I wrote this on FB but thought I'd repost it here:
Yesterday I was out flying, practicing to get ready for my next BFR (biennial flight review.) It was a beautiful day for flying, mostly clear with some scattered clouds around 4000 feet. After I landed and came back home I heard about the crash of American Airlines flight 5342, the first crash of an airliner in the US since 2009.
Commercial aviation has become so safe that we often forget about the risks inherent in aviation. But they are always there. Captain A. G. Lamplugh, a pilot in the Royal Air Force during World War 1, once noted that “aviation in itself is not inherently dangerous. But to an even greater degree than the sea, it is terribly unforgiving of any carelessness, incapacity or neglect.” And that has held very true over the years.
When I first started flying 30 years ago we had four major tools to use to maintain separation from other airplanes. The first and most important were our eyes. VFR pilots (like me) fly under those "visual flight rules" which basically mean see and avoid other airplanes. At uncontrolled airports you can fly without a radio and do all your navigation and separation with just your eyes, and for decades after that first flight in North Carolina, that's what all pilots did. And back then there were so few airplanes in the air that it usually worked. But not always. The first midair collision happened at the Milano Circuito Aereo Internazionale airshow in 1910, between a monoplane and a biplane. Both pilots survived, due both to luck and the slow airspeeds that aircraft were capable of at the time.
In 1915 pilots got the second tool that would turn out to be invaluable - radio. With radios, pilots could not only talk to each other, they could talk to the ground. At first this just meant getting weather reports and updates on the runway, but soon ground based controllers were able to talk to pilots and give them advice on where to go and how to remain separated. This is important in part because pilots do not have a 360 degree field of view; parts of the airplane block their sightlines. This is why, for example, collisions between low-wing and high-wing airplanes are more common when the low-wing is above the other aircraft; the top pilot cannot see down past the wing, and the bottom pilot cannot see up through his wing. Now a controller could easily see both and tell them how to remain separated.
The next tool we got was radar. First developed during World War II to find enemy aircraft, it was first used for air traffic control in 1952 in Washington, DC. Now controllers did not have to physically see aircraft - the radar would show them where, and how far away, they were. This was quickly improved through transponders, so the air traffic controller could not only see a blip on his screen, but also had information about the plane's ID and altitude.
The most recent innovation has been ADS-B / ATAS. This is an autonomous system that can be installed in any aircraft to both transmit the location of the aircraft and determine if a close call will occur. ADS-B "out" has been mandatory in the US in most US airspaces since 2020. It's a big advance in pilot traffic awareness, since warnings no longer have to go through air traffic control, and you will immediately see any traffic that's heading towards you if you have the right receiver. Larger aircraft even have the ability to autonomously avoid other aircraft based on information from a similar system called TCAS.
But with all these systems, it still often comes down to what you can see - and even modern air traffic control uses this regularly. As I was flying back to the airport yesterday the tower said "One one bravo, you're number two following a Cherokee at your 11, base to final at 1200 feet, report traffic in sight." Which in plain english means there's a small plane to my left just below my altitude, and I should tell the tower when I see them. I strained to find the tiny dot against all the houses, buildings and cars but could not see anything. Ten seconds later I got another "11B, report traffic in sight." At that point I saw the Cherokee a few miles away, just finishing the turn onto final. "11B has traffic in sight," I reported. They immediately replied with "11B follow the Cherokee, clear to land 24." Which means I could now land on runway 24 without any additional communication.
This whole exchange happened because even though air traffic control can see us both on radar (and likely out the window at this point) the primary method of clearance in VFR is always the pilot's eyes. And once I could see him, the odds of me accidentally turning into him or overtaking him on final were very low - and the controller could turn his attention to other things.
I was thinking about this as I was going over the transcript from air traffic control from yesterday's crash. The relevant sections are these:
15:50 (ATC) PAT25 traffic just south of Wilson Bridge CRJ is 1200 feet for runway 33
17:30 (ATC) PAT25 do you have the CRJ in sight?
