Transponder should be in ALT on ground

[FastEddieB]

No FAR.

It's in the AIM. Section 4-1-20(a)(3).

AHA!!!

But like traffic patterns, that's not regulatory - they can't make him do it!

Recommendations and AIM procedures are for the sheeple.

The whole anti-authority thing, after all.

Probably pictures himself thusly:

 

[Cpt_Kirk]

Having trouble parsing your intent.

From now on, in my Sky Arrow:

After engine start, turn the transponder on ALT instead of SBY*.

Move "Transponder...OFF" from After Landing Checklist to Shutdown Checklist.

No more nor less work nor complication than before.

As I said before, just as easy to comply with as not.


*My Garmin automatically switched from SBY to ALT after takeoff. Since its not hooked up to a GPS, my assumption was it senses rapid altitude change.

edited to add: looks like I was right on what switches the 327 from SBY to ALT:

"Automatic ALT/STBY Mode Switching
If the GTX 327 is configured with Automated Airborne Determination, ALT mode selection occurs when lift-off is sensed. When the aircraft is on the ground, the transponder automatically selects and displays STBY. The transponder does not respond to ATCRBS interrogations when STBY is annunciated. When a delay time is set (dependent upon installation configuration), the GTX 327 waits the specified length of time after landing before changing to STBY mode."

The switch never moves from ALT in the Bonanza, Mooney, or Saratoga. Other than to change the squawk, the transponder is never touched.

 

[FastEddieB]

The switch never moves from ALT in the Bonanza, Mooney, or Saratoga. Other than to change the squawk, the transponder is never touched.

Got it.

I do not have an avionics master in my Sky Arrow - with only a com and a transponder it would be kind of superfluous.

So, I do have to turn it on and off. Now I'll just turn it on hitting the ALT button instead of the SBY button, is all.

 

[Ravioli]

I like this recommendation... I had STBY on the ground and ALT just before taking the runway beat into my brain...

Don't know how many times I've gotten to 800' to hear "Cherokee 1234, squawk altitude" and I get to say "got it, sorry, 234"

One less thing to forget now that I'll be ALT all the time.

 

[brian109]

My CFI has been teaching me yes to ALT

 

[James331]

AHA!!!

But like traffic patterns, that's not regulatory - they can't make him do it!

Recommendations and AIM procedures are for the sheeple.

The whole anti-authority thing, after all.

Probably pictures himself thusly:

Careful

You bet traffic pattern direction is a regulation, get caught flying a right pattern in a left pattern, you could easily find yourself in a enforcement action.

 

[orange]

Flew into Bradley (KBDL) yesterday and the airport diagram has a notation "ASDE-X SURVEILLANCE SYSTEM IN USE. OPERATE TRANSPONDERS WITH MODE C ON ALL TWYS AND RWYS."

This is ground radar so they can track your movement on the ground.

 

[Cpt_Kirk]

When I worked at Hartsfield, we used an ASDE-X-type system to track our inbounds and outbounds. This is similar to what it looks like to a controller in the tower.

This was the lineup after weather moved through.

 

[FastEddieB]

Careful

You bet traffic pattern direction is a regulation, get caught flying a right pattern in a left pattern, you could easily find yourself in a enforcement action.

Yep, but the real rebels just like to come straight in! Pattern be damned!

Can't tell them what to do!

 

[James331]

Yep, but the real rebels just like to come straight in! Pattern be damned!

Can't tell them what to do!

Well guess you got me twice.

For the most part I come in the fastest way possible, be it a downwind, base, or straight in, I still make L or R turns as depected by the airport. Or for IFR it's just whatever the IAP is.

 

[ethosunum]

For DC sfra:

Remain on the code until you land: Used when Potomac hands an inbound VFR flight off to the tower or authorizes change to advisory frequency for non-towered airports. It reminds pilots to remain on the assigned discrete tran-sponder code until after landing. NEVER squawk 1200 inside the DC SFRA.

So sounds like while you might not technicality need to stay on your assigned code they don't want you on 1200 either.

 

[flyingron]

Yep, even 1205 is OK, just not 1200 apparently from talking to IAD tower.

And for those who quibble about Mode S selective call and the squitter working on the ground, yes but irrelevant. It doesn't respond to normal (A/C and non selective mode S) interrogations and that's what the ground radar is doing (actually not even using mode S at all).

 

[PeeGee]

When I worked at Hartsfield, we used an ASDE-X-type system to track our inbounds and outbounds. This is similar to what it looks like to a controller in the tower.

