Posts about: "Separation (ALL)" [Posts: 442 Page: 4 of 23]¶

And the US is the only place where this happens as a matter of routine. Take a look at Europe and see how separation is much more strictly applied.

The whole mechanism of "aircraft in sight" no longer works, when the airspace is crowded: "Which aircraft are you supposed to have in sight" ???????

Yep, the system in place just does not work once the airspace becomes crowded, "IE which airplane are you supposed to have in sight" ?

With only one other airplane, it's clear, with more than 1, it becomes a gamble.


For VFR there is a missed approach procedure: Back into the circuit. Which will be a bit hairy, when the "miss" happens (long) before reaching the runway. Depending on the aircraft type, 2 circuit types may be defined: A small one for slow stuff and a large one for the bigger ones. And as usual with VFR traffic, ATC or self-communication is needed to pick the moment of the next landing attempt.

One can discuss whether this is a procedure or not, though there is at least "something".

PAT25 twice asks for, and is given, visual separation.

Seems pretty obvious where the blame lies.

But blame is not what we\x92re searching for in accident investigations.

Funny, I\x92m hearing a lot of professional pilots here say exactly that, one way or another.

I don\x92t like saying this, but reading your posts, my gut feeling is you may be part of the problem.

It\x92s well-known that modern airliners are specifically designed to be flown safely by the average pilot, not the cream. If ATC procedures aren\x92t designed and operated in a similar vein, does it need, a) a professional pilot to infer increased risk, or b) plain common sense?

I would much rather be on the flight that refuses to accept a night visual separation than hope my pilot is above average. Why?

Because hope is a poor hedge (if you like gambling analogies).

Quite right. However, I'm not investigating this accident. Nobody on PPRuNe is. It's a rumour network.

Perhaps I should rephrase. Responsibility for separation was given to PAT25. Failure to maintain separation was caused by PAT25 not maintaining the separation that they were responsible for. Ergo, the collision was caused by a reduction in separation to zero, which was the responsibility of PAT25.

Excellent remark . Unfortunately this how TWR controllers are being instructed in academies to do visual separation. In my (old) days visual separation was an exception, today in the US it is a standard method of working to enable more traffic in the system that the standard rules would allow.

I'm worried about the potential politicisation of any subsequent inquiry into this terrible incident, especially in the current US political climate. So many things lined up for this to go wrong, and the investigation needs to go hammer and tongs at all of them and not scapegoat one individual thing or oversimplify. Things like:
- A nationwide over-reliance on visual separation with commercial passenger traffic
- US exceptionalism regarding how brilliant they are (how many times in the last 24 hours have you heard someone rabbit on about how the USA has the safest aviation in the world...) the inquiry needs to tear this to shreds.
- An ATM system running beyond capacity
- Deference to government and military (both in general life and aviation)

I have little to no hope that in the current political climate a review will be held with enough freedom to do all of the work it needs to.

SIr Charles Haddon-Cave QC said it best in the Nimrod Review, the independent review into the loss of RAF Nimrod XV230. The damning review into UK military aviation safety was simply titled:

"A failure of leadership, culture and priorities"

For direct cause, I would agree. However, IMO, one needs to look into the system of root causes that enabled the direct cause to occur, to learn lessons and take meaningful action.

Others, far more qualified than me, have already described these root causes.

As it's a rumour network...

Perhaps the "responsibility" should never have been "given" to a helicopter to maintain separation on the basis of visual identification of another aircraft, at night, in close proximity to an airport in Class B airspace.

Are you sure that makes for a good strategy to prevent future re- occurrence?

Interesting viewpoint.
My take is, in order.
5) No, I don't think he was overwhelmed. He was shot through with adrenaline and shocked as anyone would be having just witnessed two aircraft he was talking to seconds before vanish in a fireball, realising his career, reputation, life and future sanity was irrevocably blown to pieces no matter the cause.
No, no and thrice no. Assuming the tapes are in real time there are considerable gaps between transmissions so he most certainly did not 'have' to speak so quickly. He had plenty of time to speak clearly and coherently instead of spouting those eruptions of incoherent, almost incomprehensible babble.
Sadly - reprehensibly, this style of unnecessarily theatrical auctioneer-style unpunctuated babble seems all too frequent in the States. Tower frequencies are usually if not almost invariably much less time-pressurised as they handle fewer aircraft in a well spaced sequence than in a termnal control area.

6) Concur 100%. And they failed miserably to achieve this. I've been flying for several decades and struggle to hear one word in three (and only assume much of the rest because I know what to expect - a human factors disaster) of that controller's outbursts, and the shoddy partial readbacks are shocking to European ears.

7) Once again, NO! Even if super-busy (and I'd argue especially if super busy) it is essential to keep r/t steady, clear and comprehensible; gabbling that fast might save half a second on an exchange, but no frequency is so busy it requires that, least of all a Tower. He only had three or four aircraft to deal with for simple go-arounds, all well spaced out on approach. He pretty much had time to recite half the Lord's Prayer to each.

