Date: 201410
Local time of day: 1801-2400
Location: LGA.Airport, NY
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B LGA
ATC / advisory: TRACON N90
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Fatigue; Training / Qualification
Second reporter function: Captain; Pilot Flying
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Procedure; Airport
Primary problem: Ambiguous

Narrative: Due to delays [we] agreed to a duty day extension. CA was flying. Got hit by static or lightening on descent into LGA.  Told to expect VOR RWY 4 which we briefed and set up for. A short while later told RWY 4 was closing (we could blame port authority if we didn't like said the controller) and to expect ILS 22 circle to 13. Barely had enough time to set up and brief this as we were almost on top of the airport. WX was 1900 BKN and good vis although we were IMC at 3000 which made us wonder if it really was 1900 BKN. There was discussion of DA. Chart said 780 but our mins are 1000 so not totally sure what to set but assumed we'd see the runway well above that anyhow. Got RWY insight around 1800 or so. Descended to 600 or so before starting to maneuver. The CA asked for help keeping oriented and I did the best I could but was difficult as I was looking cross cockpit out his window. I did say to not go any lower until we turned final and he concurred. I also said to keep turning as it looked like we were close but I might have messed him up as we weren't quite as close as I thought. We overshot final a little and came out a little high. Got a bank angle and sink rate warning but frankly it didn't look that bad and we did [land] in touchdown zone. Unfortunately I can't remember the exact parameters but it might have been a little unstable.I know you think us professional pilots should be able to do any maneuver in any kind of weather at anytime. It's just not the case. We hardly ever circle; let alone at night in marginal VMC to a short runway. The circle wouldn't have been necessary in the first place if operational reality governed operations in NYC approach airspace rather the Port Authority demands. Fatigue is also a factor. The company shouldn't auto assume these duty extensions. Everyone was go go go. It's hard to be the lone wolf and say no.


Second narrative: We were at our crew duty limit without an extension. The flight plan and weather made it possible for us to continue with an extension. The FO and I discussed the extension and we accepted the extension since both of us felt fine. The flight was uneventful until the approach into LGA. We set up and brief the approach to VOR 4 approach. As we got closer to LGA; the port authority closed runway 4. We were now flying the ILS 22; circle to land 13. We had the weather for the approach and circle. We briefed the approach and the way we were going to circle to 13. We configured the airplane and was on speed and altitude then we started to circle. I had 13 in sight and I started to descend to align myself for proper glide path and proper alignment for 13. The FO told me to watch my altitude (low) during the first part of the circle. On the last part of the turn I over banked a little; but corrected the bank angle quickly to align the aircraft to the runway. We were still a little high and I corrected the descent rate. We were on airspeed; but descent was near 1;000 feet. We landed within the touchdown zone and taxi to the gate. At the hotel I realized that we set the wrong MDA. The MDA should of been higher.We were rushed into the circle to land approach and should of asked for extended vectors or holding to properly brief the approach. I should of review not only the entire approach plate but add Vol. 1 to review circling approaches and minimums for a circle. Port Authority should not overrule safety in aviation. They put aircraft in a higher risk level. While flying the approach; two aircraft went around. We were at the limits of a stabilized approach and would of gone around if the FO directed a go around and attempted the approach again. We were in our extension duty day when this event happen; I will not extend our duty day again without examining every piece of information that's available to me.


Synopsis: B737-800 flight crew extends their duty day at the company's request to fly a leg to LGA. Expecting the VOR RWY 4 and briefing same; ATC issues a clearance for the ILS RWY 22 circle to land Runway 13. The approach is accomplished successfully although the approach may have been unstabilized and the minimums used were not to company standards.