Clearance interpretation results in air carrier widebody transport missing altitude restriction on l...

Attributes
ACN	93604
Time
Date	198808
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : lax
State Reference	CA
Altitude	msl bound lower : 12500 msl bound upper : 14000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	approach : straight in arrival : profile descent
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 14000 flight time type : 450
ASRS Report	93604
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot altitude deviation : crossing restriction not met other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation other
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Were cleared for a runway 25L profile descent, then about tnp were cleared to intercept runway 24R approach. It puts the pilot free at that time to no longer go by the runway 25L profile descent, which has a 14000' and 18000' at civet. We crossed abeam civet at around 12500' and the center got very upset. The clearance to intercept runway 24R approach does not include runway 25L profile descent. There was no conflict of any traffic, alarms or anything, but a low altitude at abeam civet going to runway 24R, which is not the runway 25L profile. Callback conversation with reporter revealed the following: PIC called center after landing and they stated they had about 6 similar busts at civet that day. Later when they returned on another trip the center was issuing the clearance in a different way. Reporter stated that they should also have a profile for the runway 24 complex which would help do away with confusion. Claims runway 24 localizer too unstable that far out to use for navigation. Also stated that when clearance thought they should have requested clarification, but frequency was so busy did not want to bust in.

Original NASA ASRS Text

Title: CLRNC INTERP RESULTS IN ACR WDB MISSING ALT RESTRICTION ON LAX PROFILE APCH.

Narrative: WERE CLRED FOR A RWY 25L PROFILE DSCNT, THEN ABOUT TNP WERE CLRED TO INTERCEPT RWY 24R APCH. IT PUTS THE PLT FREE AT THAT TIME TO NO LONGER GO BY THE RWY 25L PROFILE DSCNT, WHICH HAS A 14000' AND 18000' AT CIVET. WE CROSSED ABEAM CIVET AT AROUND 12500' AND THE CENTER GOT VERY UPSET. THE CLRNC TO INTERCEPT RWY 24R APCH DOES NOT INCLUDE RWY 25L PROFILE DSCNT. THERE WAS NO CONFLICT OF ANY TFC, ALARMS OR ANYTHING, BUT A LOW ALT AT ABEAM CIVET GOING TO RWY 24R, WHICH IS NOT THE RWY 25L PROFILE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: PIC CALLED CENTER AFTER LNDG AND THEY STATED THEY HAD ABOUT 6 SIMILAR BUSTS AT CIVET THAT DAY. LATER WHEN THEY RETURNED ON ANOTHER TRIP THE CENTER WAS ISSUING THE CLRNC IN A DIFFERENT WAY. RPTR STATED THAT THEY SHOULD ALSO HAVE A PROFILE FOR THE RWY 24 COMPLEX WHICH WOULD HELP DO AWAY WITH CONFUSION. CLAIMS RWY 24 LOC TOO UNSTABLE THAT FAR OUT TO USE FOR NAV. ALSO STATED THAT WHEN CLRNC THOUGHT THEY SHOULD HAVE REQUESTED CLARIFICATION, BUT FREQ WAS SO BUSY DID NOT WANT TO BUST IN.

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.

Clearance interpretation results in air carrier widebody transport missing altitude restriction on lax profile approach.