Questions tagged [transponder]
A radar transponder is a radio beacon on an aircraft that replies to a radar interrogation. The transponder encodes information into the reply, allowing air traffic control to know the aircraft's altitude and identity.
112
questions
11
votes
2
answers
2k
views
Are transponders sometimes referred to as ‘parrots’?
Looking at the A/FD for Anchorage Ted Stevens Intl (PANC), there are a couple of entries in in the airport remarks for a piece of onboard equipment called a ‘parrot’.
I am not familiar with this ...
- 74.3k
1
vote
0
answers
83
views
ADS-L Protocol implementation
I am trying to implement the ADS-L protocol in my application, but I did not fully understand it yet.
Data link layer (page 13):
Why CRC is at offset (Packet Length +1)Bytes if the CRC is included in ...
- 11
1
vote
1
answer
247
views
What is the squawk for VFR flying?
I'm used to using squawk 7000 for VFR flight. But lately I've seen 1200 also being used. I don't know which one is the default for VFR flying, because it seems like both codes are widely used.
- 31
1
vote
1
answer
261
views
Why and how can TCAS and SSR transponder work at the received frequency of each other?
The TCAS sends interrogation pulses at 1030 MHz and receives replies at 1090 MHz. And the transponder replies interrogations at 1030 MHz receiving at 1090 MHz. There could be interference between them,...
- 63
1
vote
1
answer
141
views
Can an aircraft transmit Mode C when Mode A is in STANDBY or OFF?
I am a software developer in the aviation industry, so I do apologize if my terminology is not correct. What I want to know is - are there any cases in which the aircraft's Mode A is switched to OFF ...
- 13
1
vote
1
answer
113
views
Reasons for ADSB PAPR Report Altitude Errors
We have just test flown a new 1090 ADSB installation, using Apareo Stratus ESG Transponder, which has internal GPS.
The PAPR for the test flight show both Baro Alt and Geo Alt errors in the Missing ...
- 41
0
votes
2
answers
189
views
Are squawk codes linked with flight info such as route and flight data?
So squawk codes are given to an aircraft prior to departure. We know that if the pilot inputs the wrong code, the data will not show up. So are squawk codes linked via computer to the aircraft’s ...
- 6,484
1
vote
0
answers
97
views
Mode S Transmission from Boeing 737 Integrated Standby Flight Display (ISFD) data?
During a recent flight, while in communication with London control*, we received a query about our RVSM (Reduced Vertical Separation Minima) compliance. Both the Captain's and First Officer's ...
- 2,735
3
votes
1
answer
642
views
Where on the aircraft are transponders mounted?
For civil acft like B737-800 or B777-200, where is the location of transponder?
I'm asking about the "responder", not the cockpit device.
- 147
0
votes
0
answers
82
views
How does ADS-B get pressure altitude? [duplicate]
I have learned that ADS-B out broadcasts both Pressure altitude and GPS Altitude.
GPS altitude is, obviously, available from the GPS, but where and how does it determine pressure altitude? Does it ...
- 6,108
1
vote
1
answer
286
views
Why are there not more emergency squawk codes? [duplicate]
7500 is used for hijacking, 7600 for radio failure, and 7700 for any other emergency. I understand that 7600 and 7500 need special handling (you can't talk to ATC if your radio has failed, and a ...
- 7,097
2
votes
0
answers
145
views
Should the transponder be set to 2000 then STB or STB then 2000?
For Airbus aircraft，after the engines are turned off，we set the transponder squawk code to 2000 and then the mode to STB.
Is it mandatory to set transponder 2000 and then STB？Can we set STB and then ...
- 51
1
vote
1
answer
203
views
Why does secondary radar interrogate Mode S or A/C transponders using intermode?
The MSSR MODE S Radar uses different protocols to interrogate A/C or Mode S transponders:
Mode S ALL CALL:
...
- 153
0
votes
1
answer
1k
views
How does AWACS pick up enemy info like speed and altitude without transponder interrogation?
So basically, IFF can pick up friendly vehicles. I'm assuming that enemy planes will have their transponder off to minimize speed and altitude data. How does the AWACS determine enemy info to pass on ...
- 6,484
2
votes
1
answer
455
views
Even if an intruder aircraft isn't equipped with TCAS, can I detect them with my TCAS?
I'm wondering about the TCAS operation concept.
If aircraft "A" is equipped with TCAS I or TCAS II equipment,
and aircraft "B" isn't equipped with either TCAS transponder or ...
- 21