SWA147 approach at LGA 23Mar24

[GregAmy]

This is an interesting exchange...

Southwest Boeing 737-8H4 (N8554X) performing flight SWA147 from Nashville to LaGuardia was on the second attempt to land when the aircraft suddenly deviated to the right of the approach path coming dangerously close to the control Tower at around 150-200 feet height.
Air traffic controller yelled the pilots to go around and climb immediately.

https://www.youtube.com/watch?v=xauO-7FH8qI

[biscuit74]

Sounds like a challenging day for all, with tailwinds, wind shear and variable RVR. Good decision to divert after two go arounds and several other aircraft doing likewise.

[BFSGrad]

Based ADS-B data, aircraft passed just to the NW of the tower at a pressure-corrected altitude of 1030 ft, which would give a 790 ft vertical clearance with the 240 ft tower.

[DIBO]

Where are the METAR's when you need them :E found the 29.79 QNH on the audio recording
My crude estimate, it's more around 700-800AGL range, concur with previous poster around 1000ftAGL, when passing abeam the tower, but already with a decent RoC.
And a Topgun style (the movie) lateral separation.
Whoever kicked the crew back into reality, did a great job!
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/638x626/swa147_c_f7823d2094717d6ea82221d74fde594eb0acc76a.jpg


But it's another tower I would be more worried about (although this one, most likely, had no people residing in it).
They were really aiming for 'The Korean Church of Queens' with its 60ish feet tower+cross, with a positive RoC only just about to kick in.
And laterally, within a wingspan or so... even too close for Maverick
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/696x770/swa147_b_5aa5b0446624107c9b7d45be0ee9d4ba1992ab18.jpg

[bean]

Detailed analysis
https://youtu.be/DPCTrHJn4H4
Scary

[Chiefttp]

Just throwing this out there. The ILS to Rwy 4 at LGA has a note on the approach plate prohibiting auto-pilot coupled approaches. Hence the pilot was hand flying, which could explain why they got so far off the localizer course. Challenging weather for a hand flown approach. Hopefully the most experienced pilot was the one flying it.

[Jet Jockey A4]

Just throwing this out there. The ILS to Rwy 4 at LGA has a note on the approach plate prohibiting auto-pilot coupled approaches. Hence the pilot was hand flying, which could explain why they got so far off the localizer course. Challenging weather for a hand flown approach. Hopefully the most experienced pilot was the one flying it.


Say what? There is no excuse for being so far off the localiser or G/S if you are flying manually.

[DIBO]

By the time they were abeam the app.lights, they were some 9+degrees off localiser centerline, approx. 450m from the centerline
And only just about to start the G/A (some 400ft above rooftops)

[FlightDetent]

Many companies have formalized limits for pilots when it becomes mandatory to stop pushing and go around. Am I wrong to suppose SWA has those too, namely after skidding over at Burbank twice? That's a lot of practical experience.

The other thing that springs to mind, long lost information from the ATPL books, is that LLZ 1 dot deviation at RWY THR marks the physical runway edges. Thus LOC antenna placement (in terms of distance behind the THR) is defined by the spread angle and the sideline anchor points for 1 dot at THR.

Any armchair investigator can take Google maps now (or AIP data from US equivalent), locate the antenna and draw the protection area of 1 dot LLZ. In general I believe, again - ready to be re-educated -, 1 dot LLZ marks the acceptable range of being "on course" i.e. within the qualified lateral protection zone to follow the GP.

[ATC Watcher]

Besides the deviation, low height AGL, etc, it is another interesting non standard R/T , luckily the go around and climb "order" by the TWR was performed by the right aircraft.

[moosepileit]

Localizer is 700 feet wide at threshold, standard.

Long and wide, short and skinny, both adjusted to 700 feet wide. Third of a dot is autoland limit on my jet. That's 58'. On visuals, SOP is lateral confines NLT 200'.

A good read-

https://code7700.com/ils.htm#section3

[Lake1952]

Another situation where the CVR will have been recorded over with the flight having diverted. I assume that the crew has been interviewed.

[Lake1952]

Just throwing this out there. The ILS to Rwy 4 at LGA has a note on the approach plate prohibiting auto-pilot coupled approaches. Hence the pilot was hand flying, which could explain why they got so far off the localizer course. Challenging weather for a hand flown approach. Hopefully the most experienced pilot was the one flying it.

