N465FLRaytheon Aircraft 400A · 2005

On March 14, 2016, at 1508 eastern standard time, a Raytheon 400A, N465FL, was substantially damaged when it was involved in an accident at Richard B. Russell Regional Airport (RMG), Rome, Georgia. The two pilots sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight.

According to the pilot flying (PF), the flight was uneventful until the landing. While completing the descent checklist, and while passing through 18,000 ft mean sea level (msl), the pilot monitoring (PM) received the 1449 Automated Surface Observing System (ASOS) weather at the destination airport and briefed the PF that the wind was variable at 6 knots, gusting to 17 knots. He also noted that he had selected a visual approach to runway 7. The flight was later cleared for the approach by air traffic control. The PF stated that he then programmed the flight management system for a visual approach to runway 7 with a 3-mile final approach leg before he briefed the reference speed (Vref) as 107 knots and the go-around speed as 129 knots based on the airplane’s weight.

As the airplane approached the airport between about 2,000 and 2,100 ft msl, the crew entered the downwind leg of the airport traffic pattern for runway 7 at an airspeed of about 200 knots. The PF slowed the airplane to about 170 knots and called for 10° of flaps. The PF mentioned that the airplane’s flightpath was near high terrain, so the PM pressed the “Terrain Inhibit” button to inhibit any possible nuisance alarms. The PF then called for 20° of flaps, started descending from the traffic pattern altitude, and began a left descending turn to the base leg of the traffic pattern with 30° of flaps. The PM stated that the gear down and before landing checklists had been complete abeam the numbers for runway 07. The PF stated that he overshot the final approach and had to turn back toward the final runway centerline as the airplane was “pushed by the winds.” Additionally, the PF described the presence of moderate turbulence during the final approach. About 500 ft above ground level (agl), both pilots acknowledged that the approach was “stabilized” while the airspeed was fluctuating between 112 and 115 knots.

When the airplane was about 200 ft agl, both pilots noticed that it was beginning to descend and the airspeed was starting to decrease. The PM told the PF to “add power.” The PF added power, and noted that, during the last 200 ft of the approach, the wind was “gusty,” that a left crosswind existed, that the ground speed seemed “very fast,” and that considerable power was required to maintain airspeed. Between about 75 and 100 ft agl, the PF asked the PM for the wind information, and the PM stated that the wind was variable at 6 knots, gusting to 17 knots. Neither pilot reported seeing the windsock located off the right side of the runway.

Both pilots noticed that the ground speed was “very fast,” but they chose to continue the approach. The PF stated that, when the airplane “abruptly” touched down, it was at an airspeed about 5 knots above Vref and that the airplane was “well within the touchdown zone.” Upon touchdown, the PF applied normal braking while the PM applied the speed brakes. Neither pilot felt the airplane decelerating, so the PF applied harder pressure to the brakes with no effect. Subsequently, the PM said, “max brakes,” and started applying full braking pressure. However, they still did not feel the airplane decelerate or the antiskid system activate. When it was evident that the airplane was going to depart the end of the runway, the PM applied the emergency brakes, at which point, he felt some deceleration. However, the airplane overran the end of the runway, travelled through grass and mud for several hundred feet, and then skidded to a stop.

The airplane was manufactured in 2005 and in July 2014, it underwent a supplemental type certificate design change to modify the airplane from a 400A to a 400XT model, which included replacement of the engines, removal of the thrust reversers, and several other avionic, aerodynamic, airframe and cabin interior enhancements. The main landing gear wheels were equipped with hydraulic disc brakes, which could be actuated from either the pilot's or copilot's rudder pedals. The airplane was also equipped with an antiskid system powered through a switch in the cockpit.

A review of the operator’s maintenance records revealed that, between December 2014 and March 2016, three discrepancies related to the airplane’s antiskid and brake systems were reported. The discrepancies that were reported included: 1) In December 2014, “no initial braking after landing” for about 3 to 5 seconds, although the braking during taxi operations was reported to “seem normal.” The corrective action included inspection, troubleshooting, and brake bleeding. Air was found in the left brake system and bled out. 2) In December 2015, “on landing the antiskid was cycling on/off excessively,” the airplane “would not slow down,” although the braking during taxi operations was reported to “be normal”. The corrective action noted an operation check with no defects discovered. 3) In January 2016, “antiskid not modulating/braking action poor”. The corrective action included bleeding the brake system and performing a taxi test. No further defects were noted.

At 1449, about 20 minutes before the accident, the recorded ASOS weather at RMG included, in part, wind variable at 6 knots, gusting to 17 knots, which is the information the pilots received while passing through 18,000 ft msl during their descent to the airport. At 1505, about 3 minutes before the accident, the reported weather at RMG included, in part, winds from 240° at 16 knots, gusting to 26 knots. Assuming these conditions, a 3- to 5-knot crosswind and 16- to 26-knot tailwind existed about the time of the landing on runway 7.

Following the accident, the PF reported that he believed that the airplane needed 2,900 ft of runway to safely land. Review of the airplane’s unfactored landing distance performance chart reveal that assuming the weather conditions reported 3 minutes before the accident, and an airplane weight of 12,600 lbs, the landing distance needed was about 4,175 ft.

During a postaccident examination of the runway, tire skid marks were found beginning about 1,000 ft from the approach end of the runway 7. The tire marks swerved slightly toward the right about 20 ft right of the centerline and then slightly left toward the centerline and extended to the runway end. Further down the runway, the tire marks became increasingly more pronounced, flattened out, and widened. The tire marks continued and veered left through grass and mud for another 370 ft past the departure end of the runway, where the airplane came to rest (see figure 1).

Figure 1 - Overhead view of runway layout showing the approximate measurements of the skid marks and the airplane’s final resting location.

Postaccident examination of the airplane revealed that the nose landing gear (NLG) had collapsed, and the forward portion fuselage of the fuselage was substantially damaged. A review of the engines’ full authority digital electronic control data revealed that no faults pertinent to the accident were recorded. The hydraulic brake system was bled, and no gas bubbles were found in the fluid. The antiskid control box was bench tested, and it passed all performed tests. The power brake control valve was bench tested. Plots generated by the left and right and servo modulation tests and power brake valve test showed results outside of the limits for a new production valve. The left tests were repeated, and the results improved. Overall, the plots were consistent with a functioning, in-service valve with no anomalies observed that would not have affected braking or antiskid operations. Fluid samples from the left and right brake ports and pressure port were within acceptable limits. The unit passed all other performed tests.

The left wheel speed transducer was bench tested, and it passed all performed tests. The right wheel speed transducer was also bench tested, and it failed the test at the lowest speed setting of 100 Hz. The transducer was then tested at the highest speed setting of 1,200 Hz, and it functioned as expected. The noted anomaly likely would only have impacted braking at speeds below about 10 knots. Overall, examination and testing of the brake and antiskid systems revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation during the landing.