ILS 23 in BUF
 

SWAPA Pilots,

There is a potentially significant hazard concerning the ILS to runway 23 in BUF.

Information has been received indicating it is possible to obtain a significant nose pitch up, in some cases as much as 30 degrees, if the glide slope is allowed to capture before established on centerline. Pilots who are preparing to configure and land have the potential to experience abrupt pitch up, slow airspeed, and approach to stall if conditions present themselves in a certain manner.

This effect is the result of an earthen obstruction close enough to the ILS to affect the integrity of the glide slope signal. This has resulted in the issuance of an advisory given on ATIS which states that "the ILS Glide Slope for runway 23 is unusable beyond 5 degrees right of course."
When attempting to intercept the runway 23 ILS from right traffic, the ILS glide slope indication may read full deflection down. Just prior to intercept it may then move up in such as manner as to enable approach mode to capture in such a way as to result in a nose up pitch and loss of airspeed.

Southwest Airlines has issued a notice reading: "Until further notice, when executing the KBUF ILS/LOC Runway 23, DO NOT select Approach Mode until established on the localizer inbound."
This issue is being addressed on several levels in an attempt to address procedures, facilities, and communication regarding this matter. If you experience any issues related to this, please file an ASAP form and or call SWAPA Safety at SWAPA toll free.

WOw, I didn't even THINK about this happening. All the big talk on icing. I wonder if this happened and the icing just made things worse. This is a problem up in Duluth as well. We had a huge issue one day with severe pitch issues in icing conditions going down to minimums. We had to disconnect the AP after the first 2 huge oscillations. If we didn't disconnect as soon as we did we would have most certainly stalled.

You know, a few years ago and in VMC, I was flying into BUF intercepting the ILS below glidepath and my aircraft did pitch up as if to climb to intercept the glide path. I kicked off the AP and landed uneventfully. I did have at least 1 pax comment on the way out. The pitch up was that noticeable...hmm. This was circa 2005. I don't remember the rwy.

Interesting, thanks for sharing this info

Not shooting the messenger, but my BS flag goes up on this one...

A pile of dirt can bend a glideslope enough to have an autopilot pitch 30 degrees nose up to intercept? And this phenomenon is only 5 degrees off centerline?

If true, instead of MANPADS all the terrorists need is a bulldozer to push some dirt around and planes will be stalling and crashing all over the USA?

I think if this was the case we'd have seen more than a memo to SWA crews. Like maybe a NOTAM or something.

Just my .02

I'll contact the person who I got this from tomorrow, but I will say the ATIS in BUF mentions GS issues 5 degrees right of course on ILS 23

And the Colgan crew came in from the left for RWY-23.

As far as I can remember, the ATIS always broadcast that message. The memo mentions the pitch up when turning in from right traffic, but I am almost positive that Colgan would have made a left turn to intercept the course.

Beat me to it Tony

This actually seems like a reasonable concern.

Makes you go hmmm.

Anybody thought the a good upset could have had the seat slide back with the pilot holding it?

Had that happen more than once in a Cessna.

True.

Can happen in any plane that sees a lot of use, and pilots who may not make sure the seat is locked down.

That's more what I'd expect, a little disemmination of information along normal channels- ATIS, NOTAMs, maybe an AIRMET-NovemberFoxtrot (as archaic as they may be, it's what we've got)

If BUF ILS 23 has a lethal defect I'd expect more than an internal memo circulating around one airline. And maybe lots of lawsuits.

Thanks for posting this. This does make sense and maybe that is why they have the note in the atis about the glideslope. After all i will be flying into buf tonight probably on this approach in the snow.

I dont see this being a problem. I fly in and out of buffalo daily with no problems. MONITOR THE AIRPLANE PEOPLE. Dont get complacent with the autopilot.

I have to believe that the NTSB is evaluating every possible scenario, and if this really is on ATIS, im sure they are looking into it also. this is just the thought that hit me when I read this, I realize this is all probably coincidence, but wow the timing makes you go HMMMM

The dash 8 will not even capture the glideslope unless the loc is already captured anyway.

Even then it would not pitch up 30 degrees to capture either. If I recall correctly it doesnt even capture until it is within a 1 1/2 dot scale or so.

Cool thanks for clearing that up, I kinda wondered but that makes sense

Now it looks like they tried to recover from a stall by raising the nose! WOW!

yeah its not looking good, but just remember, I am sure he KNEW the right thing to do, but fatigue, surprise, stress..........it does strange things to the human body/mind

How about cut back on maximum duty time?

yeah, we have to be careful because more rest, shorter work days will equal unproductive trips and not many days off..........

Received a copy of this last night from my dad as well. But, like many of you have already stated, I was fairly certain they would have intercepted from the left, and if the avionics are anything like that of the mighty saabypoo, the GS will not capture until the LOC does.

