MD-11
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 90; Flight Crew Type 1000
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Company Policy
Taxiing out on Aircraft X [I] noted to Captain I felt some vibration in [the] yoke during the elevator check. Because of a similar instance on Aircraft Y (where the aircraft was removed from service) I had seen this anomaly. In sequence; awaiting takeoff and stopped; he ran the elevator and found it to be normal. We assumed it was our light weight or a nose wheel shimmy that led to the vibration. Flew a manual departure until about 17;000 feet when AP (Auto Pilot) 2 was engaged. Turning final into ZZZ; outside the marker I turned the AP off; tried to roll out of the turn manually and noticed controls were very heavy/almost unresponsive. Turning in opposite direction the controls were equally heavy. Force required to turn was about three to four times heavier than normal. It felt as though the AP was still engaged or we were flying in manual reversion. Verified AP was off. Asked Captain to try it and he agreed; noting a slight roll to right requiring left aileron to remain wings level and that the elevator was also very heavy. Captain elected to do the landing; used power to help control rate of descent and some rudder to augment roll (rudder was fine). AP Single Land and No-Autoland alerts observed 2 miles out. Captain elected to disregard these level one alerts and focus on flying the airplane. Asked me to back him up on controls. Discussed how we would perform a go-around and use the AP if necessary for a go-around if control became unmanageable. Glide slope was intermittent due to other Aircraft on either side of the antenna on the ground (so use of AP was inappropriate for this landing). Small inputs by Captain were difficult; but deliberate and perfect. Landing was within normal parameters. We agreed to leave aircraft configured as it was to the blocks. Maintenance met us and ran the controls on RMP's. Thankfully; the problem persisted so they were able to witness the same difficulty moving the yoke. In the half hour we spent writing this up; I overheard the Maintenance Supervisor leaning towards swapping the FCC's (Flight Control Computers) as a fix. Thankfully; the line mechanics insisted AP was red for at least 12 hours and pushed to dig further into it. They eventually found a faulty actuator in the right wing. This is as much as I know about the current situation on Aircraft X. Thankfully; the weather was VFR; with 8 kts down the runway. Gusty winds or high crosswinds would have made it extremely difficult (if not impossible) to land this airplane safely. Submitting this [report] due to the grave nature of this flight control malfunction; which could have resulted in a hull loss or fatalities under other circumstances.Explanation of recommendations: This same anomaly has occurred at least three times in the past six months at our company after disconnecting the AP on approach: the previous flight of Aircraft X two days earlier; our flight on this same Aircraft X; and on Aircraft Z a few months ago. There was also an incident last winter on Aircraft A in ZZZ1; which nearly resulted in the loss of the airplane due to the crew's inability to control excessive up/down pitch forces. Aircraft Y was removed from service for strong vibrations that shook the entire airplane during the elevator check (my flight). Two recommendations/notifications have been generated over the past 6 months regarding these events. These notifications emphasized the use of the Jammed or Restricted Flight Control Checklist in the AOM. Unfortunately; these notifications appear to be more legal posturing rather than a serious; proactive effort to address what seems to be a systemic problem. Despite these (known) incidents; I have been told by company management and safety representatives that a fleet-wide inspection is unwarranted/unnecessary. If this is true and recommendations/notifications are favorable to an in-depth inspection of all company MD11's prior to heavy checks; I suggest the following procedures be implemented immediately.Recommend Control Check be performed at flap extension; prior to aircraft movement. As a considerably 'long' airplane; any anomalies in the flight control check would be/are difficult to detect during taxi; due to bouncing of aircraft on taxi. If a manual landing is planned; recommend disconnection of AP above 3;000 feet AGL; prior to approach; and re-engagement later; if desired. While a briefing on the use of automation is already required by FOM; this would allow crews the time (and altitude) to discover controllability problems prior to being committed to land or to doing an unwanted go-around with limited/partial control. Part of our decision to continue was not wanting to be 25 degrees nose high; light-weight at full power; with limited lateral/longitudinal control.Aircraft X had been written up two days earlier for the same malfunction. In this case; the previous crew wrote that the ailerons 'were stiff and unresponsive' and elected to do an Auto-Land instead of a manual landing. Having flown the MD11 for several years I can tell you that doing an auto-land with a single AP (because manual controls aren't working) is a last resort. Recommend mandatory review of aircraft history for flight control issues as a first course of action prior to troubleshooting. In our case; this did not happen and Maintenance began troubleshooting prior to reviewing the history.Recommend the FDR/CFDS (Flight Data Recorder/Centralized Fault And Display System) and all other available reporting systems be reviewed on our flight to determine the position of the AP clutches; control wheel deflections; control wheel forces; control surface positions; etc.; to rule out partial AP engagement after AP disengagement.
While turning final for Runway XXR at ZZZ the FO (First Officer); PF (Pilot Flying) disconnected the AP (autopilot). The aircraft was configured gear down and flaps 35. The FO verbalized to me that the flight controls seemed extremely heavy (as if the AP were still engaged). We verified the AP had disconnected. We positively transferred control of the aircraft to the Captain. I immediately noticed a very heavy feel to both the elevator and aileron controls. It felt similar to flying a B727 in Manual Reversion. The aircraft also had a slight rolling tendency to the right; which necessitated a left aileron control input to maintain heading. A slight push on the rudder pedals found the rudder operating normally. We checked for alerts and warnings. Nothing was displayed at this time. We quickly discussed requesting priority handling and possible go-around; but I felt due to our proximity to the runway; continuing for a landing with the FO backing me up on the controls was most prudent.Both crewmembers were aware of the QRH Non Alert; Controls Jammed or Restricted Checklist; and its reference to engaging the AP. It was about this time we received a Single Land/No auto land Misc. Que message. I chose to manually land the aircraft as I had positive control. Had we gone around we had already discussed engaging the AP; this was from our working knowledge of the Jammed or Restricted Checklist. The Que alerts were our first visual indication of a possible FCC (Flight Control Computer) failure. The landing and rollout were normal for conditions. We chose to leave the aircraft configured for landing with the flaps extended to give maintenance the opportunity to inspect the aircraft and this was relayed through ZZZ Operations to the mechanics. The mechanics joined us in the cockpit and with the Aux Hydraulics pumps operating they were able to experience the same difficulties we had encountered in-flight. We stayed with the mechanics to answer all questions and spent about a half an hour preparing the write up in the logbook.As I have had time to reflect on this event some facts have become crystal clear. As the MD11 has become 'long in the tooth' having seasoned well-trained crews in the cockpit is imperative. Having just finished 6 month training I had just discussed; face to face with other crew-members events similar to this one. Distance based learning would not have helped. We had just discussed; in detail; the Non alert Jammed or Restricted procedures. I was very fortunate to have an experienced FO who is extremely professional and knowledgeable; an excellent aviator he injected great insight and ideas throughout the entire event. As with any event more questions arise. Are the controls jammed; restricted or are they binding? Are these problems truly an FCC issue? What about the increased occurrence across the fleet type? Will this checklist work or not for an FCC issue caused by binding? Lastly; we all are aware of the FCC's control of the control actuators electrically with the AP on; but a blanket statement to engage the AP if you are manually controlling the aircraft in the checklist may come to bite a less experienced crew.
MD-11 flight crew reported heavy/unresponsive flight controls during approach to landing. Flight crew stated this is a recurring issue on the MD-11 aircraft fleet.