Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Distraction; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
General None Reported / Taken
Chart Or Publication; Human Factors; Procedure
I was PF on this leg; first flight in 40 days.  During approach prep for LGA ILS 4; review of briefing strip indicated 'Autopilot Coupled approach not authorized.'  Review of other available approaches with similar 3.1 degree glideslopes and initial approach fixes have no restrictions.  Since weather was rain with low ceilings; the ILS was the approach with the best capability. Trying to hand-fly an ILS in bad weather didn't seem to be a viable option or the safest; and ceilings were low enough to require an ILS approach. I shot the approach with both APs engaged; monitored flight path compliance; and was able to take over visually around 400 feet AGL; landing in the first 1;200 feet of runway.  This breakout point is similar to the DH for the RNAV GPS to Runway 4; which is allowed to be coupled.  After returning home I inquired about why this restriction was listed; and what we are expected to do when bad weather requires approach to LGA Runway 4.  New to aircraft; had not flown in 40 days. Had not been in situation where a published ILS approach could not be used with an autopilot. 1. Provide a precision approach into LGA Runway 4 suitable for low ceiling/bad weather.2. Provide some insight into why the coupled ILS is not as safe as a hand-flown ILS along the exact same flight path.  3. Provide some insight into why the RNAV GPS 4 can be coupled and flies the same flight path.  (If the coupled ILS can only go down to 400-500 AGL; that seems like a more correct limitation than to completely limit AP use for an entire approach.)4. Make this a review item in the company pages and provide some guidance on how best to handle this.5. ATIS should not advertise ILS 4 as the active approach in bad weather when the approach is not authorized to be coupled. Should advertise 'ILS and RNAV Runway 4.'
Air carrier First Officer reported concerns with the LGA ILS 4 approach identified as 'Autopilot Coupled approach not authorized.'