<< >> NASA ASRS Report 385005, November 1997

An air carrier medium large transport aircraft on STAR into mex descended to ILS approach altitude prior to approach clearance. Controller intervened and reminded flight crew of altitude requirement.

Attributes
ACN	385005
Time
Date	199711
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mex
State Reference	FO
Altitude	msl bound lower : 9500 msl bound upper : 9700
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mex
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 16000 flight time type : 12000
ASRS Report	385005
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

We were cleared on the mateo five arrival and the ILS DME runway 5R. On the 160 degree radial of smo, we descended to 9500 ft, as is specified on the ILS runway 5 approach plate. Approach control asked what our altitude was, and we replied '9500 ft.' approach said the altitude should be 9700 ft, as shown on the mateo five arrival. We climbed to 9700 ft and completed the approach and landing. If the commercial charts are correct, then the approach procedures are unnecessarily confusing. I have always made it a point to transition from a STAR to an approach plate as early as possible. The first officer and I both noted the difference in altitudes shown on the mateo five as compared to the ILS runway 5, during our approach brief. It was my belief that the 9700 ft altitude was on the STAR in case it was used with another approach like an NDB runway 5 approach. Since the STAR transitioned to an ILS runway 5R, which specifies 9500 ft, I thought the 9500 ft altitude held precedence.

Related reports:

• Miscom between air carrier medium large transport flight cre...

	Enter your search terms Submit search form
	Web www.37000feet.com

Original NASA ASRS Text

Title: AN ACR MLG ACFT ON STAR INTO MEX DSNDED TO ILS APCH ALT PRIOR TO APCH CLRNC. CTLR INTERVENED AND REMINDED FLC OF ALT REQUIREMENT.

Narrative: WE WERE CLRED ON THE MATEO FIVE ARR AND THE ILS DME RWY 5R. ON THE 160 DEG RADIAL OF SMO, WE DSNDED TO 9500 FT, AS IS SPECIFIED ON THE ILS RWY 5 APCH PLATE. APCH CTL ASKED WHAT OUR ALT WAS, AND WE REPLIED '9500 FT.' APCH SAID THE ALT SHOULD BE 9700 FT, AS SHOWN ON THE MATEO FIVE ARR. WE CLBED TO 9700 FT AND COMPLETED THE APCH AND LNDG. IF THE COMMERCIAL CHARTS ARE CORRECT, THEN THE APCH PROCS ARE UNNECESSARILY CONFUSING. I HAVE ALWAYS MADE IT A POINT TO TRANSITION FROM A STAR TO AN APCH PLATE AS EARLY AS POSSIBLE. THE FO AND I BOTH NOTED THE DIFFERENCE IN ALTS SHOWN ON THE MATEO FIVE AS COMPARED TO THE ILS RWY 5, DURING OUR APCH BRIEF. IT WAS MY BELIEF THAT THE 9700 FT ALT WAS ON THE STAR IN CASE IT WAS USED WITH ANOTHER APCH LIKE AN NDB RWY 5 APCH. SINCE THE STAR TRANSITIONED TO AN ILS RWY 5R, WHICH SPECIFIES 9500 FT, I THOUGHT THE 9500 FT ALT HELD PRECEDENCE.

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.