Altimeter VS Squawk

file the report and make the call.
Already filed, called but they told me the person I need to speak to comes in later and to call then. He told me there aren't any notes there and told me not to sweat it. Got my name and number, now i'm waiting until the afternoon.
The altimeter is corrected for pressure changes as you adjust it for altimeter settings to obtaine true altitude. The trainspnder only records pressure altitude and transmit pressure altitude to ATC. ATC computers knows also what the altimeter setting is and applies it to the transponder it sees. So unless the altimeter setting is 29.92 then the altimeter and the transponder will never agree. The transponder is adjusted at ATC.

Thanks, I did not know this.
 
The altimeter is corrected for pressure changes as you adjust it for altimeter settings to obtaine true altitude.

Not true.

True Altitude is defined as one's actual height above msl, and not something an altimeter will generally show, even with the correct altimeter setting set.
 
I skimmed through this so forgive me if someone already mentioned it. It is possible your altimeter is not 100% accurate. I know you're VFR, but I believe the tolerance for a plane's IFR certification is 125 ft. I had to have my altimeter overhauled a few years ago b/c it was too far off at the higher altitudes.
 
I skimmed through this so forgive me if someone already mentioned it. It is possible your altimeter is not 100% accurate. I know you're VFR, but I believe the tolerance for a plane's IFR certification is 125 ft. I had to have my altimeter overhauled a few years ago b/c it was too far off at the higher altitudes.

I forget the actual testing requirement accuracy but for IFR flight it's supposed to be within 75 ft of the field elevation with the local altimeter set.
 
I forget the actual testing requirement accuracy but for IFR flight it's supposed to be within 75 ft of the field elevation with the local altimeter set.

you may be right. I had 75 and 125 in my head. I did a google search and it said 125 max throughout the entire test range.
 
I think that's what they are suggesting. I flew at about 1000-1100 on the outskirts of that core while monitoring my Garmin and Fore-flight to make sure I was outside of it.

Ok, well, your OP took everyone down a long rabbit trail...

Bear in mind your map in Foreflight may not be perfectly geo-referenced. I use Garmin Pilot, and there are places where I know exactly where I am while driving down the highway, but on the chart GP shows me in the field a half mile away. I'd give myself a little more margin next time I fly that route.
 
File the NASA anyways, you got nothing to loose at this point.

This is a common misunderstanding. You NEVER have anything to lose by filing the ASRS "NASA" report, except a bit of time and the ink you put on the paper. File them early and often, every time there is any question about a safety issue (in this case, an alleged Bravo bust). -Skip
 
When was your last transponder check, and did you get it an "IFR" or "VFR" check?

VFR the encoder gets checked for accuracy but does not get compared to the altimeter, IFR they check the encoder, static system, and altimeter.

In either case, there are tolerances on everything.

Plus, the encoder is not compensated for barometric pressure.

Plus, the baro correction ATC is using may not match what you actually have dialed into your altimeter.

When you set the Kolsman - how close does the altimeter come to the field elevation?
 
This is a common misunderstanding. You NEVER have anything to lose by filing the ASRS "NASA" report, except a bit of time and the ink you put on the paper. File them early and often, every time there is any question about a safety issue (in this case, an alleged Bravo bust). -Skip

I'm not going to get into it, but yeah, of they knew who you were enough to give you a number, for sure file a NASA.
 
file the report and make the call.

"Making the call" is rarely, if ever, a good idea. Under some relatively new procedures, called "QA/QC," controllers have lost almost all of their discretion in referring pilot deviations to the FSDO. Gone are the days when you got a "talking to" and the buck stopped there. Calling does little more than give ATC more information upon which to build a case against the pilot. Depending on how the airplane is registered, calling may be the only way that ATC/FSDO is able to ascertain the identity of the pilot flying the airplane.
 
When he first called me, he got me confused with another tail number and told me "Oh, we already sent that to the FSDO" you're boned etc, etc. Told him my tail number and explained to him what happened, talked to the guy for 5 minutes, he told me merry christmas and to get the plane checked. That was the end of it.


