I fly frequently on business and always carry my laptop, Blackberry phone and sometimes my tablet with me. The cabin crew always say to turn off and put away all electronic items for take-off and landing. What is the reason for it ?
Question asked by Jane.
We have become so dependent on computers and small electronic gadgets, that it is now difficult to live without them. A few months ago I misplaced my Blackberry, but fortunately I found it after three days. It was like loosing my right arm.
Electronic items like laptop computers, cellular phones, tablets, games and many others emit electromagnetic field, whenever they are turned on. This is even if the transmitting functions of these devices are turned off. Some items emit stronger electromagnetic field that others. Due to electromagnetic interference (EMI) with aircraft electronic systems, their performance and operation may be adversely affected. Autopilots and Flight Guidance systems are of primary concern, particularly when an airplane is in critical phase of flight, like take-off and landing. There have been reports of malfunctions of cabin pressure control systems, brake and anti-skid control and other aircraft systems, which have been suspected due to electromagnetic interference.
Several years ago one of these incidents occurred on one of my flights from Toronto to Europe. Half way across the Atlantic ocean the cabin pressure became erratic. I asked one of the flight attendants to check if anyone was using any electronic devices. She found, there was a gentleman near the front of the airplane using a calculator. I asked her to explain to him what was happening and if he would turn it off. Sure enough, after he turned off the calculator cabin pressure became stable again.
With so many electronic products on the markets today, it is impossible to test each one of them, during its normal operation, as well as if the item malfunctions, to determine what effect it would have on all airplane systems. Therefore, as we always do in aviation, it is always better to be conservative and to err on the safe side. This all comes down to a simple rule; all portable electronic devices must be turned off prior to take-off and landing.
Perhaps in the future this may change, as electronic products are designed better and produce less electromagnetic emissions. A lot of airplanes in the sky today have been designed 20 or more years ago and use technology of that time. Systems in new airplanes will be designed to be less susceptible to this kind of interference.
At altitude, in cruise flight, use of electronic items is allowed. In this phase of flight a possible malfunction of an aircraft system is not as critical. There are some systems now and others in development, that will turn an airplane cabin into a wireless hot spot and passengers will be able to use Internet during the flight. Also there are a few airlines and others are in a trial stage, where pilots use tablets to access all navigation charts, airplane and company manuals. If tablets will replace all paper books and manuals carried in each flight deck, a weight saving of 100 kgs or more could be realized. This translates into fuel savings, as well as lower carbon emissions.
A bit more about Captain Dan:
Captain Dan Baz enrolled in Flight School at the age of 16.
He has completed studies in Aircraft Engineering and Master of Business Administration. He has been at the controls of many different types of aircraft, from single engine Cessnas to large intercontinental jets on global routes.
Over the last four decades he has flown thousands of hours up in the blue sky.
Have a question for the Captain ? Send it to Captain Dan Baz firstname.lastname@example.org Every week a question from the readers will be selected and answer posted in this column.