NYC03IA042

The flight was at cruise altitude when the flight crew discovered that they were unable to move the control wheel for lateral (aileron) control. The rudder and elevator flight controls remained free for movement. As the flight neared its destination, the crew tried to extend with wing flaps. The leading edge slats extended, but they were unable to extend the trailing edge wing flaps. The flight landed in that condition. Post flight examination of the airplane revealed ice accumulations in all three wheel wells. The ice had accumulated on the aileron control cables, and flap extension cables, and prevented cable movement. The ice was traced to a water leak in the potable water system where a rubber hose attached to a water line fitting, under the floorboard, near the 3R door. When the floorboard in the area was lifted, upward movement of the floorboard was restricted by the rubber hose water line that was attached to the underside of the floor board. Water was observed misting from the line where it attached to the fitting. When the floorboard was lifted further, the water line pulled loose from the fitting, and water flowed out. Examination of the rubber water hose revealed it failure was due to excessive load applied to the crimped joint between the flexible hose and it end fitting. The airplane manufacturer had attached water lines to the underside of the floorboards. The airplane maintenance manuals did not contain any information about how to know if a water line was connected to the underside of a floorboard, or for disconnecting water lines attached to the underside of the floorboards prior to lifting them. There was no jammed flight control checklist in effect at the time of the incident. QAR data revealed the pilots had limited movement with the of the ailerons with the auto-pilot engaged or disengaged through roll control wheel steering (RCWS), a customer selected option for the airplane.

History of flight

On January 14, 2003, at 1407 eastern standard time, a McDonnell Douglas MD-11-C, Italian registration I-DUPA, operated by Alitalia Airlines as flight 604, was reported to have landed with no lateral roll control at John F. Kennedy International Airport (JFK), Jamaica, New York. There were no injuries to the 3 Italian certificated pilots, 8 flight attendants, or 131 passengers. Visual meteorological conditions prevailed. Flight 604 was conducted on an instrument flight rules (IFR) flight plan under 14 CFR Part 129.

The flight departed from Milano, Italy at 0446. There were no reported problems with the departure or initial en route phases of the flight.

According to a written statement from the captain, and a follow-up telephone interview, the flight was about 70 to 80 nautical miles east northeast of JFK, at FL 380 (38,000 feet), when he first noticed a problem. He had received a radar vector and attempted to use the auto-pilot to make the heading change. When the turn command was applied, the autopilot performed an uncommanded disconnect. The captain then elected to hand fly the airplane and observed that the control wheel would not move in the lateral or roll axis (ailerons) of the airplane. However, the control wheel was free to move in the longitudinal axis (elevator), and the rudder pedals were free to move about the yaw axis. The captain declared an emergency and requested a long approach to runway 31L at JFK.

In preparation for landing, the flight crew extended the leading edge wing slats without incident. As the flap handle was positioned to extend trailing edge wing flaps, a warning light illuminated which indicated a difference between the selected flap position and the actual flap position. The flight crew elected to continue with a no-flap approach to runway 31L. The wind was aligned with the runway, and the pilot landed without further incident. After landing, the airplane taxied to the gate where the passengers deplaned through the jetway.

The incident occurred during the hours of daylight at 40 degrees, 38 minutes, 23 seconds north latitude, and 73 degrees, 46 minutes, 44 seconds west longitude.

Personnel information

The flight crew was certified in accordance with the Italian government.

Aircraft information

The airplane was a combi configuration, with passengers in the front, and cargo in the aft portion of the cabin.

Potable Water System

The potable water system on the airplane consisted of 4-63 gallon tanks, with 2 mounted on each side of the airplane. The number-1 system was on the left side of the airplane and number-2 system was on the right side of the airplane. The water tanks were tied together by a common manifold, and were pressurized to 40 psi with bleed air. The water tanks were located under the main cabin floorboards, adjacent to the L1 and R1 doors. The water was used at the flight attendant stations and lavatories.

