Posts about: "VFR" [Posts: 141 Page: 5 of 8]¶

Conflating VFR and Visual Separation is driving me nuts. Is this an EU thing?
You can be VFR in the Class B and treated exactly like an IFR flight. The clearance requirement from clouds VFR is just "clear of" clouds. You can have clouds three inches over you and five inches under you with each wingtip 3 inches away from them and still be VFR. This is much reduced from C, D, and E because you are under positive control. The helo was let loose to provide their own visual separation, which is a totally separate thing.

Yes, but their ATC transponder was obviously operating normally in C mode. That should be enough to show PAT25 on CRJ screen as traffic, even if no RA was given (bearing in mind, they were cca 300ft AGL) It is of course completelly unreasonable to expect that CRJ crew should see or even avoid the Blackhawk incoming from (slightly) right, as they were merely 20-ish seconds from touchdown and manually aligning with the runway. Also, I believe that operating ATC transponder on Blackhawk allowed for clear view on ATC screen and I wonder if there was no alarm triggered on ATC computers - they probably do have such guard software in operation on DCA?
In another midair collision report, that happened in July 2022 at NorthLas Vegas airport, NTSB put out this:
Interviews with personnel at the air traffic control tower indicated that staffing was deficient, and most staff were required to work mandatory overtime shifts, reaching an annual average of 400 to 500 hours of overtime per controller. According to the air traffic manager (ATM), the inadequate staffing had resulted in reduced training discissions, and the management team was unable to appropriately monitor employee performance. The ATM stated that everyone on the team was exhausted, and that work/life balance was non-existent. It is likely that the cumulative effects of continued deficient staffing, excessive overtime, reduced training, and inadequate recovery time between shifts took a considerable toll on the control tower workforce.
I wonder, how this situation is with DCA ATC service.
I am not trying to blame ATC either. He issued clearance to PAT25 to cross behind and asked (and got) confirmation for CRJ in sight twice. It seems quite clear that helicopter crew did not look at the same airplane that ATC was asking about.
What baffles me here is, that it was obvious a routine procedure to let helicopters cross active runway heading less than 2 miles from runway treshold, leaving practically zero margin for error. Backups, designed to catch pilots or ATC errors (TCAS and ATC alarms) cannot catch up in short time left if someone makes a mistake, so this arrangement as based on "see and avoid" concept, in the night, with many lights in the background and a fact, that other aircraft on collision course does not move relatively on the screen, but just grows bigger. Unfortunatelly, that dot on the screen that will kill you starts growing bigger only in the last few seconds.
If I would ask ATC to cross runway heading DAY VFR so close to runway treshold at my airport with incoming commercial traffic, I would be denied 100 times out of 100 attempts. (and probably called nuts).
My guess on this tragedy is, that thru the years, the system was trying to pack more and more aircraft in the same space and same infrastructure, by gradually squeezing margins and safegueards, until one day, Jenga tower collapsed.

I believe visual separation from other aircraft is a very different scenario to visual separation from ground obstacles (VFR).

Waiting for the tower to have no aircraft below ~700ft in the approach area, if we're assuming a 1.5Nm separation, could be quite a while.

This seems to be an EU-centric idea, one could get the impression there is no such thing as VFR over there, or if there is it is restricted to some farm field far away from anything.

A lot of posters are applying air traffic processes from their home country, not all of which are bad. It seems to me however if you\x92re going to try to understand the lead up to the accident, and then assign blame, at least understand the process that was being used.

+1 to everything you and Wide Mouth Frog said.

I sincerely hope the NTSB can avoid being distracted by the distractions of altimetry and the missing ATC words on the Blackhawk CVR.

Upthread, Luca Lion calculated the 3 degree PAPI approach path as crossing the eastern riverbank at 270ft. If that's correct, then the CRJ's 313ft radar height 2 seconds before collision puts it at least 43ft above the approach path, so the Blackhawk's radio height deviation of 78ft would have contributed only about 35ft to the erosion of any intended "procedural separation" (*) between the aircraft. Or, to put it another way, the same outcome would have resulted if the Blackhawk had been at 235ft radio and the CRJ on the glide. Height keeping of plus or minus 35ft can only be achieved by instrument flying, which is obviously not compatible with visual separation (or indeed VFR) so cannot be reasonably cited as part of a safety case for the procedure. And of course a landing aircraft could easily be below the glide. Altimetry and height keeping are not the cause of this accident.

Missing the word "circling" wouldn't have influenced the helo crew getting visual with the CRJ at the time of the trasnmission. At best, it would have given them an extra nudge that "runway 33" (which was audible) meant the CRJ would be taking an easterly flight path. Missing "pass behind" with only a few seconds to collision was irrelevant if, as seems likely, the helo crew did not see the CRJ at that point.

