Posts by user "island_airphoto" [Posts: 73 Total up-votes: 89 Page: 4 of 4]¶

Originally Posted by galaxy flyer

I\x92d love to know the reported ceiling was that day? There are ceiling and visibility minimums for visual approaches and I really doubt BWI traffic is stooging around in the weather calling \x93visual\x94; too easy to get caught.

Originally Posted by Cobraguy

Thinking about what Deltafox44 said in comment #1178, that induces me to ask if there ever was a quantitative analysis to assure/confirm that it would be "Extremely Improbable" that such a collision could occur. I believe an analysis of the type would need to prove (or disprove) that the probability of two aircraft could result in conflicting flight paths (a catastrophic condition).

Thinking about the helicopter route, and the possible errors in the helicopter-borne equipment, the Static ports could be subject to some biases, and could be variable as a function go helicopter airspeed, vertical velocity, side slip.
Add to that a possible error or change in local baro (In-Hg) as one transits from their departure point into another area, the two cockpit baro altimeters' displayed altitudes can contribute to errors, but the altitude reporting to the tower is based on 29.92, so any error in setting AAU-31 or AAU-32 In-Hg applies only to the cockpit displays; the Tower receives Alt value referenced to 29.92 inches and corrects it locally for their displays and conflict alerting algorithms.

For the approach without benefit of a Glide Slope, the VASI or PAPI is visual and thus "probably" more challenging to maintain nominal approach angle to the runway. There should have been some documented analysis, backed up by data that helps to define the worst-case vertical departure from nominal approach angle on the PAPI/VASI approach; that needs to be part of a worst-case combined analysis, and I think needs to be better than "10 to the minus nine". Need to have data from both low-hour and high-hour pilots on a non-coupled approach.

Next quasi- related thought::: when the CVR recorded a verbal disparity of 100 feet between pilot and examiner, shouldn't that have raised questions of "Why"- especially when at low altitudes MSL? As I understand it, there would be 3 or 4 places where Baro Alt was displayed; the two mechanical bar alt indicators, AND the altitude display(s) on the pilot(s) NVG HUDS. If the pilot under evaluation was fully on the ANVIS HUD, and if that pilot failed to set the Bar Alt "correction" in terms go In-Hg, then the pilot could readily be seeing inaccurate Bar Alt digits on the HUD.

I believe there procedurally had to be a separate action to set In-Hg ( or to sync the HUD to the AAU-31 and AAU-32 values). It would not take much of an error in ANVIS HUD In-Hg setting to cause a substantial error in the Altitude digits displayed on the HUD.
Add/multiply these error sources up, and then see if the defined helicopter route met the 10 to the minus nine value.

Originally Posted by dbcooper8

Very informative video thanks to Austin Roth.

The chart for route 4 shows a single line above 200 ft indicating its the maximum permissible altitude. Also the wording on the chart is "at or below". IF, as the video suggests, 200 ft was the only recommended altitude then I would expect it to have a line above and below it with the appropriate wording "at" only. Route 6 has a 1500 ft altitude with a line above and below and with "at" only in the wording.

From the FAA chart I believe altitudes below 200 ft are permissable and expected along route 4.

Originally Posted by galaxy flyer

Nice but you have to have it and not sure of the H-60 fit. Besides, I don’t think you can declare visual using only ADS info

Originally Posted by Stagformation

So in the accident in question the LC issued an en-route clearance to the Blackhawk to which there was no read back at all, because the helicopter crew never heard it. Subsequently I don\x92t think we see the LC chasing up for one, let alone correcting any errors as he ought \x97 he was just too busy doing the work of two people. The purpose of the system broke down.

Originally Posted by BugBear

WillowRun

From your perspective then, could you clarify :

Controlled Airspace, See and Avoid re same, duty of care re ATCre controlled Airspace, specifically short finals, etc?
May as well add split or proportional liability??

I am trying to get even a basic understanding of how a large helicopter flew in visual flight rules into a jetliner on short final, which was on an IMC approach, on slope. Both were \x93legal\x94. The helicopter busted altitude by 125 feet vertically, and just exactly enough horizontally. Que?

Originally Posted by WillowRun 6-3

"..... this was definitely not a case of "Well, they had the traffic info so they should have avoided it!" - it's wayyyyyy more subtle and complex than that. . . ."

