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.
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Why does the A320 transponder's CLR button do two different things, depending on how many digits were entered?
I have to admit I've only flown in simulators but everyone of them implements the "CLR" button of the transponder in an A320 (maybe also others) the following way:
It removes the fourth ...
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Why bits are mixed up (interleaved) during ATC transponder mode A and mode C reply format?
In the image above from radartutorial.eu, we can see that the sequence of bits are c1 a1 c2 a2 c4 a4 during the reply of ATC transponder mode A.
Why are the bits not transmitted like c1 c2 c4 then a1 ...
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What information does Mode S provide?
What information about own aircraft does TCAS Mode s( all call) send in the interrogation?
What information does Mode S transponder(intruder)replay to TCAS interrogation?
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Is a Mode S transponder required as part of TCAS I?
Is a Mode S transponder required as part of TCAS I?
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What is the difference between SSR and ADS-B?
Can someone explain what is the difference between SSR transponder and ADS-B. From what I know ADS-B is a capability that can be incorporated into a transponder, but I do not understand the difference ...
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How can I know if the Garmin GTX 345 transponder supports modes A and C?
How can I know if the GTX 345 supports mode A/C?
I did not find a mention in the installation manual the capability of mode A/C.
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Are mode C altitude returns valid for aircraft separation?
According to FAA JO 7110.65 5-12-8 'Validation of MODE C READOUT', Mode C is valid if there is less than 300 feet deviation from the pilot reported altitude.
If ATC instruct 'A' aircraft to maintain 5,...
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Why does CFR §91.215 part (b) list specific areas for transponder operations?
Why does part (b) list individual sections where transponder operations are required when part (c) states that transponder operation is required in all controlled airspace? All sections listed in part ...
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How are both squawk and altitude transmited when operating a Transponder in Mode C?
I know that in Mode $3$ (which includes Mode A and Mode C) the aircraft transmits $12$ information pulses. That corresponds to $2^{12}=4096$ squawk combinations in Mode A which are sent to ATC to ...
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Is it legal to fly without a transponder?
Everything is legal / airworthy.
Except:
Transponder is installed. It does work. It has NOT been inspected in any time frame that would show it is properly maintained.
Flight is
Golf, Echo, Delta &...
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Should I contact ATC if I don't have a transponder?
The flight school I usually rent from is under the shelf of class C airspace. If you're going out to a practice area, the standard procedure is to contact approach control and get a squawk code, so ...
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Is it possible for squawk to change automatically in emergency situations?
It might be a silly question, but is it possible for an airliner to automatically switch the squawk code to emergency (7700) during a flight? (For example in case of losing all engines)
Thank You In ...
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Does the FAA construe FAR 91.225 to prohibit aircraft w/o electrical systems w/o ADS-B-out from flying above 10,000' MSL unless below 2500' AGL?
Does the FAA construe FAR 91.225 as imposing a general prohibition on flight above 10,000' MSL (excluding airspace below 2500' AGL) in aircraft without ADS-B-out, even for aircraft without engine-...
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Are there any situations where it's beneficial to disable altitude reporting in TCAS?
Having altitude reporting enabled persistently seems like a pretty common-sense thing to do -- it enables RA in addition to TA, the benefits of which are fairly obvious. That said, most of the common ...
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Would FAR 91.227, or any other regulation, forbid use of ADS-B-out in an unregistered ultralight?
In the US, would FAR 91.227, or any other regulation or law, forbid use of ADS-B-out in an unregistered ultralight? Could the N-number field simply be left blank, without violating any regulation or ...
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Why do I never see fighter jets on sites like FlighRadar24 and ADBSExchange.com [duplicate]
On ADS-B Exchange they even have a filter option for military aircraft, and it will show all kinds of transport, mid-air refuelers, helicopters, and even training aircraft like the Texan, but I don't ...
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Is a Mode C or S Transponder a type of Mode 3 Transponder?
Mode A transponders are sometimes referred to as Mode 3/A transponders. According to NATO STANAG 4193 (not publicly available, summary from Wikipedia), the "3" in that description refers to the mode ...
