Crash at Reagan National Airport, DC. Helicopter crash into airliner.

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.
 
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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We get TA's on a regular basis. I've only had one RA.

There's not much we can do from a TA. I try to look outside and look at the display but half the time the traffic is buzzing around erratically like a bee. I don't expect the CRJ crew could have done anything or been able to determine the proper course of action to avoid a collision even if they tried.
 
dmspilot said:
There's not much we can do from a TA. I try to look outside and look at the display but half the time the traffic is buzzing around erratically like a bee. I don't expect the CRJ crew could have done anything or been able to determine the proper course of action to avoid a collision even if they tried.
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So, let's say the FO was PM and thus was able to take his focus away from the runway. TA happens 18 seconds prior to collision, FO looks at the screen for 5 seconds, looks out the window for 5 seconds, sees a chopper coming right at them... Do you think he'd have just let it happen? Or would he have yanked on the yoke to avoid death and called for a go-around?

That may have been what happened, but took 17 seconds instead of 10.
 
flyingcheesehead said:
So, let's say the FO was PM and thus was able to take his focus away from the runway. TA happens 18 seconds prior to collision, FO looks at the screen for 5 seconds, looks out the window for 5 seconds, sees a chopper coming right at them... Do you think he'd have just let it happen? Or would he have yanked on the yoke to avoid death and called for a go-around?

That may have been what happened, but took 17 seconds instead of 10.
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No, I don't think they would "have just let it happen." The point of my post is it's very hard to spot traffic from a TA. I can't remember if it was this thread or another forum but someone mentioned that TCAS is very inaccurate in azimuth. The number of times a TA helped me visually acquire traffic is almost 0. That's why we have RAs.

17 seconds from TA to action is not a surprising amount of time. The PM would have to 1) see and identify the chopper as traffic and not some irrelevant light from the ground, 2) determine its relative motion, 3) realize it was on a collision course, 4) use spatial and relational awareness to determine the best way to avoid a collision, 5) figure out how to communicate this to the other captain and do so. Then more time would be needed for 5) the captain to process the FO's directive and take action, and 6) for the airplane to respond to control inputs.

I believe research from FAA or NASA determined it takes ~15 seconds or so to avoid a collision because of the process I just described. I'll try to see if I find it.
 
dmspilot said:
I believe research from FAA or NASA determined it takes ~15 seconds or so to avoid a collision because of the process I just described. I'll try to see if I find it.
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This is what I was thinking of, AC90-48C. Estimate 12.5 seconds ~after~ you see it. With 10 seconds of looking (5 at the display and 5 out the window) that totals 22.5 seconds. Too long.

Screenshot 2025-02-02 at 4.10.00 AM.png
 
Albany Tom said:
I don't think I've commented on this thread before...not because I'm shy, but because I really don't have anything to add. Terrible at reading minds, even my own. I was loudly thinking that the helicopter route seems pretty close to the approach path to that runway, but I don't think I wrote it down. Maybe google is reading MY thoughts...
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Sorry…thought I had that fixed. Deleted the post this time.
 
dmspilot said:
This is what I was thinking of, AC90-48C. Estimate 12.5 seconds ~after~ you see it. With 10 seconds of looking (5 at the display and 5 out the window) that totals 22.5 seconds. Too long.

View attachment 137721
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This like Sully into the Hudson. They put pilots into the Sim and they coulda have made Teterboro. But they knew ahead of time what was happening.
 
Chip Sylverne said:
Obviously, the helo wasn't at 200', begging the question as to why the ATC radar was reading at least 100' low.
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Doesn't the ATC radar show what the aircraft's Mode C is reporting?
AV8R_87 said:
Wrong altimeter setting?
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That wouldn't affect the encoder.

A static system issue could result in both the encoder and the cockpit altimeter display being off by the same amount. Do those choppers have a radar altimeter as well?
 
I'm gonna ask a stupid question..............is there any chance the RJ was a little low (as well as the helo being too high)? for anyone who is overly familiar with that approach, or where they were in relation to landing since they really weren't technically on the approach to 33, does their altitude seem reasonable for where they were? I dunno, just a thought. someone smarter than me (ie everyone) could prob do a simple 'measure distance' in google maps from the point of impact to the touchdown zone and see if that looks about right.
 
Dana said:
Doesn't the ATC radar show what the aircraft's Mode C is reporting?

That wouldn't affect the encoder.

A static system issue could result in both the encoder and the cockpit altimeter display being off by the same amount. Do those choppers have a radar altimeter as well?
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The briefer didn't discuss what the ATC radar showed in relation to the RJ's altitude. The question was asked and deflected as part of the ongoing investigation.
 
One question I would have liked to see asked in the presser (edit: looks like eman asked), but what altitude should the crj have been at. Is 125' deconfliction actually correct. That seems nuts, especially on a bumpy day.
 
Racerx said:
One question I would have liked to see asked in the presser (edit: looks like eman asked), but what altitude should the crj have been at. Is 125' deconfliction actually correct. That seems nuts, especially on a bumpy day.
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I thought I read that helo corridor was not supposed to be used when RWY 33 was in use, presumably because of the lack of vertical separation.
 
