Plane Crash In DC

The ATC system functioned correctly. It warned the controller of a conflict, which he then attempted to resolve with the helicopter pilot. The existing system is by no means WWII era, and has successfully avoided a fatal comair accident in the U.S. for 16 years.

The airspace around DC is a mess mostly because Republicans in Congress kept pushing the limits with VIP helo flights and increased traffic to DCA. The "smartest minds in the entire world" appear to be techno-toddlers with insufficient grasp of the systems they are tackling and little if any oversight.

The shortage of controllers was addressed by increased recruitment, which the Republicans have now dismissed as DEI.

The vast number of FAA people are not controllers or onsite operations people. It is entirely appropriate for them to work remotely.

It is entirely irresponsible for Duffy to place blame before his NTSB has completed their investigation.
 
Andy_Ross said:
A team from SpaceX is visited the Air Traffic Control Command Centre in Virginia today to help overhaul the system in the wake of last month’s deadly air disaster in Washington, DC, Secretary of Transportation Sean Duffy has announced.
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As someone who has designed, coded, installed, and supported software for 40 years, this is terrifying.
 

Juan Browne is quite scathing about the way operations are conducted in the airspace around DC

He also brings up a valid point that using barometric altitude is risky at such low altitudes. For those who don't understand what this means, here is a quick primer.

ATC issues a figure for the airport under its control that indicates atmospheric pressure adjusted to mean sea level for their airfield, usually given in hectopascals, a.k.a as millibars (mb). This is called QNH. When the pilot dials in this QNH figure, his altimeter will read the known field elevation (for reference, one atmosphere is 1013.25).

Altimeter.png

Usually, this is not a problem, but there are often differences between the QNH figures at different but proximate airfields. I have piloted a light aircraft from Nelson Airport (elevation 16 ft) to Blenheim Airport (elevation 108 feet) and back many times - a distance of only 60 kilometres as the crow flies, and at times, I have encountered up to six mb difference, for example, 1011 mb at Nelson, 1017 mb at Blenheim. A difference of 1 mb translates to 26.25 feet (8 meters), so 6 mb difference is about 160 feet. 3 mb of that difference is down to the two airfields' respective field elevations, but the other 3 mb is due to differences in meterological conditions, i.e. what the barometric pressure would be at those locations if they were at mean sea level (MSL)

Now, in terms of the 1000ft separation rules for east-west flights, 6mb - 160 feet doesn't mean much when you're flying at cruising altitude - the Cherokee 140 I used to fly had a cruising altitude of about 7000 to 8000 feet. However, it takes on much more importance at lower altitudes... when you're supposed to be flying no higher than 200 feet, 6 mb would be a big discrepancy.

Now, I don't know what the respective QNH figures were for Fort Belvoir (DAA) and Ronald Reagan Washington National Airport (DCA) on the night of the crash. The two are only 18 km apart, so I consider a significant difference in the QNH figure would be unlikely, but not impossible. The field elevation of DAA is 73.5 ft (22.4 m) and that of DCA is 14 feet, so thats a difference of 2.3 millibars. Even if there was a difference in the weather over that distance leading to a difference in MSL barometric pressure, I don't think that is hugely significant, but IMO, it should not be overlooked as a contributing factor.

PS: and before some pedant brings it up, yes, I know you still use inches of mercury in the US... it makes no difference - its just a unit of measurement, and the principle is exacly the same.
 
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JimOfAllTrades said:
As someone who has designed, coded, installed, and supported software for 40 years, this is terrifying.
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Knowing the Techno Toddlers, someone will accidentally put a minus sign in some equation or other to do with separation, and cause ALL the flights to crash into each other. Of course, that issue will be fixed "in the next dot release" of their ATC software. Meanwhile, whenever that happens, just close and re-open that app. Worst case when all the aircraft stall, CTL-ALT-DEL.
 
Gord_in_Toronto said:
Worth a read with respect to staffing shortages and the impact on safety:

www.newsweek.com

FAA's staffing troubles make flying more dangerous, controllers say

Low staffing levels in the high-pressure job bring long hours, widespread mandatory overtime and high rates of turnover, air traffic controllers told Newsweek.
www.newsweek.com www.newsweek.com
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The problem is people, not software. Elon Musk cannot help here, because the solution is to make work conditions more attractive. This means recruiting more people and paying them a fair salary, which is not something Musk favors. Driving wages down to where no one wants to do the high-stress job is a no-brainer cause for attrition and short-staffing.
 
