61
votes
Accepted
Why are commercial flights not (publicly) trackable in some locations?
The reason is that there is no member of the general public in those areas with an ADS-B receiver sharing live data with the public tracking sites.
Websites like Flight Radar 24 rely largely on ...
- 84.5k
26
votes
Accepted
Do pilots ever use the aircraft's ICAO 24-bit address when communicating with ATC?
Typically pilots do not know the 24-bit aircraft address of their aircraft.
The 24 bit address is intended for data protocol level of communications and is not used in voice communication. Therefor ...
- 84.5k
26
votes
Accepted
Why are Search & Rescue aircraft looking for the OceanGate Titan submarine not visible on ADS-B Exchange?
ADS-B is line-of-sight. For an aircraft to be visible to an ADS-B receiver, it needs to be above the horizon. The wreck of the Titanic is 600 kilometers from the nearest land, so in order to be ...
- 5,731
23
votes
Why are Search & Rescue aircraft looking for the OceanGate Titan submarine not visible on ADS-B Exchange?
The aircraft probably do not transmit ADS-B messages, many military aircraft don't. The only way ADS-B exchange can locate these aircraft in such case is by using multilateration.
Multilateration only ...
- 84.5k
21
votes
Why are transponders to be turned off when in formation?
Because otherwise, being so close together, they would all have their transponders trigger at the same moment in the sweep, and all reply at the same moment, and all of the replies would arrive at the ...
- 769
18
votes
What does prevent installing an ADS-B transponder on a vehicle?
Use of ADB-S transmitters is limited by regulation: in the US, frequency use is limited to FCC license holders; FCC licenses are delivered only after approval by FAA, the aviation agency; FAA approves ...
- 80.9k
18
votes
Why are transponders to be turned off when in formation?
In the US enroute environment, a formation flight is controlled through the flight leader, which is assigned a discrete transponder code. Controllers separate a standard formation from other aircraft ...
- 2,286
13
votes
Accepted
On an ADS-B In display, do the pilots see the squawk code or call sign for other aircraft?
ADS-B is part of a system that compromises a number of different things. ADS-B (In) means that your aircraft is capable of receiving the ADS-B data, FIS-B and TIS-B as well. FIS-B broadcasts ...
- 36.2k
12
votes
Accepted
Why does ADS-B altitude from multiple landed planes vary so much from one plane to another?
The aircraft do not send out altitude when they are on the ground.
On the ground, aircraft send out the surface messages, which combine position, speed and heading.
The airborne message formats ...
- 84.5k
11
votes
Accepted
Why weren't SA-On GPS units updated to become SA-Aware?
As the linked ICAO article on GPS accuracy states, the issue is not just the navigation accuracy but the reported accuracy which is critical when used for ADS-B.
From the report:
3.2.1 For GPS ...
- 20.2k
10
votes
My N number showed up on another plane's flight on FlightRadar24. How does that happen?
FR24 may not actually receive any N-number from the aircraft. It's not unlikely that it only receives the Mode-S transponder code and cross-references that with a database to your N-number.
So the ...
- 13.7k
9
votes
Accepted
Does ADS-B signal contain the aircraft type?
No, the airplane type is not in the signal. The identification contains the ICAO 24bit (Mode S) code. You then need to map that to a registration which will have the type. As mentioned in the ...
- 6,081
9
votes
Accepted
Can ATC provide vectors and separation service to and between IFR aircraft in areas where radar coverage does not exist using ADS-B only?
Yes. In the United States, ADS-B may be used as the sole surveillance source for the provision of ATC services (including IFR-IFR separation) provided that the automation system ("radar scope&...
- 17k
9
votes
Accepted
Can I fly NYC Hudson River SFRA without ADS-B?
Assuming that your aircraft is certificated with an electrical system, no, you cannot fly the Hudson River SFRA unless you have either an approved ADS-B installation or a waiver/authorization from the ...
- 17k
8
votes
Accepted
Are ADS-B Airborne Squitters inherently inaccurate?
Yes, there is a inherently inaccuracy caused by the delay between a position is determined by the GPS receiver and the time it is transmitted.
However, for installation certified for the EU and USA ...
- 84.5k
8
votes
Accepted
How to leverage Lynx NGT-9000's integrated GPS/WAAS?
Sorry, but windmills approach certified GPS systems do not work that way: A GPS approved for IFR navigation and approaches, like a Garmin 430W or GTN650 or an Avidyne IFD440, are more than just an ...
- 68.7k
8
votes
Accepted
What's required for the ADS-B to function? A GPS or Mode S Transponder?
ADS-B, Automatic Dependent Surveillance - Broadcast, is a broadcast of the aircraft's position and other information.
The position is determined by a GPS receiver. It is possible to use another ...
- 84.5k
8
votes
Accepted
Why does ADS-B broadcast velocity?
The "position" and "velocity" include more than what the title would suggest.
Airborne position gives you:
Latitude/longitude
Altitude
Airborne velocity gives you:
Horizontal ground speed vector
...
- 73.8k
8
votes
Accepted
Why do ADS-B outages occur without simultaneous RAIM outages?
RAIM (Receiver Autonomous Integrity Monitoring) is a function within an avaition GPS receiver. It uses redundant measurements for a consistency check to determine the intergrity of the position ...
- 84.5k
8
votes
Accepted
What is the broadcast rate of an ADS-B message?
It depends on the Message Format TYPE Code and the aircraft state. In your example, being on final approach would have no effect as the primary state criteria is being airborne (vs. surface). The ...
- 20.2k
8
votes
What's the relation between ADS-B and MODE S
Your questions answered shortly
What's the 1090 ES?
SSR protocol is used to manage transmissions on SSR frequencies (1030 and 1090 MHz). Mode S is a part of this protocol to manage data exchange ...
- 80.9k
7
votes
Accepted
Will 1090 Mhz band become too congested in the future?
There are some areas where the 1090 MHz frequency is already very busy. The area around Frankfurt am Main in Germany and the Los Angeles Basin airspace is the USA are the most congested in the world.
...
- 84.5k
7
votes
Accepted
Is it recommended to have an ADS-B transponder in ALT mode on the ground?
Yes, it's in the the AIM 4-1-20:
3. Transponder and ADS-B operations on the
ground. Civil and military aircraft should operate with the transponder in
the altitude reporting mode (consult the ...
- 72k
7
votes
Accepted
Can ADS-B used for voice communications?
Why dont we ditch the old radio system full of parasties and use ADS-B instead for voice communications instead?
Well, why don't we use televisions for washing dishes? Because televisions don't wash ...
- 5,801
7
votes
Accepted
Question about congestion of the 1090MHz frequency
Additionally, there will be more aircraft interrogating (on 1030MHz) and responding to interrogations on 1090MHz for transponder based systems (TCAS, SSR).
Actually, no. More Mode S (vs Mode A/C) ...
- 27.9k
7
votes
My N number showed up on another plane's flight on FlightRadar24. How does that happen?
Flight tracking sites like FR24 use both ADSB data and official radar tracks.
The first possibility is that someone misconfigured their ADSB to use your hex code/tail number. This seems unlikely since ...
- 27.9k
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