A320 flight crew encounters mountain wave activity. Aircraft has overspd and altitude excursion.

Attributes
ACN	560291
Time
Date	200209
Day	Tue
Local Time Of Day	1801 To 2400
Place
State Reference	NE
Altitude	msl single value : 37000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 13000 flight time type : 490
ASRS Report	560291
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude inflight encounter : turbulence non adherence : far other anomaly
Independent Detector	aircraft equipment : altitude alert aircraft equipment other aircraft equipment : ecam warning other flight crewa other flight crewb
Resolutory Action	flight crew : exited adverse environment flight crew : overrode automation flight crew : regained aircraft control flight crew : returned to assigned altitude
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Aircraft Environmental Factor Flight Crew Human Performance
Primary Problem	Environmental Factor
Air Traffic Incident	Pilot Deviation

Narrative:

During cruise, entered mountain wave and wind change with light turbulence. Speed increased from 260 KIAS/mach .84 to 275 KIAS/mach .84 in 2 seconds. Remained in overspd range for 4 seconds. When airspeed increase detected approaching red arc, selected mach .76. Airspeed continued to increase accompanied by altitude increase from updraft. Received master warning for overspd followed by altitude alert as aircraft continued to climb. Seat belt sign was turned on. FMA read mach/altitude cruise/navigation. However, we did not detect that the autoplt was disengaged. After airspeed decreased and descent correction not being made, pulled for operation dec. When still not correcting, pushed autoplt disconnect button and realized, at that time, that the autoplt was not engaged. A correction was hand flown without incident and reported to ATC. I now remember that the autoplt disengaged at mach .83 and a pitch up was initiated, until I reduced below mach .83. Resulted in significant climb rate sustained by 1-G which was commanded using neutral stick. Long stability was not sacrificed with airspeed decrease. The autoplt disengagement was masked by master warning for overspd and altitude alert. The autoplt disengage ECAM was present but unnoticed by self or first officer as all eyes were elsewhere. The situation resulted in a total altitude increase of almost 1000 ft. There was no warning of mountain wave or wind change but some of the altitude increase would have been controled with sooner awareness of autoplt disengagement. Awareness of this possible scenario and discussion with other A-320 pilots may aid others in making a quicker response. A different aural warning, as with all other aircraft I've flown, for overspd would also enhance detection of both warnings.

Original NASA ASRS Text

Title: A320 FLC ENCOUNTERS MOUNTAIN WAVE ACTIVITY. ACFT HAS OVERSPD AND ALT EXCURSION.

Narrative: DURING CRUISE, ENTERED MOUNTAIN WAVE AND WIND CHANGE WITH LIGHT TURB. SPD INCREASED FROM 260 KIAS/MACH .84 TO 275 KIAS/MACH .84 IN 2 SECONDS. REMAINED IN OVERSPD RANGE FOR 4 SECONDS. WHEN AIRSPD INCREASE DETECTED APCHING RED ARC, SELECTED MACH .76. AIRSPD CONTINUED TO INCREASE ACCOMPANIED BY ALT INCREASE FROM UPDRAFT. RECEIVED MASTER WARNING FOR OVERSPD FOLLOWED BY ALT ALERT AS ACFT CONTINUED TO CLB. SEAT BELT SIGN WAS TURNED ON. FMA READ MACH/ALT CRUISE/NAV. HOWEVER, WE DID NOT DETECT THAT THE AUTOPLT WAS DISENGAGED. AFTER AIRSPD DECREASED AND DSCNT CORRECTION NOT BEING MADE, PULLED FOR OP DEC. WHEN STILL NOT CORRECTING, PUSHED AUTOPLT DISCONNECT BUTTON AND REALIZED, AT THAT TIME, THAT THE AUTOPLT WAS NOT ENGAGED. A CORRECTION WAS HAND FLOWN WITHOUT INCIDENT AND RPTED TO ATC. I NOW REMEMBER THAT THE AUTOPLT DISENGAGED AT MACH .83 AND A PITCH UP WAS INITIATED, UNTIL I REDUCED BELOW MACH .83. RESULTED IN SIGNIFICANT CLB RATE SUSTAINED BY 1-G WHICH WAS COMMANDED USING NEUTRAL STICK. LONG STABILITY WAS NOT SACRIFICED WITH AIRSPD DECREASE. THE AUTOPLT DISENGAGEMENT WAS MASKED BY MASTER WARNING FOR OVERSPD AND ALT ALERT. THE AUTOPLT DISENGAGE ECAM WAS PRESENT BUT UNNOTICED BY SELF OR FO AS ALL EYES WERE ELSEWHERE. THE SIT RESULTED IN A TOTAL ALT INCREASE OF ALMOST 1000 FT. THERE WAS NO WARNING OF MOUNTAIN WAVE OR WIND CHANGE BUT SOME OF THE ALT INCREASE WOULD HAVE BEEN CTLED WITH SOONER AWARENESS OF AUTOPLT DISENGAGEMENT. AWARENESS OF THIS POSSIBLE SCENARIO AND DISCUSSION WITH OTHER A-320 PLTS MAY AID OTHERS IN MAKING A QUICKER RESPONSE. A DIFFERENT AURAL WARNING, AS WITH ALL OTHER ACFT I'VE FLOWN, FOR OVERSPD WOULD ALSO ENHANCE DETECTION OF BOTH WARNINGS.

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.