Posts about: "Visual Separation" [Posts: 250 Page: 9 of 13]¶

Pretty much it, everyone had to be lucky every time, gravity only had to be lucky once. The altimeter issues are a red herring at best, the helicopter crew were not trying to go directly under the airplane.

I agree that the DC controllers should not be scapegoated. At the same time, the concept of professionalism must be addressed. The concept that professionals in a field must alone (without management, without lawyers, without the public) maintain the best practices of the given professional discipline.

In the US, physicians who work for "Health Maintenance Organizations" are asked to practice medicine, at times, in a "basically unsafe" manner...to keep patients moving. On occasion, such practices will bite a patient (and sometimes the physician). As a whole, HMO physicians do not enjoy the best reputation.

From my perspective, there is practically no difference between the plight of an American air traffic controller and an American HMO physician. Both are expected to "squeeze one more in." Both fields are staffed by above-average capable individuals who thrive on challenges. Both are managed in such a manner that they cannot say "no" and also keep their job. In this regard, at least physicians have job portability.

But the take home point is that one cannot admit to knowing a practice is fundamentally unsafe, yet do it anyway. The public, rightfully, should not accept this. I have no solution except more staff and/or more airports (and not some next-gen whizzbang computer system).

It's an interesting comparison, but I am not sure it's fair to say that a controller would know that visual separation at night is unsafe or appreciate the counterintuitive point that NVG make it less safe. Of course, they *should* know, but since they don't need to have night flying (or any flying) experience of their own, they are reliant on being educated on that point. That would be a matter for the regulator (specifically, pilots and human factors specialists within the regulator) to ensure. The same goes for the more robust option of prohibiting night visual separation entirely.
Returning to your doctor analogy: if front line medics prescribed a drug which years later turned out to be harmful to patients, despite following all professional best practice and having no reason at the time to suspect that the drug had been wrongly certified, it would be grossly unfair to hold the medics responsible. Instead we would turn to the drug regulator and those who carried out the trials.

The point is that PAT25 could have been tightly hugging the eastern bank at precisely 200 feet, and yet everyone would still have died if the CRJ had been slightly below its proper approach path (as it might easily have been). Yes, you can say that *this* accident wouldn't have happened if the helo had been at 200 feet, but that gets us precisely nowhere in preventing recurrence.

Systems that rely on human perfection are 100% guaranteed to fail. The only question is how often. The system in place at DCA required helo pilots to assume responsibility for visual (*not vertical*) avoidance of collisions in order to fulfil their ordered missions. Given what we know about human visual performance at night, that would eventually end badly, and sure enough it did. There is a strong element of the pilots having been set up to fail, which is why no-one here is going hard on them.

Altimetry and height keeping would be important matters for investigators if the collision had occurred due to a breakdown in vertical separation, which as a minimum would involve 500 feet (and more often 1000 feet) of planned spacing to account for instrument and height keeping errors. FAA instrument rating standards require pilots to be able to maintain altitude plus or minus 100 feet. This helicopter was being flown VFR at very low height, which means that looking outside takes primacy over monitoring instruments. I'm sure helo pilots could fly along at 175ft plus or minus 25ft if they really tried, but you can be certain they wouldn't be looking out for traffic (as is required when holding responsibility for visual separation).

However, as there was no vertical separation built into this procedure, all of this is at best a distraction. The more important questions are why procedural barriers were not in place to stop the route being used during landings on runway 33, and whether visual separation at night is an adequate barrier to collision when airliners and their human cargo are involved.

N123, join the downwind, your traffic is a 737 on final 2 miles out, turn base behind him, you are #2. I can do that at night unless there are other 737s lined up and then I have to figure out which one.
N123, do you see the closest plane lined up, pass right below and behind him and never mind all the other planes right behind. Ah......NO.
There is night visual and there is night nutty visual. The first example leaves a lot of room for error and time for ATC to see if it is going wrong.

Easy Street:
"However, as there was no vertical separation built into this procedure, all of this is at best a distraction. The more important questions are why procedural barriers were not in place to stop the route being used during landings on runway 33, and whether visual separation at night is an adequate barrier to collision when airliners and their human cargo are involved."

Aircraft accidents bring lawsuits - like it or not.

