# Tag Info

33

There is a technical reason for this. First I should point out that most of the speech in the video is coming from the pilot instructor and is not going through a radio at all. It it simply the sound right out of his headset. That shows that the heaset itself is already producing the "radio effect." Basically what you're hearing is all the frequencies below ...

31

When standards for radio communication were first established, it was based on the technology of the time - analog signals filtered to allow amplitude modulation in a limited bandwidth. Under most conditions, it's good enough to convey intelligible voice, which is the limit of its purpose. Time and technology have changed... theoretically, a digital system ...

26

156.8 MHz Crews don't listen to channel 16 of the marine band. Channel 16 is used by marine with FM, while a VHF aviation receiver demodulates only AM, and the upper limit of the VHF band for aviation is 137 MHz. Channel 16 is monitored by local marine agencies -- coast guards -- e.g. CROSS in France and USCG in the US. Aircraft are only required to ...

22

Electromagnetic waves propagate actually using different means at the same time: Space wave (direct line of sight) Sky wave. Ground wave (or surface wave) Space wave vs sky wave vs ground wave Note: Electromagnetic waves are not entirely understood. The terminology around ground waves varies with authors. Some authors don't make a difference between space ...

17

Long story short, ATC has no reason to contact you but if they were to try they'd probably use 121.5 (see below). You're not in their airspace and the whole purpose of that airspace is to ensure separation, so as long as you remain clear of it they won't be concerned about you although they'll probably report your position to the 747. As for your specific ...

17

Cellular communication has multiple issues: When a plane is up more than a few thousand feet, a cell phone would see, and try to talk to, multiple cell towers at once. At best, this is inefficient and overloads the cell network. At worst, the network can get confused and drop calls. (not something you want when trying to get ATC directions) When a plane ...

17

Can you physically make it work? Yes. But you have to have an adaptor that fixes several compatibility issues. Headphone impedance Impedance is usually referred to in high and low range. Military headphones are low impedance, 19$\Omega$. Civil aviation uses 300$\Omega$, high impedance headphones. Impedance matching is not vital, but can cause some ...

16

Numbering the radios that I can think of offhand in the old 747-100 and -200 aircraft that I used to fly produces: 2 VHF voice communications radios. 2 VHF navigation radio receivers for receiving VOR and LOC signals. The LOC frequencies are paired with UHF frequencies for receiving glideslope signals. 1 ADF (automatic direction finding) receiver. 1 HF (...

15

This is probably more a travel question than an aviation one, but I did some Googling of various aviation and travel sites and the consensus seems to be this: You can carry the scanner with you, but if you're unlucky and encounter the wrong TSA agent on the wrong day then you may be asked a lot of questions at security (the TSA's "Can I Bring..." tool seems ...

14

The safest way to refuel an aircraft is with everything turned off and the airframe grounded (or bonded) to the fueling system. This is often not practical (particularly for airliners), so a number of other rules exist to make refueling as safe as possible -- not using HF radio while refueling is one of them. So why is the HF radio singled out? Power, ...

13

FYI, the runway is supposed to be closed XXX with NOTAM when it is mowed. There is no FAA or FCC limit on constructing homemade airband receivers in the United States. You can also construct transceivers. As long as you do not sell a transmitter you are allowed to make and operate up to 5 of them. The exemptions covering low power transmitters are covered ...

13

No, it should not be used. Twin antennae, as you have shown, are balanced and fed into a balun (BALanced to UNbalanced) to feed the single transmission line to the receiver. Together, they provide the correct impedance for the aerial system. With an antenna broken, it is likely that the impedance of the circuit is wrong and therefore, the input to the ...

12

"two-way radio communication and navigation equipment suitable for the route to be flown", that last requirement being just wonderfully ambiguous regarding what you as a pilot may want or need … That statement isn't ambiguous at all. You can file and fly IFR with a transponder and a VHF comm radio if you can get controllers to issue you radar vectors for ...

12

Firstly, it is worth noting that the blocked radio transmission is only one point on a very long list of factors that caused the horrible accident on Tenerife. There is enough redundancy in aviation systems and procedures that a single fault somewhere in the system will [almost] never be enough to cause an accident. Weather, stress, a terrorist attack, ...

12

I have not heard the actual audio in context; I've only read the transcripts. However, from the transcripts, I see the timing between some of their calls as a bit confusing and unusual. 01:01:14 | MH370 | Malaysian 3 7 0 maintaining level 3 5 0 This is slightly odd, because 11 minutes earlier they were told to climb to 350. I do not think it is common to ...

