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Lead Balloon
January 31, 2025, 10:05:00 GMT
permalink Post: 11818064

Quote:

Originally Posted by Chesty Morgan

Quite right. However, I'm not investigating this accident. Nobody on PPRuNe is. It's a rumour network.

Perhaps I should rephrase. Responsibility for separation was given to PAT25. Failure to maintain separation was caused by PAT25 not maintaining the separation that they were responsible for. Ergo, the collision was caused by a reduction in separation to zero, which was the responsibility of PAT25.

As it's a rumour network...

Perhaps the "responsibility" should never have been "given" to a helicopter to maintain separation on the basis of visual identification of another aircraft, at night, in close proximity to an airport in Class B airspace.

Subjects PAT25 Separation (ALL)

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Lead Balloon
February 01, 2025, 00:06:00 GMT
permalink Post: 11818639

Quote:

Originally Posted by Chesty Morgan

Perhaps not, but it was. That they maybe shouldn't have been given that responsibility doesn't abrogate them from such.

It's akin to blaming someone else when you fly in to a hill under your own terrain separation.

I find that logic to be circular and the analogy to be a false equivalence.

To take the analogy first, when a PIC takes responsibility for separation from terrain, that PIC is putting only one aircraft and its POB at risk: The aircraft that the PIC is flying. In the case of the current tragedy, the system seems effectively to have put responsibility for the safety of two aircraft (at least) and all their POB into the lap of the PIC of one of them, on the basis of the (demonstrably dangerous) assumption that the PIC could reliably sight and follow a specific aircraft, at night, without any risk of misidentification.

Speaking of assumptions, I'm confident that the passengers on the CRJ would have assumed - reasonably I'd suggest - that the ATC system would always 'have their back'. I'm also confident that there will be a lot of grieving people at the moment, simply unable to grapple with the enormity of the realisation that the assumption was dangerously na\xefve. (Presumably, similar airspace arrangements continue in place at other locations, where the system continues to allocate responsibility similarly?)

Note that I do not presume to allocate responsibility for the tragedy to any individual/s. If I were pressed, I would allocate responsibility to whomever 'signed off' on arrangements in Class B airspace that entailed such a durr-obvious risk of precisely what happened.

Last edited by Lead Balloon; 1st February 2025 at 00:24 .

Subjects ATC CRJ Separation (ALL)

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Lead Balloon
February 01, 2025, 22:36:00 GMT
permalink Post: 11819353

Quote:

Originally Posted by YRP

Absolutely on the lookout.

No the airspace does not take the blame. Apparently the hello pilots missed the lookout. And the controller could have been clearer, instead of “still in sight?” perhaps “the RJ is now 1/2 mile 10 o’clock, confirm you have him?”.

(not criticizing him, guessing that he saw them closer than expected, was concerned, and made a very quick call)

But the airspace & procedure seems to not tolerate mistakes. There ought to be some safety margin. While not the primary fault, it could be improved.

The procedures effectively abdicate separation responsibility to a single point of failure, where failure is not unlikely and, as a consequence of the airspace design, failure results in high probabilities of collision.

The difficulties of identifying a specific aircraft, at night, in a background of stationary and moving lights, when moving objects on a collision course will always appear stationary to each other, are well known, as are the probabilities of mis-identification. The airspace design 'squeezes' inbound aircraft and transiting helicopters to practicality the same altitude, when instrument and other tolerances are taken into consideration.

I'm guessing that those focusing on the helo pilot's lookout and aircraft identification responsibilities haven't done much flying, at night, over a busy city. Maybe the procedure and airspace designers haven't either, though I get the distinct whiff of political and bureaucratic expediency in the helicopter lane design. I'm also guessing that earlier near misses in similar circumstances will be identified, where the ball on the Roulette Wheel fortunately didn't land on 00.

Last edited by Lead Balloon; 1st February 2025 at 23:06 .

