Night Vision Goggles (NVG) Page: 6 of 6

Easy Street
December 20, 2025, 19:34:00 GMT
permalink Post: 12008689

I've seen pictures of US military aircraft using devices such as Sentry to feed EFBs with ADSB data, but have no idea if that's widespread throughout the services or indeed was in use during this accident. However, what I do know is that it would be very unlikely that either helo pilot would have the capacity to scan down onto a knee-mounted EFB while flying VFR over a dark river on NVG at 200 feet (and in the non-handling pilot's case, monitoring the handling pilot's height and talking her down). Integration of an audio warning from the EFB to the intercom system would be needed to draw attention to conflictions, and I very much doubt that would have been implemented. Remember, they thought they had the traffic in sight, so there was nothing pressing them to check for other traffic given they were in (supposedly) fully-controlled Class B.

Subjects ADSB (All) Night Vision Goggles (NVG) Traffic in Sight VFR

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JohnDixson
January 31, 2026, 18:23:00 GMT
permalink Post: 12030315

This was supposed to be a checkride including Night vision Goggle usage and a bunch of submittals regarding the use and accuracy of the bardo metric altimeter system, and not much, if anything regarding the radar altimeter system accuracy.
The UH-60 Maintenance Test Flight Manual includes a barometric altimeter accuracy check, which is accomplished by calling the tower for the local altimeter setting, set the altimeter accordingly and comparing the altimeter readout to the elevation of that heliport/airport. THE ACCEPTED MAXIMUM ERROR IS 70 FEET. So, the baro altimeter readout can be 70 ft off and you are OK to fly: VFR or IFR.

The radar altimeter ( APN-171 or later APN-209 ) accuracy is similar at +/- 3 ft then 3% of indicated altitude, so, for the H-4 Route Maximum altitude of 200 ft. The Rad Alt could be as much as 9 ft off.

The NVGs do show Rad Alt.

Haven\x92t seen any submittal indicating the Rad Alt was inoperative or unusable.

Subjects Altimeter (All) Barometric Altimeter IFR Night Vision Goggles (NVG) Radar Radio Altimeter VFR

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DaveReidUK
January 31, 2026, 21:00:00 GMT
permalink Post: 12030376

Quote:

Originally Posted by JohnDixson

None of the references to NVGs in the hearing made mention of a HUD capability.

The Helicopter Operations presentation included a slide stating that pilots are "Trained to use barometric altimeter to navigate helicopter route ceilings".

Subjects Altimeter (All) Barometric Altimeter HUD IFR Night Vision Goggles (NVG) Radar Radio Altimeter VFR

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BFSGrad
January 31, 2026, 22:24:00 GMT
permalink Post: 12030414

Quote:

Originally Posted by JohnDixson

The radar altimeter ( APN-171 or later APN-209 ) accuracy is similar at +/- 3 ft then 3% of indicated altitude, so, for the H-4 Route Maximum altitude of 200 ft. The Rad Alt could be as much as 9 ft off. The NVGs do show Rad Alt. Haven\x92t seen any submittal indicating the Rad Alt was inoperative or unusable.

Extensive discussion in the interview transcripts about why all of the DC area helicopter pilots (medical, LEO, military) use baro rather than radar altitude when flying the DC helicopter routes.

Subjects Altimeter (All) Night Vision Goggles (NVG) Radar Radio Altimeter

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Musician
February 18, 2026, 06:15:00 GMT
permalink Post: 12038986

Quote:

Originally Posted by Chiefttp

The Helicopter Pilot flying the helicopter flew 56 hours the previous year prior, a little more than 4.5 hours per month! Only 4.4 hours in the previous 60 days! And She was on a checkride! Any military pilot will attest to the fact that when your due a checkride you try to get some practice flying prior to the checkride. I guess all the additional duties precluded that .Tough to stay proficient flying so little…..

No, she did get some practice in, it's in the report:

A pilot who flew with the accident pilot stated that she practiced basic flight maneuvers and NVG tasks in preparation for her upcoming evaluation flight. He recalled that the pilot seemed “rusty” due to a lack of recent flying but that, otherwise, nothing stood out about her performance.

.
The PF actually had more hours on the "accident helicopter make and model" than the instructor pilot, and people who flew with her in 2023 and 2024 thought she was flying well enough.

Subjects Night Vision Goggles (NVG)

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Chiefttp
February 18, 2026, 13:19:00 GMT
permalink Post: 12039167

I was just quoting from the final report, Page 12“

”with 56 hours in the previous year and

4.4 hours in the previous 60 days. The pilot had 136 hours of NVG time, 2.9 hours of

which were in the previous 60 days.”

Last edited by Chiefttp; 18th February 2026 at 14:14 .

Subjects Final Report Night Vision Goggles (NVG)

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island_airphoto
February 19, 2026, 04:20:00 GMT
permalink Post: 12039466

Quote:

Originally Posted by Musician

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,

20:46:07.9 RDO-1 PAT two five has the traffic in sight request visual separation .

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?

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.

Subjects CVR Night Vision Goggles (NVG) Normalization of Deviance Separation (ALL) Traffic in Sight Visual Separation

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Easy Street
February 19, 2026, 22:33:00 GMT
permalink Post: 12039929

Quote:

Originally Posted by Chiefttp

Island Airphoto,
NVG\x92s are vision enhancers, by multiples at night. Also, This was an evaluation flight/checkride, so the other pilot was performing EP duties, not IP duties. She wasn\x92t a student on this flight, She was to act as the PIC\x85.

Quote:

Originally Posted by Musician

Then why did the PNF decide to request visual separation?

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.

Subjects ATC Night Vision Goggles (NVG) Separation (ALL) Visual Separation

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Musician
February 19, 2026, 22:41:00 GMT
permalink Post: 12039932

Thank you!

Quote:

Originally Posted by Easy Street

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.

Not to mention the animation:

Subjects Night Vision Goggles (NVG)

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Easy Street
February 19, 2026, 23:25:00 GMT
permalink Post: 12039945

Quote:

Originally Posted by Musician

Thank you!

Not to mention the animation:
https://youtu.be/LJ10ZOcWuC4

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.

Last edited by Easy Street; 19th February 2026 at 23:35 .

Subjects Night Vision Goggles (NVG)

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Chiefttp
February 20, 2026, 10:23:00 GMT
permalink Post: 12040136

Island Airphoto,
Agree with your comment about NVG blooming and excessive cultural lighting in the DC area, far from ideal. In this case it would be interesting to see if identifying other airborne traffic is enhanced with NVG’s or diminished. I always felt my vision was enhanced, especially looking at airborne traffic, even with an excess of cultural light. Having said this, if the traffic your trying to ID is not the correct aircraft, the advantages of NVG’s are a moot point.

Subjects Night Vision Goggles (NVG)

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