Have you wondered why there is an Airplane mode on your mobile phones? This mode on your smartphone is a simple way to switch off all radio transmissions and receptions without hindering any other feature of your phone. Switching off all mobile communication is mandatory during flights. Earlier phones did not have this feature, and we had to switch off phones.
But then those phones were only meant for telephone calls, not ‘smart work.’ Today, we do much more with our smartphones, which may hinder our health, privacy, and quiet times.
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Air Travel and mobile tech
The first thing the air service personnel announces is switching off or putting our phones in Airplane mode. Such announcements were not made on flights some 30 years ago. Then mobile technology had not yet evolved, and the aircraft were also not as sophisticated.
Today, we have technology extensively using wireless radio frequency (RF) communication. One such is Flyby Wire, which uses telecommunication technologies to control actuators and sensors on aircraft. This technology has reduced the weight and increased the speed of response of various actuators and ease of operation for the pilots.
No longer are metal wires running across the floor of your aircraft to these actuators, nor are their motors driving the actuator motors. Everything has been replaced by electronics and solid-state silicone devices, easily controlled by RF modules. As you can see in the block diagram of a typical flyby wire system, there are ample opportunities to incorporate several other automation devices to reduce human intervention, making the aircraft much more stable and reliable.
How does Flyby Wire function
When the pilot moves the control stick and operator other switches, electronic sensors and microcontrollers receive and interpret these inputs and send out electronic (wireless) signals to actuators.
Actuators like elevators and rudders respond and move the control surface accordingly and send out feedback via wireless signals.
An overall feedback system is constantly working to keep the system in a stable condition, which also leads to precise operations.
Does the flyby technology get affected by mobile signals?
This technology is found on most modern aircraft, designed and tested by the most sophisticated and accurate test setups. This electronic equipment is shielded from RF interference and does not interfere with other electronic equipment outside their systems. These systems are designed to handle RF signals, noise, and other glitches in the onboard electrical and electronic systems and undergo a strict approval process.
Some of the design considerations to shield this equipment and regulatory aspects are:
Elaborate EMI/EMC design
All systems use shielded cables and components to shield them from ‘Electro Magnetic Interference’ (EMI). These systems are immune to RF signals of any kind near them. This also means they will not be affected by mobile signals!
Nor do the signals from the Fly-By-Wire system affect other components and equipment around the aircraft; they are designed for Electro Magnetic Compatibility (EMC).
Aviation safety standards are met.
All aircraft systems, including FBW, comply with safety standards like FAA (Federal Aviation Administration), EASA (European Union Aviation Safety Agency), and DGCA (Directorate General of Civil Aviation). These standards ensure the critical systems in the aircraft are immune to external RF sources, which include mobile radio signals.
Risk from Mobile devices
The RF emissions from a mobile are normally low power and very unlikely to interfere with the FBW system, though they may affect it indirectly. Despite this, when numerous mobiles are operating, the cumulative effect of all RF signals can affect non-critical systems like ATC communication and navigation. This is why airlines ask passengers to switch off or put mobiles in airplane mode as a blanket requirement.
Conclusion
While the RF signals from your mobiles do not affect critical systems on board a plane, it is wise to consider the following:
- Switching phones off does not emit RF waves, which has been found to reduce stress in humans!
- Switched-off mobiles give us time for other tasks! Mobile addiction is another type that is rampant these days!
- When there is no signal from the tower (which is the case on aeroplanes), the mobile continuously searches for a non-existing signal. Also, it increases its transmitter power, thinking the base station signal may be far off, thus draining the mobile battery.
- During takeoffs and landings, the altimeter comes into use and operates at frequencies around 4 GHz, close to that of mobile frequencies of around 5 GHz. There is a chance that the error will be introduced.
So it is wise to be prudent! For a better and safer journey.
