Shadre Reevis

"Slid off runway upon exit.." I think that means they were already slowed and turning off, and the nose wheel just slipped during their turnoff.

pangolin

http://archive-server.liveatc.net/kc...2019-2000Z.mp3

Poor quality but it's something.

MrWizard

[QUOTE=pangolin;2741617]http://archive-server.liveatc.net/kc...2019-2000Z.mp3

There is, within that unofficial recording of the FAA tower and approach frequencies, a clear indication that the tower passed to the aircraft a PIREP of braking action NIL at far end. FWIW.

In other news, have any of you called the SOC number lately?

"Welcome to the Mesa Airlines Systems Operation Center in Phoenix. Please listen carefully, our menu has changed.

Press 1 to hear NO
Press 2 to hear WHAT PART OF NO DON'T YOU UNDERSTAND?
Press 3 to hear WE CAN'T DO THAT
Press 4 to hear WHY ARE YOU STILL HERE?
Press 5 to hear THE ROLLING STONES IN A VINTAGE CLIP OF (I CAN'T GET NO) SATISFACTION
Press 1 to return to the main menu at any time."

calmwinds

[QUOTE=MrWizard;2744536]I wouldn’t want to be that Captain.

pangolin

[QUOTE=calmwinds;2744570]I did some research about how much braking action 3 increases landing distance. I found something interesting in that pilots reporting braking action almost always report poorer braking action at the end of the rollout than at the touchdown point. It was determined that this was probably a subjective error driven by the perception between how hard the brakes are pressed and what actually happens.

It was part of a boeing training PPT online that I just can't find again - if I do I'll post the link here - but it indicated that in point of fact the braking is just different at that point because of no thrust reverse and different behavior of the anti-skid at different points etc.

I doubt it helps here and I don't know the winds but I can see things happening there. Sometimes the ILS is the only option to get down and sometimes that means a tailwind landing that's right at the edge of the numbers.


I found it - look at slide 29:

http://www.vipa.asn.au/sites/default...%20runways.pdf

Here's what it says:

brakes to stop the airplane during the stop
● Conjecture
– Since the flight crew used moderate braking during the first part of the stop
and the reversers were deployed, and aerodynamic drag was high
– The deceleration rate was as expected for the amount of wheel braking
used by flight crew hence the report of good
– However later in the stop maximum wheel braking was applied but now the
speed was lower
– Less drag, less reverse thrust (speed effect)
– The deceleration rate was less than expected for the amount of wheel
braking used by flight crew hence the report of poor
– The perception was the runway had gotten slipperier part way down the runway
– No evidence in FDR data that runway slipperiness changed

MrWizard

[QUOTE=pangolin;2744923][QUOTE=calmwinds;2744570]

I did some research about how much braking action 3 increases landing distance....
****
All true .. except .. does that absolve the crew from landing with a PIREP of NIL?

Weather below at time of arrival, pulled from a different source since the NWS/NOAA archival engine is down due to federal funding. This is raw data, corrected to local time not UTC (aircraft landing 1426 CST). ILS 02 was used and the winds were reported to be almost zero tailwind (averaged between reports, 125 deg, 7 knots). The crew apparently had legal visibility to initiate the approach and continue to landing if able.


COU,2019-01-11 14:20,M,M,M,120.00,7.00,0.06,30.16,M,0.50,M,OVC,M, M,M,499.00,M,M,M,SN FG,KCOU 112020Z AUTO 12007KT 1/2SM SN FG OVC004 00/00 A3015 RMK P0005 T00000000 MADISHF
COU,2019-01-11 14:25,M,M,M,130.00,7.00,0.06,30.16,M,0.50,M,OVC,M, M,M,499.00,M,M,M,SN FG,KCOU 112025Z AUTO 13007KT 1/2SM SN FG OVC004 00/00 A3015 RMK P0005 T00000000 MADISHF

Weather was somewhat challenging enroute, but not necessarily flat-out nasty. OTOH, what the radar shows doesn't show what the crew experienced.

pangolin

Braking action nil prohibits landing - but it's reported 3 x 3 x 3.

Braking action was reported nil after taxiway bravo - last 10% of the runway. Is the pirep controlling? Is rollout braking action controlling?


[QUOTE=MrWizard;2744936][QUOTE=pangolin;2744923]

calmwinds

Nil is a Pirep. 3/3/3 is TALPA. A Pirep is required to take precedence over TALPA. TALPA can never be better than a PIREP.

The ATIS should have been changed to 3/3/0.

MrWizard

[QUOTE=calmwinds;2744971]Nil is a Pirep. 3/3/3 is TALPA. A Pirep is required to take precedence over TALPA. TALPA can never be better than a PIREP.


GOM says braking reports if NIL suspend airline operations at that airport .. although, I think it means that specific runway, not the entire airport. GOM also refers to the specific AFM.

CRJ 900 AFM addresses braking reports for both departures and arrivals. For landings, a diversion "should be considered" if the braking action is reported poor.

It was reported worse than poor.

pangolin

I just listened to it again.

The Pirep predated the work on the runway. The new condition codes of 3/3/3 were AFTER working on the runway AFTER the PIREP.

So I don't think the pirep was controlling.


[QUOTE=MrWizard;2744975]