This was the lineup after weather moved through.

tracon and center also have the aerobahn data.
it's a very slick system.

 

[Cpt_Kirk]

tracon and center also have the aerobahn data.
it's a very slick system.

Except for when it crashes. People who used it as a crutch had a baaad time when it went down.

 

[PeeGee]

Except for when it crashes. People who used it as a crutch had a baaad time when it went down.

it does do that occasionally.... like every 3 days. and takes like an hour to reboot it seems.

 

[Turningfinal]

Yep, even 1205 is OK, just not 1200 apparently from talking to IAD tower.

And for those who quibble about Mode S selective call and the squitter working on the ground, yes but irrelevant. It doesn't respond to normal (A/C and non selective mode S) interrogations and that's what the ground radar is doing (actually not even using mode S at all).

Garmin Mode-S transponders which automatically go into a GND mode do respond to ASDE/ASDE-X/ASSC interrogations today.

That being said, however, Garmin will be releasing an update to the GTX series of transponders which essentially disables GND mode and leaves the transponder in ALT mode.

 

[denverpilot]

Hm, now I have to figure out what to do during the "camera" phase of "lights, camera, action".

Check it anyway. Touch it and confirm. And touch and confirm the correct code.

It's been ALT all the time in the AIM (and in that notice now, trying to remind people) for years now.

The CFI in the OP needs to crack a book once in a while.

 

[pstan]

What TCAS indications in flight then...

Help me here folks, if an aircraft is holding short squawking C, what should I see/hear from my tcas while I am conducting a straight in approach to the same runway?

Never an RA?

Never a TA?

Something about my tcas reads the other's C, compares to rad alt, decides the other is on the ground and thus does not display the target nor provide any audio?

Stan

 

[Larry in TN]

Re: What TCAS indications in flight then...

Help me here folks, if an aircraft is holding short squawking C, what should I see/hear from my tcas while I am conducting a straight in approach to the same runway?

If you have a true TCAS, TAs and RAs are inhibited below specific altitudes so you'll hear nothing. You'll get a yellow TA aircraft target but no alert; no audio.

 

[pstan]

Re: What TCAS indications in flight then...

If you have a true TCAS, TAs and RAs are inhibited below specific altitudes so you'll hear nothing. You'll get a yellow TA aircraft target but no alert; no audio.

Larry,

No TA below a certain altitude? what altitude would that be?

I believe my tcas goes "TA only" below approximately 1000 feet rad alt approach

And I thought I still got a "traffic traffic" audio.

So, all the aircraft on the ground show amber on my tcas display?

 

[Palmpilot]

There is none that I know of.

Just a recommendation/request from the FAA. Allegedly in the interest of safety through consistent transponder usage procedures.

Since its just as easy to comply with as not, the only reason not to would seem to be psychological in nature.

Unless someone can come up with a good reason I have not heard.

The reason I've been told is to avoid distracting pilots on final with traffic alerts from aircraft on the ground. (The aircraft where I'm based do not have the same type of traffic alerting systems that the airlines have, so I'm guessing they do not have the filtering feature that Larry mentioned.)

Personally, I like the new recommendation, because it makes me less likely to forget to put the transponder in ALT mode.

 

[Henning]

I asked the CFII who gave me my recent IPC whether or not my transponder should be set to ALT on the ground. He said "no" and wondered where I had heard that. The avionics shop who installed my GTN has the transponder programmed to switch from STBY to ALT when the groundspeed exceeds 30 kts and vice versa. Evidently avionics techs are under the same impression as the CFII.

According to this safety alert I received in an email today from the FAA, it says a transponder should ALWAYS be in the ALT position while moving on the ground at all airports.

The alert clearly says this applies to General Aviation (GA) aircraft. I just want to make sure that GA includes single engine piston aircraft in this situation. Do others interpret it that way?

http://www.faa.gov/other_visit/avia...afety/safo/all_safos/media/2015/SAFO15006.pdf

Always on ALT unless NOTAM says not to is the way I handle it.

 

[Larry in TN]

No TA below a certain altitude? what altitude would that be?

I believe my tcas goes "TA only" below approximately 1000 feet rad alt approach

And I thought I still got a "traffic traffic" audio.

So, all the aircraft on the ground show amber on my tcas display?

There are multiple steps in the inhibit logic.

