Posts about: "ADSB (All)" [Posts: 130 Page: 4 of 7]¶

See the below post 1180 and some earlier ones:

The horizontal boundaries of the route are not precisely defined. Even then, it's not a very steep slope and the horizontal position does not make a huge difference.

75' is plainly inadequate vertical clearance between two aircraft and doubling/tripling that would still be unacceptably close. Separation was surely expected to be achieved horizontally but the enforcement/implementation was lacking.

Disappointed to hear that. Searching for or expecting genuine emotion in the political theater of a congressional hearing is like searching for virtue in a brothel.

I also watched the hearing and learned little new from the parade of platitudes and witness obfuscation. I thought far too much time was spent on ADS-B (an acronym which Maria Cantwell is incapable of uttering correctly). No discussion on use of visual separation. There were a few new points:

1. Cause of spurious DCA TCAS alerts. ME links in related thread.
2. When NTSB examined other Blackhawks of 12th AB fleet, found significant number which did not transmit ADS-B even when ADS-B switched on. One helo (accident helo?) was found to have not transmitted ADS-B for past 700+ days.

Dumbo Question 1.

How would the successful transmission of ADSB Out information by the Blackhawk have changed the outcome on January 29?

After watching the US Congress “grill” the military, FAA and NTSB how could they participate in a conspiracy of silence…

The NTSB will be seen as either very dumb or deceitful or both.

Now what was the number of the Q ANON Pizza shop, I feel like some truth tonight.

Send it to me via Signal. What a joke! The relatives of the crash victims were there to watch the farce.

The small elephant in the room…

Unfortunately, and I hate to say this, I have reached a conclusion beyond those reached by other posters to this forum, to wit:
The US Army, in order to meet its mission requirements, really does not want civilian pilots (commercial or otherwise) to know where its helicopters are. My evidence for this is: The eagerness of the US Army pilots to assume responsibility for seeing and avoiding commercial aircraft; The DCA tower procedures that do not allow civilian fixed wing pilots to hear the conversations between the tower and the helicopters; The Army practice of turning off ADS-B out while on missions and training flights that follow mission profiles (as explained by the USA general in the hearing); The Army's refusal to produce the memo regarding its use of ADS-B to Senator Cruz.
Should the policies adopted by the US Army be regarded as the fundamental cause of this accident?

Dumbo Question 2

Given the extraordinary level of interest in the US Army Blackhawk carriage, activation and transmission of ADSB Out information in the US Congress in the last couple of days, do you think the NTSB could have confirmed (facts) how that information would have been displayed in the cockpit of the CRJ and the ATC TWR cab at Washington DC Reagan?

The small elephant in the room.

ATCDumbo
I'm all ears, excellent point. This focus on ADSB-OUT, and ADSB-IN is really a furphy in terms of this investigation to determine the facts, the whole facts and nothing but the facts.

If 5342 had ADSB-IN then PAT25 not having or not displaying ADSB-OUT could be relevant depending on 5342's cockpit display, the training of the pilots and their scanning.
5342 didn't have ADSB-IN so move along, move along, nothing to see, these aren't the droids you're looking for.

**Caveat. If the TWR display were using ADS-B for their updates and to generate Collision Alerts then the absence of PAT25 ADSB-OUT could be relevant.
But would the TWR ATC even know (or care) whether PAT-25 was ADSB-OUT capable. TWR ATC involves looking out the windows and judging the relative positions of aircraft.

Note: ATC display systems are not referenced in the NTSB Aviation Investigation Preliminary Report. This seems to be a glaring omission. So perhaps the NTSB are either very dumb or deceitful or both.

To further illustrate the focus on ADSB. Figure 1 Google Earth image with preliminary ADS-B data for flight 5342 and radar data for PAT25.
The ADS-B plots are 1 seconds intervals, the radar data are 4 second interval (as stated during US Congress Q&A).
So the focus is on the whizz bang ADS-B kit rather than what the ATC saw on their display.

