone who comes here several times a day."
A
pilot who often flies to China and Southeast Asia, and who spoke with CNN on
condition of anonymity, says pilots and air traffic controllers generally enjoy
a good relationship, especially in Hong Kong where ATC standards are high.
"But
China can be a bit of an issue," he says. "We should all be speaking English,
but for a lot of people it's their second language."
The
pilot says airlines have varying policies on recruiting pilots with good
English, and this can cause problems.
Patter
and chatter
The International Civil Aviation Organization (ICAO), a United
Nations agency that sets and regulates standards of air safety, says
standardized phraseology is an important part of pilot-controller
dialogue.
For example, before the 1977 KLM-Pan Am crash, the pilot reportedly
told traffic control, "We are now at takeoff" as he moved down the runway.
The
controller understood this to mean the plane was ready to take off, but was
still stationary and waiting for further instructions.
At
any airport if you have humans involved there are going to be errors.
For
this reason the controller didn't warn the pilot about another plane on the
runway, which was obscured by thick fog.
"Pilot
and air traffic controller radiotelephony communication is an important part of
training leading up to licensing for both functions," says an ICAO spokesperson.
"ICAO guidance requires that both controllers and pilots use standardized
phraseology in their communication exchanges.
"ICAO is continuously reviewing
and updating its standardized phraseology guidelines to better meet the needs of
the air transport system and ICAO language proficiency requirements have been in
place since March 2008."
The
relationship between controllers and pilots functions well generally, says South
African Airways pilot Sarah Jones, who flies across South Africa and
Africa.
"There
are lots of structures in place to try and prevent miscommunication between us.
Obviously, there has to be trust," she says.
While
Jones says ATC standards are high in airports such as OR Tambo in Johannesburg,
they're not as good at some other African airports.
She
says it can be challenging when controllers and other pilots don't speak
English.
"You have to be very vigilant, listening to the other traffic and
having good situational awareness," she says. "It's an issue when they are
speaking, say, French or Brazilian, and you can't understand what other pilots
are telling ATC in airports where you would be more naturally cautious
anyway."
Human error inevitable
Pilot
errors are common, says one air traffic controller, but rarely dangerous or even
noticed.
Pilot errors are common, says one air traffic controller, but
rarely dangerous or even noticed.
Errors that occur as a result of
pilot-controller misunderstandings are normal, but go largely unnoticed by
passengers, according to the pilots and controllers interviewed for this
story.
As
air traffic increases, so does the potential for poor communication.
That's
why it's important to have solid backup procedures in place, says Heathrow air
traffic controller Ady Dolan.
Dolan
works for UK-based NATS, a provider of air traffic services in the UK and more
than 30 other countries.
The
company also provides strategies for dealing with potential problems.
"At any
airport if you have humans involved there are going to be errors," he says. "Our
job as an ATC provider is to spot the potential for that error before it takes
place and then when it does happen to have mitigations in place to correct
that."
He
says typical errors might be "simple," like a plane ending up facing south
instead of north on a stand.
"Safety
has not been compromised, but you as an ATC need to have in mind the aircraft
may end up facing south instead of north. It's the kind of human error that
takes place on a daily basis; it has no impact (but) is not noticed."
The
pilot who flies to China and Southeast Asia says the nature of flying and human
beings means "dozens" of small mistakes are made regularly.
"There are
mistakes, but we are there to manage it and that's where standards of training
and checking and a rigorous operating procedure come in," he says. "It means you
can get on the deck with a pilot you have never flown with before.
"It's only
a minor risk, but there is always the potential for things to go wrong and to
escalate into a position where things could be harmful.
"That's why it's
positive that cases like the ones in Hong Kong have come to light and are being
investigated.
"As far as ATC goes, if they tell you to descend to a certain
level, one pilot sets the level and the other gets the reading and repeats it
and then the other repeats it again. It's a system of double checking.
"That
doesn't mean we never have 'altitude busts' [aircraft descending to altitudes
for which they aren't given clearance] but there is very good backup with
Traffic Collision Avoidance System and Ground Proximity Warning System."
Sarah
Jones agrees on the potential for errors.
The aircraft may end up facing
south instead of north ... it has no impact (but) is not noticed.
"If ATC
gives you a climb instruction and a heading instruction you could get those
confused," she explains. "That's why you always have one pilot flying and one
monitoring.
"Mistakes can happen regularly but they get corrected quickly. If
there is any possible confusion you always double check with ATC quickly, that's
the system."
Electronic
communication replacing human contact
The daily process of handling weather,
delays, spacing aircraft evenly for landing and takeoffs and squeezing maximum
capacity for runways is getting more complicated.
Sarah Jones says that the
balancing act between safety and keeping traffic moving is maintained by mutual
respect.
ICAO also believes the potential for things to go wrong can be
handled.
"The role of effective communication has long been considered a key
component of safety," says the spokesperson. "ICAO has dedicated and continues
to dedicate much effort and resources to ensuring our guidance in this area is
comprehensive and aligned with operational needs."
The increasing use of
technology over human voices to communicate with the flight deck offers one
solution.
For
example, Heathrow conveys electronic clearances for takeoff directly to the
flight deck. Even so, it's unlikely we'll see computers completely taking over
traffic control in this generation.
"You've got to be able to trust the
information that is being passed to you or the whole system falls apart," says
Dolan. "If the pilot is in any doubt as to the safety of the instructions and is
having to second guess things you know you are in a bad situation."
