Posts by user "Easy Street" [Posts: 42 Total up-votes: 107 Page: 3 of 3]¶

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.

The narrator states this up front, but for anyone who watches with the sound off (!), an important point to bear in mind with this video is that the simulated view through the NVG is not representative of the light amplifying and wavelength filtering effects of the tubes: it's just a green-tinted version of the basic scene. The main differences with NVG are the way that amplification varies from red (high) through green (none, which is why HUDs use green writing) to violet (filtered out), and the way that bright (especially bright red) lights obliterate other light in their local scene. The photos in the report show those features very well.