Date: 201601
Local time of day: 1201-1800
Location: C90.TRACON, IL
Flight conditions: VMC
Light: Dusk
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ORD
ATC / advisory: TRACON C90
Aircraft component: Autoflight System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: Initially I briefed and prepared for an Autoland approach into ORD as the weather was near Cat 1 minimums. The weather was improving as we got closer; so the First Officer and I discussed that we would continue with the Autoland approach just for practice. I was flying with the A Autopilot on. When cleared for the approach; and while intercepting the Localizer; I engaged the B Autopilot. During the approach; the First Officer noticed that while both Autopilots were engaged; only his Flight Director was showing Master.At this point; I clicked off the Autopilots and asked the First Officer to then re-engage them. He turned the Flight Directors off; re-engaged my FD first; then his FD next. Then he re-engaged the APs by selecting the A Autopilot first; but was not able to get the A Autopilot to engage first for some reason. After a second attempt; he was able to engage the A Autopilot after engaging the B Autopilot first. This provided us with two Autopilots; but only the First Officer's Flight Director Master Light was illuminated. We also had both Flight Directors with correct indications; Approach Mode still engaged and all other indications appearing normal.Since the weather had improved to 800 overcast and 2 miles visibility while on the arrival; and we were well outside of the Final Approach Fix; I quickly re-briefed the Cat 1 minimums and requirements and we continued to the FAF. I left both Autopilots on while I configured the aircraft and the First Officer ran the Landing Checklist.Just after passing the FAF; I noticed the 'Self Test' of the Autoland System and the Flare Armed indication. The First Officer and I discussed that the Autoland System passed the 'Self Test' and we had all of the necessary equipment (including both Autopilots; Flight Director bars and Flare Armed indicated) for the Autoland except the Master FD light on my side. At this point and around 1000 feet; we were in visual conditions. I then stated that I had visual conditions and would proceed visually.I continued to let the Autopilots fly the airplane as we again discussed that we believed the Autoland Systems was working for us because the system passed the 'Self Test' and we had no Warnings/Cautions/Alerts/Abnormal annunciations at all. At the expected altitude of around 300-350 feet; the trim began correctly biasing for the flare. Yet again; the First Officer and I confirmed that everything appeared to be working correctly. Though I had been pondering the disconnecting of the Autopilot the whole way down on the approach; I still believed that everything was working for the Autoland; we were in visual conditions and my hands were at the controls to immediately disconnect the Autopilot and Autothrottles if needed as suggested during a visual or Cat 1 Autoland. Just as we passed over the numbers to Runway 27R; the flare engaged; the airplane smoothly touched down and I assumed control by disengaging the Autopilots and Autothrottles.At the gate and just not feeling right about it; we elected to enter a Maintenance Log Item to explain our experience and have the system checked. We also discussed our experience with the outbound crew.Also; the First Officer and I discussed our experience again after we had a chance to decompress and elected to file FSAP Reports as we realized that the most conservative action would have been for me to disconnect the automation and manually land the airplane. Additionally; while we had already discussed and agreed earlier that we would have performed the Go-Around at the FAF if the weather was not continuing to improve and while there was no doubt in my mind that I would have immediately disengaged any and all automation at the first hint of a deviation or drift; I believe after 6 days straight of flying; I was tired and got lulled into complacency; a little 'get-home-itis' and let my guard down on Autoland procedures because of the visual conditions and my past experience in a Fail-Operational Autoland System from another Boeing that has an Autoland Status Annunciator. Again; I believe that the best choice would have been to manually land the airplane and save the systems discussion for after the flight.As an aside; I am still fairly new on the airplane and wish I had a lot more experience with the systems. If there was one additional suggestion or change I could recommend regarding this experience; I would highly advocate more systems education and review classes for this fleet. As some recent Transition Pilots I have spoken with from other Boeing Fleets would agree; I did not feel there was enough time given to operational-type systems training during Transition training and most of the training was quite rushed. While I have many hours of experience in commercial airliners; most of that time was in another Boeing with slightly different procedures and Autoland Systems. In all of my previous fleets; there were always fairly robust and comprehensive systems review videos and handouts that incorporated most of the major systems in an operational and phase-of-flight presentation that supplemented the Flight Manual. Additionally; there were voluntary Systems Review classes every day at the training center. I believe better systems knowledge will help pilots coming from other airplanes to more quickly identify systems or maintenance issues that will expedite the operation and avoid unnecessary delays and incorrect decision making.


Second narrative: After block in; the Captain asked how I thought the issue should be written up. That led us to researching the FM about approach indications and questioning if we should have continued the Autoland without the Captain's Master light illuminated. Since the weather was CAT I and we are allowed to do CAT I Autolands with the understanding that the aircraft may require manual intervention in such situations; I don't doubt the legality of our decision to continue; but I do think that next time; without proper indications; the autoland should be abandoned and a CAT I approach flown using non-Autoland procedures.


Synopsis: B737 flight crew reported executing an autoland even though the Captain's Master light was not illuminated as required.