There is reference to ATC radios, and 5342 was on frequency 119.1 MHZ and PAT25 was on frequency 134.35 MHZ. The ATC could've had them on the same frequency (changed PAT25 to 119.1 MHZ) but this would be abnormal. ATC Voice Switch systems like Frequentis, SITTI and Rohde & Schwarz typically have a frequency coupling, whereby controller broadcasts on multiple frequencies (2 or more) and voice communications on one frequency are heard on the other. In this case, ATC would broadcast on 119.1 MHZ and 134.55 MHZ and 5342 would hear instructions for aircraft on 134.55 MHZ, and PAT25 would hear instructions for aircraft on 119.1 MHZ.

Yes, visual separation is typically used close to an aerodrome where the ATC is applying visual separation to reduce the standard from 3NM to something less, 2NM, 1NM, or even less, depending on the circumstance which includes weather (included visibility), day / night, workload to monitor the separation, plus other considerations such as equipment.

I just wonder how many of the January Route 4 Helicopter plots crossing RWY 33 Approach (post 1346) were the result of ATC issuing a control instruction to change the track to closer to the shoreline or further over water.

Use of Route 4 during RWY 33 Approaches or RWY 15 Departures is possible providing a clearance limit is imposed prior to assigning relevant traffic, positive control instruction(s) and in the case of 5342, advising them of the relative position of PAT25 and that PAT25 would be maintaining separation from them.

Example for Route 4 southbound would be a clearance limit of Hains Point. Helicopter would be released past this point when there is no conflict (nil traffic) or assigned separation to avoid (pass behind). If there is a in-line stream of arriving traffic then Route 4 may not be available.

Sydney KSA has something similar for one of their helicopter routes - BONDI 5 (yep, named after the beach), delays may occur when RWY 07 is in use for DEP, or RWY 25 is in use for ARR. Further, the route is not available when RWY 16 PRM approaches are being conducted. Sydney KSA helicopter routes are in text form - TRACK TO..., TRACK VIA..., EAST OF..., and the INBOUND routes to Sydney KSA have a clearance limit in the clearance. A map display is very useful however it should be based on route descriptions. Perhaps the committee of 17 knows the history of the helicopter routes in and around DCA.

No, I think the US Army policies with regard to ADS-B will be found to be irrelevant to this accident. Brigadier General Matthew Braman is correct in that the US Army, and other government agencies with policing, security and counter intelligence responsibilities do not want their aircraft tracked on FR24 and the like. The MOU is key and may not see the light of day in the public domain. National Security will trump (sorry) other considerations, even safety, especially with so many high profile score buildings adjacent to DCA.

I'm applying SLF/attorney license here (hey, there's poetic license, so why not?) of repeating - with some editing - a post I placed on the R&N thread about testing at DCA.

1) Regarding ADSB-Out being turned off, what is the reason there was such emphasis placed on this at the recent Congressional hearing (and just scoring media points per usual in Committee hearings doesn't qualify as a "reason" in this context). Is the reason that there are objections to running the kinds of tests in question (per the R&N thread) in or near DCA airspace? Is it valid to say there is no connection to the chain of causes-and-effects which led to the midair collision on Janaury 29 (but if there is, what is that connection, specifically)? Is the reason some connection with the occurence of TA's and RA's on TCAS as documented by NTSB? (although other posts on the R&N thread indicate that ADSB-out isn't connected to TCAS advisories . . . that is, if I understood those other posts). Or something else? I'm dismissing the mere fact that FR24 doesn't provide information to enthusiasts as the reason for such emphasis in the hearing.

2) If the Army operates certain "missions" with ADSB-Out turned off, and it conducts these operations based on national security concerns, my initial thought about this practice is, . . . . . . . hey, isn't there a discretionary function involved in deciding what avionics (or electronics system if this isn't within the technical definition and scope of "avionics") to operate based on national security concerns? So the Senator declaring that there is "no justification" seems to deliberately overlook the existence in the Federal Tort Claims Act of the exception. (I realize there has not been, to my knowledge at least, any lawsuits filed yet. But they're certainly going to happen.)

