The not-so-friendly skies?

[Roller]

As if worrying about your plane running into an octagon, cylinder, or round object weren't enough, here's a report about United Airlines flight 1722 from Maui to San Francisco on December 18 that caught my attention. The news services highlighting this story quote the following article from The Air Current, an aviation site:

United dive after Maui departure adds to list of industry close calls

The previously unreported December incident saw the Boeing 777 come within 800 feet of the Pacific Ocean.

theaircurrent.com

But here's the weirder part. I downloaded profiles for the flight from two places. Flightradar24's data indicates a dive down to 775 feet shortly after takeoff, but flightaware.com shows what appears to be a normal climb. Also, The Air Current piece says the Boeing 777 descended and then climbed at around 8,600 feet per minute, reaching a force of up to 2.7Gs. This would have been frightfully obvious to the passengers, so I find it hard to believe this incident hasn't been reported or received widespread attention on social media in the nearly two months that have elapsed since the flight.

More to come...

 

[AG_PhamD]

From what I’ve read based on the location and weather it possibly could have been a microburst.

Another theory is that the autopilot could have been set to an altitude 0 by the previous crew or maintenance and that. Then the crew failed to enter in an appropriate altitude and verify it in their checklists. Upon climbing out and activating autopilot, the plane would then follow the instructions into the ground. This has reportedly happened numerous times, perhaps most notably in the 2021 Emirates Boeing 777 crash in Dubai. I believe everyone survived and in this case it was the flight director rather than the autopilot, which frankly is even worse. There was also a Bombardier Dash 8 several years ago in the UK that had an incident due to the autopilot being engaged with the altitude being set to zero.

 

[Roller]

Follow-up on this incident. Here's an account from a passenger on the flight:

https://www.cnn.com/travel/article/united-777-plunge-takeoff-hawaii/index.html

I still haven't seen an explanation for the discrepancy in the fight profile data, but the dive and recovery did happen. I'm sure the pilot and co-pilot will be or already have been interviewed. But if the flight was deemed to have ended normally, there may be no CVR or FDR data to examine.

 

[rdrr]

Wonder how often these types of close calls happen? I am pretty sure I was on a flight that had a close call ground incident that didn't get reported.

It was sometime in 2017 and I had a BOS -> HOU -> MSY flight on Southwest. I don't fly them since this incident. While taxiing in HOU we had to cross an active runway, and we were stopped as flights were landing. For whatever reason the pilot(s) rev'd up the engines and released the brakes as another plane was about to land and use the runway we were about to cross. I am not kidding you, when I say we wouldn't have made it, because I audibly gasp (as did everyone on my side of the plane did). Either the control tower screamed at the crew over the radio, or they recognized at the last minute the absolute peril that they were about roll into. But everything shutdown, the whole plane shuddered as I can only imagine the pilot applying any "brakes" they had. Most everyone was thrown forward to the seat in front of them, and that other plane went by us on the runway. I have no idea how close it actually was, but I can tell you I everyone including the flight attendants looked scared crapless.

 

[Roller]

Wonder how often these types of close calls happen? I am pretty sure I was on a flight that had a close call ground incident that didn't get reported.

It was sometime in 2017 and I had a BOS -> HOU -> MSY flight on Southwest. I don't fly them since this incident. While taxiing in HOU we had to cross an active runway, and we were stopped as flights were landing. For whatever reason the pilot(s) rev'd up the engines and released the brakes as another plane was about to land and use the runway we were about to cross. I am not kidding you, when I say we wouldn't have made it, because I audibly gasp (as did everyone on my side of the plane did). Either the control tower screamed at the crew over the radio, or they recognized at the last minute the absolute peril that they were about roll into. But everything shutdown, the whole plane shuddered as I can only imagine the pilot applying any "brakes" they had. Most everyone was thrown forward to the seat in front of them, and that other plane went by us on the runway. I have no idea how close it actually was, but I can tell you I everyone including the flight attendants looked scared crapless.

Thee have been several well-publicized close calls lately, especially runway incursions. The United dive was unusual, though.