Subjects ATC Close Calls Separation (ALL)

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Lead Balloon
February 02, 2025, 00:38:00 GMT
permalink Post: 11819412

That's assuming perfect equipment accuracy. My understanding is that the tolerance of e.g. an IFR altimeter in the USA is 75'. If that's correct, one IF aircraft with a 'legal' altimeter indicating 325' could in fact be at 250' and another IFR aircraft with a 'legal' altimeter indicating 175' could in fact be at ... 250'. I'm hoping that the avionics in the aircraft involved in this terrible tragedy were more accurate than that, but I always exercise caution in taking numbers out of avionics and ATC systems as 'gospel truth' to the foot. The altitudes on RADAR displays don't increase and decrease in 1 foot increments; nor do the outputs of aircraft transponders. RADALT is different.

Subjects ATC IFR

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Lead Balloon
February 02, 2025, 03:23:00 GMT
permalink Post: 11819488

Quote:

Originally Posted by photonclock

Of course. So lets assume the readings to be at the outside of the envelope to the benefit of both aircraft, ie, CRJ at 350 (325 +/- 25 as stated by NTSB), and 200 +/- 75 for the helicopter, so 125. That's 225 feet of vertical-only separation. Is that considered acceptable? If not, why did ATC allow it?

ATC didn't "allow it".

The procedures allowed the controller to hand responsibility for separation to the helo pilot, once the helo was instructed to pass behind an aircraft which the helo said it had identified (twice I think?). However, it seems that the helo identified the wrong aircraft. That's hardly surprising when it's night, there's lots of stationary and moving lights around, and one of the apparently stationary lights is in fact bolted to an aircraft with which you're on a collision course.

Subjects ATC CRJ NTSB Pass Behind Pass Behind (All) Separation (ALL)

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Lead Balloon
February 02, 2025, 04:12:00 GMT
permalink Post: 11819502

Quote:

Originally Posted by JRBarrett

The maximum allowable altimeter error between sea level and 1000 feet is +/- 20 feet, and even a simple stand-alone barometric altimeter has to be able to meet that requirement. The RVSM-certified Air Data Computers on something like a CRJ are typically much more precise than that - more like +/- 5 feet at almost all altitudes. I would assume the air data system on a Blackhawk would be equally precise at low levels.

Thanks JRB. Regulatory reference? I'm not saying you're wrong. But I can't find anything other than the 75'. (The acceptable 'split' between 2 on board altimeters is a different tolerance, I believe.)

Subjects Barometric Altimeter Blackhawk (H-60) CRJ

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Lead Balloon
February 02, 2025, 06:03:00 GMT
permalink Post: 11819532

Quote:

Originally Posted by photonclock

Well, that's interesting. You seem to be saying that "the system" worked as designed? FDR notes immediately before your reply:

Did ATC do all of that? Having listened to the ATC comms (including the UHF) a few times, I believe they did, for the most part? They mentioned CRJ (of what use is mentioning the type at night, I have no idea, but they did), they mentioned where it was and where it was headed, and they received two acknowledgments...

So that means this collision occurred entirely within all established protocls?

These aircraft crashed, as per the system specifications.

So the system is, to put it plainly...FUBAR?

That's not good.

I agree. I expressed my inexpert opinion earlier:

The procedures effectively abdicate separation responsibility to a single point of failure, where failure is not unlikely and, as a consequence of the airspace design, failure results in high probabilities of collision.

The difficulties of identifying a specific aircraft, at night, in a background of stationary and moving lights, when moving objects on a collision course will always appear stationary to each other, are well known, as are the probabilities of mis-identification. The airspace design 'squeezes' inbound aircraft and transiting helicopters to practicality the same altitude, when instrument and other tolerances are taken into consideration.

Subjects ATC CRJ Separation (ALL)

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Lead Balloon
February 02, 2025, 11:38:00 GMT
permalink Post: 11819710

Quote:

Originally Posted by DP.

Mere SLF here - I work in risk management (in a different industry) and so have an interest here, along with a lifelong interest in aviation - fully ready to be modded if I'm talking out of turn!

I accept the point regarding the likely economic impact. However I think its worth making the point that in the context of that '16 years without a fatality' record. there have been a number of potentially serious near-misses on the ground (JBU at BOS, AAL/DAL at JFK, SWA/FDX at AUS, etc etc) that are indicative of a system operating beyond its capacity and implementing procedures that are deemed to be of an acceptable risk profile in order to stretch that capacity. It was fortunate that those previous incidents were narrowly avoided. Wednesday night was where that luck, sadly, ran out.