17:32 (ATC) PAT25 pass behind the CRJ
18:05 (Unknown) Tower did you see that?
Again in English, at 15 minutes and 50 seconds into the recording, the airport tower (responsible for all traffic in about a 5 mile radius) first tells PAT25 - the helicopter - that they have jet traffic that they might conflict with. We can't hear the helicopter's response (they may have been using a different frequency to respond) but we can infer their replies from what the air traffic controller was saying.
Their reply to the first ATC transmission was likely something like "PAT25 looking for traffic" since at night in a crowded airspace, there's a lot to look at before you find the one bit of moving light that is your traffic.
Two minutes later, ATC asks them again because it's been a while and they are getting closer. ATC is getting more insistent because if they CAN'T see them they can't reasonably avoid them, even if they have ADS-B or a similar system. And if they still could not see them after those two minutes, the next transmission from ATC would have likely been an avoidance instruction, something like "PAT25 turn left heading XX, maintain YY feet" to ensure they were clear.
However PAT25 likely replied that the traffic was in sight, because the next transmission from the controller, two seconds later, is "pass behind the CRJ." (CRJ stands for Canadair Regional Jet, the sort of aircraft American 5342 was.) At this point, once the controller knows that they have the aircraft in sight, they can see and avoid the aircraft themselves.
About 30 seconds later another pilot says "did you see that?" indicating the collision.
So it's way too early to determine exactly what happened and why, but from the ATC recordings it sounds like ATC was relying on the helicopter to see and avoid the CRJ, based on their visual contact with it. And that's not at all unusual for helicopters operating in busy airspaces, since they often operate near airports but below approach/departure corridors.
The politics has already started, unfortunately. Trump has blamed DEI, Barack Obama and Joe Biden respectively for the crash, and there is currently no FAA administrator (or deputy administrator) after Elon Musk forced out the former administrator, Mike Whitaker. Hopefully these impediments will not have too much of an effect om the investigation.
Yesterday I was out flying, practicing to get ready for my next BFR (biennial flight review.) It was a beautiful day for flying, mostly clear with some scattered clouds around 4000 feet. After I landed and came back home I heard about the crash of American Airlines flight 5342, the first crash of an airliner in the US since 2009.
Commercial aviation has become so safe that we often forget about the risks inherent in aviation. But they are always there. Captain A. G. Lamplugh, a pilot in the Royal Air Force during World War 1, once noted that “aviation in itself is not inherently dangerous. But to an even greater degree than the sea, it is terribly unforgiving of any carelessness, incapacity or neglect.” And that has held very true over the years.
When I first started flying 30 years ago we had four major tools to use to maintain separation from other airplanes. The first and most important were our eyes. VFR pilots (like me) fly under those "visual flight rules" which basically mean see and avoid other airplanes. At uncontrolled airports you can fly without a radio and do all your navigation and separation with just your eyes, and for decades after that first flight in North Carolina, that's what all pilots did. And back then there were so few airplanes in the air that it usually worked. But not always. The first midair collision happened at the Milano Circuito Aereo Internazionale airshow in 1910, between a monoplane and a biplane. Both pilots survived, due both to luck and the slow airspeeds that aircraft were capable of at the time.
In 1915 pilots got the second tool that would turn out to be invaluable - radio. With radios, pilots could not only talk to each other, they could talk to the ground. At first this just meant getting weather reports and updates on the runway, but soon ground based controllers were able to talk to pilots and give them advice on where to go and how to remain separated. This is important in part because pilots do not have a 360 degree field of view; parts of the airplane block their sightlines. This is why, for example, collisions between low-wing and high-wing airplanes are more common when the low-wing is above the other aircraft; the top pilot cannot see down past the wing, and the bottom pilot cannot see up through his wing. Now a controller could easily see both and tell them how to remain separated.