On an unrelated note, got checked out in a 152 today with a tail number that had 3 letter N-number NXX. That's new. Boy that thing climbed like a slug with two people in it. :eek:
 
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When he first called me, he got me confused with another tail number and told me "Oh, we already sent that to the FSDO" you're boned etc, etc. Told him my tail number and explained to him what happened, talked to the guy for 5 minutes, he told me merry christmas and to get the plane checked. That was the end of it.


On an unrelated note, got checked out in a 152 today with a tail number that had 3 letter N-number NXX. That's new. Boy that thing climbed like a slug with two people in it. :eek:

Hopefully that's the end of it, but don't be shocked if it's not. Sometimes even the controller you spoke with might have thought it was the end of it, but his supervisor, or someone else above him, might disagree, and send it to the FSDO anyway. And now they've got your "confession" on tape (you did expect your call to be recorded, right?), as well as (presumably) plenty of identifying information to know it was you flying the plane.
 
T.K, I'm glad it worked out, but if you're anything like I was during my training, I knew SQUAT about the systems in the airplane. I was a good stick, I knew the regs, my airspace awareness was solid and my comms were good but I truly had no idea how most things actually worked in the airplane.

People were giving you some great information in this thread, but I get the sense you may not have been taking it in (and still haven't). You just sound relieved that it's all over.

During my PPL check ride, the DPE asked me to explain the vacuum system in the airplane and what instruments I would lose it if were to fail. I gave him the textbook answer, to which he said, "the answer was a great recital of the textbook answer," then he leaned in for effect and growled, "except this airplane doesn't HAVE a vacuum system!" He then ripped me a new one (as politely as possible) saying that I needed to make it my mission to learn the systems. He was right.


I should really get on that :)
 
Hopefully that's the end of it, but don't be shocked if it's not. Sometimes even the controller you spoke with might have thought it was the end of it, but his supervisor, or someone else above him, might disagree, and send it to the FSDO anyway. And now they've got your "confession" on tape (you did expect your call to be recorded, right?), as well as (presumably) plenty of identifying information to know it was you flying the plane.

Don't scare me like that. They do that? We both basically agreed that it was the end of it. I never really said that I did anything wrong. I didn't talk to the controller but the the guy below the supervisor.
 
Don't scare me like that. They do that? We both basically agreed that it was the end of it. I never really said that I did anything wrong. I didn't talk to the controller but the the guy below the supervisor.

Not trying to scare you, just to impress upon you the gravity of the situation and the possible implications/consequences. Your deviation into Class B is recorded on a radar tape. As I understand it, those tapes, especially deviations, get independently reviewed by a group located in Dallas (QA/QC). The controller gets in trouble if he/she doesn't "report" those deviations to his higher-up (taking away the discretion). Basically, a paper trail of little "reports" is created and some middle-manager FAA/ATC drone very well may just forward it to the FSDO because that's what the rules say he's supposed to do, even though the guy you spoke to said it was "over." I can tell you from experience that "this is the last you'll hear of it" may only mean "this is the last you'll hear of it FROM ME."

At this point, these are nothing but lessons for the future. It's not really your fault, instructors, mostly due to their own ignorance/lack of training, do a ****-poor job of making sure students are prepared for these kinds of situations. Nobody tells you the right way to handle being told to call ATC (nor does anyone tell you that you're under ABSOLUTELY NO OBLIGATION to actually call), and the gut-level, human reaction is to call and try to talk yourself out of it or beg for mercy ("If I can just explain what happened they'll understand...). Unfortunately, that reaction is rarely successful anymore because of the aforementioned changes to internal ATC procedures.

Again, not trying to scare you, but it's important that you (and others) understand the process and the risks. File your NASA form, have a beer, and don't worry about it unless and until a letter shows up in the mail. If that happens, find a local aviation attorney to help you out (or call AOPA Legal Services if you pay for that).
 
Not trying to scare you, just to impress upon you the gravity of the situation and the possible implications/consequences. Your deviation into Class B is recorded on a radar tape. As I understand it, those tapes, especially deviations, get independently reviewed by a group located in Dallas (QA/QC). The controller gets in trouble if he/she doesn't "report" those deviations to his higher-up (taking away the discretion). Basically, a paper trail of little "reports" is created and some middle-manager FAA/ATC drone very well may just forward it to the FSDO because that's what the rules say he's supposed to do, even though the guy you spoke to said it was "over." I can tell you from experience that "this is the last you'll hear of it" may only mean "this is the last you'll hear of it FROM ME."

