DC9-30 has altitude deviation during descent.

Attributes
ACN	300920
Time
Date	199504
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ape
State Reference	OH
Altitude	msl bound lower : 10700 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : day
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 240 flight time total : 14885 flight time type : 2300
ASRS Report	300920
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flight pit - day given descent clearance to cross mecan intersection at 11000 ft. Captain flying and aircraft descended through 11000 ft. At 10800 ft copilot brought to captain's attention that leveloff was to be at 11000 ft. Aircraft descended to 10700 before climbing back to 11000 ft. At this time it was discussed that the aircraft altitude alerter aural warning might not have sounded. The alerter was monitored throughout the remainder of flight and was operating normally. On ground at day, alerter tested normal. During the next flight from day - dca flight, it was determined that the altitude alerter at times (intermittent) would give a soft chirp instead of a chime. This was then written up in the aircraft log back at dca and corrective action taken by maintenance. On subsequent flts the alerter performed ok.

Original NASA ASRS Text

Title: DC9-30 HAS ALTDEV DURING DSCNT.

Narrative: FLT PIT - DAY GIVEN DSCNT CLRNC TO CROSS MECAN INTXN AT 11000 FT. CAPT FLYING AND ACFT DSNDED THROUGH 11000 FT. AT 10800 FT COPLT BROUGHT TO CAPT'S ATTN THAT LEVELOFF WAS TO BE AT 11000 FT. ACFT DSNDED TO 10700 BEFORE CLBING BACK TO 11000 FT. AT THIS TIME IT WAS DISCUSSED THAT THE ACFT ALT ALERTER AURAL WARNING MIGHT NOT HAVE SOUNDED. THE ALERTER WAS MONITORED THROUGHOUT THE REMAINDER OF FLT AND WAS OPERATING NORMALLY. ON GND AT DAY, ALERTER TESTED NORMAL. DURING THE NEXT FLT FROM DAY - DCA FLT, IT WAS DETERMINED THAT THE ALT ALERTER AT TIMES (INTERMITTENT) WOULD GIVE A SOFT CHIRP INSTEAD OF A CHIME. THIS WAS THEN WRITTEN UP IN THE ACFT LOG BACK AT DCA AND CORRECTIVE ACTION TAKEN BY MAINT. ON SUBSEQUENT FLTS THE ALERTER PERFORMED OK.

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.