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|
Attributes | |
ACN | 668736 |
Time | |
Date | 200508 |
Local Time Of Day | 1201 To 1800 |
Place | |
Locale Reference | navaid : rmg.vortac |
State Reference | GA |
Altitude | msl single value : 33000 |
Environment | |
Flight Conditions | VMC |
Weather Elements | Thunderstorm |
Light | Daylight |
Aircraft 1 | |
Controlling Facilities | artcc : ztl.artcc |
Operator | common carrier : air carrier |
Make Model Name | B757 Undifferentiated or Other Model |
Operating Under FAR Part | Part 121 |
Flight Phase | cruise : level cruise : holding |
Route In Use | arrival : on vectors arrival star : erlin |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : cfi pilot : atp |
Experience | flight time last 90 days : 130 flight time total : 9000 flight time type : 2400 |
ASRS Report | 668736 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : atp |
Experience | flight time last 90 days : 100 flight time total : 11000 flight time type : 5100 |
ASRS Report | 668735 |
Events | |
Anomaly | altitude deviation : excursion from assigned altitude non adherence : far non adherence : clearance other anomaly other spatial deviation |
Independent Detector | other flight crewa other flight crewb |
Resolutory Action | controller : issued new clearance flight crew : exited adverse environment |
Supplementary | |
Problem Areas | Flight Crew Human Performance ATC Human Performance Weather |
Primary Problem | Weather |
Air Traffic Incident | Pilot Deviation |
Narrative:
We were on the outbound leg of a 15 mi leg holding pattern at the rome VOR as published; altitude FL330. Upon commencing the right turn to the inbound leg; I told the PF (captain) that the autoplt turn radius would not complete the inbound turn prior to clipping the edge of the thunderstorm that had matured on the northwest side of the holding pattern. As I saw the captain evaluating my comment; I indicated the need to disconnect the autoplt and manually increase the turning bank angle to result in less of a cloud entry. This he did and steepened the right turn to somewhere around a comfortable 40-degree bank. During this; I increased the power to maintain airspeed and verbally notified the PF. Moments later; seeing that the aircraft would not completely avoid the thunderstorm cloud edge; the captain abandoned this plan and started to reverse his right turn and assertively rolled into a left bank. He verbalized his change of plan to me simultaneously with the reversal of bank. I immediately verbalized 'no; no; no; you're only going to be in it for a couple of seconds.' the decision was long made; as the turn was already strong to the left. It now was a matter for me to give as much back up on flying the aircraft as I could. Several times I adjusted power and verbalized such. The storm was being avoided for the most part and visual conditions were being maintained. This I was pleased with. However; when I realized the wing buffet I was feeling was not being caused by the nearby storm cell; I called that out to the captain's attention. Something to the effect; 'that's wing buffet.' the bank I noted was at 60 degrees exactly. Both prior to the wing buffet and during; I applied normal flying corrective control wheel adjustments to our situation. Every time the captain felt me on the controls he said 'I have it.' when both roll and pitch and cloud avoidance were near completion; the captain told me to call ATC. The circuit had been completely busy throughout the maneuver and by the time a transmission could be initiated; we were well west of the holding pattern and at FL292. Finally; I told ATC; 'XXXX we're west of the holding pattern at FL293 climbing FL330; we deviated from clearance to avoid a thunderstorm.' ATC worked us back into the flow with several more turns at erlin and arrival and landing on runway 27L. We were late to discover the problem with the thunderstorm as the actual position of the higher level (portion) of the thunderstorm cloud was in our holding pattern; but the radar displayed position of the storm was not even close to the magenta line on our HSI. The radar tilt was adjusted several times and was at the correct setting but did not display the upper icy/drier portion of the cloud. The thunderstorm was rapidly maturing. Supplemental information from acn 668735: ride conditions at the time were smooth; and there had been no turbulence reports from other aircraft or ATC. The seatbelt sign was off. Approximately 1/2 way through a turn from the outbound leg of the holding pattern to the inbound leg; both the first officer and myself believed that the then existing turn radius would be insufficient to adequately clear the WX. I decided to turn toward the northwest; increase the bank angle; and sacrifice altitude to ensure adequate performance margin on the aircraft. As soon as possible (ZTL was quite congested); the first officer radioed our actions to ZTL; and we received an amended clearance. ZTL provided us with maneuvering airspace and vectored us back onto the arrival into atl. Due to task saturation during this event; I was late turning on the seatbelt sign. At one point; the on-board leader called the cockpit and suggested I make a PA to the passenger; which I did do. The remainder of the flight was uneventful. Upon deplaning; I received no injury report from flight attendants or passenger; although the flight attendants mentioned that some passenger were noticeably apprehensive during the time we were turning to avoid the WX. Several factors contributed to this event: radio traffic congestion; not appreciating the speed at which these thunderstorm cells were building and moving; pilot task saturation planning and communicating with a dispatcher about possible divert options; the difficultyin reconciling radar and visual information about thunderstorms at relatively close range; and a tendency to delay declaring an emergency and instead simply ask for an amended clearance. The problem could have been avoided by being more aggressive with ATC about relocating the holding pattern or associated protected airspace to provide for a more cautious displacement between the aircraft and the WX.