Dana said:
Doesn't the ATC radar show what the aircraft's Mode C is reporting?
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I've wondered about this. What was the barometer at the time? Could it be that the helo was at 200' pressure altitude and ~300' true altitude?
 
The helo should have had his barometric altimeter set at field elevation at the last place landed.

Most of the airports I have flown from/to have that posted on a sign at the departure points on the airport. Helipads usually do too.
 
eman1200 said:
I'm gonna ask a stupid question..............is there any chance the RJ was a little low (as well as the helo being too high)? for anyone who is overly familiar with that approach, or where they were in relation to landing since they really weren't technically on the approach to 33, does their altitude seem reasonable for where they were? I dunno, just a thought. someone smarter than me (ie everyone) could prob do a simple 'measure distance' in google maps from the point of impact to the touchdown zone and see if that looks about right.
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The collision occurred 2400 feet from the runway threshold. Looking at the approach plate for RNAV 33, the aircraft should have been at 490' 1.4 NM out at IDTEK, so without doing the gs calculations it seems pretty reasonable to me in visual conditions.
 
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Chip Sylverne said:
The collision occurred 2400 feet from the runway threshold. Looking at the approach plate for RNAV 33, the aircraft should have been at 490' 1.4 NM out at IDTEK, so without doing the gs calculations it seems pretty reasonable to me in visual conditions.
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So....they weren't cleared for a visual approach? or were they following the plate?
 
Let'sgoflying! said:
What? Airplane 272’agl, helo route 200’agl? So, someone was planning a crash?
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I have been trying to get this point across throughout this thread but apparently I have repeatedly failed.

Minimum vertical separation is 500'. Having a helicopter pass under an airplane on Final to Rwy 33 is NOT acceptable. Vertical separation can NOT be applied in this situation. You either have visual separation or you delay the helicopter from crossing the final until no airplanes will be there.

Chip Sylverne said:
The briefer ducked the question as to what the ATC screen display read of the RJ's altitude, and how or why that may have differed from the aircrafts confirmed altitude.
...
begging the question as to why the ATC radar was reading at least 100' low.
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It was addressed. The radar update time is every 4 to 5 seconds so what the controller sees is always from a few seconds ago. Also, the altitude reporting system does not have the level of precision to display indicated altitude (what the pilot is flying) to within 100' or 200'. That why the absolute minimum vertical separating that can be applied by radar is 500'.

flyingcheesehead said:
TA happens 18 seconds prior to collision
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TA's are programming to alert when 40 seconds from the closest point of approach. That calculation is done based on the current rates of closure. That rate changes as an aircraft turns or maneuvers.

An inconsistency from the press conference was that he said that there was an aural TA alert AFTER the 500' call-out. The aural alert is suppressed below 500' RA and the 500' call is also based on RA. Did TCAS give an aural alert when it should have been suppressed or was he incorrect that the TA was aural vs. just displayed? I don't know.

Roller said:
Also they brought up another point, IMO VHF should be mandatory outside of military only airspace in CONUS, would be a great benefit to SA
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Even if the helicopter was on VHF, he would have been on the helicopter VHF frequency (134.35), not the one used for airplanes (119.1).

eman1200 said:
is there any chance the RJ was a little low
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Yes. We are always bracketing when tracking a glideslope, glidepath, or PAPI.

Racerx said:
Is 125' deconfliction actually correct. That seems nuts, especially on a bumpy day.
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Minimum vertical separation is 500'. Having a helicopter pass under an airplane on Final to Rwy 33 is NOT acceptable. Vertical separation can NOT be applied in this situation. You either have visual separation or you delay the helicopter from crossing the final until no airplanes will be there.

Half Fast said:
I've wondered about this. What was the barometer at the time? Could it be that the helo was at 200' pressure altitude and ~300' true altitude?
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It's not about True Altitude because none of the altimeters in any of the aircraft are capable of displaying True Altitude. It is about Indicated Altitude.

The ATC radar system receives pressure altitude, to the nearest 100' (Mode-C), 50' (Mode-S), or 25' (ADSB-OUT) and corrects it for the local altimeter setting.

A perfect altimeter, with the local altimeter setting set perfectly, will display True Altitude only when on the ground at the reporting station. Any deviations from that and your indicated altitude will differ somewhat from True Altitude.

Don't attribute more precision to the displayed altitudes than the overall altimetry system is capable of producing.

geezer said:
The helo should have had his barometric altimeter set at field elevation at the last place landed.
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No. Both aircraft should have been set to the altimeter setting from the current DCA ATIS. That is another source of error in the altitude readings.

Checkout_my_Six said:
So....they weren't cleared for a visual approach? or were they following the plate?
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They were cleared for the MT VERNON VISUAL charted visual procedure. They were then switched to a visual (non-charted) to Rwy 33.
 
