Widebody Transport
Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Became Reoriented; Flight Crew Regained Aircraft Control
Airport; Weather; Company Policy
Latest report: wind 290/9. Mu 26;24;23 runway sanded and treated. Braking action actually nil. Darn near slid off the side of the runway. There is too much ambiguity regarding mu values. The FOM cautions that no reliable correlation exist between mu and braking action. Mu and braking action are now strongly correlated in my mind.
Upon landing; the aircraft started to skid uncontrollably. It is a short runway (7;351 feet) so I felt obligated to apply brakes and reverse thrust right after touchdown. Touchdown occurred on speed and glide path within first 1;500 feet of threshold. Aircraft began to slide to the left and to yaw right by about 30 degrees off centerline. Left main gear came so close to runway edge I thought we might have departed the runway. There was no indication of departure other than just how scary it looked. Post shutdown inspection with mechanic revealed no indications on left landing gear or brake area that aircraft departed runway. I applied differential braking and stowed thrust reverse which allowed aircraft yaw to be corrected and aircraft to be slowly brought back to center of runway. Further braking turned out to be poor or nil for the rest of the rollout. Every time I hit the brakes we went in to another skid. I could not stop the aircraft until the very last brick of the runway. I applied intermittent braking all the way to gain some deceleration but it was a very close thing until the very end to determine if we would stop or not. Landing data showed us 7;330 feet for min braking for conditions. We should not be flying a large aircraft into this field at night to arrive just at tower opening. It is a short runway and information updates during flight planning and approach planning during flight comes from aged sources. MU data was a couple hours old; it indicated medium to poor braking (26; 24; 23 on one report and 28; 24; 24 on another report). Wind data indicated 170/ 10 knots. We planned on flying the RNAV to 17R. As we approached and tower opened; the wind was reported at 290/09 knots which forced us to have to reevaluate landing conditions while already in the approach phase; reload new approach (ILS to 35L); rebrief it; and recheck landing data for stop distance and crosswind component vs braking action in a relatively short time. All of that was accomplished and a stable approach executed. Since no other aircraft had landed recently we had no PIREPs to indicate runway condition and tower had reported the runway had been sanded and treated before we landed. This gave us a false sense of security as to runway conditions and not enough time to fully evaluate all factors. Had the tower been open; other aircraft landing and reporting conditions; we probably would have opted to go to our alternate. A short runway; non-tower ops; early morning landing in winter conditions; and a large aircraft are a serious safety problem. Stop flying large aircraft into this non-tower environment in early morning. Delay scheduled landing until after tower ops have been going for at least an hour or two so that approaching aircraft have better information to use to make earlier evaluations with more accurate data. This was a really close call. We are asking for a disaster here if we keep doing this.
Air carrier flight crew reports landing with Mu readings of 26; 24; 23 and finding the braking action to be nil. The Tower had just opened and the readings were old.