And thus the perpetually (usually unspoken) questions arise: Are the lives lost in this tragedy merely the price inevitably to be paid in return for airspace arrangements and an ATC system that would cost more than those lost lives were 'worth', if the system and arrangements had been more effective at preventing this kind of collision? Or is it mere luck that many other circumstances created by these airspace arrangements and the ATC system have ended with near misses rather than tragedy, thus justifying more expenditure on the airspace arrangements and the ATC system so as to prevent those near misses becoming collisions? (And let's not forget that the amount of concrete available on the ground at airports drives traffic capacity.)

Despite what's said almost universally by politicians and aviation authorities worldwide, the answers are driven and determined by politics, not the laws of physics and probabilities. "Safety is always our highest priority" is a meaningless but comforting sop for the public.

Ponder this question: If the POB the CRJ were senior politicians and important bureaucrats instead of the actual POB killed in this tragedy, would the investigation be carried out any differently, and its outcomes be any different, than if the POB were us nobodies?

I earnestly (perhaps naively) hope that the NTSB has and continues to have the corporate competence and the corporate integrity to investigate the circumstances of this tragedy, comprehensively, and to make frank and fearless findings and recommendations based on the objective facts and objective risks.

Subjects ATC CRJ Close Calls Findings NTSB

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Lead Balloon
February 08, 2025, 05:02:00 GMT
permalink Post: 11824104

Quote:

Originally Posted by BrogulT

There's a designated holding point on the route. IDK exactly what that means, but it must mean something, right?

The river is 4000 feet wide just south of that designated point. I imagine there is a procedure otherwise what would be the point?

The other option is that they would have to have the landing traffic go around.

If I've read the chart legend correctly, that triangle at Hains Point is a "Non-Compulsory Reporting or Holding Point".
...

Subjects: None

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Lead Balloon
February 08, 2025, 06:25:00 GMT
permalink Post: 11824116

Quote:

Originally Posted by Someone Somewhere

It also shows that the Wilson, Memorial, and Capitol St bridges are compulsory holding points.

I don't read the chart legend as having that denotation. The words on the legend for a solid triangle are, with my bolding: Compulsory Reporting or Holding Point.

Subjects: None

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Lead Balloon
February 15, 2025, 04:03:00 GMT
permalink Post: 11828354

It appears from the NTSB's most recent press conference that the instruction "pass behind the CRJ" was not heard in the helo's CVR and, therefore by inference, not heard by the crew. Am I correct in assuming that there is no requirement to readback an instruction like that in the USA? ATC appeared not to expect one.

Subjects ATC CRJ Pass Behind Pass Behind (All)

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Lead Balloon
February 15, 2025, 10:26:00 GMT
permalink Post: 11828492

...
I was recently watching a video on the highlights of Oshkosh, the relevance of which will hopefully become clear shortly.

One part of the video was some POV footage from the cockpit of one of the Blue Angels. I had a 'double-take' and triple rewind to confirm what I thought I saw on the glareshield: I think I saw a piece of portable avionics that is very, very familiar to me.

Is any expert able to confirm what that white block on the glareshield is?

I've been in a discussion about the complexity of avionics upgrades to military flying machinery, the discussion precipitated by the differing terminology about "fitted with" and "equipped with" and "carried". And I suggest that even if the helo was "fitted with" an ADS system, at the altitude the aircraft were operating at the time of the collision any alerts may have been suppressed.

Subjects: None

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Lead Balloon
February 15, 2025, 23:36:00 GMT
permalink Post: 11828906

As someone with an insight into the complexities of retrofitting certified avionics hardware and the associated wiring, controllers and antennae to fighter jets and other military aircraft, I would be completely unsurprised if, as seems to be evident from the video imbedded at #1112, the USA’s elite, pre-eminent military aerobatics team uses a portable ADS-B unit velcro’ed to the aircraft’s glare shield. And if it’s OK for them, I can’t see why it wouldn’t be OK for the PAT helicopters and I wouldn’t be surprised if that’s the ADS-B to which various references having been made.