The video discussion posted by bean above details the reason that the LGA ILS 4 approach is not to be a coupled approach. There was a small hotel built off of the approach end of runway 4 which interferes with the GS signal. This was discovered back about 10 years ago by the FAA technical division after test flights.

So here's my question... if the GS signal is degraded to the point that modern autopilot can get spurious information, then why is the information provided by the GS valid for a hand flown approach?

I think it's time of the NY Port Authority, the FAA and the airlines to buy the Avion Hotel and tear it down!

[galaxy flyer]

The ILS 04 has always been a troublesome approach, going back decades. An FAA DC-3 Flight Check crashed testing back in the early ‘70s. Lots of buildings, hangars, the piers all make it problematic. The mins used to be about 400-1, now they’ve figured out a way to get them slightly lower. When it was 400-1, the reported weather would be 200 or 300 and mile, everybody would be getting in. An old squadron mate who was a B727 captain at the time told me it was “the most cheated on approach in the country”.

Of course, ceiling wasn’t governing, but it is indicative.

[FlightDetent]

Localizer is 700 feet wide at threshold, standard.

Long and wide, short and skinny, both adjusted to 700 feet wide. Third of a dot is autoland limit on my jet. That's 58'. On visuals, SOP is lateral confines NLT 200'.

A good read-

https://code7700.com/ils.htm#section3
Excellent, and Code7700 is so great I actually wanted to send a greeting tk the author the last week, just for appreciation. Hoping the rumors are not true.

I interpret half-scale to be 1 dot out of 2 on my ship.

However that cannot be pinpointed to RWY edge if the full LLZ beam 2.5 is 700 feet wide.

​​Noted. For a 60m wide runway it does come reasonably close to pavement edge at least.

[Lake1952]

So I am truly curious about this...from the ILS approach plate runway 4 KLGA..."Autopilot couple approach NA."

So I ask again... if an ILS GS signal isn't good enough for the electronics, why is it good enough for a hand flown approach?

[GregAmy]

So I ask again... if an ILS GS signal isn't good enough for the electronics, why is it good enough for a hand flown approach?
Because the deviations are very transient and happen quickly so the pilot won't notice them (or if they do, they'll average them out).

An autopilot would instantly jump on each one of those deviations.

I've not done that approach myself, but that's how it was explained to me by someone that has.

[Amadis of Gaul]

So I am truly curious about this...from the ILS approach plate runway 4 KLGA..."Autopilot couple approach NA."

So I ask again... if an ILS GS signal isn't good enough for the electronics, why is it good enough for a hand flown approach?

Same reason some approaches are legal for autoland and some are not.

[galaxy flyer]

There is quite a few ILSs that must be hand flown Monterey, CA for one.

[scifi]

As an ex Radio Engineer, the fact that he was quite a bit to the right of the Hotel, suggests he was following a False ILS Signal. This would be produced by diffraction of the ILS Signal. Effectively the hotel was broadcasting it's own ILS signal, because of the reflective nature of the components of the hotel construction.

[172_driver]

Could the incident of Commutair 4933 in Presque Island be of relevance to this incident? https://en.m.wikipedia.org/wiki/CommutAir_Flight_4933

...and that the ILS localizer was out of tolerance by about 200 ft (61 m) to the right, a condition that had been noticed during six previous CommutAir flights, including by the accident first officer, but had not been properly reported to the FAA

[punkalouver]

NTSB has released a video of the debriefing of the Southwest chief pilot by the FAA tower supervisor with the incident pilots listening in.















Top Gun - Tower Flyby Aftermath (youtube.com)

[Capn Bloggs]

Liked. :ok:

[WillowRun 6-3]

WSJ, reporting by AP
"Federal officials are investigating a Southwest Airlines flight that flew close to the air traffic control tower at LaGuardia Airport last month.

The Federal Aviation Administration said Thursday that the plane flew off course due to bad weather as it approached for landing.

The plane flew as low as 300 feet before an air traffic controller, speaking in an unusually urgent tone, told the pilots to abandon the landing and climb to 2,000 feet, according to audio captured by LiveATC.net (https://liveatc.net/).