The next tool we got was radar. First developed during World War II to find enemy aircraft, it was first used for air traffic control in 1952 in Washington, DC. Now controllers did not have to physically see aircraft - the radar would show them where, and how far away, they were. This was quickly improved through transponders, so the air traffic controller could not only see a blip on his screen, but also had information about the plane's ID and altitude.
The most recent innovation has been ADS-B / ATAS. This is an autonomous system that can be installed in any aircraft to both transmit the location of the aircraft and determine if a close call will occur. ADS-B "out" has been mandatory in the US in most US airspaces since 2020. It's a big advance in pilot traffic awareness, since warnings no longer have to go through air traffic control, and you will immediately see any traffic that's heading towards you if you have the right receiver. Larger aircraft even have the ability to autonomously avoid other aircraft based on information from a similar system called TCAS.
But with all these systems, it still often comes down to what you can see - and even modern air traffic control uses this regularly. As I was flying back to the airport yesterday the tower said "One one bravo, you're number two following a Cherokee at your 11, base to final at 1200 feet, report traffic in sight." Which in plain english means there's a small plane to my left just below my altitude, and I should tell the tower when I see them. I strained to find the tiny dot against all the houses, buildings and cars but could not see anything. Ten seconds later I got another "11B, report traffic in sight." At that point I saw the Cherokee a few miles away, just finishing the turn onto final. "11B has traffic in sight," I reported. They immediately replied with "11B follow the Cherokee, clear to land 24." Which means I could now land on runway 24 without any additional communication.
This whole exchange happened because even though air traffic control can see us both on radar (and likely out the window at this point) the primary method of clearance in VFR is always the pilot's eyes. And once I could see him, the odds of me accidentally turning into him or overtaking him on final were very low - and the controller could turn his attention to other things.
I was thinking about this as I was going over the transcript from air traffic control from yesterday's crash. The relevant sections are these:
15:50 (ATC) PAT25 traffic just south of Wilson Bridge CRJ is 1200 feet for runway 33
17:30 (ATC) PAT25 do you have the CRJ in sight?
17:32 (ATC) PAT25 pass behind the CRJ
18:05 (Unknown) Tower did you see that?
Again in English, at 15 minutes and 50 seconds into the recording, the airport tower (responsible for all traffic in about a 5 mile radius) first tells PAT25 - the helicopter - that they have jet traffic that they might conflict with. We can't hear the helicopter's response (they may have been using a different frequency to respond) but we can infer their replies from what the air traffic controller was saying.
Their reply to the first ATC transmission was likely something like "PAT25 looking for traffic" since at night in a crowded airspace, there's a lot to look at before you find the one bit of moving light that is your traffic.
Two minutes later, ATC asks them again because it's been a while and they are getting closer. ATC is getting more insistent because if they CAN'T see them they can't reasonably avoid them, even if they have ADS-B or a similar system. And if they still could not see them after those two minutes, the next transmission from ATC would have likely been an avoidance instruction, something like "PAT25 turn left heading XX, maintain YY feet" to ensure they were clear.
However PAT25 likely replied that the traffic was in sight, because the next transmission from the controller, two seconds later, is "pass behind the CRJ." (CRJ stands for Canadair Regional Jet, the sort of aircraft American 5342 was.) At this point, once the controller knows that they have the aircraft in sight, they can see and avoid the aircraft themselves.
About 30 seconds later another pilot says "did you see that?" indicating the collision.
So it's way too early to determine exactly what happened and why, but from the ATC recordings it sounds like ATC was relying on the helicopter to see and avoid the CRJ, based on their visual contact with it. And that's not at all unusual for helicopters operating in busy airspaces, since they often operate near airports but below approach/departure corridors.
The politics has already started, unfortunately. Trump has blamed DEI, Barack Obama and Joe Biden respectively for the crash, and there is currently no FAA administrator (or deputy administrator) after Elon Musk forced out the former administrator, Mike Whitaker. Hopefully these impediments will not have too much of an effect om the investigation.