The distribution plumbing for the potable water was routed below the passenger cabin floor along the length of the cabin. A water leak was traced to a failed hose in the vicinity of the 3R door. The failed hose was secured at its terminating end to the underside of the floorboard. Other water lines terminated similarly.

Floorboards

The main cabin floor was covered by removable floorboards. Floorboards that had water lines attached to their underside were identified by a silver colored cover plate about 5 inches in diameter, taped over 4-inch access holes. Removal of the cover plate allowed maintenance personnel to check what was immediately below the floorboard, and to disconnect any water lines or other items that may be attached to the underside of the floorboards.

Maintenance Manuals

Removal and installation of floorboards was covered in the MD-11 Aircraft Maintenance Manual (AMM), Section 53-21-04, Pages 401 through 407. The last revision was dated July 1, 2002. Although procedures for removal and installation of the floorboards was described, there was no information to alert maintenance personnel to look for the silver colored plates, and remove them to disconnect the underneath water lines prior to the removal of the floorboards.

Flight recorders

The airplane was equipped with a quick access recorder (QAR), which was similar to a flight data recorder; however, it contained more information and was not crash protected. The information contained in the QAR was used in place of the flight data recorder. Examination of the data revealed that during the approach with the auto-pilot connected, aileron movement was visible on all four ailerons. The auto-pilot was disconnected at about 120 feet, and movement was observed on all ailerons through touchdown.

Airplane examination

Post-flight examination of the airplane revealed ice had encased multiple control cables in the wheel well area, including both aileron and flap control cables.

Maintenance support was supplied to Alitalia Airlines by Delta Air Lines (DAL) maintenance personnel at JFK. According to interviews conducted with the DAL mechanics who initially observed the airplane on January 14, ice was observed in all three wheel wells. One mechanic thought the amounts were about equal in each wheel well, and the other mechanic thought there was more ice in the right wheel well. The center landing gear doors were frozen shut with ice. When opened, water was observed running from a control cable exit in the center landing gear well, overhead panel.

On January 15, 2003, two other DAL maintenance personnel worked on the airplane. Interviews disclosed that ice was still visible in all the wheel wells. In the right MLG wheel well, the aileron tension regulator was covered with ice. In the center wheel well, water was observed coming through a control cable hole.

The DAL mechanics identified the source of the water leak, and prepared the floorboards for removal. When the floorboard overlaying the water leak was initially lifted, its upward movement was restrained by the rubber hose that was connected to the underside of the floorboard. Water could be seen misting from where the hose attached to the fitting. The robber hose was not disconnected from the floorboard, and the floorboard was then lifted higher. The rubber hose pulled loose from the fitting and water came out the line with sufficient force to extend for about 6 inches. The water system was then depressurized.

A Boeing Field Service Representative (FSR) reported in part:

"...When I got to the airplane, there were two Delta mechanics already on board the airplane working to find the source of the leak. Seats, carpet and several floor panels from the aisle had already been removed (aft of the RH lavatory at door 3) and the two mechanics were in the process of removing the fasteners to the floor panel just aft of the RH lav. There was a visible flow of water draining out from under the RH floor panel aft of the lav floor panel into the bays underneath the aisle and cable runs. There was also significant pools of water present in several of the bays along the aisle (underneath the cable runs)."

"There were two holes on top of the floor panel (one near the capped water line and the other near the vacuum line), but they were small holes and difficult to view the water line through. Prior to lifting the floor panel, the two mechanics looked underneath the floor panel for a source of the leak. They were confident from the visible water flow, that the leak was coming from somewhere underneath that floor panel."

"The line was not disconnected prior to lifting the floor panel."

"Once the floor panel was lifted, the capped potable water line became fully dislodged. One mechanic covered the end of the line with his hand while the other mechanic went to turn off the water on the airplane to stop the water flow...."

Further examination revealed that a p