I'm not a member now, nor have I been a member, of the part of the profession which specializes in suing usually anybody plausible as a defendant. That doesn't mean, as an attorney first and SLF second, I don't see big problems looming ahead. (A prior post on legal factors was junked by the mods, but that was then, this is. . . .)

The FAA and the U.S. Army are privileged with sovereign immunity, as a general rule. A federal statute - the Federal Tort Claims Act - enacted a waiver of sovereign immunity BUT with an important exception. If the allegedly negligent act (or omission) was taken (or failed to be taken) as part of a "discretionary function", immunity still exists. The basic explanation is that discretionary functions involve policy judgments which, in the view of Congress, cannot be "second-guessed" in lawsuits over alleged federal agency negligence. The other half of the equation is that immunity is waived for "ministerial" actions, sort of (to over-simplify) plug-and-chug activities.

Is the construction and operation of the airspace around DCA a matter of policy judgment? I can almost hear the lawyers planning to file suit arguing that airspace rules which make simple, obvious sense are not derived from policy judgments. I can almost hear them issuing subpoenas (through the necessary international process) of Network Manager or MUAC senior managers to gain testimony that in European airspace, as others have observed about Heathrow, the airspace rules are more like "plug-and-chug" than the sometimes esoteric, and usually vague and/or ambiguous, factors which inform the choices made in - offensive phrase coming - "the policy world."

And will our fine feathered legal eagles sue American too, just to go after the deep pocket, and try to force the airline to take a position on the federal immunity questions?

It's too bad so much attention is focused on the dumb shows and noise currently meant to entertain the grandstands (if you get my meaning). There should be a way to compensate the families of the people who perished in this awful, tragic, and ultimately senseless midair collision. Is the United States civil justice system really going back to 1960 and pretending that what we are dealing with is the December 16 1960 DC-8 - L-1049 Super Constellation midair?

As another poster way, way upthread said, I feel rage.

No, it does not matter much as he was performing a visual separation ,and remember, he was instructed to pass behind so it may deviate from track. ( although they might have missed this instruction according the CVR )

Let's see if I have understood "plug and chug" correctly!

If we took the FAA to be undertaking "plug and chug" regulatory and procedural activities, unburdened by political considerations and at risk of having EASA or UK CAA regulations and procedures held up as comparators in negligence cases against it, then I think it is highly unlikely that FAA regulations would be as permissive as they are in respect of visual separation and runway occupancy (the two most obvious and frequently cited points of difference, at least where airline operations are concerned), or that DCA\x92s helicopter routes would have existed. So why such a difference in approach? Economic factors are usually held up as the reason, and I fear this takes us away from "plug and chug" regulation into policy territory where immunity would seemingly apply.

I very much doubt that any politician, corporate lobbyist or general would explicitly advance the argument that occasional accidents are a tolerable price for the traffic capacity enhancements enabled by visual separation. It'll be interesting to see whether the NTSB forces that argument into the open, or enables it to be avoided by distracting itself with altimetry and other such matters.

You should feel rage. Managing control of airspace is not a matter of political interest any more than the rules of the road for driving cars is. And in my previous tirade I forgot the earliest parts of this ****show which was an aircraft on a stabilised approach asked to circle to a lesser equipped runway in order to expedite traffic. The next time I hear someone in authority say that safety is our number one concern, I think I'll probably choke on my own vomit.

This just a catchy phrase to make passengers comfortable, just like the : " Staff are the most important asset of our company " on can see in the reception hall of many companies nowadays . The shareholders must be smiling a bit when passing thought those banners...

As many and I said before, discussion about Altimeters or width of VFR routes are just distractions to deflect from the real cause , which for me can be resumed into the lack of a safety assessment and safety case of existing procedures. We all had to do this when SMS was widely introduced in the late 90s It was not that easy , but we discovered a few holes that were closed.
Here in DCA we see a couple of procedures that would not have passed a safety case : e.g Route 4, Circling to RWY 33 with that route active, visual separation at night , use of NVG on that route ..etc,,

Flying in itself always bares a risk,, our job is to minimize the risk , not to eliminate it , but here the Regulatory ( i.e FAA) failed to minimize the risks.
As in the US the FAA is both the service provider and the Regulator , and is in addition dependent of political will and pressure for its funding , the willingness to implement unpopular measures, may be limited. A Judge might look into this differently but for those part of the discussion I hand over the floor to .Willow run 6-3 .

