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B757 flight crew reports exercising captains emergency authority when center cannot authorize a turn to avoid build ups. Turbulence is encountered as aircraft passes through cloud in turn.
| Attributes | |
| ACN | 813824 |
| Time | |
| Date | 200811 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | msl single value : 10000 |
| Environment | |
| Flight Conditions | IMC |
| Weather Elements | Thunderstorm Rain Turbulence |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : zzz.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | departure : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 210 flight time total : 13000 flight time type : 2500 |
| ASRS Report | 813824 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 210 flight time total : 12000 flight time type : 320 |
| ASRS Report | 814147 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude inflight encounter : turbulence inflight encounter : weather other anomaly other anomaly other spatial deviation |
| Independent Detector | other flight crewa |
| Resolutory Action | controller : issued new clearance flight crew : declared emergency flight crew : exited adverse environment flight crew : took evasive action |
| Consequence | other |
| Supplementary | |
| Problem Areas | Weather Flight Crew Human Performance ATC Human Performance |
| Primary Problem | Weather |
Narrative:
Takeoff and climb from ZZZ in light occasional moderate turbulence. Aircraft entered IMC approximately 2000 ft AGL. Radar showed line of WX 10 NM north of and parallel to aircraft track. Numerous cells with level 3 intensity; each a few mi wide with good gaps in between. No radar returns displayed in front of aircraft path. Cleared to climb and maintain 10000 ft on a heading of 270M degree. Autoplt engaged. Still IMC with moderate turbulence. Handed off from ZZZ departure control to center. We attempted to make contact; but were unable due to frequency congestion. We then broke out of WX into the clear and saw numerous; tightly defined cumulus clouds in our path. Tops were estimated at 16000 ft with numerous 'valleys' in between slightly above our altitude. None displayed on our WX radar regardless of tilt angle. After a few more attempts; we established contact with center and requested higher or a new heading for WX avoidance. We were told to maintain heading and altitude. All aircraft were told to just stand by because he was quite busy. I initiated a turn to the north to avoid WX and asked my first officer to tell center we were turning for weather. After a few attempts he got the message out. Center then replied to maintain heading 270 degrees. I took the radio and broadcast that we were turning to heading 350 degrees on captain's emergency authority/authorized for WX avoidance. There was no immediate reply from center. During the turn I reduced speed from 280 KIAS to 250 KTS; and set maximum bank of 30 degree on autoplt to reduce radius of turn. Despite efforts we entered the edge of the WX. Heavy turbulence encountered with deviations of +/-30-40 KIAS and +/-600 FPM. Actual altdevs were +/-300 ft. Autoplt remained engaged and we exited the WX after approximately 30 seconds. Ride improved; with concurrence of center we turned back to the west and resumed flight with no further difficulties. No known traffic conflicts. No injuries reported from crew or passenger. No apparent aircraft damage noted. In an abundance of caution we entered an item in the aircraft logbook to reflect turbulence encountered. Maintenance removed aircraft from service to perform required checks. I do not know the results of that inspection.
Original NASA ASRS Text
Title: B757 FLIGHT CREW REPORTS EXERCISING CAPTAINS EMERGENCY AUTHORITY WHEN CENTER CANNOT AUTHORIZE A TURN TO AVOID BUILD UPS. TURBULENCE IS ENCOUNTERED AS AIRCRAFT PASSES THROUGH CLOUD IN TURN.
Narrative: TKOF AND CLB FROM ZZZ IN LIGHT OCCASIONAL MODERATE TURB. ACFT ENTERED IMC APPROX 2000 FT AGL. RADAR SHOWED LINE OF WX 10 NM N OF AND PARALLEL TO ACFT TRACK. NUMEROUS CELLS WITH LEVEL 3 INTENSITY; EACH A FEW MI WIDE WITH GOOD GAPS IN BTWN. NO RADAR RETURNS DISPLAYED IN FRONT OF ACFT PATH. CLRED TO CLB AND MAINTAIN 10000 FT ON A HDG OF 270M DEG. AUTOPLT ENGAGED. STILL IMC WITH MODERATE TURB. HANDED OFF FROM ZZZ DEP CTL TO CTR. WE ATTEMPTED TO MAKE CONTACT; BUT WERE UNABLE DUE TO FREQ CONGESTION. WE THEN BROKE OUT OF WX INTO THE CLR AND SAW NUMEROUS; TIGHTLY DEFINED CUMULUS CLOUDS IN OUR PATH. TOPS WERE ESTIMATED AT 16000 FT WITH NUMEROUS 'VALLEYS' IN BTWN SLIGHTLY ABOVE OUR ALT. NONE DISPLAYED ON OUR WX RADAR REGARDLESS OF TILT ANGLE. AFTER A FEW MORE ATTEMPTS; WE ESTABLISHED CONTACT WITH CTR AND REQUESTED HIGHER OR A NEW HDG FOR WX AVOIDANCE. WE WERE TOLD TO MAINTAIN HDG AND ALT. ALL ACFT WERE TOLD TO JUST STAND BY BECAUSE HE WAS QUITE BUSY. I INITIATED A TURN TO THE N TO AVOID WX AND ASKED MY FO TO TELL CTR WE WERE TURNING FOR WEATHER. AFTER A FEW ATTEMPTS HE GOT THE MESSAGE OUT. CTR THEN REPLIED TO MAINTAIN HDG 270 DEGS. I TOOK THE RADIO AND BROADCAST THAT WE WERE TURNING TO HDG 350 DEGS ON CAPT'S EMER AUTH FOR WX AVOIDANCE. THERE WAS NO IMMEDIATE REPLY FROM CTR. DURING THE TURN I REDUCED SPD FROM 280 KIAS TO 250 KTS; AND SET MAX BANK OF 30 DEG ON AUTOPLT TO REDUCE RADIUS OF TURN. DESPITE EFFORTS WE ENTERED THE EDGE OF THE WX. HVY TURB ENCOUNTERED WITH DEVS OF +/-30-40 KIAS AND +/-600 FPM. ACTUAL ALTDEVS WERE +/-300 FT. AUTOPLT REMAINED ENGAGED AND WE EXITED THE WX AFTER APPROX 30 SECONDS. RIDE IMPROVED; WITH CONCURRENCE OF CTR WE TURNED BACK TO THE W AND RESUMED FLT WITH NO FURTHER DIFFICULTIES. NO KNOWN TFC CONFLICTS. NO INJURIES RPTED FROM CREW OR PAX. NO APPARENT ACFT DAMAGE NOTED. IN AN ABUNDANCE OF CAUTION WE ENTERED AN ITEM IN THE ACFT LOGBOOK TO REFLECT TURB ENCOUNTERED. MAINT REMOVED ACFT FROM SVC TO PERFORM REQUIRED CHKS. I DO NOT KNOW THE RESULTS OF THAT INSPECTION.
Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.