SWA Safety ALERT RW 23 ILS KBUF

[atrdriver]

not true, the 737 autopilot will most definitely capture the GS before being in VOR/LOC. although in this case I don't think it matters, as you pointed out.

From section 6.4 page 17 of the CAL 737 flight manual:

"Glideslope capture is inhibited prior to localizer capture."

It is true of all transport catagory aircraft because often times the G/S is unreliable more than 30 degrees or so off the loc, and often the mode is armed outside of that arc.

 

[CRJ puppy]

Anybody verify that this is a real alert, and not some snarky, in poor taste attempt at humor?

It's real. I posted a comment the day after the accident on another thread about this but no one noticed.

Have been in VMC when the AP chased these erroneous signals. It's quite dramatic and you need to disconnect the autopilot quickly or doo doo would happen fast!

There is a notam about the GS being unusable x number of degrees of centerline, but no explanation as to why.

 

[DBacks]

Does anyone know if radar recorded the aircraft climbing a few hundred feet before it plunged to earth? From what I have read the only radar returns were of the aircraft rapidly descending.

 

[firstthird]

From section 6.4 page 17 of the CAL 737 flight manual:

"Glideslope capture is inhibited prior to localizer capture."

I'm sure your book says that. SWAs says something along the lines of "if you think that GS capture will occur prior to VORLOC capture, consider arming VORLOC instead of APP."

and, I've seen it happen. There are a lot of 737s out there and there are differences. Shoot, my squadron in the navy had 3, all delivered within a year of each other, and one would capture the GS first while the other two would not.

 

[atrdriver]

I'm sure your book says that. SWAs says something along the lines of "if you think that GS capture will occur prior to VORLOC capture, consider arming VORLOC instead of APP."

and, I've seen it happen. There are a lot of 737s out there and there are differences. Shoot, my squadron in the navy had 3, all delivered within a year of each other, and one would capture the GS first while the other two would not.

Well, FWIW, I got into the habit of arming LOC only until it was captured, then arming the ILS because I had it bite me a couple of times while on the ATR.

 

[Kream926]

guys thats been NOTAM'd and on the ATIS since probably 1998 when i started flying there

 

[atrdriver]

guys thats been NOTAM'd and on the ATIS since probably 1998 when i started flying there

So that means that it couldn't have bitten someone? The Rockies have been there for 20 million years, but every now and then someone flies into them.

 

[Kream926]

true but like some other guy said GS capture inhibited unless LOC capture. at least that how it is in the ERJ. if the LOC was captured they well would have been within 5 degrees

 

[atrdriver]

true but like some other guy said GS capture inhibited unless LOC capture. at least that how it is in the ERJ. if the LOC was captured they well would have been within 5 degrees

I have many times, on several aircraft types, when APPR was armed the LOC signal would jump, erroniously, causing the A/P to try to capture it. Since the GS needle is off scale top, the AP would try to climb to catch it while the AP started a turn to catch the false LOC, since it thinks it has LOC capture. It happens. And it would go a long way toward explaining something like this. If the crew was distracted by ice, or something else, they would have been surprised, and who knows what could have happened.

 

[Propsync]

I have many times, on several aircraft types, when APPR was armed the LOC signal would jump, erroniously, causing the A/P to try to capture it. Since the GS needle is off scale top, the AP would try to climb to catch it while the AP started a turn to catch the false LOC, since it thinks it has LOC capture. It happens.

Yup. I've seen this on the 328jet. Maybe twice. Want to say ILS 23 into MSN. Now I kinda wish I would have filled out a report of some type.

 

[Bako Cap]

Base to final 24R in LAX has an erronious signal that is several degrees to the right of the actual localizer. The AP on the CRJ will sometimes capture the false localizer and turn inbound only to turn back to intercept the real localizer.

 

[Britpilot]

I have many times, on several aircraft types, when APPR was armed the LOC signal would jump, erroniously, causing the A/P to try to capture it.

Saw this last week in a 737-700. Not the first time either. Also seen it go after the slope (climb) without LOC capture. It happens.

 

[DiverDriver]

Anybody verify that this is a real alert, and not some snarky, in poor taste attempt at humor?

I don't know about this alert but a NOTAM has been posted about this for months that I've been operating into BUF over the winter. Not sure how old the NOTAM is but it has been awhile.

 

[Stifler's Mom]

Base to final 24R in LAX has an erronious signal that is several degrees to the right of the actual localizer. The AP on the CRJ will sometimes capture the false localizer and turn inbound only to turn back to intercept the real localizer.

CAE...ILS 23 when capturing from the South. Not sure what the heck the plane sensed, but it was waaaay off.

 

[XShuttle]

From section 6.4 page 17 of the CAL 737 flight manual:

"Glideslope capture is inhibited prior to localizer capture."

It is true of all transport catagory aircraft because often times the G/S is unreliable more than 30 degrees or so off the loc, and often the mode is armed outside of that arc.

Not true......A319/320 and the 737-300 (UAL's at least) will capture G/S prior to LOC capture.