Norman Alexander said:
Knowing the Techno Toddlers, someone will accidentally put a minus sign in some equation or other to do with separation, and cause ALL the flights to crash into each other. Of course, that issue will be fixed "in the next dot release" of their ATC software. Meanwhile, whenever that happens, just close and re-open that app. Worst case when all the aircraft stall, CTL-ALT-DEL.
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Agreed. Nothing I've seen in the resumes of the Techno Toddlers indicates they have any experience with high-availability critical systems. This is not a skill you can learn by camping out on the server room floor.
 
smartcooky said:

Juan Browne is quite scathing about the way operations are conducted in the airspace around DC
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He's never one to pull punches.

smartcooky said:
He also brings up a valid point that using barometric altitude is risky at such low altitudes.
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Everything you say is spot on. Not only can meteorological conditions vary over a short distance, they can vary over a short period of time. Your briefed altimeter setting can be up to nearly an hour old.

Further, in my experience a barometric altimeter tends to lag. Not a problem in cruise flight where your vertical velocity is small and your altitudes and separations large. But if you're at 200 feet trying to fly a specific altitude profile, I would expect a barometric altimeter to lag a couple of seconds behind your true altitude.

I expect that the questions to be studied in the investigation will include why the helicopter pilots were relying on the barometric altimeter, why the two pilots at the helicopter controls differed in their altitude reading, and why the FDR in the helicopter does not record barometric altitude and altimeter setting. We do have the helicopter's radar altimeter reading at the time of collision.
 
Again, even if he was at 200ft, and all instruments correctly showed that, and recorder recorded it, it would not be safe. Altitude was not the problem. The whole idea if visual separation at night was the problem.
 
Dr.Sid said:
Again, even if he was at 200ft, and all instruments correctly showed that, and recorder recorded it, it would not be safe. Altitude was not the problem. The whole idea if visual separation at night was the problem.
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A point we need to reinforce. TCAS signaled a conflict. ATC automation signaled a conflict. All the technology worked. The controller responded to the collision alert by attempting to reverify the helicopter's visual situation. The instruction was the pass behind the airliner, not under or over it. Relying on visual separation rules at night in heavily congested airspace with reduced oversight is probably going to be one of those "normalization of deviance" cases. The near-misses were a warning. The most consequential difference between a near-miss and a midair is that you walk away from a near-miss. The operational and situational factors are only slightly different.
 
JayUtah said:
The problem is people, not software. Elon Musk cannot help here, because the solution is to make work conditions more attractive. This means recruiting more people and paying them a fair salary, which is not something Musk favors. Driving wages down to where no one wants to do the high-stress job is a no-brainer cause for attrition and short-staffing.
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ATC has 59,000 applications a year with maybe 1,000 making the cut. Starting salary and earning potential seem attractive. What other skills/jobs are competing for these jobs at a comparable salary?
 
Skeptical Greg said:
ATC has 59,000 applications a year with maybe 1,000 making the cut. Starting salary and earning potential seem attractive. What other skills/jobs are competing for these jobs at a comparable salary?
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Given the complaints about mandatory overtime and stressed staff, it must be a management problem. Not enough people hired to cover the workload.
 
Skeptical Greg said:
Or not enough qualified applicants?

How can management fill those empty chairs?
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Make the position more attractive by offering and guaranteeing pay and benefits that reflect the importance of the position. And broaden recruiting efforts to cast a wider net.

Skeptical Greg said:
Better infrastructure might help.
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Better tools always help. But the problem in DC wasn't that the machinery didn't work. It's that the situation was allowed to become essentially uncontrollable. The system functioned as designed, but the human element seems to have failed.
 
Skeptical Greg said:
Or not enough qualified applicants?

How can management fill those empty chairs?

Better infrastructure might help.

Or should we do nothing of merit, like we haven't for how long?
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How about better primary education of potential hires. If you have demands for a left-handed spoon-benders but your country never teaches left-handed spoon-bending in schools...you ain't filling those positions. Unless, of course, other countries DO teach left-handed spoon-bending. But then...they would be unwelcome immigrants, liable to be dragged to Gitmo at any random time without your say-so in it.
 
How about better primary education of potential hires.
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Yes that would help under any circumstances for any skill set.
At what point would you suggest we start grooming applicants as air traffic controllers?
If a legal immigrant has air traffic control skills, they shouldn't have any problem with the application process as it is.
 
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Skeptical Greg said:
That will always be a problem until we have something better to replace it .. (..hmmmm)
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Of course. What technology improvements do you think would have helped in the DC crash?

You are always going to have human pilots. So simply removing humans from thee cockpit and the control towers is not a panacea. That said, we have continually improved the infrastructure and in-cockpit automation because it's clearly helpful.
 
smartcooky said:
PS: and before some pedant brings it up, yes, I know you still use inches of mercury in the US... it makes no difference - its just a unit of measurement, and the principle is exacly the same.
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We are fiercely proud of our system of weights and measures.

 
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