At this point, these are nothing but lessons for the future. It's not really your fault, instructors, mostly due to their own ignorance/lack of training, do a ****-poor job of making sure students are prepared for these kinds of situations. Nobody tells you the right way to handle being told to call ATC (nor does anyone tell you that you're under ABSOLUTELY NO OBLIGATION to actually call), and the gut-level, human reaction is to call and try to talk yourself out of it or beg for mercy ("If I can just explain what happened they'll understand...). Unfortunately, that reaction is rarely successful anymore because of the aforementioned changes to internal ATC procedures.

Again, not trying to scare you, but it's important that you (and others) understand the process and the risks. File your NASA form, have a beer, and don't worry about it unless and until a letter shows up in the mail. If that happens, find a local aviation attorney to help you out (or call AOPA Legal Services if you pay for that).

Can't it be worse if you land and don't call? I thought you had to. Please explain. I'm sure they can just dig up the records for who rented the plane out.

I spoke to the guy from FAA ATCT/TRACON in terminal services.
 
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Hopefully that's the end of it, but don't be shocked if it's not. Sometimes even the controller you spoke with might have thought it was the end of it, but his supervisor, or someone else above him, might disagree, and send it to the FSDO anyway. And now they've got your "confession" on tape (you did expect your call to be recorded, right?), as well as (presumably) plenty of identifying information to know it was you flying the plane.

The OP made no confession of busting the B. He was at 1,100 ft with a shelf of 1200 ft. He can have a properly set altimeter in the Kolsman window and still have a transponder reading high. Nothing wrong with that.

ATC still does have descretion in what they report outside of the TARP or "snitch patch" automatic reporting. TARP only reports loss of prescribed separation and not air space violation. The individual controller does air space. Sometimes they have time to follow up and have the pilot make the call, other times they don't care. In this case, prior to being sent to the FSDO, the facilities QA guy will review it first to even see if it warrants being sent up. Plenty of stuff can be swept under the rug even today.
 
Great thread as I was just thinking about this today. I was flying at 7,000 feet and my GTX transponder display showed a pressure altitude of 7,200 feet. Does ATC see whatever is on my GTX display? I wouldn't actually do this, but theoretically, if I had flown at 6,800 feet, would it show at 7,000 feet on the controller's display?

The encoding altitude part of the transponder reports based on 29.92. ATC computers correct it to local altimeter pressure before display. They should see what your altimeter says within a few feet.
 
Can't it be worse if you land and don't call? I thought you had to. Please explain. I'm sure they can just dig up the records for who rented the plane out.

I spoke to the guy from FAA ATCT/TRACON in terminal services.

If you don't call you can be assured it would go to FSDO and they would find out who the renter was.

There was a new "rule/policy" about a year or more ago that all perceived deviations go to FSDO. Controller has no choice.
 
The encoding altitude part of the transponder reports based on 29.92. ATC computers correct it to local altimeter pressure before display. They should see what your altimeter says within a few feet.

Within a few feet?

That hasn't been my experience, even on new turboprop 135 ships
 
I'd just like to clarify at 1100ft with current altimeter set 30.00 in my altimeter window they said radar showed me at 1400.

Basically here is the timeline:

I land

I get a phone number and call them, controller said don't sweat it. Told to just explain it to another guy (FAA ATCT/TRACON in terminal services) tomorrow.

Following day I get a phone call from him, he says "Well radar picked you up at 1400" and "I wont argue about that with you, if so, thats an aircraft problem" we talk some more about the local airspace and where I was. he says "Well ok, you seem to know about the class B here well so i'll just close this out" I confirm that it's the end of it he says "Right, it's not going to FSDO or anything like that" and "to get the plane checked out - merry christmas."

Thats about it, and I had filed the NASA report yesterday.
 
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Don't scare me like that. They do that? We both basically agreed that it was the end of it. I never really said that I did anything wrong. I didn't talk to the controller but the the guy below the supervisor.