Of course, this all said, the indictment of the structure and operation of the portion of the NAS in which DCA is situated might (as suggested previosly) itself be adjudged inconsistent and non-compliant with basic standards of aviation safety. The only not-crazy-sounding justification for that state of affairs would seem to be "but we have to move traffic in volume." As a legal wrangle over whether that obvious judgment of a "policy" nature is or is not a proper basis for keeping federal immunity in place in a particular matter . . . I am quite skeptical such a legal wrangle would ever make it as far as an actual courtroom proceeding. But will Congress not try to manuever itself into the issue for all the usual reasons - some people want actually to address the problem constructively, some just want to please their donors, and some just follow the crowd, or so it always appears.

3) Something about discovery in civil litigation was underscored by the exchange in the video clip: there's an Army memo, dated Aug. 9, 2024 as referenced by Sen. Cruz, about operating in the NAS with ADSB-Out turned off. And the Army so far declines to turn it over to the Committee. (Applying the rough equivalent of a pre-snap read by a QB, the manner in which the Army witness replied to Sen. Cruz's questions gave the impression that the Army and DoD will strongly resist the memo in question becoming public.)

[Okay, I'll refrain from speculating how much fun it would be to decide which officer or officers would be presented as the Person(s) Most Knowledgeable about the matters discussed in this memo (on the Army side, receiving the Rule 30(b)(6) deposition notice), or similarly, how much fun would be had by counsel describing the "subject matter(s)" which must be specifically iterated in a Rule 30(b)(6) deposition notice (on the plaintiffs' side).]

4. I'm very determinedly hoping this won't be read or even misinterpreted as an offensive point. In the YT video produced by "Mover" in which he interviewed a former Army helicopter aviator (post 1228), it was possible to draw the impression that Army helicopter pilots operating in the airspace in which DCA is situated have a certain attitude toward FAA ATC. That is, the Army operates - one could get the impression - in its own "airspace system" and deals with FAA ATC only as much and only as quickly as necessary. Listening to the pertient Jan. 29 ATC R/T, and knowing the visual difficulties presented by the basic facts of nighttime in that specific area of the DCA airspace, plus NVGs, an observer could get the impression that the Army aviator handling the R/T was doing so in a perfunctory manner on Jan. 29.

To explain further, upthread (in post 1261) in the context of a Mover/Gonky YT video (post 1228) someone much more knowledgeable than myself observed that the way in which the Army pilot interviewed in the video described communications with FAA ATCOs in DCA airspace was as if Army chopper pilots view FAA ATCOs somewhat as a nuisance. Far be it from me to fault any pilot over any practice or custom in anything, including comms with ATCOs. But faulting any pilot is not the point. The point is that in that YT video, as related that other poster, --
"it was suggested that it\x92s perfectly OK to second guess what ATC might have said to you, reply to that, and then if no correction is forthcoming you can comply with your guess. As others have pointed out implicitly, that works if there\x92s only one error involved, but here there were three: an untrue statement, leading to a wrongly issued clearance, and a missing read back."

It is known that ADSB-Out is not active on the Army and other certain missions in the relevant airspace. Is there also a pattern or practice of operating with a mindset that FAA ATC is a necessary nuisance, to be indulged but not focused upon as closely as other airspace users? If any reader asserts this question accuses the Army pilots or any one of them in the helicopter on January 29 of negligence - that would be incorrect. The way in which the airspace had been designed, managed and operated handed those pilots a pre-determined normalization of complacency - so it appears, does it not?. They operated their flight within the system they had been given, which does not constitute negligence. The designers, managers, and operators of that system . . . well, it will be for the courts to sort out whether the exception to the removal of federal immunity to tort claims applies to those systemic level actions, or not. If it were not for the existence of the discretionary function exception, I personally believe the race to the courthouse would already have been a feeding frenzy worthy of the most biting negative stereotypes about lawyers.