Regrets: in my post trying to comment on Sailvi767's observation regarding the RJ crew having the best situational awareness, in retrospect I should have emphasized and explained what I meant by using the the word "imminent". The thread previously did clearly reference factors such as the inhibition of TAs and RAs at specified heights, and the TA alert. What seemed different in the post about the RJ crew's SA was what I, as only SLF/attorney, understood as the suggestion that a different crew with different mindset might have realized before the last second prior to impact that "erring on the side of caution" was the correct action to take. Please note - this is not an effort to put words into Sailvi767's post whatsoever.

Perhaps it was already pretty clear to others, but I had thought - for the reasons your post H&H talks about - that naming the airline as a defendant in the lawsuits would be just for form's sake at best, and to draw in its insurance coverages. Every law student (in the U.S. that is, I don't know about other systems) is taught that a shorthand for negligence is whether the alleged negligent party "knew or should have known" about the risk of harm the party was creating. The observation that I think the post about the RJ crew's SA justifies is certainly not that they "knew". But it does suggest that although it is highly unlikely they "should have known", there either are some facts supporting the assertion that they "could have known", or at least enough facts to warrant making the airline a defendant.

About prior safety-related reports and whether any risk assessments were done and what those assessments showed, it appears very likely if not certain that some answers to "who knows" will be found through the discovery process particularly, although not only, if the airline is named as defendant.

(Lastly, I apologize for convoluting the thread.)
WR 6-3

Originally Posted by ST Dog

Once the recording/transcript is available I'll try to find it. I remember it struck me as odd.



Was it her that later said she'd use baro since the route was MSL not AGL?

Again need to recheck against the transcript. my memory may be fuzzy. I was doing 3 different things at the time.

I have several things I want to revisit from the 2 days so far.

Originally Posted by Capn Bloggs

What load of codswallop. Now we'll have every dogsbody pilot peering at their ADS-B In screens and asking ATC "is that return going to miss us?". TCAS does not require ADS-B, only a transponder (Mode S best). ADS-B In in busy CTAs/zones will be a distracting nightmare for crews.

Every pax jet is separated by SIDs and STARs, with either lateral and/or vertical separation. That is what is required here with the choppers. Playing TCAS dodgem-cars below 1000ft when you're trying to land is not the way to go.

Point 3 is the only one that makes any real sense. The rest sound good only to the great-unwashed.

Originally Posted by Propellerhead

Suing AA is just corporate greed by the lawyers. Don\x92t see how any of this is the fault of the airline pilots.

Originally Posted by ATC Watcher

I personally do not think ADS-B on the helicopter would have changed anything , From what I understand , if it had it could have been spotted earlier by ATC , the conflict alert might have sounded a couple of seconds earlier , etc .. pure speculation .

It would not have changed much for the AA CRJ either , the TA would have been more precise and maybe a second or two earlier , but he had already 2 TAs and most certainly so short from landing the PF was focusing on the PAPI not his TA display

It might have changed something if the Heli was equipped with a CDTI ( ADS-B in display) as it is a powerful tool to help identify traffic visually. But not separate yourself from another aircraft . One thing people in offices making such statements forget is that to provide separations maneuvers ATC needs a stable radar picture , with antennas firmly on the ground facing North . Inside an aircraft constantly moving the picture moves with it , (as you can see on your TCAS display ) Extremely complex to separate yourself using that kind of picture when both you and the target are moving. AWACS operators are trained to do this , but not your average pilot .

So I think this ADS-B on the Military Helis is a red herring made by politicians wanting to appear to “do something “ and perhaps distract the public from the FAA and regulator failures on both the design of the airspace / routes and the lack of action after numerous previous serious incidents reports ,

Originally Posted by ATC Watcher

I think we misunderstood each other or I was was not clear enough : I was refereeing to ADS-B out not in ;

That would mainly be for the benefit of ATC .
ADS-B in, together with a CDTI, is what I said to be L
So in fact we both agree .

Originally Posted by Sailvi767

They had TCAS in the RJ. I am not sure what additional aid ADSB would have provided. ADSB would however have provided extremely valuable data to the Helo if the RJ had ADSB out. It still may have provided data even without ADSB out if the RJ was still painting on the approach radars depending on altitude. A radar rebroadcast is not quite as accurate but at least as good as TCAS.