No, it's paranoia. I got the same statements when I reported my "possible PD" on the board. I did the same thing you did, and the PD resolved with remedial training for the controller. Really.

You did everything right. Just, some people seem to think all government is out to get them. Except it really isn't. These guys are trying to prevent another Cerritos midair, and that's it. If it takes a 5 minute phone call, that's great. If it takes hunting down some ***hole who tries to hide everything, I'm sure you can see the concern.

Even if it did go up the chain to the FSDO, you're showing the right attitudes, and it would resolve minimally. Trying to hide would be substantially worse.
 
I'd just like to clarify at 1100ft with current altimeter set 30.00 in my altimeter window they said radar showed me at 1400.

Basically here is the timeline:

I land

I get a phone number and call them, controller said don't sweat it. Told to just explain it to another guy (FAA ATCT/TRACON in terminal services) tomorrow.

Following day I get a phone call from him, he says "Well radar picked you up at 1400" and "I wont argue about that with you, if so, thats an aircraft problem" we talk some more about the local airspace and where I was. he says "Well ok, you seem to know about the class B here well so i'll just close this out" I confirm that it's the end of it he says "Right, it's not going to FSDO or anything like that" and "to get the plane checked out - merry christmas."

Thats about it, and I had filed the NASA report yesterday.

Well a 300 ft difference is out of tolerance, so make sure you do get it fixed before you fly it again in an area that requires a transponder.

Despite what a lot of people think, your situation is the norm. Controllers don't want to file anything that creates more paperwork for them. Friend of mine woks a class B and he said he doesn't waste is time for someone in the bottom of the B unless it's a TCAS issue. No one cares about a 300 ft error in a transponder unless IFR separation is lost. In that case it is indeed out of their hands and the report will go to the area manager.

There's nothing to lose by calling ATC. It's not a trick to try and get you to admit fault. They have the proof in the radar tapes anyway. The call is either to talk to you about something they observed, or if indeed it is a pilot deviation, it's to inform you of what the witnessed and t tell you they are sending the report to the FSDO. The phraseology for a PD is standard and must be issued. If you are at fault, then admit your fault. You'd be admitting fault in an ASRS anyway. You're absolved from any penalty/ suspension so it doesn't matter.
 
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I'd just like to clarify at 1100ft with current altimeter set 30.00 in my altimeter window they said radar showed me at 1400.

That is consistent with your own observation of 1000 on the altimeter and 1200 on the transponder. With a pressure setting of 30.00, the FAA computer would add 80 feet to the 1200, making the difference of 300 feet to the nearest 100 feet. So 1100 on your altimeter would likely show as 1400 on the radar screen. Which is wrong, your altimeter or your encoder, is not known and you or the aircraft owner needs to get it taken care of.
 
If you don't call you can be assured it would go to FSDO and they would find out who the renter was.

There was a new "rule/policy" about a year or more ago that all perceived deviations go to FSDO. Controller has no choice.

You probably underestimate how difficult it can be to actually figure out who the renter is, assuming no flight plan was filed. If the flight school/FBO doesn't want to cooperate (they're under no obligation to, probably depends entirely on management and the relationship with the pilot in question), it can be very difficult, and a lengthy process, for the FAA to figure out who was flying the plane.
 
Here is the problem, I took off from KVDF at about 1000 with altimeter 30.00. My transponder showed 1200. Here is my flight path:

Direct Chemical plant at 1000 over the water direct skyway bridge then at 800ft outside of the shore until I made a turn into Clearwater beach and climbed to 1200 on a course parallel out of Campbell bridge. Contact APP and he is SWAMPED, told to standby, so I decend to 1000 - 1100ft and follow the magenta shade around surface area of Class B direct brewery and landed at KVDF.

Land and FBO has a phone number for me to call. I turned pale white and call them. The guy seemed calm and just told me that they showed me as inside Bravo near the surface area at 1300 or something like that. I have to call another person tomorrow morning and explain to him something about my flight.

You were unable to contact approach, so you were squawking 1200. You landed at an uncontrolled airport. Someone, nobody knows who, or in what kind of airplane, busted bravo. Approach calls the FBO to tell them to have someone call. You were the first to walk in the door - so you got the message so you take the blame for someone busting B. Why? What makes you think it was you? How do you (or anyone else) know it wasn't that geezer in a Bonanza that landed a few minutes behind you?
 