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Why is Mode C helpful for ASDE-X systems?
Airports that operate an ASDE-X system require aircraft to operate transponders in mode C while moving on the surface.
While I understand the general purpose of operating the transponder to ...
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Are Transponder Mode A and C still in use?
Are the ATC transponder Mode A and Mode C still in use (according to ICAO or FAA rules)?
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FAR 91.215 (b)(3)(ii) — transponders— does the “or below 10,000' MSL” clause have any practical significance?
Here are some of the airspaces where FAR 91.215 requires aircraft to have transponders--
(b) ...
(2) All aircraft. In all airspace within 30 nautical miles of an
airport listed in appendix D,...
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1answer
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FAR 91.215— may an aircraft with no electrical system and no transponder overfly Wheeler AAF at 9500' MSL?
Here are some of the airspaces where FAR 91.215 requires aircraft to have transponders--
(b) ...
(2) All aircraft. In all airspace within 30 nautical miles of an
airport listed in appendix D,...
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What additional airspace will be off-limits to an a/c w/ no elect. system or xponder under 91.225 (ADS-B) compared to under 91.215?
Under FAR 91.225 (requirement for ADS-B-out), what additional airspace over the 48 contiguous states in the U.S. will be off-limits to an aircraft w/ no electrical system or transponder, compared to ...
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How feasible digital radio communications would be? [closed]
Its been over 100 years since we first flew and we still use analog radio with parasites and "radio effect" which changes your sound.
Why don't we ditch the old system and make a mandate a new law ...
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Why do (or did, until very recently) aircraft transponders wait to be interrogated before broadcasting beacon signals?
An aircraft’s transponder transmits signals that announce (at the very least) the aircraft’s identity, altitude, and direction of motion (plus, for most newer aircraft, a whole slew of other useful ...
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Why does setting the Legacy 600's transponder to standby mode also deactivate its TCAS?
In 2006, a 737 operating as Gol Transportes Aéreos Flight 1907 crashed following a collision with a Legacy 600 business jet; the Legacy's transponder proved to have been in standby mode1 at the time ...
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188 views
What does the future of the weather radars look like?
Planes had weather radars for a long time (Dassault Falcon and Learjet35A) which was useful since you either had to ask ATC, listen the ATIS frequency or ask the flight advisory before flight planning ...
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What is the purpose of squawking 7777?
Aircraft use transponders to communicate to ATC their position and status. Some squawk codes are reserved, such as 7700 (emergency), 7600 (communication failure), 7500 (hijacking), 1202 (glider), 1200 ...
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What do you squawk when multiple conditions apply?
There are three standard transponder codes for exceptional situations: 7500 (hijacking), 7600 (radio failure), and 7700 (general emergency). Which code do you use if multiple situations apply? For ...
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Is a mode C transponder required underneath Class C airspace?
FAR 91.215 states that a mode C transponder is required for...
all aircraft in all airspace above the ceiling and within the lateral
boundaries of a Class B or Class C airspace area designated ...
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Should I switch the transponder to STBY or not while changing codes?
I´m now reading Bob Gardner’s book “Say again, please” and there is this instruction on page 54:
Do not turn the transponder function switch to STBY while changing codes.
What is the reason for ...
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In a part 91 formation flight within a mode C veil, are all the aircraft required to have their transponders on?
Two aircraft are planning on conducting a standard formation flight (aircraft remaining within 1 mile of each other) as follows in the U.S.:
Maintaining VFR below 10,000 MSL;
Remaining outside/clear ...
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1answer
389 views
How to keep a Garmin GTX330 turned off when powering on avionics?
There seems to be an option in the GTX 330 settings that keeps to unit from powering on when receiveing power from the power system.
I flew in two different airplanes and one immediately powered on ...
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If a pilot has the wrong altimeter setting, will his transponder mode C altitude be off too? [duplicate]
Just wondering if the transponder mode C reported altitude will be off if the pilot accidentally has the wrong altimeter setting.
