Posts about: "Visual Separation" [Posts: 268 Page: 14 of 14]¶

For Chiefttp:
The question of currency, proficiency, and recency fairly leap off of the page, yes.
Inconvenient facts never stopped a lawyer from bringing a case to court, though.
No, it does not.
Wrong. Visual lookout is a responsibility for all members of the crew. That's a shared responsibility, and briefed before every flight. Note that in a Blackhawk, there are a variety of zones where the pilots are effectively blind (starting at about the four o'clock position and reaching to about 8 o'clock position) but the forward quarter isn't usually one of those. (Won't comment on the goggle issue here...)
Not just pre-flight checks.
I am not sure how much low level, over water, at night flying that you have done, but I have done quite a bit of that. If you are flying in such a regime, and there is a substantial mismatch between your radalt, and your baralt, and you have a hard altitude limit, you don't ignore your radalt.

The PIC reported 'traffic in sight' when he clearly hadn't, he should never have asked for visual separation (normalisation of deviance).
We don't know of any gestures, if any pilot pointed at lights, but there is nothing in the CVR transcript that indicates the PF was aware of the traffic, or that the PIC pointed the traffic out to her; the PF certainly did not factor in the decision to request visual separation.

So when the PIC transmitted, what would you have the PF do? Ask the instructor where it is? Or trust the instructor, and concentrate on flying?
or did the PF know that neither of them could identify the traffic, but accepted it as normal?

I check my altimeter every time I fly, I think pretty much everyone does. An instructor is of course responsible for what his student does, so there is that.

Any student flying in some scenario where they don't have good vision themselves like wearing NVG gear or foggles puts an enormous amount of trust in their instructor.

Then why did the PNF decide to request visual separation?

When the altimeter setting is placed in the aircraft on the ground, the pilot should take note of how much difference there is from actual field elevation and then consider what should be done for compensation for any error. On most VFR flights, a 100' error does not have much relevance. On the other hand, if you were to know that you are going to pass extremely close to something that you do not want to be close to, then it can become significant. An example might be for the people who like to fly 100 feet vertically from airspace that they are not allowed to enter. This situation might be another example where good airmanship can make a difference(specifically to compensating for an altimeter error).

I have not read this report, as I am deep into many other ones these days but I did take a quick glance on page 242 that was referenced and it talks about altimeter additive errors. The report states: "The allowable tolerances are additive, with the total error having the potential of exceeding 100 ft.". The report also states: "The NTSB concludes that, due to additive allowable tolerances of the helicopter\x92s pitot-static/altimeter system, it is likely that the crew of PAT25 observed a barometric altimeter altitude about 100 ft lower than the helicopter\x92s true altitude, resulting in the crew erroneously believing that they were under the published maximum altitude for Route 4".

My question to other people on this thread is: Did the NTSB do some sort of evaluation of this particular helicopter in order to come to a reasonable conclusion that all errors were in such a way that they were all in the direction of resulting in the helicopter being higher than indicated as opposed to errors potentially cancelling each other out(or partially so)?

Once only, not repeatedly. She's following the river when they come out of the side arm, but in the wrong direction. My understanding is that the PNF is supposed to be navigating, though.
The landing at the helipad where she abandoned because the wind made the helicopter hard to control, and she lost sight of the landing zone? and then the instructor calls "go around", possibly because of some deer?
I don't think the handling played a part at all.

What I do see is that when the instructor is flying, he's having some altitude excursions as well.

There's also a visual separation while the instructor is flying, and it plays out like this: .
and only then does she call 'traffic in sight maintaining visual separation'.

For the CRJ, the instructor calls 'traffic in sight' without ascertaining that the PF sees it. When the tower cautions them again, the CRJ still hasn't turned, so while it's visible, it doesn't appear a threat. I think both pilots expect the CRJ to be to their right, because that's where the bridge is when ATC tells them where the CRJ is initially, and because the instructor thinks that ATC wants them to move left. They don't understand that the CRJ is on their left and will be turning onto the runway heading.

I imagine, based on that, that the PF believed the instructor has the CRJ in sight on his side. If she did see the CRJ, it would've been well above and on a diverging course, except for the final 6 seconds or so; it wouldn't have appeared to be a threat.

With his radio call, the instructor put himself in the position of being responsible for avoiding AA5342, but he didn't actually know where it was (maybe he thought he did).
There are a lot of factors contributing to that, but that's the big hole here for me.

Pages 238 and 253-254 deal with this:

• "The speed of the accident IP\x92s reply suggests a rote response that occurred without positively identifying flight 5342. This also seems likely because the IP never pointed out or discussed the traffic with the pilot" (p238)
• "requesting and receiving approval for visual separation was normal practice" (p253)
• "An Army standardization instructor pilot stated in a post accident interview that he sometimes responded to traffic advisories before visually acquiring the traffic if he knew that it was far away and was not an imminent threat. The accident IP\x92s significant experience flying on the DC helicopter routes and the speed of his reply to the controller\x92s traffic advisory support the likelihood that he 253 Aviation Investigation Report AIR-26-02 had also developed this habit." (p253-254)

My experience is in two-seat fast jets, but when acting as PIC/PF I would absolutely not expect PNF or WSO to seek my approval before requesting routine clearances from ATC. It's abundantly clear that "visual separation" was routine here, and although it seems likely to have been a rote response in this instance, in my opinion it would have been perfectly in order for PNF to make the request without consulting PIC if he had positively identified the traffic.

Clearly, he hadn't. I'm impressed with the NTSB's reporting on this aspect: the difficulties of using NVG to identify and visually separate from other aircraft are very well described in the narrative, and the photographs through NVG from representative vantage points illustrate them superbly for the uninitiated.