11

For navigation and communication radios the feature of having a second readout that can be pre-set to the next frequency is useful since the next frequency is usually known in advance. Your next transponder code is a somewhat random number and the moment that you will get it is not as predictable as a frequency change. Therefore there is no need for a pre-...

10

What are the requirements for radio systems in aircraft? Generally there aren't any, at least as far as "being required to have radios". It is perfectly legal to fly around in most of the United States in a Piper Cub with no radios of any kind. Indeed, unless it's been retrofitted with one a Piper Cub would have no electrical system at all - so you would ...

9

Navigation receivers can be used as a fall back for regular VHF/HF radio transceivers Before data links, there were essentially two types of radio receivers in the flight deck, and this is still the case for most GA aircraft: "COM" used for voice communication, and "NAV" used to receive navigation signals. When COM transceivers fail, the pilot is left ...

9

As mentioned in comments radiocommunication includes all forms of radio links, hence includes cellular networks. Cell size A cellular network covering any land is not realistic, not mentioning water areas. Given the size of a cell, at most 20 km for GSM (1G/2G), and much less for UMTS/LTE (3G), this would lead to prohibitive costs: Continents represent ...

9

There is always a backup radio system as well as a several backup systems like for example a backup CWP (controller worker position) in case the primary fails. PANS-ATM (ICAO doc 4444) in chapter 2.5 SAFETY REVIEWS mentions that Operational and technical issues to ensure that: [...] communications, navigation, surveillance and other safety significant ...

9

In North America, just buy an air-band radio and listen to Raleigh-Durham tower all you like, or if your ham unit receives the aviation VHF frequencies, do that. Or find it on LiveATC.net It's only illegal to broadcast without authorization, not listen in.

8

Depending on the aircraft you could be looking at one of a few things. (source) On some older aircraft it may be the communications antenna for older style radios (pre UHF/VHF days). Most of these radios have been phased out for some time but you will see it in pictures. The more common thing you are seeing (based on your top of the fuselage to front of ...

8

For the GoPro specifically there are audio recording cables you can buy which connect to your intercom jack and provide a pass-thru connection for your headset. There are other cable options available to support recording on different devices (e.g. iPhone/Android phones and tablets). As is often the case with "aviation" accessories these can be somewhat ...

8

Here are some things you can do, there are probably more. I'm assuming you're mainly interested in checking COM, not NAV. Controlled airport Check if you can hear the ATIS, Ground or Tower; if you can, then at least you know you can receive. But you might as well just call Ground immediately and ask for a radio check. The correct phraseology in the US (see ...

8

If the power fails, the tower will automatically switch to backup power generated by local diesel generators. If that fails, there are backup handheld radios. If those fail, the tower has a battery powered light gun for transmitting visual signals. So the risk of losing all forms of communication is next to none. Everything is backed up in ATC. Radios, ...

8

The VOR/Localizer/Glide Slope antenna is usually V-shaped and points backwards on the vertical stabilizer of the plane. On some aircraft, they point forward. They look like old-fashioned wire clothes hanger wire. Newer versions can be blade shaped. sometimes they are boomerang shaped like the old car phone antennas of the 90s.) They usually have a splitter ...

8

Digital is not always better. Digital modes have been created for amateur radio use; the amateur radio VHF 2m band (144–148 MHz) is very similar to the VHF aircraft band (108–137 MHz). I have a radio that uses both FM and a digital mode on the amateur 2m band. Here are some notable differences between FM and digital: When the signals are ...

7

In the US, it's perfectly legal to bring an airband receiver or scanner through security and on to an airplane. There are restrictions on using radios (even if receive only) onboard an aircraft. Furthermore, you are required by the FAA to comply all pilot and flight attendant instructions (and they usually say turnoff all radios). There is however a ...

7

The "long wire" antenna is an HF antenna, and operates in the 2 to 30 Mhz band. Not all aircraft will use them, only aircraft that need to communicate further than a VHF radio. Typically these are found on larger aircraft including some larger helicopters. The Sea King helicopter uses this antenna as well. It is still appropriate today as the propagation ...

7

Yes. In the Navy, our primary source of altitude indication under 5,000ft is the radar altimeter. The AGL over the ocean conveniently also happens to be the MSL as well.

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