In 2004 in the SAAB I had a false loc/gs capture going into PWM. We were maybe 6 miles south of the ILS 11, due south of AIMME, at about 5000 ft day VFR. The autopilot was engaged and the approach mode armed. The loc and gs captured. Chasing the signals the aircraft instantly and suddenly pitched down about 10 degrees, maybe a little more, and banked to the right. I clicked off the a/p and recovered. It was disconcerting to say the least.

I have had the ATR pitch up abruptly to capture a GS once. It was very strange, and only happened once.

That's just scary stuff

Why would you arm the approach that far off course? AIMEE is more than 16 miles from the loc antenna. The service volume is 35 degrees to 10 miles and 10 degrees to 18 miles. If you were 5 miles south of the loc you were outside the 10 degree service volume. My airline requires the localizer to be armed and captured before selecting the approach mode. I've seen the flight director do some weird things but arming an approach that far out is just asking for trouble.

Ya... the RJ is the same way. It won't capture the GS until the localizer is captured. The 737, though, WILL capture the GS before it captures the localizer hence the memo given to the Southwest pilots. At Delta, we were trained to not arm APPR mode until the localizer is captured. I'm sure Southwest does the same thing, but it's nice to have a "heads up."

Still, this makes you wonder if this might have been a factor in the Colgan accident.

I've seen phantom localizers as well, and watched the autopilot capture and try to follow it, there are a couple airports that it's happened at, but i cant remember which ones. Also had a situation in MKE with a localizer bouncing moving from side to side, half scale deflection and immediately back the other way.

Ya... scary stuff. A friend of mine was flying the Brasilia when he had the autopilot start aggressively banking and pitching the aircraft. They had to pull the circuit breakers to get control. After they landed, the mechanic pulled the autopilot panel and found soda had been spilled on it! In other words, there are a lot of possibilities.

It should be simple for the NTSB to determine if the pitch up occurred before or after the AP disengaged.

This is ILS glitch is interesting, but my gut feeling is that neither a modern airplane nor a professional crew would allow a GS to put them in an uncontrollable flight regime.

I once had the auto pilot parallel a LOC in the CRJ. I took it off and hand flew it. And no it was not attempting to account for wind. The CRJ sucks at intercepting on strong cross winds.

We have to remember, it is a computer flying data generated by other computers and computers mess up. We all have had our home computers do stuff that a quick reboot fixed. (A reboot sometimes works on the CRJ too.)

Personally I don't arm APR (I select LOC only) until the LOC is at least alive. I can only speak for the models I've flown, but they all will capture a glideslope whether you're on course or not.
I've seen some pretty wild pitch maneuvers when the AP captures a "false" glideslope well off course. And yet I'll bet half the pilots I fly with arm APR as soon as they hear "cleared approach".
Yes, I've made it a two step operation and added the risk I'll forget to select APR. I'll take it as the lesser of evils.

CNN just had "breaking news" about the ILS in BUF. I think this was the first time I have heard a report on 3407 where they did not blame Marvin and his actions.

You're quite right. I shouldn't have and don't anymore. I arm the loc when cleared for the approach, wait for the loc to capture, and then arm the app mode when at or below the gs. If I'm above the gs, I manage the descent with v/s and drag.

ILS 27 at IAH coming in from over SBI. I've seen it there too.

Rick, I agree. Having flown with Marvin, I just don't believe he would allow that to happen. But I also can't believe he allowed the a/c to slow with the additional drag of gear and flaps to the point of getting the stick shaker/pusher as stated in the WSJ report. He was better than that. While I hate it, we'll just have to wait for the NTSB determination.

I agree, Marvin was a VERY sharp guy, and I'm sure Becki was as well although I didn't know her. The NTSB will uncover the truth in due time.

are you all aware that the localizer was reported + or minus 1 dot at 1500' by dl 1998, the next a/c to land after colgan didn't?

even spookier is that tower asked them to verify the localizer -- told them it looked fine [green] to them in the tower but wanted a report anyway.

I just did this approach and can state, without hesitation, that there is a major issue with the glide slope.

Approach had us turn to intercept the loc between the LOM (Klump) and the fix outside of the LOM (Trava). When we were approximately 2 miles north of course at 2300, and 3 miles from Trava, the GS was showing that we were above it. (First glaring issue)

As we were intercepting the loc, I watched the GS go from one dot low to full scale high in about 1/4 mile and about 1.5 to 2.5 from Klump.

If we would have had the approach mode set to capture the GS, the autopilot would have had a very significant nose up attitude to chase the GS.

Since I saw the notice to the SWAPA, we did the same thing and only armed the nav until the glideslope made sense.

We were in hard IFR with 30 xwinds and blowing snow and had to turn the autopilot off to handle the conditions.

BE CAREFUL WITH THIS APPROACH!!!

Want to guess where they learned about it:rolleyes: