Air carrier flight was cleared to descend through altitude occupied by reporter.

Attributes
ACN	98389
Time
Date	198811
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gdl
State Reference	FO
Altitude	msl bound lower : 31000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : j11
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 250 flight time total : 5500
ASRS Report	98389
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : published procedure non adherence : far
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation

Narrative:

The following narrative describes 2 very similar incidents experienced by the same crew on flight xxyz on 2 successive trips flown from pvr to iah. 1) on 11/tue/88 at approximately XA10 local time, flight xxyz was cruising at FL310 on J11 between gdl and agu traveling northbound. MMMX cleared a company flight abx over agu traveling southbound to descend from FL330 to FL290. Based on position reports which I analyzed, I immediately advised center that we were approaching agu from the south and that there was a conflict. Center immediately asked our position (approximately 15 mi south of agu) and cancelled the descent for flight abx. Shortly after this exchange we observed flight abx passing directly overhead at FL330. I believe both incident highlight the importance of proper radio calls, position reports, navigation procedures as well as situation awareness, especially during non radar international flying. Both of these incidents have been briefed to our flight operations, and steps have been taken to correct the problem with MMMX.

Original NASA ASRS Text

Title: ACR FLT WAS CLEARED TO DESCEND THROUGH ALT OCCUPIED BY REPORTER.

Narrative: THE FOLLOWING NARRATIVE DESCRIBES 2 VERY SIMILAR INCIDENTS EXPERIENCED BY THE SAME CREW ON FLT XXYZ ON 2 SUCCESSIVE TRIPS FLOWN FROM PVR TO IAH. 1) ON 11/TUE/88 AT APPROX XA10 LCL TIME, FLT XXYZ WAS CRUISING AT FL310 ON J11 BTWN GDL AND AGU TRAVELING NBND. MMMX CLRED A COMPANY FLT ABX OVER AGU TRAVELING SBND TO DSND FROM FL330 TO FL290. BASED ON POS RPTS WHICH I ANALYZED, I IMMEDIATELY ADVISED CENTER THAT WE WERE APCHING AGU FROM THE S AND THAT THERE WAS A CONFLICT. CENTER IMMEDIATELY ASKED OUR POS (APPROX 15 MI S OF AGU) AND CANCELLED THE DSCNT FOR FLT ABX. SHORTLY AFTER THIS EXCHANGE WE OBSERVED FLT ABX PASSING DIRECTLY OVERHEAD AT FL330. I BELIEVE BOTH INCIDENT HIGHLIGHT THE IMPORTANCE OF PROPER RADIO CALLS, POS RPTS, NAV PROCS AS WELL AS SITUATION AWARENESS, ESPECIALLY DURING NON RADAR INTL FLYING. BOTH OF THESE INCIDENTS HAVE BEEN BRIEFED TO OUR FLT OPS, AND STEPS HAVE BEEN TAKEN TO CORRECT THE PROB WITH MMMX.

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.