Larry in TN said:
It was addressed. The radar update time is every 4 to 5 seconds so what the controller sees is always from a few seconds ago. Also, the altitude reporting system does not have the level of precision to display indicated altitude (what the pilot is flying) to within 100' or 200'. That why the absolute minimum vertical separating that can be applied by radar is 500'.
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The reporters were not getting this message. I think he misspoke originally and said the crj was shown on the scope at 200, but I think he meant pat25

I thought Brice Banning was going to make the press glaze over with the depth of facts, knowing they have no clue what most of things meant. Both NTSB guys were pretty great.
 
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Baked Potato said:
Do Blackhawks have radar altimeters?
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I don't know, but I would be surprised if they did not.

You don't use RA for flying a specific altitude, though. It just tells you how far you are above whatever is directly underneath you and work from 2,500' (above the surface) and lower.
 
Roller said:
We have traffic on our ND displays


Also they brought up another point, IMO VHF should be mandatory outside of military only airspace in CONUS, would be a great benefit to SA
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Does that come from ADSB or does is come from plain old mode S transponder?
 
Dana said:
Do those choppers have a radar altimeter as well?
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Yes.

Larry in TN said:
Even if the helicopter was on VHF, he would have been on the helicopter VHF frequency (134.35), not the one used for airplanes (119.1).
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Maybe that needs to stop as well.
Wasn't there another mid-air a year or two ago where SA was lost because the two aircraft on parallel runways were on different frequencies, and an alert passed to one of them was not received by the other?
Either way, this stupidity of operating on UHF in national airspace should stop. They all have VHF these days, and they can chat on UHF in MOAs and restricted areas.
 
Blackhawks have Radar Alts…
 
Just watched the briefing by the NTSB. I’ve done mishap investigation for the AF, I’m glad I only had to brief generals, and not the media. That was a bit brutal relative to the altitudes. No wonder there was a lot of discussion about releasing what they have as preliminary data.
 
eman1200 said:
I'm gonna ask a stupid question..............is there any chance the RJ was a little low (as well as the helo being too high)? for anyone who is overly familiar with that approach, or where they were in relation to landing since they really weren't technically on the approach to 33, does their altitude seem reasonable for where they were? I dunno, just a thought. someone smarter than me (ie everyone) could prob do a simple 'measure distance' in google maps from the point of impact to the touchdown zone and see if that looks about right.
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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.
1738514679968.png
 
Racerx said:
The reporters were not getting this message. I think he misspoke originally and said the crj was shown on the scope at 200, but I think he meant pat25

I thought Brice Banning was going to make the press glaze over with the depth of facts, knowing they have no clue what most of things meant. Both NTSB guys were pretty great.
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That addresses reasons why the helo altitude as displayed on the screen was inaccurate, but it doesn't address what the RJ's altitude was as displayed on the screen and whether or it was more or less accurate. If one was 100' low, and the other was 100' high, your 500' buffer should assumed to be 300'..
 
Chip Sylverne said:
That addresses reasons why the helo altitude as displayed on the screen was inaccurate, but it doesn't address what the RJ's altitude was as displayed on the screen and whether or it was more or less accurate. If one was 100' low, and the other was 100' high, your 500' buffer should assumed to be 300'..
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Why would that be relevant when visual separation was issued?
 
midwestpa24 said:
Largely to avoid overflight of security sensitive areas in DC.
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Not really. The routing really hasn't changed much in decades. There used to be a P-area over the mall itself, but I could coming from IAD get direct WAS and then the 100° radial just along the south edge of the prohibited area. Didn't need to fly anywhere near the rivers. The rivers are primarily indeed to get noise abatement and to avoid obstacles on the Virginia side.
 
AKiss20 said:
Doesn’t mean he is always right. He kept insisting that PAT25 had ADSB-Out despite multiple pieces of evidence to the contrary being presented.
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Me? That was based on the initial report of a VH-60M. If I’d had known it was a UH-60L, I would have said “there’s a good chance they have ADS-B out.” Heck, it’s still possible they had it, just might have been turned off or inop.

Not sure the relevance that some are trying to make of the lack of “out” anyway. TCAS doesn’t need out and ATC doesn’t need out. ATC still had a valid track on PAT’s mode S. Yes, there’s a better refresh rate with ADS-B out for ATC but that’s only if it’s selected. You can see on the ATC tapes, both aircraft had about a 4-5 sec refresh. That’s based on single source radar and its secondary radar antenna up top. Not sure if DCA has selectable FUSION with overlapping radars but that’s not what was displayed on that recording.
 
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Military isn’t using UHF for their own secret purposes. Yes, it can be used exclusively for things like HAVE QUICK but it’s primarily to reduce frequency congestion. At my old facility, if the fighters were using the same VHF that the civilian aircraft were using, working approach control would be a mess. Everyone would be blocking each other’s transmissions. It would also delay important tasks such as issuing approach clearances.

The other benefit, and it’s most applicable in the DCA area, is it’s better at low altitude vs VHF. VHF commonly gets blocked due to terrain / obstructions. UHF has excellent reception at the lower altitudes.
 
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