I suppose the operational question is whether the aircraft on which these portable units are used are permitted to fly without them on board and working. My guess is that there will be no prohibition. They are just ‘nice to haves’ but not essential for the ops in which they engage.

And there’s a causal question anyway: Would a functioning ADS-B system – portable or otherwise - on the PAT helo have made any difference? The answer depends on the variables around the alert suppression parameters in each aircraft’s systems and the effectiveness of the format of alerts – if any – given in each cockpit.

Subjects ADSB (All)

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Lead Balloon
February 16, 2025, 03:52:00 GMT
permalink Post: 11828969

Quote:

Originally Posted by island_airphoto

For us lowly civilians a Velcro ADS-B receiver isn't getting you within 30 miles of KDCA, you need it to transmit too. The helicopter having even receive ADS-B would have helped hugely if they looked at it, the fact they weren't looking at the plane they thought they were would have been pretty apparent.

Who said \x93receiver\x94 alone? I think you\x92ll find that those units transmit as well. I have a similar unit clipped to a suction cup on the windscreen of my aircraft.

What they could have seen and heard in the PAT helo depends on a lot on the matters to which I referred, among others, in my earlier post.

Subjects ADSB (All) KDCA

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Lead Balloon
February 16, 2025, 06:04:00 GMT
permalink Post: 11828994

Quote:

Originally Posted by island_airphoto

Those things do not transmit, see https://stratusbyappareo.com/product...s-b-receivers/ .

I stand corrected.

The one I use looks similar but is a different brand and is a portable ADS-B In/Out transceiver . Looks like it's not compatible with whatever systems are in use in the USA.

But I reiterate that w hat they could have seen and heard in the PAT helo, had it been fitted with an ADS-B "receiver" depends a lot on the matters to which I referred, among others, in my earlier post.

Last edited by Lead Balloon; 16th February 2025 at 06:33 .

Subjects ADSB (All)

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Lead Balloon
August 02, 2025, 09:04:00 GMT
permalink Post: 11932221

I think this is Day 1:

Subjects: None

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Lead Balloon January 31, 2025, 10:05:00 GMT permalink Post: 11818064	Quote: Originally Posted by Chesty Morgan Quite right. However, I'm not investigating this accident. Nobody on PPRuNe is. It's a rumour network. Perhaps I should rephrase. Responsibility for separation was given to PAT25. Failure to maintain separation was caused by PAT25 not maintaining the separation that they were responsible for. Ergo, the collision was caused by a reduction in separation to zero, which was the responsibility of PAT25. As it's a rumour network... Perhaps the "responsibility" should never have been "given" to a helicopter to maintain separation on the basis of visual identification of another aircraft, at night, in close proximity to an airport in Class B airspace. Subjects PAT25 Separation (ALL) Links are to this post in the relevant subject page so that this post can be seen in context. 4 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 01, 2025, 00:06:00 GMT permalink Post: 11818639	Quote: Originally Posted by Chesty Morgan Perhaps not, but it was. That they maybe shouldn't have been given that responsibility doesn't abrogate them from such. It's akin to blaming someone else when you fly in to a hill under your own terrain separation. I find that logic to be circular and the analogy to be a false equivalence. To take the analogy first, when a PIC takes responsibility for separation from terrain, that PIC is putting only one aircraft and its POB at risk: The aircraft that the PIC is flying. In the case of the current tragedy, the system seems effectively to have put responsibility for the safety of two aircraft (at least) and all their POB into the lap of the PIC of one of them, on the basis of the (demonstrably dangerous) assumption that the PIC could reliably sight and follow a specific aircraft, at night, without any risk of misidentification. Speaking of assumptions, I'm confident that the passengers on the CRJ would have assumed - reasonably I'd suggest - that the ATC system would always 'have their back'. I'm also confident that there will be a lot of grieving people at the moment, simply unable to grapple with the enormity of the realisation that the assumption was dangerously na\xefve. (Presumably, similar airspace arrangements continue in place at other locations, where the system continues to allocate responsibility similarly?) Note that I do not presume to allocate responsibility for the tragedy to any individual/s. If I were pressed, I would allocate responsibility to whomever 'signed off' on arrangements in Class B airspace that entailed such a durr-obvious risk of precisely what happened. Last edited by Lead Balloon; 1st February 2025 at 00:24 . Subjects ATC CRJ Separation (ALL) Links are to this post in the relevant subject page so that this post can be seen in context. 2 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 01, 2025, 22:36:00 GMT permalink Post: 11819353	Quote: Originally Posted by YRP Absolutely on the lookout. No the airspace does not take the blame. Apparently the hello pilots missed the lookout. And the controller could have been clearer, instead of “still in sight?” perhaps “the RJ is now 1/2 mile 10 o’clock, confirm you have him?”. (not criticizing him, guessing that he saw them closer than expected, was concerned, and made a very quick call) But the airspace & procedure seems to not tolerate mistakes. There ought to be some safety margin. While not the primary fault, it could be improved. The procedures effectively abdicate separation responsibility to a single point of failure, where failure is not unlikely and, as a consequence of the airspace design, failure results in high probabilities of collision. The difficulties of identifying a specific aircraft, at night, in a background of stationary and moving lights, when moving objects on a collision course will always appear stationary to each other, are well known, as are the probabilities of mis-identification. The airspace design 'squeezes' inbound aircraft and transiting helicopters to practicality the same altitude, when instrument and other tolerances are taken into consideration. I'm guessing that those focusing on the helo pilot's lookout and aircraft identification responsibilities haven't done much flying, at night, over a busy city. Maybe the procedure and airspace designers haven't either, though I get the distinct whiff of political and bureaucratic expediency in the helicopter lane design. I'm also guessing that earlier near misses in similar circumstances will be identified, where the ball on the Roulette Wheel fortunately didn't land on 00. Last edited by Lead Balloon; 1st February 2025 at 23:06 . Subjects ATC Close Calls Separation (ALL) Links are to this post in the relevant subject page so that this post can be seen in context. 6 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 02, 2025, 00:38:00 GMT permalink Post: 11819412	That's assuming perfect equipment accuracy. My understanding is that the tolerance of e.g. an IFR altimeter in the USA is 75'. If that's correct, one IF aircraft with a 'legal' altimeter indicating 325' could in fact be at 250' and another IFR aircraft with a 'legal' altimeter indicating 175' could in fact be at ... 250'. I'm hoping that the avionics in the aircraft involved in this terrible tragedy were more accurate than that, but I always exercise caution in taking numbers out of avionics and ATC systems as 'gospel truth' to the foot. The altitudes on RADAR displays don't increase and decrease in 1 foot increments; nor do the outputs of aircraft transponders. RADALT is different. Subjects ATC IFR Links are to this post in the relevant subject page so that this post can be seen in context. 