I have not read, in any detail, exactly what has been said about altimeters , mode C, VFR routes, visual separation at night, mistakes by ATC or pilots - any , or all of these may have been contributory causes to this accident but; there was one overriding cause of this tragedy, & that was the existence of a dangerous route & procedure in a very low level & high pressure & demanding traffic situation. In short, these sort of routes should never be allowed anywhere near short finals at a busy commercial airport. If the helicopter route had not existed, this accident could, & would, never have happened. End of story - almost.

The more posts I've read on this thread, the more I'm anticipating that court actions seeking compensation for the families of the people killed in this accident will encounter very tough barriers.

This is an excerpt from a website of an actually well-known, very accomplished, and respected group of lawyers who specialize in (among other things) aviation matters. I'm not using their name and I don't have any approval, express or implied, to use information from their website - but if justice is to be sought for the victims' families, public discussion is - or should be - encouraged.

"A discretionary function is an action of a governmental nature exercised by a federal employee, but in order for that action to be considered a discretionary function, it must pass a two-part test:

There must be an element of judgment or choice. That is, if a federal statute or regulation prescribes a course of action for an employee to follow, there is no discretion.
That judgment or choice must be susceptible to policy analysis.
The Federal Tort Claims Act contains a discretionary function exception that says the U.S. cannot be held liable for any employee\x92s failure to exercise or perform a discretionary duty.

Within the legal field of aviation accidents, discretionary duties for which the U.S. is not liable include the following:

Aircraft \x93spot check\x94 certifications
Weather forecasting
Failure to install equipment
The FAA\x92s design of flight procedures
The types of actions that are considered not discretionary, and therefore, open the U.S. government to litigation are:

The failure to issue air traffic control manual warnings
If air traffic control fails to warn of weather dangers
The failure to maintain equipment
Relaying incorrect instructions to pilots."
END OF EXCERPT [not intended as legal advice here or on its original internet page]

So to return to ATC Watcher's point...... the more posts I read about this midair collision (plus other information such as NTSB briefings) the more I am anticipating that it will require an act of Congress to provide for compensation for the families of the victims. Isn't it the obvious fact that convenience for people who work in Washington and travel "back home" generally speaking on weekends and when Congress isn't convened, is a prime and central reason for the way DCA airspace has been constructed and managed? Is it really going to be the case that because the lawsuits will - in all likelihood - fail to overcome the "discretionary function" exception, that the 67 families will be without a remedy? Is that how it works, then?

In case anyone thinks my sense of being horrified at this accident is clouding reason or logic, consider this - the book Collision Course discusses the PATCO union's genesis, the strike, and so on. PATCO's earliest stirrings resulted in large part from the 1960 midair over New York. Is the United States aviation sector willing to accept an outcome of this accident that in effect travels back over six decades? The point is, given the long-term shortage of ATCOs in this country . . . I don't think a court is capable of ruling that the situation, allowed and in fact enabled by Congress and successive White House presidential administrations, is subject to "negligence" analysis in the currently applicable legal sense. All this being said, this is how I arrive at thinking that in the interests of justice, some other means of providing for the loved ones of 67 souls who were on board needs to be determined and implemented.

Which, put another way, means no visual separation, and I think that's the right answer. I would commend the DCA authorities also to a scheme we had in London where regular users of the routes such as PAT are given a number to call before planned movements to see if it was likely to come off. Another trick that I've seen is to add a suffix to the callsign for aircraft on a priority shout (eg. helimed).

Doesn't PAT callsign in itself have priority?

I agree that is a solution, indeed the obvious one from my European point of view. What I was trying and failing to think of was a route design which guaranteed separation without ATC intervention, which is what I thought meleagertoo was asking for.

However, from a US point of view, this is arguably the solution which was in place on the night. It's just that the means of actively keeping the traffic apart, ie visual separation, failed. I am prepared to accept that FAA-style "visual separation" is slightly more robust than "see and avoid" in that it requires ATC to confirm that the pilot has the specific traffic in sight before relaxing separation minima, but the question for the FAA is whether "slightly more robust" is good enough when airliners are involved, particularly at night given the increased potential for misidentification.

