69

Short answer: ILS is rather sensitive to interference and not all electronic devices take much precaution in avoiding the generation of interference. The pilot wants to be sure that the readings he's getting on the localizer and glideslope are accurate, since he can't actually see the runway to verify the final approach path visually. Longer answer: ILS is ...


50

Most modern aircraft, which includes long range airliners since around 1970, all airliners since not much later, and basically anything with glass cockpit, do have very accurate accelerometers for all three axis, as part of the inertial reference system. They are important instruments for the autopilot, as they provide faster feedback on the effect of ...


31

Why aren't cell phones allowed?/ What problems to cell phones cause? Most of these cases apparently originate from a series of unexplained events in the 90s which were believe to be caused by electronic gadgets, hence the ban. This was when cell phones appeared, and there was an aggressive ban as a result. NASA has a list which includes some of these and ...


19

You can read this related question if you want to learn more about the interference between electronic devices and airplanes. An answer there links to a very good document written by NASA on the topic. Long story short: Electronic devices are complicated. Airliners are complicated. Therefore, we can not predict exactly what the interference between them ...


18

Because it says "drag", my guess is that implies an external antenna. For example (which I found using a Google search), Commercial and Large VIP Aircraft Broadband Internet Solutions HR6400 Antenna System The HR6400 antenna system for commercial and large VIP aircraft provides passengers and crew true wireless broadband Internet access. No matter ...


18

Having worked as a software engineer on the lateral guidance subsystem of the FMCS (Flight Management and Control System) for the Airbus A310 about 30 years ago I found @reirab's answer fascinating. I can fill in some gaps as to how the information from the different systems is used and why the ILS information is particularly critical. On the A310 3 sets ...


16

Relatively short answer Cospas-Sarsat: Feasible but... It's possible, but there are many individual elements involved. It's a matter of probability that most of the time there will be a combination preventing the link to work. If you know what to do and take care of ensuring a good direct line of sight (LOS) you may be able to avoid some of these ...


16

There is a pretty great article on the design of the 777 electrical system here. Power for avionics needs to be clean to ensure there are no spikes or dips that would cause avionic failures as this could lead to otherwise avoidable emergency declarations. The avionics and passenger power systems are two completely different systems. The 28V ...


15

Several of the answers here seem to suggest that this only happens in first or business class. While that was historically true, it's not so true anymore. Airlines such as Cathay Pacific and Korean Air, for instance, have them at every seat in most (or all?) of their long-haul aircraft. Delta also has it in parts of economy on several of their long-haul ...


15

On the Embraer 170/190-series, the normal display layout is as follows: There is an automatic display reversion logic when one or more panels fail. The following image shows this logic: There is also a manual reversion switch located near each pilot's outboard knee, which controls what is displayed on the panel: All images sourced from an Embraer Airplane ...


14

I am a private pilot, and sometimes, the cellphones cause interference with the radio. Most of the time, cellphones are not a problem, but once in a while, I have to turn mine off because it is causing parasitic noises on the radio. I don't know how bad it would actually be in a passenger aircraft. But if it is similar to my experience in small aircraft, ...


14

Yes there are standards. There are industry standards which not regulatory standards, but they have been deemed acceptable by the regulatory agencies (e.g. FAA). So following them is usually accepted without issue. The FAA also provides guidance in the form of an Advisory Circular, AC 25-11B Electronic Flight Displays. You have two separate things to ...


13

AC to AC conversion with frequency change from 400 Hz to 50/60 Hz is obtained by transforming AC to DC first (usually to 28 VDC to be compatible with batteries) and then using a static power inverter to convert from DC to AC. The inverter performs the voltage transformation in the same step. From an EASA certification perspective, electricity quality is ...


11

Cribbing liberally from Manfred's answer on a related question, it basically works like this: The airline contracts with a communication company and installs satellite transceivers and "small cell" cellular equipment on their aircraft. Your phone talks to the on-board cellular equipment just like it would to a cell site on the ground, but the information is ...


11

This depends on the airline, but to answer your question: Yes, some airlines do have electrical outlets in the cabin. It seems that since the FAA relaxed the rules on portable devices that the airlines are seeing the need to add them to more of their fleet. For example: US Airways has a Business Tools webpage which tells which of their aircraft have ...