Years ago, I liked to listen to ATC communications on United, a practice they since abandoned. I was once on a flight where the controller had to call our plane several times before one of the pilots responded. I was wondering if I should go knock on the cockpit door.

There have also been times when I noticed the flaps were retracted as we were turning on to the runway, leading me to wonder if I should say or do anything. Made me empathize with William Shatner's character in The Twilight Zone episode where he kept seeing demons on the wing.

 

[AG_PhamD]

Follow-up on this incident. Here's an account from a passenger on the flight:

https://www.cnn.com/travel/article/united-777-plunge-takeoff-hawaii/index.html

I still haven't seen an explanation for the discrepancy in the fight profile data, but the dive and recovery did happen. I'm sure the pilot and co-pilot will be or already have been interviewed. But if the flight was deemed to have ended normally, there may be no CVR or FDR data to examine.

I would hope such data was preserved. The CVR may have been overwritten within the duration of the flight. I believe this incident was self-reported by the pilots and surely the passengers complained… but actually I believe I read that the plane exceeded its G-limits (something close 3G’s) which would, if the systems worked as intended, the plane should have been inspected before flying along again and I would think the FDR data would have been saved and reviewed. If not for some reason, at least some of the flight data could have been retained on the quick access recorder for some time.

Given that the flight continued onto its destination, I would assume the pilots knew whatever happened was not a mechanical problem. Also, it’s reported that the pilots underwent “retraining”, again pointing to pilot error. I assume the airline knows what happened. Why they’re not being transparent is a bit of an issue.

 

[Roller]

I would hope such data was preserved. The CVR may have been overwritten within the duration of the flight. I believe this incident was self-reported by the pilots and surely the passengers complained… but actually I believe I read that the plane exceeded its G-limits (something close 3G’s) which would, if the systems worked as intended, the plane should have been inspected before flying along again and I would think the FDR data would have been saved and reviewed. If not for some reason, at least some of the flight data could have been retained on the quick access recorder for some time.

Given that the flight continued onto its destination, I would assume the pilots knew whatever happened was not a mechanical problem. Also, it’s reported that the pilots underwent “retraining”, again pointing to pilot error. I assume the airline knows what happened. Why they’re not being transparent is a bit of an issue.

I don't know if the CVR and/or FDR data were retained, though it would obviously be better if they were. But the entire story remains puzzling. Another report in The Air Current says the NTSB didn't even open an investigation until after their initial article, which was published nearly eight weeks after the incident. The passenger who recounted his experience said the aircraft was in clouds during the dive, so he was unaware they were so close to the water until after the flight. If the numbers are correct, the plane was only ~5 seconds from crashing into the Pacific, so it's probably better the passengers couldn't see what was going on.

 

[AG_PhamD]

I don't know if the CVR and/or FDR data were retained, though it would obviously be better if they were. But the entire story remains puzzling. Another report in The Air Current says the NTSB didn't even open an investigation until after their initial article, which was published nearly eight weeks after the incident. The passenger who recounted his experience said the aircraft was in clouds during the dive, so he was unaware they were so close to the water until after the flight. If the numbers are correct, the plane was only ~5 seconds from crashing into the Pacific, so it's probably better the passengers couldn't see what was going on.

I could be mistaken but I think the NTSB only required to investigate if there is truly an accident (resulting in death, serious injury, or damage). Even then they are not a regulatory agency. I believe the FAA considers accidents under the same definition. So even though the plane was seconds away from catastrophe, because no one suffered serious injury and the plane did not receive significant damage, there was no cause for automatic investigation.

Perhaps some of the pilots here (@Huntn) could comment on this as they would presumably know how these things work.

I would think however if the plane exceeded its G-limits (which on a commercial airliner is reported back to the airline), the FDR and QAR would be retained for purposes of dealing with the required inspection.

And while I believe the pilots or airline self-reported this incident, it does seem rather troubling that potentially human errors in particular could happen (perhaps repeatedly) and not be passed up the chain to the authorities to recognize patterns of mistakes to inform pilots of such mistakes and potentially mandate changes in systems.

