A B737 crew received an egpws obstacle warning near the oma runway 14L bufft FAF descending to 2400 ...

Attributes
ACN	816784
Time
Date	200812
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : oma.airport
State Reference	NE
Altitude	msl single value : 2400
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tower : oma.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 14l
Flight Phase	descent : approach
Route In Use	approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 250 flight time type : 10000
ASRS Report	816784
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 163 flight time type : 14000
ASRS Report	816774
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : executed go around
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We were vectored onto the localizer for ILS runway 14L at oma. We were IMC at the time and I had flaps 5 degrees and was at 180 KTS. We had been cleared to 3;000 ft to intercept the localizer then cleared for the approach. The autopilot was engaged and at localizer capture I armed the approach mode. The captain asked if I wanted to go to 2;400 ft. I agreed and used the vertical speed mode to descend. I had a descent rate of about 500 FPM. We leveled off at 2;400 ft just outside bufft FAF; the GS was coming into view when we got an 'obstacle' warning. We got a second one and I started the go around and climb. I don't recall if we got a third warning; but I do know the 2 warnings came in rapid succession. From the first warning to the start of the go around took no more than a couple of seconds. We leveled off at 3;000 ft. The controller was very nonchalant about our go around and seemed to indicate that he had seen this before with company aircraft. We thought that this might be a software problem. We were vectored again for the ILS runway 14L. This time I chose to intercept the GS at 3;000 ft. This time the approach was uneventful. Check the database for the obstacles on that approach. Callback conversation with reporter revealed the following information: the reporter determined that the 1352 ft tower near bufft was the obstacle seen by the egpws. The aircraft's rate of descent; while not unusual; was just enough to trigger the obstacle warning.

Original NASA ASRS Text

Title: A B737 crew received an EGPWS Obstacle warning near the OMA Runway 14L BUFFT FAF descending to 2400 ft at 600 fpm. A go around was completed followed by an uneventful approach.

Narrative: We were vectored onto the LOC for ILS Runway 14L at OMA. We were IMC at the time and I had Flaps 5 degrees and was at 180 KTS. We had been cleared to 3;000 FT to intercept the LOC then cleared for the approach. The autopilot was engaged and at LOC capture I armed the Approach Mode. The Captain asked if I wanted to go to 2;400 FT. I agreed and used the vertical speed mode to descend. I had a descent rate of about 500 FPM. We leveled off at 2;400 FT just outside BUFFT FAF; the GS was coming into view when we got an 'obstacle' warning. We got a second one and I started the go around and climb. I don't recall if we got a third warning; but I do know the 2 warnings came in rapid succession. From the first warning to the start of the go around took no more than a couple of seconds. We leveled off at 3;000 FT. The Controller was very nonchalant about our go around and seemed to indicate that he had seen this before with company aircraft. We thought that this might be a software problem. We were vectored again for the ILS Runway 14L. This time I chose to intercept the GS at 3;000 FT. This time the approach was uneventful. Check the database for the obstacles on that approach. Callback conversation with Reporter revealed the following information: The reporter determined that the 1352 FT tower near BUFFT was the obstacle seen by the EGPWS. The aircraft's rate of descent; while not unusual; was just enough to trigger the obstacle warning.

Data retrieved from NASA's ASRS site as of May 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.

A B737 crew received an egpws obstacle warning near the oma runway 14L bufft FAF descending to 2400 ft at 600 fpm. A go around was completed followed by an uneventful approach.