(*) The quotes around "procedural separation" are intended to convey a tone of disgust and sarcasm.

Following "5*why", keep asking...
Why did the did miss part of the message
Why was the incomplete read back missed
Why does missing a few words lead to this disaster within seconds.

Does this lead an answer like: helicopter in a very busy airspace, busy controllers (insufficient time to be fully focused on full read backs) being by default too close to (and even needing to cross) the glideslope.
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I believe radalts are configured to display height above gear; so add ≈16' height of Blackhawk to 278' yielding 294'. Then there's rotor bowing, and how much higher will the tail rotor arc be at the speed the helo was flying?

Likely the Kollsman settings will be recoverable. Barometric altimeters used in VFR can be way off, but transponder calibration depends on a calibrated altimeter. The NTSB will be looking at maintenance records.

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.

She said there were no defined boundaries, though there were marked in blue on the maps. As already noted here, the width of the routes (as marked on the maps) is different from one map to another, especially when not at the same scale. There is a good reason for not having precise boundaries, they are VFR routes and there is no means to determine the position from the center of the route with a good accuracy, it is just visual navigation. And at night.

Errr. No means to identify the East bank of a major river in the middle of a well lit city at night ? Not sure about that. They are what they are though and I'm sure Jennifer would have checked her facts. Just by way of comparison, I can assure you if you were 1000ft away from the London Heliroutes over Heathrow you'd have the undivided attention of the controller.

Width of routes on the map is irrelevant as in VFR you fly from point to point. or it is following a landmark, a river, road, or here a river bank. It is a track and it has no width .

On rare occasion (for my civilian flying) I have been given a VFR clearance at an unusually low altitude (flying along Miami Beach being one example), and occasionally a routing I consider more risky (over water or a built up area with no where to go if the engine quits). Usually, I have accepted and flown the cleared routing, though there have been times I have requested a variation to reduce risk. These have been occasional for me, therefore I treated them as such, and my awareness went up considerably. To me, a situation which deviates from my "normal" requires heightened vigilance I'm a little nervous doing something I would not normally do.

So if the Blackhawk pilots either flew this low altitude route regularly, or it was an operational norm for that pilot group/operation, pilots would begin to relax with it - it's "normal" I opine that it is never normal to fly at 200 feet AGL in a built up area, nor close to the approach path for a busy airport. So if the training and operational norms of this routing lead pilots to think it is normal, they treat it that way, and vigilance goes down. This was an accident waiting to happen, because of normalization of deviance form established norms of flying.

I've learned the hard way that when ATC asks if you have X aircraft in sight, once you think you do, mentally map the path of that aircraft, then start looking for the one you have not seen yet - particularly with two pilots! You get a clearance to pass at 200 AGL under the approach path of a busy airport at night - that's unusual, and spidy senses should be tingling lots! This hyper awareness should be being trained into the operation - a preflight briefing from the lead "On this flight, we could expect this routing and clearance. This will be unusual, and we're going to be extra aware by doing the following....".

So it's easy to blame the Blackhawk pilots, and yes, they wear some of this, but the military let the pilots down by not categorizing this flight as "high risk", and ATC let the pilots down by clearing a routing which had the potential to provide only a hundreds of feet vertical separation, rather than insisting on both vertical, lateral, and projected path separation, and thereafter, telling the Blackhawk pilots all of the airplanes they should be seeing, not just the one, which seems to have been misunderstood.

I have been instructed to orbit to allow for a passing aircraft to clear in front of me, why not this time? Maybe that low altitude air route is too small for a normal orbit? Another red lag about that route not being a good idea!

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.

as active ATCO I can say only this (to addition to what I've already said) - I will never, ever allow any flying object to cross path of another flying object, especially when one of them is landing. This practice of my US colleagues to frequently offload separation duties to the pilots is just not acceptable. As if there is not enough incident contributing factors, they tend to add some of their own. I said (to disbelief of the attendees) at IFATCA conference just after Uberlingen - let's be honest, at the end of the day, it was ATCO who cleared both airplanes to the same level...
It may sound harsh, but after years of struggle for non-punitive environment, some have deduced this as non-punitive environment for any kind of incident (or even accident).
Back to case in DCA - to expect self separation of night VFR and IFR conducting visual approach agreed hasty and under pressure in the area where none of them is capable of sudden change of trajectory is just pouring gasoline to the fire already raging.

1.5 nm or 500\x92 is separation for IFR/VFR traffic, not IFR separation. So, an IFR aircraft in VMC might only have those separation distances with a VFR, not IFR aircraft.

Point taken but in reality, a low level (<200\x92) helicopter route is unlikely to have IFR traffic on it? Also, the conflict alerting systems now have real meaning to ATC rather than just being annoyances: something *must* be done to avoid a loss of separation. IFR/IFR minima (3nm/500\x92?) are higher for good reasons.