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 ...
DeltaLima's user avatar
  • 83.4k
34 votes
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What are these vehicles with no callsign used for?

They have Mode-S transponders / ADS-B transmitters specifically for vehicles such a the ERA SQUID, Thales MOSQUITO or Saab Sensis VeeLoPDF. Typically vehicles that operate on taxiways and runways ...
DeltaLima's user avatar
  • 83.4k
26 votes
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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 ...
DeltaLima's user avatar
  • 83.4k
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 ...
Mark's user avatar
  • 5,552
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 ...
DeltaLima's user avatar
  • 83.4k
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 ...
hobbs's user avatar
  • 769
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 ...
RetiredATC's user avatar
  • 1,944
17 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 ...
mins's user avatar
  • 73.2k
13 votes
Accepted

How can I determine takeoff and landing from an ADS-B feed?

It depends on the type of ADS-B feed you have. On the lowest level, the messages transmitted from the aircraft, usually contain information about the air/ground status of the aircraft1. When the ...
DeltaLima's user avatar
  • 83.4k
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 ...
Ron Beyer's user avatar
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12 votes
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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 ...
DeltaLima's user avatar
  • 83.4k
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 ...
Gerry's user avatar
  • 19.8k
10 votes

What is the difference between ADS-B UAT and ADS-B ES?

ADS-B UAT operates on 978 MHz and are available for aircraft that operate below 18,000 FT MSL. UAT transceivers can display aviation weather products (FIS-B) as well as traffic from ground radio ...
wbeard52's user avatar
  • 12.7k
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 ...
Sanchises's user avatar
  • 13.3k
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 ...
BowlOfRed's user avatar
  • 5,601
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&...
randomhead's user avatar
  • 15.2k
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 ...
randomhead's user avatar
  • 15.2k
8 votes

What are the options for installing ADS-B OUT in a Cessna Citation to meet the regulations?

It depends on what kind of Citation you are talking about. I found a presentation by Textron(ppt) that discusses ADS-B installation for various models. Textron is focussing on creating Service ...
DeltaLima's user avatar
  • 83.4k
8 votes

What are these vehicles with no callsign used for?

On this question it is mentioned that ground support vehicles are equipped with ground transponders that work with the airport ground radar. I doubt they have ADS-B. They are most likely getting a ...
TomMcW's user avatar
  • 28.5k
8 votes
Accepted

How many commercial jetliners are equipped with ADS–B?

The majority of commercial airliners are currently equipped. I don't have the latest statistics, but for Europe over 80% of the airliners were equipped with 1090 Extended Squitter ADS-B two years ago. ...
DeltaLima's user avatar
  • 83.4k
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 ...
DeltaLima's user avatar
  • 83.4k
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 ...
voretaq7's user avatar
  • 68.4k
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 ...
DeltaLima's user avatar
  • 83.4k
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 ...
DeltaLima's user avatar
  • 83.4k
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 ...
Gerry's user avatar
  • 19.8k

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