CHI04LA086

The aircraft was substantially damaged when the nose wheel collapsed as the pilot attempted to taxi back onto the runway after departing the pavement during landing rollout on runway 3. The nose wheel steering was inoperative and had been deferred in accordance with the operator's Minimum Equipment List (MEL). In that situation, the nose wheel was in the "free castor mode." The MEL states that directional control is to be maintained by using brakes and differential power. The pilot reported that the landing touch down was on the centerline, however, shortly afterward the aircraft encountered an "overwhelming" wind gust which caused it to weathervane to the left. He reported that he applied full right rudder and differential right braking which was effective in stopping the aircraft's drift. However, the aircraft encountered a second "much stronger and sustained" gust, which caused the aircraft to "veer strongly to the left." His subsequent efforts to maintain directional control through the use of differential braking and differential engine thrust were insufficient to keep the aircraft from departing the runway pavement. The aircraft came to rest in the soft grass adjacent to the runway. The pilot attempted to taxi back onto the runway, however, the nose wheel contacted the edge of the pavement and collapsed. Distinct ruts were observed in the soft turf adjacent to the left side of the runway. The nose wheel tire track approached the edge of the pavement at approximately a 20-degree angle and terminated at the edge of the runway. The track was approximately eight inches deep relative to the level of the runway pavement. The published maximum demonstrated crosswind component for the aircraft was 22 knots. The operator did not impose a crosswind component limitation on operations in general or on operations with the nose wheel steering inoperative under the MEL. Surface winds provided to the flight crew by the control tower were 310 degrees at 23 knots, gusting to 30 knots.

On March 15, 2004, at 1715 central standard time, a Beech 1900D, N155ZV, operated by Air Midwest Airlines and piloted by an airline transport pilot, was substantially damaged when the nose gear collapsed after landing on runway 3 (7,000 feet by 150 feet, concrete) at the Manhattan Regional Airport (MHK), Manhattan, Kansas. The flight was operating under 14 CFR Part 121 as US Airways Express flight 5208 and was on an Instrument Flight Rules (IFR) flight plan. Visual meteorological conditions prevailed at the time of the accident. The two pilots and three passengers reported no injuries. The flight departed the Salina Municipal Airport (SLN), Salina, Kansas, at 1645.

The captain reported that the flight was initially dispatched that day with the nose wheel steering inoperative in accordance with the operator's Minimum Equipment List (MEL). He noted that he had flown three previous legs that day in the accident aircraft. Approximately one hour earlier he had landed at MHK in "very similar winds," according to the captain.

The captain stated that during the landing roll the aircraft encountered a wind gust, which was "overwhelming and caused the aircraft to weathervane to the left." He noted that the aircraft began to drift to the left and his application of full right rudder had almost no effect. He reported that he applied right differential braking, which was successful in stopping the aircraft's drift, but was not enough to bring the aircraft back to the runway centerline.

According to the captain, the aircraft encountered a second "much stronger and sustained" gust, which caused the aircraft to "veer strongly to the left." He reported that he attempted to maintain directional control by using differential braking and differential power. However, these efforts were not successful. The aircraft departed the left side of the runway and rolled to a stop "as if it were on top of grass over firm dirt." The captain noted that the aircraft did not appear to "sink in" as it stopped.

The captain stated that the aircraft seemed to be undamaged and that all instrument indications were normal. He applied power in an attempt to taxi back onto the runway. However, when the nose wheel contacted the edge of the pavement it collapsed.

A witness to the accident reported that he saw the aircraft come to a complete stop in the grass off the left side of runway 3. He noted that it was stopped about 20 seconds when he heard "considerable" power applied to the engines and the aircraft began to move forward. He stated that a few seconds later the nose gear collapsed and the aircraft's nose impacted the pavement. At the same time, the left propeller blades "disintegrated."

Distinct ruts were observed in the soft turf adjacent to the left side of the runway. A single track consistent with the left main landing gear departing the pavement began about 3,500 feet from the threshold. It then paralleled the runway edge for about 300 feet. The track then turned further left, away from the runway centerline.

From this point, three parallel tracks were observed which progressed in a straight line to a position about 4,100 feet from the runway threshold. The tracks then continued in an arc to the right consistent with a right turn. The tracks ended at the accident site adjacent to the runway pavement. The nose wheel tire track approached the edge of the pavement at approximately a 20-degree angle and terminated at the edge of the runway. The track was approximately eight inches deep relative to the level of the runway pavement.

Winds recorded at MHK were as follows: At 1637, 310 degrees at 12 knots, gusting to 24 knots; and at 1734, 310 degrees at 16 knots, gusting to 25 knots. According to the recorded communications between the aircraft and MHK tower, the crew was advised that winds were from 310 degrees at 23 knots, gusting to 30 knots, during approach for landing.

The discrepancy log for the accident aircraft contained an entry which stated: "Nose wheel steering disconnect actuator appears inop." The corrective action listed in the log stated: "Complied with M.E.L. procedures per M.E.L. 32-5." According to the contract maintenance company, which performed the work, the MEL number was incorrectly noted in the log. The correct MEL was 32-4 and this was the procedure performed.

The Air Midwest MEL required that maintenance personnel verify that the actuator is in the extended position and to disconnect the cannon plug controlling the unit. The MEL also stated: "Nose wheel will be in the free castor mode. Maintain directional control using brakes and differential power."

According to the operator, the published maximum demonstrated crosswind component for the 1900D is 22 knots. The operator did not impose a crosswind component limitation for general operations, nor did it impose a crosswind limitation for operation with the nose wheel steering inoperative under the MEL.

The operator stated that they do not provide training specific to the 1900D for operations with the nose wheel steering inoperative.