2 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 02, 2025, 03:23:00 GMT permalink Post: 11819488	Quote: Originally Posted by photonclock Of course. So lets assume the readings to be at the outside of the envelope to the benefit of both aircraft, ie, CRJ at 350 (325 +/- 25 as stated by NTSB), and 200 +/- 75 for the helicopter, so 125. That's 225 feet of vertical-only separation. Is that considered acceptable? If not, why did ATC allow it? ATC didn't "allow it". The procedures allowed the controller to hand responsibility for separation to the helo pilot, once the helo was instructed to pass behind an aircraft which the helo said it had identified (twice I think?). However, it seems that the helo identified the wrong aircraft. That's hardly surprising when it's night, there's lots of stationary and moving lights around, and one of the apparently stationary lights is in fact bolted to an aircraft with which you're on a collision course. Subjects ATC CRJ NTSB Pass Behind Pass Behind (All) Separation (ALL) Links are to this post in the relevant subject page so that this post can be seen in context. 13 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 02, 2025, 04:12:00 GMT permalink Post: 11819502	Quote: Originally Posted by JRBarrett The maximum allowable altimeter error between sea level and 1000 feet is +/- 20 feet, and even a simple stand-alone barometric altimeter has to be able to meet that requirement. The RVSM-certified Air Data Computers on something like a CRJ are typically much more precise than that - more like +/- 5 feet at almost all altitudes. I would assume the air data system on a Blackhawk would be equally precise at low levels. Thanks JRB. Regulatory reference? I'm not saying you're wrong. But I can't find anything other than the 75'. (The acceptable 'split' between 2 on board altimeters is a different tolerance, I believe.) Subjects Barometric Altimeter Blackhawk (H-60) CRJ Links are to this post in the relevant subject page so that this post can be seen in context. No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 02, 2025, 06:03:00 GMT permalink Post: 11819532	Quote: Originally Posted by photonclock Well, that's interesting. You seem to be saying that "the system" worked as designed? FDR notes immediately before your reply: Did ATC do all of that? Having listened to the ATC comms (including the UHF) a few times, I believe they did, for the most part? They mentioned CRJ (of what use is mentioning the type at night, I have no idea, but they did), they mentioned where it was and where it was headed, and they received two acknowledgments... So that means this collision occurred entirely within all established protocls? These aircraft crashed, as per the system specifications. So the system is, to put it plainly...FUBAR? That's not good. I agree. I expressed my inexpert opinion earlier: The procedures effectively abdicate separation responsibility to a single point of failure, where failure is not unlikely and, as a consequence of the airspace design, failure results in high probabilities of collision. The difficulties of identifying a specific aircraft, at night, in a background of stationary and moving lights, when moving objects on a collision course will always appear stationary to each other, are well known, as are the probabilities of mis-identification. The airspace design 'squeezes' inbound aircraft and transiting helicopters to practicality the same altitude, when instrument and other tolerances are taken into consideration. Subjects ATC CRJ Separation (ALL) Links are to this post in the relevant subject page so that this post can be seen in context. 1 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 02, 2025, 11:38:00 GMT permalink Post: 11819710	Quote: Originally Posted by DP. Mere SLF here - I work in risk management (in a different industry) and so have an interest here, along with a lifelong interest in aviation - fully ready to be modded if I'm talking out of turn! I accept the point regarding the likely economic impact. However I think its worth making the point that in the context of that '16 years without a fatality' record. there have been a number of potentially serious near-misses on the ground (JBU at BOS, AAL/DAL at JFK, SWA/FDX at AUS, etc etc) that are indicative of a system operating beyond its capacity and implementing procedures that are deemed to be of an acceptable risk profile in order to stretch that capacity. It was fortunate that those previous incidents were narrowly avoided. Wednesday night was where that luck, sadly, ran out. And thus the perpetually (usually unspoken) questions arise: Are the lives lost in this tragedy merely the price inevitably to be paid in return for airspace arrangements and an ATC system that would cost more than those lost lives were 'worth', if the system and arrangements had been more effective at preventing this kind of collision? Or is it mere luck that many other circumstances created by these airspace arrangements and the ATC system have ended with near misses rather than tragedy, thus justifying more expenditure on the airspace arrangements and the ATC system so as to prevent those near misses becoming collisions? (And let's not forget that the amount of concrete available on the ground at airports drives traffic capacity.) Despite what's said almost universally by politicians and aviation authorities worldwide, the answers are driven and determined by politics, not the laws of physics and probabilities. "Safety is always our highest priority" is a meaningless but comforting sop for the public. Ponder this question: If the POB the CRJ were senior politicians and important bureaucrats instead of the actual POB killed in this tragedy, would the investigation be carried out any differently, and its outcomes be any different, than if the POB were us nobodies? I earnestly (perhaps naively) hope that the NTSB has and continues to have the corporate competence and the corporate integrity to investigate the circumstances of this tragedy, comprehensively, and to make frank and fearless findings and recommendations based on the objective facts and objective risks. Subjects ATC CRJ Close Calls Findings NTSB Links are to this post in the relevant subject page so that this post can be seen in context. 