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The encoding altitude part of the transponder reports based on 29.92. ATC computers correct it to local altimeter pressure before display. They should see what your altimeter says within a few feet.

But they use two different pressure sources, so they likely will not. It's not like they're linked to the same diaphragm.
 
But they use two different pressure sources, so they likely will not. It's not like they're linked to the same diaphragm.

In 41 yrs of flying it has not been an issue.
Controller verifies altitude on radar contact, normally within 100ft of what my altimeter says, maybe a little more if I'm changing altitude. He's happy, I'm happy.

IFR, assigned 7000MSL and I'm level. ATC sees 70C for altitude and does not see a change unless I get more than 200 ft off assigned altitude. At least that's the way it was when I was a controller.
 
In 41 yrs of flying it has not been an issue.
Controller verifies altitude on radar contact, normally within 100ft of what my altimeter says, maybe a little more if I'm changing altitude. He's happy, I'm happy.

IFR, assigned 7000MSL and I'm level. ATC sees 70C for altitude and does not see a change unless I get more than 200 ft off assigned altitude. At least that's the way it was when I was a controller.
And with rounding, that means it only needs to be +/- 50 between the alt encoder and your altimeter to show up correctly on the money. A 100 foot discrepancy between reported and mode c won't raise any questions. Even a couple hundred, who would think much unless you wind up reportedly busting airspace? Even the ambient pressure difference between a reporting station and your location could cause that discrepancy on the console.
 
Well a 300 ft difference is out of tolerance, so make sure you do get it fixed before you fly it again in an area that requires a transponder.

Despite what a lot of people think, your situation is the norm. Controllers don't want to file anything that creates more paperwork for them. Friend of mine woks a class B and he said he doesn't waste is time for someone in the bottom of the B unless it's a TCAS issue. No one cares about a 300 ft error in a transponder unless IFR separation is lost. In that case it is indeed out of their hands and the report will go to the area manager.

There's nothing to lose by calling ATC. It's not a trick to try and get you to admit fault. They have the proof in the radar tapes anyway. The call is either to talk to you about something they observed, or if indeed it is a pilot deviation, it's to inform you of what the witnessed and t tell you they are sending the report to the FSDO. The phraseology for a PD is standard and must be issued. If you are at fault, then admit your fault. You'd be admitting fault in an ASRS anyway. You're absolved from any penalty/ suspension so it doesn't matter.
At least one popular text on aviation law, used in some law-school classes and relied on by Capt. R. (when it agreed with him) suggests that it a pilot is given a number to call, he should land, put his plane away, and go home. That's not legal advice for this or any particular situation, I'm just pointing out that at least some "recognized authorities" on the subject disagree that there's nothing to lose by calling ATC. It may be that in some situations, the risk of not calling is greater than the risk of calling, but that's a legal question, best answered by a lawyer, not a flying question, best answered by pilots. JMHO, of course.
 
At least one popular text on aviation law, used in some law-school classes and relied on by Capt. R. (when it agreed with him) suggests that it a pilot is given a number to call, he should land, put his plane away, and go home. That's not legal advice for this or any particular situation, I'm just pointing out that at least some "recognized authorities" on the subject disagree that there's nothing to lose by calling ATC. It may be that in some situations, the risk of not calling is greater than the risk of calling, but that's a legal question, best answered by a lawyer, not a flying question, best answered by pilots. JMHO, of course.

But when you've filed an ASRS, what legalities are involved? You've already admitted fault and no civil penalties or suspension will occur because of filing the ASRS. Calling ATC just reiterates what is given in the ASRS.

I knew a friend from the military who violated a sensitive area in restricted air space. He was given the number to call and never did. Ended up being suspended for 30 days. I would bet anything that if he called ATC and apologized, they never would have filed a report on him.
 
I was digging around because the person I spoke to said "I'll close it out" and along the lines of "This is it nothing more will come of it." I'm so curious and partially stressed because of this. I'm sure my mode C was faulty in this case but it seems like they did something different with my case. Not to mention I was unable to be in contact in the air with them. I'm curious how all of this happens as it seems like there isn't a sure fire way to figure out if it's truly closed and done or if it can still come back to haunt you.