It for example the autopilot altitude was set to zero, given the number of accidents or near accidents created by this mistake, it seems only logical to have planes better indicate such a setting. Again, I’m not a pilot, but I would assume there could be situations where the autopilot could be set to 0 or below the normal operating threshold (ie the runway is below sea level, which I assume is rare). Perhaps locking out such settings or having the the values flash anything below X number of feet would be wise. Or maybe in the future better integrating the autopilot settings into the GPS/terrain avoidance to indicate unreasonable settings. But perhaps such suggestions have already been made. Understandably changes in aviation don’t necessarily move very quickly and changes can incur substantial costs.

 

[Roller]

It's premature to assign a cause, other than consider pilot error as more likely than equipment failure, mostly because of reports that the crew has received additional training. I agree the NTSB may not have been required to investigate, but they apparently started to after the report was published. So they weren't aware of the incident until then or they were told about it sooner but only decided to begin looking into it once it became public. Either way, it's odd.

 

[Huntn]

I could be mistaken but I think the NTSB only required to investigate if there is truly an accident (resulting in death, serious injury, or damage). Even then they are not a regulatory agency. I believe the FAA considers accidents under the same definition. So even though the plane was seconds away from catastrophe, because no one suffered serious injury and the plane did not receive significant damage, there was no cause for automatic investigation.

Perhaps some of the pilots here (@Huntn) could comment on this as they would presumably know how these things work.

I would think however if the plane exceeded its G-limits (which on a commercial airliner is reported back to the airline), the FDR and QAR would be retained for purposes of dealing with the required inspection.

And while I believe the pilots or airline self-reported this incident, it does seem rather troubling that potentially human errors in particular could happen (perhaps repeatedly) and not be passed up the chain to the authorities to recognize patterns of mistakes to inform pilots of such mistakes and potentially mandate changes in systems.

It for example the autopilot altitude was set to zero, given the number of accidents or near accidents created by this mistake, it seems only logical to have planes better indicate such a setting. Again, I’m not a pilot, but I would assume there could be situations where the autopilot could be set to 0 or below the normal operating threshold (ie the runway is below sea level, which I assume is rare). Perhaps locking out such settings or having the the values flash anything below X number of feet would be wise. Or maybe in the future better integrating the autopilot settings into the GPS/terrain avoidance to indicate unreasonable settings. But perhaps such suggestions have already been made. Understandably changes in aviation don’t necessarily move very quickly and changes can incur substantial costs.

I’m not an expert in NTSB, but my impression is that they are involved in primarily accidents, the FAA is involved in incidents.

The new smart planes allow you to set an altitude and the autopilot will fly to and level at that altitude, but you’d never be doing this for landing, For landing if on autopilot you‘d intercept and connect with the glide slope, and the aircraft can take this all the way to a zero zero landing. Talk about being reliant on technology.

And if you did try to just set the autopilot altitude, below the landing elevation, in the newer planes that Flight Control System would trigger for being too low to the ground and not configured to land (if you are not configured) and actually take control of the plane and initiate a climb. But it’s not smart enough to know in a manual landing if there is a runway you are trying to land on or not. This is why in the early years of the A320 an Airbus crashed at the Paris air show, pilots were flying around in landing configuration sight seeing, I think with guest passengers onboard, so the aircraft did not care when they allowed it to settle into a grove of trees.

 

[AG_PhamD]

FAA investigating 'close call' between JetBlue, Learjet at Logan Airport

The FAA is investigating a close call between a Learjet and a JetBlue flight Monday night at Boston Logan International Airport.

www.wcvb.com

Wow.

A landing JetBLUE Embraer 190 came within an estimated 530ft of colliding with a LearJet at Boston Logan Airport. The LearJet, allegedly without clearance, took off on a perpendicular runway while the JetBLUE flight was landing. The JetBLUE flight apparently touched down (or partially touched down?) and immediately had to abort its landing and climb to avoid a collision.

