Loss of aircraft control -- WX factors -- an air carrier cruising above the clouds enters or comes n...

Attributes
ACN	313283
Time
Date	199508
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : fmn
State Reference	NM
Altitude	msl bound lower : 39000 msl bound upper : 40000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	artcc : zab
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute airway : zab
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 20000 flight time type : 2100
ASRS Report	313283
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : clearance other anomaly other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : regained aircraft control
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation other

Narrative:

In cruise at FL390 in thin tops with hazy visibility, aircraft abruptly encountered moderate turbulence and moderate precipitation in updraft conditions. Aircraft speed varied from overspd to vls (stall plus 5 percent). Engines spooled down, rate of climb plus 3600 FPM with airspeed at overspd to full power with rate of climb negative 2500 FPM in moderate turbulence and precipitation lasting about 45 seconds. Disconnected autoplt, held attitude. Altitude excursion to 40000 ft. Event ended abruptly, called ATC and returned to FL390. No aircraft damage or passenger injuries. 1 flight attendant bumped her head, slight injury. Flight returned to normal to destination. Callback conversation with reporter revealed the following information: the reporter was flying an A320 aircraft above the tops of some thunderstorms at night when he encountered an updraft that caused the aircraft to accelerate and start to climb. He disconnected the autoplt and flew an attitude that would maintain a stable platform for a recovery from the upset. The aircraft climbed, due to the updraft, to 40000 ft and the autothrottles started to retard to slow the indicated overspd. The captain was concerned that the autothrottle computer would overreact so he watched carefully that the throttles did not go to idle. The throttles did retard about 20 percent below cruise setting which was acceptable. During the recovery, the captain gently lowered the nose about 4 degrees below the cruise attitude and returned to FL390. The first officer was at that time reporting the incident to the ARTCC radar controller. The first officer was very helpful during the incident, reading off airspeed, altitude and power settings and communicating with center. There were no injuries and no damage and the company and the FAA had no follow up.

Original NASA ASRS Text

Title: LOSS OF ACFT CTL -- WX FACTORS -- AN ACR CRUISING ABOVE THE CLOUDS ENTERS OR COMES NEAR THE TOP OF A TSTM AND GAINS 1000 FT AND HAS GREAT AIRSPD EXCURSIONS, BUT NO INJURIES OR DAMAGE.

Narrative: IN CRUISE AT FL390 IN THIN TOPS WITH HAZY VISIBILITY, ACFT ABRUPTLY ENCOUNTERED MODERATE TURB AND MODERATE PRECIPITATION IN UPDRAFT CONDITIONS. ACFT SPD VARIED FROM OVERSPD TO VLS (STALL PLUS 5 PERCENT). ENGS SPOOLED DOWN, RATE OF CLB PLUS 3600 FPM WITH AIRSPD AT OVERSPD TO FULL PWR WITH RATE OF CLB NEGATIVE 2500 FPM IN MODERATE TURB AND PRECIPITATION LASTING ABOUT 45 SECONDS. DISCONNECTED AUTOPLT, HELD ATTITUDE. ALT EXCURSION TO 40000 FT. EVENT ENDED ABRUPTLY, CALLED ATC AND RETURNED TO FL390. NO ACFT DAMAGE OR PAX INJURIES. 1 FLT ATTENDANT BUMPED HER HEAD, SLIGHT INJURY. FLT RETURNED TO NORMAL TO DEST. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING AN A320 ACFT ABOVE THE TOPS OF SOME TSTMS AT NIGHT WHEN HE ENCOUNTERED AN UPDRAFT THAT CAUSED THE ACFT TO ACCELERATE AND START TO CLB. HE DISCONNECTED THE AUTOPLT AND FLEW AN ATTITUDE THAT WOULD MAINTAIN A STABLE PLATFORM FOR A RECOVERY FROM THE UPSET. THE ACFT CLBED, DUE TO THE UPDRAFT, TO 40000 FT AND THE AUTOTHROTTLES STARTED TO RETARD TO SLOW THE INDICATED OVERSPD. THE CAPT WAS CONCERNED THAT THE AUTOTHROTTLE COMPUTER WOULD OVERREACT SO HE WATCHED CAREFULLY THAT THE THROTTLES DID NOT GO TO IDLE. THE THROTTLES DID RETARD ABOUT 20 PERCENT BELOW CRUISE SETTING WHICH WAS ACCEPTABLE. DURING THE RECOVERY, THE CAPT GENTLY LOWERED THE NOSE ABOUT 4 DEGS BELOW THE CRUISE ATTITUDE AND RETURNED TO FL390. THE FO WAS AT THAT TIME RPTING THE INCIDENT TO THE ARTCC RADAR CTLR. THE FO WAS VERY HELPFUL DURING THE INCIDENT, READING OFF AIRSPD, ALT AND PWR SETTINGS AND COMMUNICATING WITH CTR. THERE WERE NO INJURIES AND NO DAMAGE AND THE COMPANY AND THE FAA HAD NO FOLLOW UP.

Data retrieved from NASA's ASRS site as of July 2007 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.

Loss of aircraft control -- WX factors -- an air carrier cruising above the clouds enters or comes near the top of a thunderstorm and gains 1000 ft and has great airspeed excursions, but no injuries or damage.