This crazy r/t seems to be a cultural thing and needs to be changed, as do some fundamental procedures like having helo lanes crossing final approach tracks at essentially the same height instead of with decent vertical separation. Why wasn't the helilane at 800ft or 1000ft as a Heathrow? No aircraft is up there one mile out from finals while every single one is at 300ft. Madness. Just madness. It's like a figure 8 banger race dodging cars at the intersection. If there was a flyover - vertical separation too accidents would be all but eliminated.

And this buisness of "...pass behind the CRJ on finals" when no none can determine whether the lights in sight are a CRJ, a Cessna or the Space Shuttle or in what sequence they are landing. It might work in daylight but imho it assumes unreasonable levels of instant almost head-on aircraft recognition - a disastrous human factors trap quite aside from the additional one of assumption.

I'm not having a go at the poor controller who imho is compleely blameless, he did his job as well as the flawed system that indoctrinated him allowed.

As for 'stopping' helicopters in a free- air hover. This is (in my experience) never ever requested, done or attempted as a traffic avoidance method. I can only assume people suggesting this have absolutely zero knowlege of flying helos and the litany of pitfalls and hazards it would generate, helos simply do not 'stop' in midair unless they have to for SAR, load-lfting ot maybe surveillance. If necessary, as in holding at 'dual taxiways' between the Heathrow runways at 1000ft you'd slow to a sensible speed, maybe 50-60Kts in a tight orbit and even that is 'interesting' in 40Kts of wind. "Are you visual with landing traffic 2 mile final" identifies the traffic far, far better than "the CRJ on finals" when there might be three in a row, not to mention assuming superhuman powers of head-on distant aircraft recognition even in daylight - and impossible at night!!! Crossing clearance is then "cross over the threshold after the landing traffic" where no aeroplane ever is at 1000ft. (bar a g/a when there is enough time to skedaddle and avoid) With any significant wind a hover would have to be into wind, ie more or less tail -on to the conflicting traffic, an utterly absurd concept. Bin this one people, please.

As for the appalling behaviour of the 'president' to instantly apportion blame with no understanding of either the situation or accident investigation in general whatsoever - which anyway is not his job and none of his business, thereby prejudicing any enquiry (what pressure does this put on the investigators and report writers, federal employees, when they are all but directed by their deranged and vindictive boss what they are expected to report? This is a very, very dangerous precedent that smacks more of a shonky third world dictatorship than a western democracy.

Quote from an NTSB report

\x94 The NTSB determines that the probable cause of the accident was the failure of the flight crew to comply with the provisions of a maintain visual separation clearance including the requirement to inform the controller when they no longer had the other aircraft in sight.
Contributing to the accident were the air traffic control procedures in effect which authorized the controllers to use visual separation procedures to separate two aircraft on potentially conflicting tracks when the capability was available to provide either lateral or vertical radar separation to either aircraft. \x93

That was of course PSA 182 I\x92m not entirely sure that after a lengthy investigation the report won\x92t say something similar.

This visual separation at night thing is bananas. Heli confirms he is visual with RJ, but ATC is relying on him actually having made visual with the correct aircraft.

This version of the Vasaviation video includes the heli R/T.

At 00:26 ATC informs them about the CRJ, and PAT25 requests visual separation. At 01:08 the conflict alert sounds and ATC instructs them to pass behind. This is not read back; instead PAT25 affirms they have the traffic in sight and asks again for visual separation. ATC seems to approve this request for the second time, but this transmission is not very clear.

If this goes to civil litigation, which is quite possible, I wonder if the lawyers will question the ability (not flying ability, but human limitations in the environment) of the helicopter commander to make a safe enough identification of the CRJ under the circumstances and then extrapolate it back down the ATC chain to question the point you make? That I feel, would be difficult to defend against under a 'balance of probability' standard and could be embarrassing to a number of parties.

Do you have a link to any such video? Because if this is genuinely what you've heard I'd like to know the source and origin. Because there's other content out there which has the helo acknowledging (twice) sight of the aircraft and requesting visual separation. But they then proceed to fly right into the traffic they apparently have sight of. So...

Perhaps not, but it was. That they maybe shouldn't have been given that responsibility doesn't abrogate them from such.

It's akin to blaming someone else when you fly in to a hill under your own terrain separation.

It is really like that? Yes, I have seen the map but honestly I don't know how it works in real life. Do they really just fly bellow aircraft on final with vertical separation like 100-200 ft or they have to avoid them, let's say cross behind. What is too close in this case?

I know the mods don't want this to descend into politics, but will the FAA really be able to deliver a report that's free from political interference, bearing in mind the above plus the current administration just having forced its current head out of office ? Nobody particularly enjoys the process, but separation of concerns and independent oversight is widely understood to be important, particularly in safety-critical industries like aviation where the consequences of incidents can be grave. Is this a cultural shift in the US, and deliberate avoidance of regulatory oversight has become normalised? I'm also thinking of the ongoing multiple Boeing fiascos, for example.