The controller said the plane wasn’t lined up with the runway; it appeared to be east of the intended landing route. “He was not going to land on the runway,” the controller said. The flight was diverted to Baltimore, where the plane landed safely. Southwest didn’t immediately respond to a request for comment."

[OldnGrounded]

WSJ, reporting by AP
"Federal officials are investigating a Southwest Airlines flight that flew close to the air traffic control tower at LaGuardia Airport last month.

Yes, it's suddenly everywhere:

https://news.google.com/stories/CAAqNggKIjBDQklTSGpvSmMzUnZjbmt0TXpZd1NoRUtEd2ptbnYyaUN4SFd0 SGFsSlk4WWV5Z0FQAQ?hl=en-US&gl=US&ceid=US%3Aen

Unsurprisingly, the Daily Mail prominently features a deliberately-misleading photo and claims that the aircraft "came within 67 feet of the air traffic control tower."

https://www.dailymail.co.uk/news/article-13275935/Southwest-Airlines-flight-near-miss-LaGuardia-Airports-control-tower-FAA-investigating-plane-150-passengers-board-veered-course-air-traffic-controllers-screamed-around.html

I don't mean to minimize the incident. It's certainly concerning.

[Lake1952]

Yes, it's suddenly everywhere:

https://news.google.com/stories/CAAqNggKIjBDQklTSGpvSmMzUnZjbmt0TXpZd1NoRUtEd2ptbnYyaUN4SFd0 SGFsSlk4WWV5Z0FQAQ?hl=en-US&gl=US&ceid=US%3Aen

Unsurprisingly, the Daily Mail prominently features a deliberately-misleading photo and claims that the aircraft "came within 67 feet of the air traffic control tower."

https://www.dailymail.co.uk/news/article-13275935/Southwest-Airlines-flight-near-miss-LaGuardia-Airports-control-tower-FAA-investigating-plane-150-passengers-board-veered-course-air-traffic-controllers-screamed-around.html

I don't mean to minimize the incident. It's certainly concerning.

It did descend to within 70 feet of the tower elevation, and it wasn't far from directly overflying the tower. There is no minimizing this event...like the close call runway incursions of a year ago, another narrowly missed disaster!

[wjcandee]

It did descend to within 70 feet of the tower elevation, and it wasn't far from directly overflying the tower. There is no minimizing this event...like the close call runway incursions of a year ago, another narrowly missed disaster!

Yeah, I initially thought, "Go around in crappy weather, so what? Media hype." But when you look at the actual deviation and the fact that the crew really didn't realize how far to the right of the centerline that they actually were, it's bad.

Juan Browne has a very-good, non-dramatic video just out that lays it all out, and I commend it. That's like more than 3 dots deviation off centerline, so I'd be inclined to be judgy, but out of respect to a a generally-excellent pilot group, I will wait and be interested to see how this all happened.

https://www.youtube.com/watch?v=3FQE38L81DI

[OldnGrounded]

It did descend to within 70 feet of the tower elevation, and it wasn't far from directly overflying the tower. There is no minimizing this event...like the close call runway incursions of a year ago, another narrowly missed disaster!

True. As I said, I don't want to minimize it — it was a near miss of an accident that would have been catastrophic. But accuracy counts and we can usually count on the Daily Mail not to bother with accuracy.

[OldnGrounded]

Juan Browne has a very-good, non-dramatic video just out that lays it all out, and I commend it.

Yes, as usual, he does a very good and level-headed job of summarizing what's known so far. Thanks for the link.

Definitely scary.

[212man]

It did descend to within 70 feet of the tower elevation, and it wasn't far from directly overflying the tower. There is no minimizing this event...like the close call runway incursions of a year ago, another narrowly missed disaster!
Every aircraft that lands goes 200’ below the tower elevation. Context is everything…..

But it is a very disturbing and curious event. The wx wasn’t even that bad - visibility was 6,000’ which is a nautical mile, so it’s not even an RVR!

[alfaman]

A concern to me is why the control safety equipment didn't pick up the issue. The report seems to say all was serviceable, in which case, why didn't it alert?

[bean]

Every aircraft that lands goes 200’ below the tower elevation. Context is everything…..

But it is a very disturbing and curious event. The wx wasn’t even that bad - visibility was 6,000’ which is a nautical mile, so it’s not even an RVR!
The viz was variable. One aircraft broke off the approach because RVR went below limits, it is on the recording