I am not sure the subsequent line of discussion over how Class B requires ATC (not pilots) to separate all traffic is a very productive one. Any separation instruction given by ATC relies upon the pilot executing it, for instance by maintaining the cleared altitude. Here, it relied on the pilot not colliding with the specific traffic he had confirmed visual contact with. So far as the FAA is concerned, that's a sufficient degree of control and differs from the "see and avoid" principle applicable to VFR/VFR in Class C, and VFR/Any in Class D. Again, the question is whether that's appropriate.

That last point gives me an opportunity to make an observation I've been pondering for a while. Many European airport control zones are Class D, where on a strict reading of ICAO, VFR traffic is not required to be separated from IFR. But how many of us know a Class D zone where the controller gives traffic information and lets VFR traffic merge with IFR under see and avoid? In practice, European and especially UK ATC exercise a greater degree of control than is strictly required by the ICAO classification. At least in my experience, US airspace is operated closer to ICAO specifications ("visual separation" nothwithstanding).

I'm sure it does, but UK helimeds use the suffix to indicate they are actually on a shout, rather than training or positioning.

That's not called for. PEI 3721 has a respectful and thoughtful response to your post.

I personally don't think there's anything to be gained from going down the ICAO route. The NTSB has it's own charter and that's what dictates what happens in the USA.

I can see several ways the NTSB could take this, first the obvious one. The helicopter assumed responsibility for separation when it was not able to do so, and then found itself on track for collision. That's what I would define as true proximate cause. Then there's a step back from there which says nobody should be allowed to request and receive visual separation responsibilities in Class B airspace. That would be a good result as far as I'm concerned.

And the final step, which I think is more contentious and really hard for the US to accept, is that the culture at the FAA and within the industry is to balance safety and boosterism for the industry, and I think that is a recipe for irreconcilable conflicts. I'm not holding my breath on that one.

I'm surprised that this is your conclusion. I think what I take away from the conversations on the night was that ATC was divesting himself of responsibility, and the helicopter was trying to expedite his sortie, and nothing in the 'system' prevented them from doing that. Removal of visual separation as an option IMHO deals with that hole in the cheese. It seems like you're suggesting that the helicopter might ignore instructions to hold before the tidal basin ?

You've misunderstood. I'm not saying that visual separation was appropriate for this situation. I'm merely saying that so far as the FAA is presently concerned, it constitutes ATC-applied separation and is therefore compatible with the requirements of Class B. I posed the question of whether it is appropriate for it to be so freely applicable. FWIW, I am fairly relaxed about it for daytime parallel approaches. Where to draw the line between that and opposite-direction same-height at night?

Where have I suggested that?

Sorry, I may have over-interpreted your response. This is the line that prompted that. I agree there's room for nuances in the visual separation thing, but opposite direction at night is a bridge too far IMHO.

"Visual separation" is different from "see and avoid" in that the controller must confirm that the pilot has the factor traffic in sight before approving visual separation. The controller is only delegating the "avoid" part of the task, not the "see", which must be confirmed before the separation minima are removed. That, at least in my understanding, is how the FAA argues it to be compliant with Class B requirements. It's obviously vulnerable to misidentification of the factor traffic; don't think I'm defending it!

When genuine "see and avoid" applies (Class C VFR/VFR, Class D VFR/Any) the controller does not need to confirm that VFR pilots have visual contact before allowing separation to reduce, because there *are no* separation minima. At least, not according to ICAO.

As I mentioned earlier, European and especially UK ATC tends to apply more stringent separation than ICAO requires. The 'ATC duty of care' argument in the UK results in its Class D being operated in a similar way to US Class B, in my experience.

Lufthansa tried that at SFO in November 2023... didn't go well for them

Lufty at SFO

ATC will still have to provide you with separation, yes. But some US airports have too much traffic to operate without pilots accepting visual separation, so you may have to land elsewhere. Hence the discussion upthread about the inseparability of regulation from policy, economics and (ultimately) politics.

Post #10 on that thread...

And the last post on it, in April 2024...

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