Air carrier medium large transport altitude deviation overshot during descent into mexico city.

Attributes
ACN	85445
Time
Date	198804
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mmmx
State Reference	FO
Altitude	msl bound lower : 23000 msl bound upper : 24000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : mmmx
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 6000
ASRS Report	85445
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 9500
ASRS Report	85451
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Although this incident occurred in mexican airspace, I thought it was worth mentioning. Descent into mexico city was normal with the exception of some thunderstorms in the area. Also, 3 aircraft were all arriving near the same time with similar call signs. There was air carrier efx, air carrier jkx and air carrier lmx. During descent the controller cleared us to FL230. The call was acknowledged and 230 set and armed in the flight guidance system. Dscnts were given to the other aircraft along with spacing vectors. Upon leveling at FL230, the controller asked our altitude and we said '230.' he replied, 'no, cleared to 240.' we immediately initiated climb to FL240. Contributing factor was, I think, some confusion of the controller and the flight crews involved because several times the wrong aircraft would acknowledge instructions meant for another aircraft.

Original NASA ASRS Text

Title: ACR MLG ALT DEVIATION OVERSHOT DURING DESCENT INTO MEXICO CITY.

Narrative: ALTHOUGH THIS INCIDENT OCCURRED IN MEXICAN AIRSPACE, I THOUGHT IT WAS WORTH MENTIONING. DSCNT INTO MEXICO CITY WAS NORMAL WITH THE EXCEPTION OF SOME TSTMS IN THE AREA. ALSO, 3 ACFT WERE ALL ARRIVING NEAR THE SAME TIME WITH SIMILAR CALL SIGNS. THERE WAS ACR EFX, ACR JKX AND ACR LMX. DURING DSCNT THE CTLR CLRED US TO FL230. THE CALL WAS ACKNOWLEDGED AND 230 SET AND ARMED IN THE FLT GUIDANCE SYS. DSCNTS WERE GIVEN TO THE OTHER ACFT ALONG WITH SPACING VECTORS. UPON LEVELING AT FL230, THE CTLR ASKED OUR ALT AND WE SAID '230.' HE REPLIED, 'NO, CLRED TO 240.' WE IMMEDIATELY INITIATED CLB TO FL240. CONTRIBUTING FACTOR WAS, I THINK, SOME CONFUSION OF THE CTLR AND THE FLT CREWS INVOLVED BECAUSE SEVERAL TIMES THE WRONG ACFT WOULD ACKNOWLEDGE INSTRUCTIONS MEANT FOR ANOTHER ACFT.

Data retrieved from NASA's ASRS site as of August 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.