Original NASA ASRS Text
Title: B757 APCHED A TSTM CELL WHILE IN HOLDING AT FL330 AND WHILE ATTEMPTING TO AVOID THE CELL TURNED AT A 60 DEG BANK ANGLE AND DSNDED TO FL292.
Narrative: WE WERE ON THE OUTBOUND LEG OF A 15 MI LEG HOLDING PATTERN AT THE ROME VOR AS PUBLISHED; ALT FL330. UPON COMMENCING THE R TURN TO THE INBOUND LEG; I TOLD THE PF (CAPT) THAT THE AUTOPLT TURN RADIUS WOULD NOT COMPLETE THE INBOUND TURN PRIOR TO CLIPPING THE EDGE OF THE TSTM THAT HAD MATURED ON THE NW SIDE OF THE HOLDING PATTERN. AS I SAW THE CAPT EVALUATING MY COMMENT; I INDICATED THE NEED TO DISCONNECT THE AUTOPLT AND MANUALLY INCREASE THE TURNING BANK ANGLE TO RESULT IN LESS OF A CLOUD ENTRY. THIS HE DID AND STEEPENED THE R TURN TO SOMEWHERE AROUND A COMFORTABLE 40-DEG BANK. DURING THIS; I INCREASED THE PWR TO MAINTAIN AIRSPD AND VERBALLY NOTIFIED THE PF. MOMENTS LATER; SEEING THAT THE ACFT WOULD NOT COMPLETELY AVOID THE TSTM CLOUD EDGE; THE CAPT ABANDONED THIS PLAN AND STARTED TO REVERSE HIS R TURN AND ASSERTIVELY ROLLED INTO A L BANK. HE VERBALIZED HIS CHANGE OF PLAN TO ME SIMULTANEOUSLY WITH THE REVERSAL OF BANK. I IMMEDIATELY VERBALIZED 'NO; NO; NO; YOU'RE ONLY GOING TO BE IN IT FOR A COUPLE OF SECONDS.' THE DECISION WAS LONG MADE; AS THE TURN WAS ALREADY STRONG TO THE L. IT NOW WAS A MATTER FOR ME TO GIVE AS MUCH BACK UP ON FLYING THE ACFT AS I COULD. SEVERAL TIMES I ADJUSTED PWR AND VERBALIZED SUCH. THE STORM WAS BEING AVOIDED FOR THE MOST PART AND VISUAL CONDITIONS WERE BEING MAINTAINED. THIS I WAS PLEASED WITH. HOWEVER; WHEN I REALIZED THE WING BUFFET I WAS FEELING WAS NOT BEING CAUSED BY THE NEARBY STORM CELL; I CALLED THAT OUT TO THE CAPT'S ATTN. SOMETHING TO THE EFFECT; 'THAT'S WING BUFFET.' THE BANK I NOTED WAS AT 60 DEGS EXACTLY. BOTH PRIOR TO THE WING BUFFET AND DURING; I APPLIED NORMAL FLYING CORRECTIVE CTL WHEEL ADJUSTMENTS TO OUR SITUATION. EVERY TIME THE CAPT FELT ME ON THE CTLS HE SAID 'I HAVE IT.' WHEN BOTH ROLL AND PITCH AND CLOUD AVOIDANCE WERE NEAR COMPLETION; THE CAPT TOLD ME TO CALL ATC. THE CIRCUIT HAD BEEN COMPLETELY BUSY THROUGHOUT THE MANEUVER AND BY THE TIME A XMISSION COULD BE INITIATED; WE WERE WELL W OF THE HOLDING PATTERN AND AT FL292. FINALLY; I TOLD ATC; 'XXXX WE'RE W OF THE HOLDING PATTERN AT FL293 CLBING FL330; WE DEVIATED FROM CLRNC TO AVOID A TSTM.' ATC WORKED US BACK