B757-200 crew had an altitude deviation, after using an RNAV approach to runway 29 at ewr. The crew ...

Attributes
ACN	630735
Time
Date	200409
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ewr.airport
State Reference	NJ
Altitude	msl bound lower : 2700 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon tracon : u90.tracon
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 4l
Flight Phase	descent : approach
Route In Use	approach : circling approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 1400 flight time total : 15000 flight time type : 129
ASRS Report	630735
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : altimeters other flight crewa other flight crewb
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Altitude deviation on approach. Cleared for approach, ILS runway 4L, circle to land runway 29. FMS has RNAV from south circle runway 29 approach in database, but it is based upon ILS fixes associated with ILS runway 4R (parallel runway). The approach was thoroughly briefed, along with the fact that both the ILS runway 4L and the RNAV approachs could not be displayed on the FMS at the same time (different fix identifiers and underlying approachs). Both right and left DME's were tuned to the ILS DME for step-down fix identify. 'PNF' displayed approach with ILS idented, PF was in map mode, and ILS displayed on both ADI's. Approach cleared aircraft to maintain 3000 ft until established, cleared for approach. Turn onto final was late, resulting in some overshoot, although the autoplt captured with 40 degree correction. PF switched to approach to verify establishment on localizer for situational awareness. PF switched back to navigation, to display balance of approach. Step-down altitude was selected awaiting step-down DME fix. In switching back to navigation, DME reverted from remote to manual then back to automatic-tuning (unannunciated). Crossing DME fix, now tuned to the wrong DME, step-down was commenced. Aircraft descended approximately 300 ft before 'PNF' detected error and ATC queried altitude. Aircraft returned to correct altitude, and finished approach without further event.

Original NASA ASRS Text

Title: B757-200 CREW HAD AN ALTDEV, AFTER USING AN RNAV APCH TO RWY 29 AT EWR. THE CREW WAS CLRED FOR THE ILS RWY 4L APCH, CIRCLE TO LAND RWY 29.

Narrative: ALTDEV ON APCH. CLRED FOR APCH, ILS RWY 4L, CIRCLE TO LAND RWY 29. FMS HAS RNAV FROM S CIRCLE RWY 29 APCH IN DATABASE, BUT IT IS BASED UPON ILS FIXES ASSOCIATED WITH ILS RWY 4R (PARALLEL RWY). THE APCH WAS THOROUGHLY BRIEFED, ALONG WITH THE FACT THAT BOTH THE ILS RWY 4L AND THE RNAV APCHS COULD NOT BE DISPLAYED ON THE FMS AT THE SAME TIME (DIFFERENT FIX IDENTIFIERS AND UNDERLYING APCHS). BOTH R AND L DME'S WERE TUNED TO THE ILS DME FOR STEP-DOWN FIX IDENT. 'PNF' DISPLAYED APCH WITH ILS IDENTED, PF WAS IN MAP MODE, AND ILS DISPLAYED ON BOTH ADI'S. APCH CLRED ACFT TO MAINTAIN 3000 FT UNTIL ESTABLISHED, CLRED FOR APCH. TURN ONTO FINAL WAS LATE, RESULTING IN SOME OVERSHOOT, ALTHOUGH THE AUTOPLT CAPTURED WITH 40 DEG CORRECTION. PF SWITCHED TO APCH TO VERIFY ESTABLISHMENT ON LOC FOR SITUATIONAL AWARENESS. PF SWITCHED BACK TO NAV, TO DISPLAY BAL OF APCH. STEP-DOWN ALT WAS SELECTED AWAITING STEP-DOWN DME FIX. IN SWITCHING BACK TO NAV, DME REVERTED FROM REMOTE TO MANUAL THEN BACK TO AUTO-TUNING (UNANNUNCIATED). XING DME FIX, NOW TUNED TO THE WRONG DME, STEP-DOWN WAS COMMENCED. ACFT DSNDED APPROX 300 FT BEFORE 'PNF' DETECTED ERROR AND ATC QUERIED ALT. ACFT RETURNED TO CORRECT ALT, AND FINISHED APCH WITHOUT FURTHER EVENT.

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.

B757-200 crew had an altitude deviation, after using an RNAV approach to runway 29 at ewr. The crew was cleared for the ILS runway 4L approach, circle to land runway 29.