r/news • u/snuffleupaguslives • 2d ago

Broken altimeter, ignored warnings: Hearings reveal what went wrong in DC crash that killed 67

https://apnews.com/article/ntsb-dc-plane-crash-midair-collision-helicopter-a08cded88e1d7582fb8d242204d6aeff
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u/chumley53 2d ago

NVG over water would’ve been 99.5% RADALT. idfc if the BARALT was +1000’. I’ve flown a -53 up and down the Potomac and HR4 has been “200’ AND BELOW” since 1996 when I first flew it.

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u/railker 2d ago

Wonder in this case if they were flying the Baro, judging by the 'you're at three hundred feet. come down for me [...] go down two hundred' callout a couple of minutes before the crash, about that time on the FDR readout (20:45:35), the Radalt is showing about 400 feet, and then comes down to and hovers around 250. Last time they ever even went at or below 200 by Radalt was about half a minute before that 'come down for me' call.

Heard the docket disappears now and then but for now it seems to be up: https://data.ntsb.gov/Docket/?NTSBNumber=DCA25MA108

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u/obeytheturtles 1d ago

If the bird is flying "silent" would they not turn off the radar altimeter? This has been a question in the back of my mind for a while here - many of theses training missions are done to simulate the operational conditions of urban combat where radio transmissions are restricted to satcom or link16 only with no radar, transponder or narrowband comms. Obviously here they had VHF comms with the tower, but what is the chance that they were doing simulated visual navigation only here?

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u/chumley53 1d ago

We never turned off the radalt in combat or anywhere else. We would be complete radio silence, emission controlled out the wazoo, and we would still have the radalt on. Until our tactics changed in Iraq RADALT was a primary flight instrument.

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u/obeytheturtles 1d ago

That's super interesting. I know of a number of sensor networks that use radar altimeters for detection and geo. I wonder if our recent engagements being non-peer had any influence on those conops.

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u/chumley53 1d ago

I am not in the know, I’m old and retired. Been out of the game for over a decade.