The 530ft estimate is based on ADSB data so not 100% accurate, but with a landing speed of say 130kts/150mph… that’s literally 2 seconds of time to spare. I commend the pilots for their situational awareness. Fortunately for everyone involved the landing plane was an E190 and not something larger and less agile like a 737 or A350. It’s my understanding generally speaking larger turbofans take longer to spool up to maximum thrust, but generally takes 3-6 seconds.

The regularity these close calls are occurring with is rather alarming. I question why airports do not have the equivalent to stoplights. It’s my understanding all major airports have ground radar, planes have anti-collision systems when in flight. If a $1500 chart plotter from 10 years ago on a boat can provide collision alerts miles in advance, surely the technology exists so a commercial airliner can detect potential collisions between planes transitioning between the sky and ground.

 

[Citysnaps]

The regularity these close calls are occurring with is rather alarming. I question why airports do not have the equivalent to stoplights.

I know little about ADS-B other than playing around with it on my computer from time-to-time to see what's in the local airspace (loads of planes in the San Francisco Bay Area with three major airports and a handful of general aviation) - and planes parked or moving on the ground at airports.

Given that all commercial planes in the US are required to have ADS-B OUT (broadcasting GPS location) and ADS-B IN (for awareness of nearby surrounding aircraft), I don't understand why that can't be used in-plane to avoid potential ground (or air soon landing) collisions. Seems that could even be automated to determine intent and potential collisions.

Perhaps the latency and/or GPS update rates make that unfeasible in near-miss ground situations? OTOH, while airborne, airspace awareness and collision avoidance is what ADS-B is used for.

 

[AG_PhamD]

I know little about ADS-B other than playing around with it on my computer from time-to-time to see what's in the local airspace (loads of planes in the San Francisco Bay Area with three major airports and a handful of general aviation) - and planes parked or moving on the ground at airports.

Given that all commercial planes in the US are required to have ADS-B OUT (broadcasting GPS location) and ADS-B IN (for awareness of nearby surrounding aircraft), I don't understand why that can't be used in-plane to avoid potential ground (or air soon landing) collisions. Seems that could even be automated to determine intent and potential collisions.

Perhaps the latency and/or GPS update rates make that unfeasible in near-miss ground situations? OTOH, while airborne, airspace awareness and collision avoidance is what ADS-B is used for.

Maybe one of our resident commercial pilots can chime in here but I believe at least the older generations of TCAS does not issue warnings below a certain altitude because it’s would report too many false alarms. It’s also my understanding ATS-B data is either not used for traffic alerts or in more advanced systems is only used to help decide which planes TCAS should interrogate. TCAS uses radio signals to determine range and bearing with the other plane, who also provides altitude- so no external system must be relied upon (like GPS). More knowledgeable people feel free to correct me.

That said, with ATS-B In/Out, the pilots presumably should have the information available to see a possible traffic conflict. But they may not just get an alert. The pilots landing are likely focused on landing and are assuming the ATC has indeed cleared them for landing. The pilots taking off probably assume the same.

In this incident the plane on the ground took off despite not being cleared to do so… so I suppose it’s hard to justify electronic measures when the pilot isn’t even following basic instructions to begin with.

I wouldn’t think GPS latency has anything to do with it. I believe non-military GPS has an imposed speed limit of something Iike 1200mph (so people don’t start using it for missiles). And the fact military GPS can guide a supersonic missile to within a few feet suggests latency would not have a to be an issue. The radio communication between transponders should happen at the speed of light. I suppose you have bandwidth and processing limitations, but I wouldn’t think it’s that relevant. Indeed a second or two delay can have significant consequences moving at high speeds, but I would think software could augment this by predicting possible risks at short ranges based on expected maneuvering characteristics of planes.

 

[Citysnaps]

I wouldn’t think GPS latency has anything to do with it.

I don't think so either. I'm just grasping at straws trying to understand why reliable data that's readily available is not used to help avoid ground and near-ground collisions.

It seems intent from ADS-B Out data (a plane is about to land on a runway occupied with a plane about to take off, or, a plane taxiing is about to cross an active runway with a nearby plane taking off, etc) should be able to be inferred by using the last n seconds of ADS-B IN location data, warning both pilots with an appropriate alarm/message/warning/etc of last resort, automatically.

