B767 flight crew reported they received a GPWS terrain alert on approach into skbo when the aircraft...

Narrative:

Aircraft level at 12;000 feet cleared for ILS 13L at skbo close proximity to bog VOR. Weather was clear with 30 miles plus visibility with visual contact with terrain at all times. We were configured flaps 15. Pilot flying (PF) armed approach to follow glideslope (GS) down. Autopilot was on. Next altitude on approach allows you to descend to 10;000 feet. Wind was very gusty at this phase of flight with light turbulence. Speed brake deployed to control airspeed for flap configuration. Aircraft pitched down after flight director bars. PF arrested pitch down but heard one short caution terrain audible warning. My head was down trying to tune left VHF radio to tower frequency. Looked up and out to see aircraft well clear of any terrain. Retracted speed brake after confirming airspeed under control. The glide path was now above us and reintercepted at approx. 11;300 feet lowest altitude noted was around 10;700 feet within approach criteria. Normal landing without any over speeds. No comments from bogota approach control or tower. I would never rely on this NAVAID to bring me down in the weather. Actual glideslope should be close to the 12;000-foot crossing at bog VOR. The feather starts at 10;000 further in the approach. Could have been interference on the ground.

Original NASA ASRS Text

Title: B767 flight crew reported they received a GPWS terrain alert on approach into SKBO when the aircraft nosed over in thermals.

Narrative: Aircraft level at 12;000 feet cleared for ILS 13L at SKBO close proximity to BOG VOR. Weather was clear with 30 miles plus visibility with visual contact with terrain at all times. We were configured flaps 15. Pilot Flying (PF) armed approach to follow Glideslope (GS) down. Autopilot was on. Next altitude on approach allows you to descend to 10;000 feet. Wind was very gusty at this phase of flight with light turbulence. Speed brake deployed to control airspeed for flap configuration. Aircraft pitched down after flight director bars. PF arrested pitch down but heard one short caution terrain audible warning. My head was down trying to tune left VHF radio to tower frequency. Looked up and out to see aircraft well clear of any terrain. Retracted speed brake after confirming airspeed under control. The glide path was now above us and reintercepted at approx. 11;300 feet lowest altitude noted was around 10;700 feet within approach criteria. Normal landing without any over speeds. No comments from Bogota approach control or tower. I would never rely on this NAVAID to bring me down in the weather. Actual glideslope should be close to the 12;000-foot crossing at BOG VOR. The feather starts at 10;000 further in the approach. Could have been interference on the ground.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1228680
Time
Date	201412
Local Time Of Day	1201-1800
Place
Locale Reference	SKBO.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter Weather / Turbulence

B767 flight crew reported they received a GPWS terrain alert on approach into skbo when the aircraft nosed over in thermals.