Embraer Jet Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Confusion; Distraction
Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Airport; ATC Equipment / Nav Facility / Buildings; Weather
I am filing this report report as a method of feedback; because after we landed I was bothered as to whether or not I did the right thing.  The approach chart for the ILS 5 at ORF has a note saying that 'autopilot coupled approaches are not auth. below 744 ft.' After briefing the approach I decided to disconnect the autopilot at 744 ft msl.  At almost exactly that point on the approach; the glide slope indication became slightly unstable; the glideslope needle started indicating low scale momentarily; and then returning to center.  Because of the note on the approach chart I would say that I was mentally prepared for some kind of variation; at no time did it indicate a full scale deviation; nor did the approach become unstable.  We 'broke out' right at min's and landed safely; but after parking the aircraft; and going to the hotel I felt that the Glideslope indication was out of the ordinary and I should report it.  At no time did I feel like I should go around the glideslope needle variation never reached full scale nor did the approach become unstable. I think that whatever is the cause of the note on the approach chart about autopilot coupled approaches not being auth; below 744 [ft] msl needs to be identified and fixed.
An Air Carrier Captain noted an ORF Runway 5 glideslope deflection near 700 ft at about the point which the ILS 5 approach chart advised 'autopilot coupled approaches are not auth. below 744 ft.'