Air carrier Captain reported that his aircraft does not fly the VOR/DME approach to Runway 23R at EGCC in the managed mode as published. Instead the aircraft makes a slight jog to the right at the 4 DME point and flies an offset course to the end of the runway.

Narrative

This report is written to draw attention to an incorrectly designed managed VOR\DME approach to Runway 23R at EGCC. The coded approach in the database does not correspond correctly to the approach plate. The coded approach does not use the MCT VOR 049 radial for the final approach course. Instead it uses the EGCC23R 049 radial; a point drawn from the end of the runway offset 5 degrees from runway centerline. This difference from the actual approach plate causes the aircraft to turn right slightly at the final approach fix to intercept a course to the runway; not the VOR. This maneuver is perplexing to pilots during a critical phase and does not make sense. The aircraft never overflies the runway at the missed approach point and in fact diverges from MCT 229 final approach course during the final approach segment. The MCT VOR is positioned slightly left of runway centerline. When the approach is properly flown to the published missed approach point MCT 049R/0.3 DME; the aircraft will be lined up with runway centerline. However; when flying the managed approach; the aircraft flies along a radial that does not correspond to the published radial; and crosses a missed approach point 0.3 nautical miles north of the published map. This error must be corrected by using MCT as the final point in the FMS coding rather than the runway. Using EGCC23R as the final point on the managed approach causes the aircraft to not intercept runway centerline at the map. Please note that other offset VOR approaches do use the VOR as the final point on the approach rather than the runway. Examine the EGPF VOR05; for example.