I came across this (What are your thoughts on it?):

5-1-2. SUSPECTED EVENT
a. In order to maintain an effective Air Traffic
System, it is imperative that we identify all deficiencies
within our system and take appropriate corrective actions
necessary to fix any associated problems. Operational
errors and deviations are reported for just that reason, so
those problems (either systemic or individual) can be
corrected to enhance system integrity. The identification
of operational errors and deviations without fear of
reprisal is an absolute requirement and is the
responsibility of all of us who work within our system.
b. Accordingly, it remains Air Traffic Policy that any
employee who is aware of any occurrence that may be an
operational error, deviation, or air traffic incident (as
defined in paragraph 4-1-1, Definitions), immediately
report the occurrence to any available supervisor,
controller-in-charge (CIC) or management official.
c. Employees’ shall verbally provide the preliminary
information, of which they have knowledge, when
requested by the supervisor, controller-in-charge (CIC)
or management official to make an initial determination
as to whether an investigation is warranted. This phase
is meant only to determine the need of an investigation
and is not investigatory. Therefore, Union representation
is not required at this time.

5-1-3. INITIAL INVESTIGATIONS
The initial investigation is intended to be fact finding in
nature. It has been designed to determine what occurred
in the system, to ensure corrective action is initiated to
maintain system integrity, and to report significant
events to higher levels of management.

4-1-8. AIRSPACE INTRUSIONS
Intrusions are reported as pilot deviations in accordance
with FAA Order 8020.11.
a. ATM's (excluding AFSS and FSS managers) shall
provide guidance in facility directives for the tracking
and identification of aircraft that enter:
(1) Class A or B airspace without authorization.
(2) Class C or D airspace without establishing
communications with air traffic control (ATC).
(3) Special Use Airspace, e.g. Temporary Flight
Restriction (TFR), prohibited areas, and other restricted
airspace without authorization.
NOTE:
The Chief Counsel's office has instructed the Regional
Counsel offices to include the ATD on their distribution
lists for notification following final enforcement action
on controlled area intrusions.
b. When enforcement action is taken as a result of a
controlled area intrusion, the ATD shall be responsible
for ensuring notification through the facility ATM to the
reporting controller of the outcome of the enforcement
action.

4-1-9. INVALID MODE C REPORTING
a. In order to track and report aircraft with
transponders equipped with invalid Mode C readouts
whose pilots have been advised to stop the altitude
squawk, facility managers shall provide guidance in a
facility directive(s) to ensure that a designated facility
officer compiles a weekly list of invalid Mode C reports
and forwards this report to the Regional Flight Standards
Division. This report may be forwarded electronically
with the concurrence of the Regional Flight Standards
Division and shall include:
(1) Aircraft registration number/call sign.
(2) UTC date and UTC time of the incident.
(3) Assigned altitude and Mode C reported altitude.
(4) Facility 3-character identifier and facility type.
 
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TK I think you're stressing this more than you should. Those policies you cite have been in place forever. Doesn't mean controllers follow them to the tee. Trust me, there are far more PDs happening around the country than most pilots are aware off. As a friend of mine said "are we required to report all PDs? Yes, does it happen? No."

What has changed in recent years is the increase in Operational Error occurrances on the part of controllers. Two reasons for this. First, the FAA went to a "just culture" policy where errors are freely reported. They can do this now because they file an ATSAP. It's like a controller's ASRS form. Before, they hid mistakes to try and keep their jobs or avoid punishment. Second, the "snitch patch" is in place at most facilities and is automatically sending out reports to the area manager where as before a loss of sep could be hidden in the part of the controller.

If the controller you talked to did indeed send the report to the FSDO, what kind of punishment do you think you'd get anyway? You already filed an ASRS, at most you'd get a call from the FSDO to see if the pitot static has been tested and when the last time the transponder was tested. No harm in that. It's like when I had an emergency, FSDO called wanting to know if any damaged occurred. Nope, end of story.
 
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As a friend of mine said "are we required to report all PDs? Yes, does it happen? No."

I don't like counting on a controller, or anyone for that matter, ignoring a policy .
 
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