Flight mode, why do we need to use this when we fly?

Air travel is something that a great many of us get to do reasonably frequently.  For some, it is too often, for others it is not often enough. Whichever it is, we are all familiar with the various announcements that are made on-board, particularly this one...

"At this time, make sure your seat backs and tray tables are in their full upright position and that your seat belt is correctly fastened. Also, your portable electronic devices must be set to ‘airplane’ mode until an announcement is made upon arrival. Thank you.”

Most of us dutifully obey the instruction and reach for our device(s) switching them either off, or to the particular phone maker's version of Flight or Airplane mode.

It wasn't so many years ago that the devices had to be turned off completely from the moment you arrived at your seat until such time as the aircraft reached a certain altitude. We were led to believe that our mobile devices would interfere with the aircraft's systems and it was very much in our own interests to keep those devices switched off.

I always used to have visions of some 10-year-old kid in row 36 who managed to get his game controller linked to the flight controls and then take us through some barrel rolls and loop-de-loops.

Your new pilot, the kid with the game controller.

Things have changed a little now. Your mobile phone can be left on, with most airlines, for the whole flight and the only concession you have to make is to ensure it is in Flight Mode for the duration of the trip. This is of course only for devices weighing under 1 kg. Not because they emit a stronger signal or anything, but because they can become seriously dangerous projectiles in the event of the aircraft performing extreme maneuvers.  So you will be asked to stow those during take-off and landing.

Ok, so back to the Flight Mode question. Why do we still need to use flight mode during the course of the flight? Various sources indicate that the effect of a mobile phone or cell phone on an aircraft's flight instruments is fairly negligible. Aircraft instrumentation is state of the art as you would expect from a unit costing tens if not hundreds of millions. There are so many systems with many kilometres of wiring throughout the aircraft that need protecting from each other, never mind your mobile device. These systems are fully shielded so that attenuation or interference from outside sources cannot corrupt signals sent around the systems.

So does that mean we can go ahead and just ignore the request for flight mode from the crew then?  Not quite. There is still relatively old technology used by the flight crew. The radio. No, not the one tuned to the football, but the one used in the all-important communications with air traffic control. The giving and receiving of instructions is still done using the good old radio waves.  Mobile devices depend on microwave towers or other ground stations to provide them with the required signal to enable them to provide you with information and other services you depend on. As you can imagine, these towers get harder and hard to find as you are cruising 11 kilometres up, perhaps over sea or desert.  Your phone, being the faithful servant that it is, tries harder by cranking up the signal strength to as much as 8 watts in an effort to enable you to view those all-important food and puppy shots.

So what, I hear you say. Well, cast your mind back to the days when mobile/cell phones switched from analogue to digital signal. When you got your new digital-enabled phone, you found the signal and call quality were nice and crisp. However, if you were ever on a call near someone with an analogue phone, you knew all about it.  It sounded like your ear was being ripped apart. This is what it can be like for the pilots, maybe not quite as extreme, but an annoyance never the less.

Let's face it, if the use of mobile/cell phones was of major concern to flight safety then you can rest assured that leaving the responsibility of ensuring the devices were turned off would not be left to the travelling public.  There is no doubt that on every flight you will find a number of devices that have been left on during a flight either due to forgetfulness or laziness.

Whether it is safety critical or not, we want our pilots to be as relaxed as possible. We want them to be able to hear and be heard when they talk to the ground without the possibility of interference blurring any flight direction instructions.  So complying with the flight mode instruction still carries as much weight as it ever did.

What Does Flight Mode Do?

The control centre on your mobile or cell phone.

The flight or Airplane mode function on your phone or other radio-equipped device is the main control switch to turn off all radio-enabled functions on your device. On your typical mobile/cell phone, this includes voice/text, data (3g, 4g, 5g, etc), Bluetooth, and Wifi. You also have GPS but this doesn't actually send anything, it sits there and listens for satellite signals and then translates them into something you understand by showing it on a map. Without data, however, you won't get your map presentation so having GPS can be as useful as an ashtray on a motorbike.

For a few years now several airlines have been trialing and supplying Wifi onboard their aircraft. What this means is that you have the ability now to connect to the aircraft's onboard Wifi service and enjoy surfing the net and checking your email in the same way you can do at an internet cafe. "So hang on", I hear you say, "I had to put my phone in Flight Mode, so how can I connect using Wifi?" Very good question and by the way, bravo for putting your phone in flight mode. As I said, Flight Mode is a master switch for turning off all radio-related functions on your cell, mobile, tablet, or laptop. Once they are all off you can turn individual functions back on. So seat belts on, Flight Mode on, and then wait for the announcement that Wifi service has commenced and turn just Wifi on.

The Wifi signal is much weaker than your main mobile or cell call signal as it only needs to talk to a device mere metres from your seat to get a connection. This is not going to scream in the pilot's ear so everyone is happy.

Personally, I have mixed feelings about onboard Wi-Fi. I've always seen flying as a few hours you can step off the planet and leave your responsibilities behind with a good excuse for doing so. You know what I mean, let them miss you a little. Now I'm sure that corporate travellers will be expected to connect up and be available online or get that project completed because all resources are available. No peace for the wicked.

Flight Mode as we have seen is not going to make or break your flight as far as we can tell, but let's show some consideration for the pilots who have to talk over the interference. Your phone charge will last a lot longer in Flight Mode, so everybody is happy.

Fly safely and LIKE us if you do.