B737-500 descended well below glide path on visual approach. Deviation recognized at 1000 ft; when t...

Attributes
ACN	748880
Time
Date	200708
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : bos.airport
State Reference	MA
Altitude	msl single value : 1000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : bos.tower tower : gfk.tower
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 180 flight time total : 14000 flight time type : 9000
ASRS Report	748880
Person 2
Affiliation	government : faa
Function	controller : local
Events
Anomaly	other anomaly other spatial deviation
Independent Detector	other flight crewa other other : 2
Resolutory Action	controller : issued alert flight crew : became reoriented
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

On approach to bos runway 27; ATC (approach control) turned us on a 90 degree base that would have put us on 10+ mi final. Then approach control turned us (almost) directly to the FAF and cleared us for a visual approach. The captain was probably high/fast and deployed full speed brakes. While looking outside and switching from approach to tower; the captain descended the airplane well below the FAF altitude of 1700 ft. At 1000 ft I noticed the PAPI's were all red and looked down and saw the altimeter of 1000 ft. After checking in with tower; tower made the statement; 'air carrier X; I got an altitude alert. You ok?' I replied 'we are ok.' the captain leveled the airplane off at 1000 ft and captured the GS/PAPI from there. This (of course) is out over the water; very little (if any) ground reference in the approach area. I do not know what altitude was set in the altitude window and I do not have if it alerted us to any altitude. Upon clearance for a visual approach and turned toward the FAF; the captain or I should have set 1700 ft in the altitude alert window and targeted that altitude as the MDA until established on the glide path. Descent to 1000 ft at ripit was not acceptable and I feel this mistake in more rugged terrain would be bad. Real bad. As monitoring pilot; I failed to monitor this low altitude situation.

Original NASA ASRS Text

Title: B737-500 DESCENDED WELL BELOW GLIDE PATH ON VISUAL APCH. DEVIATION RECOGNIZED AT 1000 FT; WHEN THE FLT CREW LEVELED TO RECAPTURE NORMAL GLIDE PATH.

Narrative: ON APCH TO BOS RWY 27; ATC (APCH CTL) TURNED US ON A 90 DEG BASE THAT WOULD HAVE PUT US ON 10+ MI FINAL. THEN APCH CTL TURNED US (ALMOST) DIRECTLY TO THE FAF AND CLRED US FOR A VISUAL APCH. THE CAPT WAS PROBABLY HIGH/FAST AND DEPLOYED FULL SPD BRAKES. WHILE LOOKING OUTSIDE AND SWITCHING FROM APCH TO TWR; THE CAPT DSNDED THE AIRPLANE WELL BELOW THE FAF ALT OF 1700 FT. AT 1000 FT I NOTICED THE PAPI'S WERE ALL RED AND LOOKED DOWN AND SAW THE ALTIMETER OF 1000 FT. AFTER CHKING IN WITH TWR; TWR MADE THE STATEMENT; 'ACR X; I GOT AN ALT ALERT. YOU OK?' I REPLIED 'WE ARE OK.' THE CAPT LEVELED THE AIRPLANE OFF AT 1000 FT AND CAPTURED THE GS/PAPI FROM THERE. THIS (OF COURSE) IS OUT OVER THE WATER; VERY LITTLE (IF ANY) GND REF IN THE APCH AREA. I DO NOT KNOW WHAT ALT WAS SET IN THE ALT WINDOW AND I DO NOT HAVE IF IT ALERTED US TO ANY ALT. UPON CLRNC FOR A VISUAL APCH AND TURNED TOWARD THE FAF; THE CAPT OR I SHOULD HAVE SET 1700 FT IN THE ALT ALERT WINDOW AND TARGETED THAT ALT AS THE MDA UNTIL ESTABLISHED ON THE GLIDE PATH. DSCNT TO 1000 FT AT RIPIT WAS NOT ACCEPTABLE AND I FEEL THIS MISTAKE IN MORE RUGGED TERRAIN WOULD BE BAD. REAL BAD. AS MONITORING PLT; I FAILED TO MONITOR THIS LOW ALT SITUATION.

Data retrieved from NASA's ASRS site as of January 2009 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.

B737-500 descended well below glide path on visual approach. Deviation recognized at 1000 ft; when the flight crew leveled to recapture normal glide path.