 

[Huntn]

Maybe one of our resident commercial pilots can chime in here but I believe at least the older generations of TCAS does not issue warnings below a certain altitude because it’s would report too many false alarms. It’s also my understanding ATS-B data is either not used for traffic alerts or in more advanced systems is only used to help decide which planes TCAS should interrogate. TCAS uses radio signals to determine range and bearing with the other plane, who also provides altitude- so no external system must be relied upon (like GPS). More knowledgeable people feel free to correct me.

That said, with ATS-B In/Out, the pilots presumably should have the information available to see a possible traffic conflict. But they may not just get an alert. The pilots landing are likely focused on landing and are assuming the ATC has indeed cleared them for landing. The pilots taking off probably assume the same.

In this incident the plane on the ground took off despite not being cleared to do so… so I suppose it’s hard to justify electronic measures when the pilot isn’t even following basic instructions to begin with.

I wouldn’t think GPS latency has anything to do with it. I believe non-military GPS has an imposed speed limit of something Iike 1200mph (so people don’t start using it for missiles). And the fact military GPS can guide a supersonic missile to within a few feet suggests latency would not have a to be an issue. The radio communication between transponders should happen at the speed of light. I suppose you have bandwidth and processing limitations, but I wouldn’t think it’s that relevant. Indeed a second or two delay can have significant consequences moving at high speeds, but I would think software could augment this by predicting possible risks at short ranges based on expected maneuvering characteristics of planes.

TCAS is incredibly cool where airplanes talk to each other and coordinate avoidance. There is at least one mid air collision that resulted when a pilot did the opposite of what TCAS directed.

TCAS II RA at Very Low Altitude | SKYbrary Aviation Safety

EUROCONTROL Mode S & ACAS Programme Reminder Recently, a report has been received of a case where a Airborne Collision Avoidance System (ACAS) II Resolution Advisory was posted at approximately 100 feet AGL. The technical cause appears to be related to a radio altimeter data malfunction. Radio...

skybrary.aero

• TCAS II design progressively inhibits Resolution Advisories (RAs) depending on the height Above Ground Level (AGL) provided by the radio altimeter as follows:
  • “Increase Descent” RAs are inhibited below 1,550 ft AGL (± 100 ft)
  • “Descend” RAs are inhibited below 1,100 ft AGL (± 100 ft)
  • All RAs are inhibited below 1,000 ft AGL (± 100 ft).

 

[Roller]

I've listened to the ATC audio on two YouTube channels:





I can hear a (ground?) controller telling HPJ280 to monitor the tower frequency (132.22), followed by a tower controller instructing them to line up and wait because JetBlue 206 is about to land on a crossing runway. In neither one did I hear the HPJ280 pilot read back the instruction, though there may have been a mike click. I also can't tell how much time elapsed between the first and second instructions, as at least one of the ATC audios has been edited. So is it possible the HPJ pilot didn't hear the line up and wait instruction because they were switching frequencies?

Regardless, it appears they took off without clearance. IMO, that should at least result in a loss of the pilot's license, and should have consequences for his employer. Fortunately, the tower controller saw what was happening and instructed the JetBlue pilot to go around. It's odd that there was no transmission to HPJ280 telling them to call the tower about the incident, but maybe that was because they were already en route.

 

[Roller]

Haven't heard any more about the Logan incident, but here's another one for nervous fliers:

https://www.cnn.com/travel/article/turbulence-jet-death/index.html

I assume the death was caused by head trauma or something like that, though no details have been released. It's highly unlikely that turbulence, even severe, will damage an aircraft to the point of failure, but this and the recent Lufthansa incident are good reminders to keep your seat belt fastened unless you have to be up. I haven't yet experienced severe turbulence — what some people call severe is really moderate at most. The worst I recall was on a flight from Florida, when we were riding the cloud tops. The plane dropped suddenly, which caused my cup to be a few inches above the tray table and led the pilot to make an announcement that aircraft are built to withstand much greater stress.

