Large Transport; Low Wing; 2 Turbojet Eng
Confusion; Distraction; Training / Qualification; Workload
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Unstabilized Approach
Flight Crew Became Reoriented; Flight Crew Executed Go Around / Missed Approach
Airport; Environment - Non Weather Related; Human Factors; Procedure
ILS 22R circle to land 29 at EWR. Began circle to land procedure just inside FAF on ILS 22R at approximately 1;200 FT. Runway 29 was clearly visible in front of us as we began the turn to downwind. Runway 29 had been preprogrammed into FMCS RT2 with 5 NM Runway extension. RT2 was activated and the 5 NM point extended upon initiation of the downwind turn. Shortly after completing the downwind turn (approximately 110 heading); ATC directed us to start the base turn. The base turn -as directed - was well inside the 5 NM point depicted on the map view. Though the runway was discernible when we initiated the downwind turn; it proved increasingly difficult to keep visual contact once we began our turn to base (Runway 29 was lost in a sea of surrounding city lights). To further compound the problem; we had insidiously initiated a descent away from the circling altitude as we turned back to intercept final. We were on a dogleg heading; right of the extended centerline when the GPWS - TOO LOW OBSTACLE warning was heard at approximately 500 FT; we initiated a climb; reported the go-around and ultimately leveled at 5;000 FT per ATC instruction. We flew an uneventful subsequent approach to Runway 22R.
An Air Carrier on an EWR ILS 22R Circle to Land 29; lost the Runway 29 runway lights in the city background lights; descended too early and executed a go around after an EGPWS TOO LOW OBSTACLE warning.