Crash at Reagan National Airport, DC. Small aircraft down in the Potomac.

Kelvin said:
I thought that right away. If these guys were on night vision gear as is being reported, this would further exacerbate this issue.
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NVG in the middle of the DC Metro area? That would be pretty difficult, wouldn't it. We get Blackhawks over our field at night periodically because we're nice and dark.
 
IMO being at the same altitude isn't the issue. PAT25 was instructed to fly behind the CRJ and for some reason didn't do that. I've been in traffic patterns and on visual approaches where I've been instructed to pass behind traffic at my altitude so I adjusted my course to follow instructions. PAT25 didn't hit the CRJ because they were at the same altitude they hit because PAT25 didn't adjust their course.
 
flyingcheesehead said:
I have to say, the NTSB member giving the briefing, J. Todd Inman, does a really good job.
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While this viewpoint is widely supported in aviation forums and video comments, I’ll take the opposing viewpoint; i.e., the NTSB briefings in the Homendy era are mostly awful. An exception was a few weeks ago with the Fullerton briefing. That briefer (IIC) was excellent (Elliot Simpson?). Current briefings are mostly emotional fluff, NTSB horn-tooting and boilerplate, and an ever-growing list of entities to thank. The actual factual content makes up a shrinking minority of Homendy-era briefings. Let the IIC’s do the briefings and stick to an accident summary and known facts.
 
Location of RADALT position. Left seat location is slightly different. Pointer and digital with both low bugs and high bugs. 0-1500 ft.
IMG_9840.jpeg
 
luvflyin said:
The Vertical Glideslope Indicator VGSI, probably a PAPI, is 3 degrees. That is 319 feet per mile. The Threshold Crossing Height TCH is 37 feet. So it does not look to me like the plane was low.
View attachment 137726
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Keep in mind the PAPI are located 750’ down the runway in this case. Not that it makes what you said any less true, but calculate from there and add a few feet above sea level for the siting to get the MSL altitudes.
 
flyingcheesehead said:
The thing that gets me is that the CRJ crew did get a "Traffic, Traffic" alert 18 seconds before the collision, and as of right now it sounds like they didn't react to it until 1 second before the collision.

I do wonder who was PF and who was PM. If the FO was PF, it may have been that the captain looked at the display and couldn't see the helo. It will be interesting to see what else is on the transcript during that gap.

If there really was no reaction, those pilots may have simply been to DCA and gotten traffic calls like that enough times that they'd learned to ignore it. Normalization of deviance.
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18 seconds before the collision weren’t they still on somewhat diverging paths? The turn to final seemed to have commenced right about that moment.

A big part of this seems to be that situational awareness crumbled in regard to anticipating where the jet was going to make its turn to line up with the runway.
 
Checkout_my_Six said:
And we all know that ADS-B is very accurate for collision avoidance. ;)
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dmspilot said:
Why would that be relevant when visual separation was issued?
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Not relevant to this particular accident. However, as an IFR pilot I always had the impression tower radar was pretty accurate, so I am somewhat surprised it can be off by 100' in either direction.
 
flyingcheesehead said:
Altitude - They gave a big caveat on this because he said they have an altitude they feel very comfortable with (probably PSA CVR). They're still working on

CRJ was at 325 ±25 from ADS-B and FDR. They said they feel comfortable with this altitude being accurate.
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Others have been asking "could the CRJ have been low"? Maybe I've messed up the GS calculation, but 325' +/- 25' would put the CRJ ABOVE the 3 degree glideslope. If that's right, then no, the CRJ wasn't low.

Another topic (which I am worried is too early to bring up, but will anyway): The "organizational attitude" of the aviation battalion is surely going to get scrutiny. My experience: different organizations take on their own attitudes towards flying and standards, which can impact safety (and effectiveness, sometimes in different ways). The investigation MAY find that the aviation battalion had a history / mindset of doing what they could to expedite their particular flight - and may have not even thought about it in those terms. For example: we all know that calling traffic quickly can sometimes turn into a pecker-measuring contest, or that asking for advantage - like visual separation - can become rote. It's not hard to imagine a mindset taking hold that normalizes these things. If these attitudes are endemic to an organization, leadership isn't doing its job. I'm NOT saying that's what was going on, but I'd bet it'll be looked at closely.
 
Chip Sylverne said:
Not relevant to this particular accident. However, as an IFR pilot I always had the impression tower radar was pretty accurate, so I am somewhat surprised it can be off by 100' in either direction.
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I'm assuming the 100' thing is from the encoding altimeter... it's accuracy is entirely on the transponder in the aircraft... unless the secondary radar's altitude setting was off.
 
Chip Sylverne said:
Not relevant to this particular accident. However, as an IFR pilot I always had the impression tower radar was pretty accurate, so I am somewhat surprised it can be off by 100' in either direction.
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ATC radar doesn't generate an altitude, it displays the altitude reported from your transponder. And it's delayed.
 
Chip Sylverne said:
Not relevant to this particular accident. However, as an IFR pilot I always had the impression tower radar was pretty accurate, so I am somewhat surprised it can be off by 100' in either direction.
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I bet it's a radar slant range thing.....and there are latent delays in ADS-B.
 
The question earlier about altimeter at the time. I was 29.93 at the time of the accident. Route altitudes in this case are MSL. With DCA being only 14 ft, the difference between AGL and MSL minor. A good technique would be to adjust the high bug on the RADALT to 200 ft. That would’ve complied with the 200 ft (max) MSL for route 4.
 
Larry in TN said:
My guess is that they're thinking of it in terms of the ADSB traffic information display typical on GA aircraft avionics.
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And obviously we can’t confirm but I’d say there’s a good chance PAT had an EFB with ADS-B in portable antenna going on. Especially in a unit that operates with that much traffic. Not allowed to use the moving map for primary nav but EFBs and portable ADS-B in antennas are authorized.
 
Flying Keys said:
Keep in mind the PAPI are located 750’ down the runway in this case. Not that it makes what you said any less true, but calculate from there and add a few feet above sea level for the siting to get the MSL altitudes.
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Yeah. I did that using the TCH to calculate. The TDZE is 13 feet.
 
High school trig to the rescue. Ratio of vertical to horizontal distance is the tangent of the descent angle. So multiply distance from touchdown point by tan(3) to get altitude of glideslope.
Horizontal deviation from route 4 was equally contributory as vertical deviation. According to a post above, impact occurred 2400 feet from runway TH. Add 750 feet from TH to PAPI. Altitude is 165 feet.
Distance from TH to east bank on runway centerline is right at a mile. Add 750. Altitude is 316 feet. So the helo lost 150 feet of vertical separation by moving away from the bank.
 
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