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Why would a Mode-C transponder report a different altitude than an altimeter/GPS?
This is related to a small single-engined plane.
On a recent flight, the controller kept telling me that I was 300 ft higher than it appeared on my altimeter and GPS (which were in sync). This was ...
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When do controllers assign a squawk code to VFR aircraft in Canada?
In all of my previous flying experience the controllers provided a squawk code only when I requested flight following. On a recent flight from Buttonville, Ontario (CYKZ), the controller provided a ...
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Is a VFR flight following request implied when talking to tower and advising them of your intended airport?
If I am at a towered airport in class delta airspace and I'm departing VFR and tell the ground where I want to go, is it implied to the controller that I'm requesting VFR flight following?
Let's say ...
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What requirements do A&Ps (AMT) have to work on avionics?
Is there any additional requirement for A&Ps to work on avionics or is that even a totally different license?
I just wonder why only a few A&Ps I met, also do avionics.
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How do I tell ATC that I don't have a transponder?
If my plane doesn't have a transponder and ATC tells me to squawk some transponder code, how should I respond? Is it just as simple as "I don't have a transponder"?
This is for the United States and ...
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How does ATC locate a stealth aircraft if its transponder fails?
Stealth aircraft are built to have near-zero radar visibility, so that, in a warzone, it'll be harder for the enemy to see it on their radars to shoot it down.
However, air traffic control also use ...
asked Mar 12 '18 at 23:28
Vikki - formerly Sean
23.5k13 gold badges81 silver badges192 bronze badges
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If the static port get blocked, and no alternate static air source is fitted, will the transponder keep provide mode C?
If the static port get blocked for any reasons and the aircraft is not fitted with an alternate static source while in Mode C with SSR, will the ATC still get the height information from my ...
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Which antenna on an commercial airline airplane is used for the transponder (SSR)?
On the 767-200 image I see no SSR antenna, but since that TCAS uses the transponder I guess that are sharing the same antenna. Am I right ?]1
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What is Mode B on the transponder?
Mode A selected on the transponder provides identification of the aircraft to the secondary radar; Mode C will add an automatic height read-out of an aircraft. Mode S is a selective addressing. But ...
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What Height Atc radar reads from pilot selection [duplicate]
Just want to know whether ATC radar always reads aircraft height with respect to standard altitude setting or will read the change in height if we select QNH instead of standard 1013 hPa (QNE)?
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Which source to use when reporting the current altitude to ATC?
While flying from KSNA to KVCB VFR at night, Norcal Approach asked for my current altitude. I was somewhere between 12.0 and 12.5 depending on which reading I was going to use. ATC had me confirm. ...
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Can a TCAS be alerted when the intruder aircraft has a transponder in stand-by mode?
Can a TCAS give a TAs (traffic advisories) if the intruder aircraft has a transponder in stand-by mode?
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How does the modulation of the transponder work?
The transponder works in PCM (pulse code modulation): how does it work in the transponder? I can find explanation of what PCM is, but not if the signal sent from the transponder antenna is digital or ...
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Why don't transponders send gps coordinates and other important info in addition to altitude and transponder code?
I heard that they were waiting for the patent holder's patent to expire, but just wanted to confirm.
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Are experimental aircraft exempted from the 2 year transponder and avionics checks?
Experimental aircraft and LAS. The 2 year verification test for avionics , transponder and altitude encoder. Are experimental aircraft exempted from this test or they must comply ?
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What's required for the ADS-B to function? A GPS or Mode S Transponder?
Jeppesen defines the ADS-B as a surveillance system broadcasting GPS-derived positions and other information such as velocity over the data link. Yet, the Wiki article on ADS-B relates it to the Mode ...
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Why is the range of transponder digits 0 to 7 rather than 0 to 9?
As a controller on IVAO I sometimes assign codes like 0168 and find out later that the code isn’t valid. For me, the range 0-9 seems more logical. Why do we have to use octal numbers and not decimal?