Speaking of immunities, wasn't it generally believed that the airspace within the NAS, and especially airspace in which major airports in the United States are situated, was immune to midair collisions, in general and not only collisions sudden, without actionable warning, and with at most two or three seconds' knowledge of impending death and disaster? Mere SLF/attorney as I am, I had believed that. It follows, but only under that mindset, that what occurred was obviously negligence, and even gross negligence. The point is, expect the lawsuits to be, in a word, consistent with the ugliness one feels seeing the wreckage pulled from the Potomac, or reading about the backgrounds of 67 people. Or both.

If the US Army has to keep its flights on published routes in the nation\x92s capital \x93secret\x94 and turn off ADS-B (not saying ADS-B would have saved the day here); we\x92ve already lost the \x93war\x94. There\x92s simply no need for this training\x97in a national emergency where continuation of government mission is necessary\x97there won\x92t be any civilian traffic at DCA. We\x92re talking 9/11 or nuclear war, not \x93do you I need to get to the Pentagon for PowerPoint briefing now, CWO\x94.

There would be hundreds if not thousands of demands for entrance, egress by "critical" players... Mostly egress

Keeping each flight anonymous as possible means it will be difficult to pick off a particular General or other leader, but it's a target rich environment and picking off even one, with no one high ranking aboard is enough to send a message. While I get that being sneaky lowers the odds, they are not reduced to zero as long as there is a common hub and a few narrow courses. Like, if someone managed to smuggle an anti-helicopter missile into the area, they wouldn't need ADS-B to tell them "that's an Army helicopter."

Instead of the unavoidable chance of getting shot down there is the continuous risk of mid-air collision.

Of the two ends of these conflicting requirements, I don't see that the DoD will want to budge, and I don't see a safe resolution that works without ADS-B and other broadcasts.

At the least, in a national emergency, there would be no need to follow the defined helicopter corridors. The Georgetown residents can file their noise complaints if they want to.

Not sure that I'm following this focus on ADSB. Unless the PSA CRJ had ADSB-IN, then the absence of ADSB-OUT in the Army helicopter is irrelevant to the accident.

In recent investigations ATSB (Australia) has been pushing the merits of ADSB-IN. NTSB's (and ATSB's) remit is rather broad and can be used to push a particular agenda.

FAA (and CASA) can mandate ADSB-IN in all powered aircraft, and the US (and AU) Governments could easily fund the fitment from the Government coffers. Every billionaire in the Forbes Top 200 Richest People in America could easily afford to fund ADSB fitment. Would certainly improve their Philanthropy scores.

Be interesting to see whether PSA Airlines tick the ADSB-IN option with their next fleet order, or retrofit their fleet with ADSB-IN.

It's a general comment about dark operations when dark doesn't help as much as it would at first appear.

I agree with the rest and don't understand** the constant foot dragging by the FAA about ADS-B.


**Disclaimer: I do understand it because the FAA is under control of the Congress and the lobbyists for the aviation industry seem to have made it clear that a mandate for ADS-B will be resisted by a bunch of people who don't want to spend money on what they feel is unnecessary. Instead they go after the ones with a weak lobby, the hobby drones, to have useless short-range position transmitters that don't improve safety, but do increase cost. I also think there is some sort of cover-up in that ADS-B doesn't have enough bandwidth for the full integration such as placing transmitters on known fixed obstacles, like radio towers, and the predicted commercial drone traffic. So the FAA is stuck. Have it as a nice extra, but if they push too much and the flaws become obvious. To fix that likely requires some give from the FCC of spectrum, but the FCC has been selling prime spectrum to private industry and have lobbyists chewing on the FCC who would not give up a slice for the common good.

The Collins Proline 4 avionics system found on the CRJ has no provision for ADSB-IN, and knowing how the system works at a low level, I don\x92t think there is any way it could be added. It would probably require the addition of a dedicated display unit such as the Garmin GI-275, which is capable of displaying ADSB-IN when operating in MFD mode.

