MedSTAR Crash: NTSB Preliminary Investigation
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On May 30, 2006, at 1645 eastern daylight time, a Eurocopter EC-135P1, N601FH, was substantially damaged when it collided with terrain while maneuvering to land at the Washington Hospital Center Helipad (DC08), Washington, D.C. The certificated airline transport pilot and two medical crew members were seriously injured. The critically ill patient on board the helicopter later died at the hospital for reasons not yet determined. Visual meteorological conditions prevailed for the flight that originated at Greater Southeast Community Hospital, Washington, D.C. A company flight plan was filed for the medical transport flight conducted under 14 CFR Part 135.
The helicopter came to rest on the golf course at the Armed Forces Retirement Home approximately one-half mile north of the helipad. The elevation at both the crash site and the hospital helipad was approximately 200 feet.
A preliminary review of radar data revealed that a target identified as the accident helicopter approached the helipad from the south, and over flew the pad. The helicopter then completed a teardrop-shaped circuit on the north side of the hospital center, returned, and again over flew the pad, traveling southbound. After crossing the pad, a left-hand circuit that roughly resembled a traffic pattern was flown around the east side of the hospital grounds. The helicopter turned westbound in what approximated a base-leg turn, then the radar target was lost in the area of the crash site. The altitudes recorded from the first over flight of the helipad to the last radar target were between 200 and 300 feet msl.
The pilot was able to recall portions of the flight. On the day of the accident, he received the flight request, checked the weather, and performed a preflight inspection. He then performed a walk-around inspection with his crew prior to takeoff. The pickup of the patient and the flight to Washington Hospital Center were routine.
When the helicopter approached the pad, it "shuffled" and the engine rpm increased. The pilot increased collective pitch, and reduced the throttle on the number 1 engine to control engine and rotor rpm, then aborted the landing. He was able to control the rpm, and does not recall any visual or aural warnings regarding rpm limits. For the remainder of the flight, the number 1 engine was operated in manual mode, and the number 2 engine remained in automatic mode.
As the pilot maneuvered the helicopter over the golf course, the "shuffle" worsened, and the helicopter became uncontrollable. He remembered a building and a tree were in the helicopter's flight path as it descended, and maneuvered toward the tree. The pilot transmitted a "Mayday" call and alerted his crew prior to touchdown.
In an interview, the flight medic stated that as the helicopter terminated the first approach, he heard an audio alarm in his headset, and "it felt like the helicopter lost power." The helicopter circled for a second attempt, and as they approached the landing pad, the medic again heard the audio alarm in his headset, and the landing was aborted.
The pilot announced that he was "losing power," and couldn't slow the helicopter. As they flew around the hospital center, the pilot announced that they would return and attempt a landing at the lower helipad.
Once over the golf course, the helicopter began to vibrate. The vibration increased, the nose yawed from side to side, and the helicopter "went into a spin." It descended vertically, struck a tree, then terrain, and rolled over on its side.
The medic repeated several times that it "felt" and "sounded like" the helicopter was losing power. He added, "As long as he wasn't trying to land, he could keep flying. He couldn't slow it down, but we could have stayed up and [continued to fly]."
The flight nurse's description of the flight was similar to the medic's, and she remembered two over flights of the upper pad, and the pilot stating that they would attempt a landing at the lower pad. She did not recall hearing an audio alarm in her headset, nor did she recall the pilot announcing a loss of power. As the helicopter approached the golf course, "it slowed, rocked, and started shaking." When asked about the sound of the engines, she said, "There was a lot of sputtering. They didn't sound like they were going fast like they usually did. There was that sputtering noise, then a metallic banging."
Both the flight nurse and the medic stated that they could not view the instruments nor could they see the pilot manipulate the flight controls.
In a telephone interview, a witness stated that he heard the helicopter "sputter" as it approached, and then the sounds of impact, but he did not see the accident.
A second witness said she watched the helicopter over fly the golf course at low altitude, "up and down, kind of out of control. It seemed like they were struggling to maintain altitude." The helicopter flew out of view toward the hospital, and several minutes later, it returned over the golf course, and the sounds of impact were heard.
The pilot held an airline transport pilot certificate with a rating for airplane multi-engine land, and rotorcraft helicopter. His most recent second-class medical certificate was issued on November 8, 2005. A review of company training records revealed that the pilot had 15,613 total hours of flight experience, 12,413 hours of which were in helicopters, and 914 hours of which were in make and model. His most recent FAR Part 135 competency check was completed December 22, 2005 in the EC-135 helicopter.
The helicopter was on a manufacturer's inspection program, and it's most recent 50-hour inspection was completed May 19, 2006, at 2,977 aircraft hours. The helicopter had accrued 2,995 total flight hours.
The helicopter was examined at the site on May 30, 2006, and all major components were accounted for at the scene. Prior to examination, emergency personnel and pilots who responded to the scene manipulated flight controls, switches, and components to reduce the risk of fire.
The helicopter came to rest next to a tree that exhibited deep cuts and slash marks along its trunk from ground level to about 20 feet above the ground. Several branches were broken, and several displayed clean, angular cuts. Pieces of cut and broken branches were scattered around the wreckage.
The fuselage rested on its left side, and the cockpit and cabin areas were largely intact. The pilot's windscreen and chin bubble were broken. The tailboom was still attached, but twisted 90 degrees and rested upright. The tailrotor driveshaft and control cables were broken at the tailboom attach point. The cables and the driveshaft displayed fractures consistent with overload. The horizontal stabilizer, vertical fin, and the fenestron were all intact.
All four of the main rotor blades were fractured at the root, about 1 foot outboard of their respective hubs, but remained attached. The blades were fractured, bent, and torn along their spans, with the tips disintegrated on all but the yellow blade. Blade tip fragments, tip weights, and their associated plastic spacers were scattered about the crash site.
Examination of the wreckage resumed June 1, 2006, at Tipton Airfield, Ft. Meade, Maryland. Control continuity was established from the cyclic and collective controls to the rotor head. Tail rotor control continuity was established from the anti-torque pedals to the cable breaks in the tailboom, and then from the breaks to the fenestron.
The main transmission was intact and secure in its mounts. Continuity was established throughout the transmission to all of its accessories. The magnetic chip detectors were absent of debris.
The number one and number two flight control hydraulic systems were tested individually. Each system was pressurized individually by motoring their respective hydraulic pumps. Both lateral servos and the collective servo were actuated through their full ranges with no anomalies noted. The actuators were moved individually, and then all three were moved simultaneously through their full ranges with no anomalies noted. There was corresponding movement in the collective and cyclic controls to the rotor hubs.
The hydraulic filters were removed, and the filters and their housings were completely absent of debris.
The engines appeared intact and undamaged. They were removed, and shipped to Pratt and Whitney Canada for further examination. The electronic engine control units were shipped with the engines.
At 1652, the weather recorded at the Ronald Reagan/Washington National Airport included a broken ceiling at 6,000 feet and 8,500 feet with 7 miles visibility. The wind was from 120 degrees at 9 knots. The temperature was 89 degrees Fahrenheit, and the dewpoint was 69 degrees Fahrenheit. The altimeter setting was 30.03 inches of mercury. [/SIZE]