Flight crew descends below GS altitude on ILS approach.

Attributes
ACN	281861
Time
Date	199408
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : tgl
State Reference	FO
Altitude	msl bound lower : 2000 msl bound upper : 3000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : edbt
Operator	common carrier : air carrier
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 196 flight time total : 6500 flight time type : 3330
ASRS Report	281861
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical altitude deviation : overshoot non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Approximately 30 NM out on arrival to edbt after ocean crossing and intermediate stop at hamburg (eddh). We were cleared from FL70 to 3000 ft and cleared for the approach. The ILS had been idented by the pilot in relief seat, all checks had been completed down to 'landing.' captain flying began an aggressive descent, as he had gotten down early for arrival into eddh, and I was initially distracted by call for flaps 5 degrees while we were above flap speed. He then called for gear to slow us but kept descent rate. At about 4000 ft I saw that the GS had captured on the ILS flight director. On arrival, earlier, to hamburg we were instructed to follow GS down even though we hadn't captured the localizer and I think that was part of the mindset. The first officer then called going through 2700 ft and I as PNF concerned that we were through the altitude and that we were 17 NM from normal 3000 ft GS intercept point. I recycled the flight director and re- engaged the approach command and it captured GS (falsely) again, although it did blink several times. Approach control called us about our altitude which now was 2200 ft. Thereafter, we descended to 2000 ft then climbed to 3000 ft and reintercepted the localizer and GS. All else was normal thereafter.

Original NASA ASRS Text

Title: FLC DSNDS BELOW GS ALT ON ILS APCH.

Narrative: APPROX 30 NM OUT ON ARR TO EDBT AFTER OCEAN XING AND INTERMEDIATE STOP AT HAMBURG (EDDH). WE WERE CLRED FROM FL70 TO 3000 FT AND CLRED FOR THE APCH. THE ILS HAD BEEN IDENTED BY THE PLT IN RELIEF SEAT, ALL CHKS HAD BEEN COMPLETED DOWN TO 'LNDG.' CAPT FLYING BEGAN AN AGGRESSIVE DSCNT, AS HE HAD GOTTEN DOWN EARLY FOR ARR INTO EDDH, AND I WAS INITIALLY DISTRACTED BY CALL FOR FLAPS 5 DEGS WHILE WE WERE ABOVE FLAP SPD. HE THEN CALLED FOR GEAR TO SLOW US BUT KEPT DSCNT RATE. AT ABOUT 4000 FT I SAW THAT THE GS HAD CAPTURED ON THE ILS FLT DIRECTOR. ON ARR, EARLIER, TO HAMBURG WE WERE INSTRUCTED TO FOLLOW GS DOWN EVEN THOUGH WE HADN'T CAPTURED THE LOC AND I THINK THAT WAS PART OF THE MINDSET. THE FO THEN CALLED GOING THROUGH 2700 FT AND I AS PNF CONCERNED THAT WE WERE THROUGH THE ALT AND THAT WE WERE 17 NM FROM NORMAL 3000 FT GS INTERCEPT POINT. I RECYCLED THE FLT DIRECTOR AND RE- ENGAGED THE APCH COMMAND AND IT CAPTURED GS (FALSELY) AGAIN, ALTHOUGH IT DID BLINK SEVERAL TIMES. APCH CTL CALLED US ABOUT OUR ALT WHICH NOW WAS 2200 FT. THEREAFTER, WE DSNDED TO 2000 FT THEN CLBED TO 3000 FT AND REINTERCEPTED THE LOC AND GS. ALL ELSE WAS NORMAL THEREAFTER.

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.