Adding the mandated ADSB-OUT capability to the Proline 4 was a simpler exercise as it mainly required upgrading the TDR-94 transponders and making use of already-available ARINC-429 data from the Air Data Computers, AHRS/IRS and GPS

I feel like this ADS-B discussion at political level is just a diversion , either they have been badly briefed by their staff , or they have and are deliberately chosen to raise this in public to shift the blame game somewhere else.
Because , even if the helo had ADSB out and the CRJ an "in " receiver and a CDTI display , what would have happened then ? . The crew would have spotted the Helo, maybe asked ATC what was that , and the reply of the controller would have been something like : " it is a military helicopter on route 4 , has you in sight , passing behind ." and then would you , flying the CRJ , take evasive action or go around after hearing that ? No .
.
The primary cause of this collision is airspace design and normalization of deviance over the years. I hope the judges will see that when the trial comes. We should leave the military crew and their grieving families out of this.

NTSB chair pointing out the horizontal position of the helicopter during last weeks testimony.
The altitude is still uncertain because of difference between jet and heli values and destruction of the heli altimeter. So work on that is continuing with a focus on other sources.
But note the 75 ft separation is a maximum. So if the heli was at 200ft then it was on the glide slope.




Another interesting point is that mixed heli and fixed wing is forbidden in the yellow zone (permanently), and ADSB mandatory in the red zone. With routes 4 and 6 cut.

See post below

I tend to agree with ATC Watchers take on this.
Some people are making out that if the Helicopter had ADSB-out switched on/ activated, then this would never have happened.
Someone correct me if I am wrong but if the Blackhawk has ADSB-out switched on then nothing changes for the CRJ on that night. The TCAS behaves the same, there is no display of the Blackhawk on the CRJ\x92s Nav display\x85..nothing changes. The CRJ crew are still conducting an approach that requires a lot of fast mental processing close to the ground, at night onto a short runway while ensuring checklists/configuration etc is correct. ie they have a high workload. During this high workload phase, \x91the system\x92 has seen fit to allow a single Human ( the helicopter Captain) to be responsible for the separation of the two aircraft visually, at night, in a busy environment while conducting a check, on NVG\x92s.
Is it likey that a single Human, with the sole responsibility, will make a mistake? It\x92s not just likely, it\x92s inevitable, regardless of how sharp and well trained they are, if you run the program long enough their vision, or their SA will fail them and we get what we got here.
The system should never have devolved to the point where one person accepted the responsibility for visual sep 6nm away, at night, in a busy traffic environment while dealing with their own high workload.
The Blackhawk crew had a high workload, the CRJ crew had a high workload, the ATC had a high workload, there was no fat left in the system. Humans make mistakes and any good system will be tolerant of those mistakes.
The system was not tolerant of a mistake, ergo, the system is at fault.

Another interesting point is that mixed heli and fixed wing is forbidden in the yellow zone (permanently), and ADSB mandatory in the red zone. With routes 4 and 6 cut.



another item in the testimony was that generally 100% army helicopters flew there with ADSB set to OFF.

and that the accident heli might have put their ADSB to ON, but that the FAA had not received ADSB data from this heli in 730 days.

on ADSB there also was a difference between the Mike and Lima models,

NTSB chair indicated there was a lot more factual information. I wonder if the pull from Congress will lead to a change in the normal process, and release more factual information (with an appropriate disclaimer).

Recognizing that if the only change was ADS-B Out on the helicopter would not have changed things, the use case proposed by the FAA and shown in their promotional materials in support of ADS-B is a helicopter flying in crowded airspace with a display of nearby ADS-B Out traffic. With only half the system installed, it's not going to work.

This is from 7 years ago:

The placement of the yellow line closes down the I-395/VA-110 left hook around the East side of the Pentagon that Route 5 inbound helos were using quite routinely before the accident. And whatever restrictions are or are not in place there is virtually nothing moving on Route 5, I guess the top brass has discovered Uber Black.