Here's the inhibit logic for RAs:

• TCAS II design progressively inhibits Resolution Advisories (RAs) depending on the height Above Ground Level (AGL) provided by the radio altimeter as follows:
  • “Increase Descent” RAs are inhibited below 1,550 ft AGL (± 100 ft)
  • “Descend” RAs are inhibited below 1,100 ft AGL (± 100 ft)
  • All RAs are inhibited below 1,000 ft AGL (± 100 ft).
  • If a “Descend” RA is in progress while the aircraft is descending through 1,100 feet AGL, the RA will change to an “Adjust vertical speed” RA.

Audio commands are inhibited below 500' RA.

The only ground traffic that will show yellow are those that would meet the TA/RA logic criteria without the inhibits. The TA audio is inhibited so all you get is the TA display on the TCAS display.

 

[GeorgeC]

A small technical wrinkle:

Our club just had an Appareo Stratus ESGi installed. Out of habit, I switched it to ALT mode after engine start. After my flight, I pulled my ADS-B performance report from the FAA; everything passed except for the "air on ground" requirement. I think I should have left it in ON mode, where it responds to interrogations, but does not report altitude, and then automatically transitions to ALT mode when a gps groundspeed threshold is exceeded (no squat switch). An email to Appareo support confirmed this.

edited: added Stratus ESG Pilot's Guide pdf.

 

[luvflyin]

tracon and center also have the aerobahn data.
it's a very slick system.

Aerobahn???

 

[Palmpilot]

Aerobahn???

It looks like the person you're asking hasn't been here since December.

 

[saddletramp]

Since the thread is active. Another transponder question. I always switch to standby when told to switch my code. After the assigned code in dialed in I then switch back to alt. Is that old fashioned too?

 

[Velocity173]

Since the thread is active. Another transponder question. I always switch to standby when told to switch my code. After the assigned code in dialed in I then switch back to alt. Is that old fashioned too?

You should do that and I suppose it's a good training habit. Realistically, the odds of you dialing in a code (7500,7600,7700) that raises eyebrows on the controllers scope would be slim. If anything, it would be for a split second, and they aren't going to follow up on that.

 

[Sundancer]

I operate out of the DC FRZ. . .a friend had a hilarious incident with a passenger (CAP observer) who hit the "VFR" button on the transponder. . .he doesn't let 'em touch anything on the panel till clear of the FRZ now. Potomac was actually pretty cool about it, and he got it resolved pretty fast. Just didn't need the stress.

But I digress - I leave it in STBY until ready to taxi, then go to ALT. IFR it's hard to forget, since I'm on the phone with Potomac. But it's on the checklist twice in our airplane. It can be a pretty big deal to squawk 1200, or forget and not squawk at all, when departing from the FRZ. Once clear of the SFRA, VFR, Potomac cuts you loose, and I go 1200 then, since I don't use FF VFR.

Not a rebel, per se, but on the ground, outside the FRZ/SFRA, I'd pretty much do what made sense to me, or was convenient, unless it's black letter law. Maybe STBY or OFF might make sense to extend the life of the box, or reduce load. Dunno, but a FAA "recommendation" may makes sense. Or may not. The record is spotty. .

 

[denverpilot]

A small technical wrinkle:

Our club just had an Appareo Stratus ESGi installed. Out of habit, I switched it to ALT mode after engine start. After my flight, I pulled my ADS-B performance report from the FAA; everything passed except for the "air on ground" requirement. I think I should have left it in ON mode, where it responds to interrogations, but does not report altitude, and then automatically transitions to ALT mode when a gps groundspeed threshold is exceeded (no squat switch). An email to Appareo support confirmed this.

So the FAA is failing data they asked for in the AIM?

Hahaha. Classic.

 

[Shepherd]

sigh... Unless specifically requested, I never turn it on.

 

[Brad Z]

I operate out of the DC FRZ. . .a friend had a hilarious incident with a passenger (CAP observer) who hit the "VFR" button on the transponder. . .he doesn't let 'em touch anything on the panel till clear of the FRZ now. Potomac was actually pretty cool about it, and he got it resolved pretty fast. Just didn't need the stress.

But I digress - I leave it in STBY until ready to taxi, then go to ALT. IFR it's hard to forget, since I'm on the phone with Potomac. But it's on the checklist twice in our airplane. It can be a pretty big deal to squawk 1200, or forget and not squawk at all, when departing from the FRZ. Once clear of the SFRA, VFR, Potomac cuts you loose, and I go 1200 then, since I don't use FF VFR.

Not a rebel, per se, but on the ground, outside the FRZ/SFRA, I'd pretty much do what made sense to me, or was convenient, unless it's black letter law. Maybe STBY or OFF might make sense to extend the life of the box, or reduce load. Dunno, but a FAA "recommendation" may makes sense. Or may not. The record is spotty. .