 

[AG_PhamD]

Haven't heard any more about the Logan incident, but here's another one for nervous fliers:

https://www.cnn.com/travel/article/turbulence-jet-death/index.html

I assume the death was caused by head trauma or something like that, though no details have been released. It's highly unlikely that turbulence, even severe, will damage an aircraft to the point of failure, but this and the recent Lufthansa incident are good reminders to keep your seat belt fastened unless you have to be up. I haven't yet experienced severe turbulence — what some people call severe is really moderate at most. The worst I recall was on a flight from Florida, when we were riding the cloud tops. The plane dropped suddenly, which caused my cup to be a few inches above the tray table and led the pilot to make an announcement that aircraft are built to withstand much greater stress.

Such a freak accident and unfortunate way to die. I suppose passengers on business jets may be less likely to wear seatbelts. And if it had a couch, I don’t believe those necessarily always have seatbelts. The Challenger 300 is has a cabin ceiling of 6.1ft, which is actually a lot taller than I expected. But needless to say, there’s not much space if you do fly out of your seat.

In ATC recording the pilot reported the passenger had a “possible laceration”. I too assumed this was a head injury. But using that term and his tone doesn’t make it sound like it was perceived as that serious of a situation, at least at that time.

They landed at BDL in CT. The airport is about 20min to Hartford by car which is where the nearest hospitals are. If they knew it was serious in the air it’s possible they could have had air lifted the from the airport to the airport within minutes.

As a random aside, many of the news reports on TV show a picture of BDL’s old control tower atop the old terminal building… all of which was torn down in 2014. That tower also hadn’t been used in years before it was demolished.

When I was in 3rd grade I had a field trip to BDL’s control tower while tower controllers were going about their job… something that would obviously never ever ever be allowed today. This was obviously before 9/11, in the 90’s.

 

[Roller]

Such a freak accident and unfortunate way to die. I suppose passengers on business jets may be less likely to wear seatbelts. And if it had a couch, I don’t believe those necessarily always have seatbelts. The Challenger 300 is has a cabin ceiling of 6.1ft, which is actually a lot taller than I expected. But needless to say, there’s not much space if you do fly out of your seat.

In ATC recording the pilot reported the passenger had a “possible laceration”. I too assumed this was a head injury. But using that term and his tone doesn’t make it sound like it was perceived as that serious of a situation, at least at that time.

They landed at BDL in CT. The airport is about 20min to Hartford by car which is where the nearest hospitals are. If they knew it was serious in the air it’s possible they could have had air lifted the from the airport to the airport within minutes.

As a random aside, many of the news reports on TV show a picture of BDL’s old control tower atop the old terminal building… all of which was torn down in 2014. That tower also hadn’t been used in years before it was demolished.

When I was in 3rd grade I had a field trip to BDL’s control tower while tower controllers were going about their job… something that would obviously never ever ever be allowed today. This was obviously before 9/11, in the 90’s.

Other than an MI, which could have occurred during a severe turbulence incident but probably wouldn't have been classified as an injury, the likeliest pathology was a subdural or epidural hematoma. The seriousness might not be too apparent externally.

Funny, I also visited a control tower when I was about that age. And yeah, there's no way that would happen these days.

 

[AG_PhamD]

Other than an MI, which could have occurred during a severe turbulence incident but probably wouldn't have been classified as an injury, the likeliest pathology was a subdural or epidural hematoma. The seriousness might not be too apparent externally.

Funny, I also visited a control tower when I was about that age. And yeah, there's no way that would happen these days.

Yeah, I wouldn’t think an MI either based on the limited information we have. I would think that would be more obvious in the pilots description and doesn’t really line up the whole fatal injury due to turbulence storyline. Unless the passenger received a laceration due to turbulence and then afterwards coincidentally suffered an MI or stroke by the time they touched down or sometime thereafter. I suppose that’s not an impossibility.

I suppose it’s also possible the passenger was buckled in but something hit them.

It’ll be interesting to hear what the FAA says and what amount of medical details they can provide. Or perhaps the victim’s family will shed some light on this. I suspect the company that owns the plane will be keeping their mouth shut as they’re probably waiting to get sued.