8 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 08, 2025, 05:02:00 GMT permalink Post: 11824104	Quote: Originally Posted by BrogulT There's a designated holding point on the route. IDK exactly what that means, but it must mean something, right? The river is 4000 feet wide just south of that designated point. I imagine there is a procedure otherwise what would be the point? The other option is that they would have to have the landing traffic go around. If I've read the chart legend correctly, that triangle at Hains Point is a "Non-Compulsory Reporting or Holding Point". ... Subjects: None No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 08, 2025, 06:25:00 GMT permalink Post: 11824116	Quote: Originally Posted by Someone Somewhere It also shows that the Wilson, Memorial, and Capitol St bridges are compulsory holding points. I don't read the chart legend as having that denotation. The words on the legend for a solid triangle are, with my bolding: Compulsory Reporting or Holding Point. Subjects: None 3 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 15, 2025, 04:03:00 GMT permalink Post: 11828354	It appears from the NTSB's most recent press conference that the instruction "pass behind the CRJ" was not heard in the helo's CVR and, therefore by inference, not heard by the crew. Am I correct in assuming that there is no requirement to readback an instruction like that in the USA? ATC appeared not to expect one. Subjects ATC CRJ Pass Behind Pass Behind (All) Links are to this post in the relevant subject page so that this post can be seen in context. No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 15, 2025, 10:26:00 GMT permalink Post: 11828492	... I was recently watching a video on the highlights of Oshkosh, the relevance of which will hopefully become clear shortly. One part of the video was some POV footage from the cockpit of one of the Blue Angels. I had a 'double-take' and triple rewind to confirm what I thought I saw on the glareshield: I think I saw a piece of portable avionics that is very, very familiar to me. Is any expert able to confirm what that white block on the glareshield is? I've been in a discussion about the complexity of avionics upgrades to military flying machinery, the discussion precipitated by the differing terminology about "fitted with" and "equipped with" and "carried". And I suggest that even if the helo was "fitted with" an ADS system, at the altitude the aircraft were operating at the time of the collision any alerts may have been suppressed. Subjects: None No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 15, 2025, 23:36:00 GMT permalink Post: 11828906	As someone with an insight into the complexities of retrofitting certified avionics hardware and the associated wiring, controllers and antennae to fighter jets and other military aircraft, I would be completely unsurprised if, as seems to be evident from the video imbedded at #1112, the USA’s elite, pre-eminent military aerobatics team uses a portable ADS-B unit velcro’ed to the aircraft’s glare shield. And if it’s OK for them, I can’t see why it wouldn’t be OK for the PAT helicopters and I wouldn’t be surprised if that’s the ADS-B to which various references having been made. I suppose the operational question is whether the aircraft on which these portable units are used are permitted to fly without them on board and working. My guess is that there will be no prohibition. They are just ‘nice to haves’ but not essential for the ops in which they engage. And there’s a causal question anyway: Would a functioning ADS-B system – portable or otherwise - on the PAT helo have made any difference? The answer depends on the variables around the alert suppression parameters in each aircraft’s systems and the effectiveness of the format of alerts – if any – given in each cockpit. Subjects ADSB (All) Links are to this post in the relevant subject page so that this post can be seen in context. No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 16, 2025, 03:52:00 GMT permalink Post: 11828969	Quote: Originally Posted by island_airphoto For us lowly civilians a Velcro ADS-B receiver isn't getting you within 30 miles of KDCA, you need it to transmit too. The helicopter having even receive ADS-B would have helped hugely if they looked at it, the fact they weren't looking at the plane they thought they were would have been pretty apparent. Who said \x93receiver\x94 alone? I think you\x92ll find that those units transmit as well. I have a similar unit clipped to a suction cup on the windscreen of my aircraft. What they could have seen and heard in the PAT helo depends on a lot on the matters to which I referred, among others, in my earlier post. Subjects ADSB (All) KDCA Links are to this post in the relevant subject page so that this post can be seen in context. No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon February 16, 2025, 06:04:00 GMT permalink Post: 11828994	Quote: Originally Posted by island_airphoto Those things do not transmit, see https://stratusbyappareo.com/product...s-b-receivers/ . I stand corrected. The one I use looks similar but is a different brand and is a portable ADS-B In/Out transceiver . Looks like it's not compatible with whatever systems are in use in the USA. But I reiterate that w hat they could have seen and heard in the PAT helo, had it been fitted with an ADS-B "receiver" depends a lot on the matters to which I referred, among others, in my earlier post. Last edited by Lead Balloon; 16th February 2025 at 06:33 . Subjects ADSB (All) Links are to this post in the relevant subject page so that this post can be seen in context. No recorded likes for this post (could be before pprune supported 'likes'). Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
Lead Balloon August 02, 2025, 09:04:00 GMT permalink Post: 11932221	I think this is Day 1: You Tube Subjects: None 1 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

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