RE inside the SFRA/FRZ-- they are much better these days about such things...in the early days of the SFRA (actually it was then known as the Washington ADIZ) one radar sweep of a 1200 squawk was supposedly enough to get a phone number and subsequent violation. Many years ago I disabled the 'VFR' button on my GTX-330 transponder (it's configurable) to avoid just that sort of thing.

Even outside the SFRA Airborne I always leave my transponder squawking ALT, per 14 CFR 91.215(c).

 

[DMD3.]

I asked the CFII who gave me my recent IPC whether or not my transponder should be set to ALT on the ground. He said "no" and wondered where I had heard that. The avionics shop who installed my GTN has the transponder programmed to switch from STBY to ALT when the groundspeed exceeds 30 kts and vice versa. Evidently avionics techs are under the same impression as the CFII.

According to this safety alert I received in an email today from the FAA, it says a transponder should ALWAYS be in the ALT position while moving on the ground at all airports.

The alert clearly says this applies to General Aviation (GA) aircraft. I just want to make sure that GA includes single engine piston aircraft in this situation. Do others interpret it that way?

http://www.faa.gov/other_visit/avia...afety/safo/all_safos/media/2015/SAFO15006.pdf

We were always taught to switch the transponder to stby on the ground in the aircraft I learned to fly in. But in the aircraft I'm renting now, they have us leave it on alt at all times. My current rental aircraft is at a controlled field, so perhaps that's why.

 

[kontiki]

Understand that Mode S Transponders squit. When Mode S was first implemented it was implemented with TCAS. At that time TCAS and ATC started doing a lot more listening and fewer All Call interrogations like it used with Mode A/C.

The squitter is a broadcast message transmitted at a pseudo random interval of something less than 1/4 sec. Every Mode S broadcast contains the 24 bit ICAO code associated with the aircraft registration number in addition to what else is in the message.

When extended Mode S extended squitters were activated for ADS-B, the squitter expanded from 56 bits to 112 bits. When ADS-B is enabled, the squitter stops squitting a DF-14 message (Downlink 14 formatted message) and cuts over to a DF-17 message.

The DF-17 message has (from memory) a 32 bit word that changes through subsequent broadcasts until all the required data is pumped out. The 32 bit field can also contain event driven data too.

Airliner mode S transponders that I've been involved with all had diversity antenna installation (that is antenna on top and bottom). In the air, the squitter would alternate antennas. If the the transponder was responding to an ATC or TCAS interrogation, it transmitted on the antenna with the strongest reception.

On the ground, the bottom antenna is generally disabled and the squitter transmits on the top antenna only to support the various schemes for ground tracking of aircraft, provided the XPDR is not in STBY.

Note: I edited out some of my earlier recollection mistakes. I worked with TCAS and Transponders for airliners that operated internationally for about 10 years. There really has been a constant but nuanced evolution.

 

[denverpilot]

Judging by the above, we'll never get the point across to people that the dang rule changed in the AIM... It's been years and years...

 

[kontiki]

Just as a follow on Mode S indicates that it is Selectable (or addressable) meaning interrogations can be addressed to that one transponder and all the others that receive the interrogation will ignore it.


Sent from my iPad using Tapatalk

 

[cgrab]

One of my instructors said the last thing to do before taking the runway was "lights, camera, action" Turn on the landing light so everyone can see you taking the runway and so it will be on in the air; turn the xpndr from STBY to ALT (the camera so the radar can see you); and then start moving.

BTW, doesn't STBY stand for "sucks to be you"

 

[denverpilot]

One of my instructors said the last thing to do before taking the runway was "lights, camera, action" Turn on the landing light so everyone can see you taking the runway and so it will be on in the air; turn the xpndr from STBY to ALT (the camera so the radar can see you); and then start moving.

BTW, doesn't STBY stand for "sucks to be you"

Which is stuck in your head, and mine BTW, but totally wrong nowadays. See AIM. It was correct a couple of decades ago.

Oh, and in my head I switched "action" over the years to meaning to check the DG against the runway heading... Heh. More useful that way.

 

[Palmpilot]

Judging by the above, we'll never get the point across to people that the dang rule changed in the AIM... It's been years and years...

Rules don't use the word "should."

 

[denverpilot]

Rules don't use the word "should."

Yeah, they should just say "pretty please"... LOL.

What's your point? If you have no reason to turn it off, it's on, in the world of "should".