11

Yes, they have done a lot of testing, hence why they now finally realize that most electronics are of no harm, and you can use them. The FAA announcement page has a link to a fact sheet of their report, as well as a link to the PDF of the report. In addition to the FAA report, other agencies have weighed in (such as Boeing). Basically, the rules were ...


10

Three reasons I can think of: It's easy to detect the general presence of a specific transmitting device (a WiFi antenna, say), but very hard to precisely localize it. They could tell if there's one on the plane, but someone with a very sensitive piece of equipment would have to walk up and down the aisles pointing it at people to actually find it in ...


10

Flight controls are pretty hard to break For the 747 (at least through the -400) specifically, the controls are entirely hydromechanical, so yes, they will work without electrical power. In general, all non-FBW airliners are this way. FBW airliners vary, though. All FBW Boeings and the first generation FBW Airbii (A320 family, A330/340) have ...


10

If you are emitting RF, you can be seen. There are two ways to emit RF: 1. Transmit (or leak) a RF signal, and 2. Reflect a RF signal. A jamming device emits (usually) high amounts of RF, with the general idea that the receiver of someone's radar unit will be desensed or otherwise overwhelmed by the signal. Like putting a multicolored sun into a small ...


9

I have a SPOT Beacon that I use for occasional adventures: mostly flying small planes and kayaking. But its small enough I generally carry it with me when I fly commercial. Because it connects to satellites, no one needs to be nearby to "hear" it. I can press the SOS button most anyplace in the world and summon help. There are some remote parts of the ...


9

There are multiple aviation headsets approved by the FAA that have built-in Bluetooth. Based on that, I'm going to say that this has been tested and will not interfere with the aircraft avionics. Radio/EMI testing is part of the testing that any device approved by the FAA for use in an airplane must go through.


9

There are numerous unclassified papers talking about LOC, GS, MLS and other navaid jamming. There are also instances of that happening, both intentionally and unintentionally. The issue with consumer electronics is made worse is that local consumer electronics on the plane can have local oscillators in the receivers. They are small signals, but they are ...


8

Adding to Reirab and Brian Towers' superb answers on this topic: There are several ways an electronic device can interfere with aircraft operations, but the likelihood depends on age, aircraft design factors, and the nature of the EMI aggression (frequency, modulation type, and power -- there are also broadband EMI sources on aircraft, but we can safely ...


8

It is important to distinguish the streaming of media from the on-board server, and an internet connection to the outside world. The first is just a matter of setting up an access point inside the cabin that wouldn't have any impact on the drag. The latter requires some sort of antenna that probably needs to be placed outside to achieve a decent ...


8

Apart from Manfred's answer, there are other factors in play: Airlines make quite a nice income from the payphones in aircraft Cellphone towers typically have pretty bad (if any) reception straight up, they're designed for ground level use after all which dictates the design of their antennae (an omnidirectional one is a lot less energy efficient) People in ...


7

Cell networks require that cell towers be able to distinguish between signals coming from phones which are within the zones served by the towers, and those coming from phones in more distant zones. There are nowhere near enough radio frequencies or time slices to allow every zone in the US to have its own combination of frequency and time slice. In general,...


7

A EFB is a legal replacement for paper charts and you are not required to carry backup if you are operating as part 91 single engine piston. Advisory Circular 120-76B is in reference to part 91F (Large and Turbine-Powered Multiengine Airplanes). AC 91-78 is aimed at Part 91 operators, VFR or IFR and states that EFBs can be used in all phases of flight in ...


7

Maneuverability with this kind of drone comes with their small size and high thrust-to-weight ratio. When you scale such a dynamic system, the time scales with the square root of size, so the smaller the drone, the higher its agility. Can it do automatic stall recovery? No, because it never stalls. Can it do aerobatics? Only figures which are possible with ...


7

I think you need to define "modern" aircraft, the question is pretty broad as-is. And even interpretation of what you mean could vary. i.e. are you referring to a real time dial showing actual Gs in the cockpit? As quiet flyer noted, as a reference instrument an accelerometer is very important for aerobatic flight. However, while a real time ...


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