INTO THE FLOW WITH SEVERAL MORE TURNS AT ERLIN AND ARR AND LNDG ON RWY 27L. WE WERE LATE TO DISCOVER THE PROB WITH THE TSTM AS THE ACTUAL POS OF THE HIGHER LEVEL (PORTION) OF THE TSTM CLOUD WAS IN OUR HOLDING PATTERN; BUT THE RADAR DISPLAYED POS OF THE STORM WAS NOT EVEN CLOSE TO THE MAGENTA LINE ON OUR HSI. THE RADAR TILT WAS ADJUSTED SEVERAL TIMES AND WAS AT THE CORRECT SETTING BUT DID NOT DISPLAY THE UPPER ICY/DRIER PORTION OF THE CLOUD. THE TSTM WAS RAPIDLY MATURING. SUPPLEMENTAL INFO FROM ACN 668735: RIDE CONDITIONS AT THE TIME WERE SMOOTH; AND THERE HAD BEEN NO TURB RPTS FROM OTHER ACFT OR ATC. THE SEATBELT SIGN WAS OFF. APPROX 1/2 WAY THROUGH A TURN FROM THE OUTBOUND LEG OF THE HOLDING PATTERN TO THE INBOUND LEG; BOTH THE FO AND MYSELF BELIEVED THAT THE THEN EXISTING TURN RADIUS WOULD BE INSUFFICIENT TO ADEQUATELY CLR THE WX. I DECIDED TO TURN TOWARD THE NW; INCREASE THE BANK ANGLE; AND SACRIFICE ALT TO ENSURE ADEQUATE PERFORMANCE MARGIN ON THE ACFT. AS SOON AS POSSIBLE (ZTL WAS QUITE CONGESTED); THE FO RADIOED OUR ACTIONS TO ZTL; AND WE RECEIVED AN AMENDED CLRNC. ZTL PROVIDED US WITH MANEUVERING AIRSPACE AND VECTORED US BACK ONTO THE ARR INTO ATL. DUE TO TASK SATURATION DURING THIS EVENT; I WAS LATE TURNING ON THE SEATBELT SIGN. AT ONE POINT; THE ON-BOARD LEADER CALLED THE COCKPIT AND SUGGESTED I MAKE A PA TO THE PAX; WHICH I DID DO. THE REMAINDER OF THE FLT WAS UNEVENTFUL. UPON DEPLANING; I RECEIVED NO INJURY RPT FROM FLT ATTENDANTS OR PAX; ALTHOUGH THE FLT ATTENDANTS MENTIONED THAT SOME PAX WERE NOTICEABLY APPREHENSIVE DURING THE TIME WE WERE TURNING TO AVOID THE WX. SEVERAL FACTORS CONTRIBUTED TO THIS EVENT: RADIO TFC CONGESTION; NOT APPRECIATING THE SPD AT WHICH THESE TSTM CELLS WERE BUILDING AND MOVING; PLT TASK SATURATION PLANNING AND COMMUNICATING WITH A DISPATCHER ABOUT POSSIBLE DIVERT OPTIONS; THE DIFFICULTYIN RECONCILING RADAR AND VISUAL INFO ABOUT TSTMS AT RELATIVELY CLOSE RANGE; AND A TENDENCY TO DELAY DECLARING AN EMER AND INSTEAD SIMPLY ASK FOR AN AMENDED CLRNC. THE PROB COULD HAVE BEEN AVOIDED BY BEING MORE AGGRESSIVE WITH ATC ABOUT RELOCATING THE HOLDING PATTERN OR ASSOCIATED PROTECTED AIRSPACE TO PROVIDE FOR A MORE CAUTIOUS DISPLACEMENT BTWN THE ACFT AND THE WX.
Data retrieved from NASA's ASRS site as of January 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.