NTSB Says Passenger Jet Passed Over Less Than Two Minutes
Before Fatal Accident
From the NTSB:
On January 10, 2005, at 2311 eastern
standard time, N136LN, a Eurocopter EC135 P2, operated by Air
Methods Corporation, d.b.a. LifeNet, was destroyed during an impact
with the Potomac River near Oxon Hill, Maryland. The certificated
commercial pilot and flight medic were fatally injured, and the
flight nurse received serious injuries. Visual meteorological
conditions prevailed, and a company flight plan had been filed for
the flight. The flight originated at Washington Hospital Center
(DC08), Washington, D.C., at 2304, and was destined for the
Stafford Regional Airport (RMN), Stafford, Virginia. The air
ambulance positioning flight was conducted under 14 CFR Part
The operator of the helicopter reported that the helicopter crew
picked up a patient at the Frederick Hospital, Fredrick, Maryland,
and transported the patient to Washington Hospital Center, arriving
According to flight-following Global Positioning System (GPS)
data recorded by the operator, the helicopter lifted from
Washington Hospital Center at 2304, and proceeded southeast and
then southwest, along a route consistent with Route 1, on a
National Oceanic and Atmospheric Administration (NOAA), Washington,
D.C. Helicopter Route Chart. The helicopter turned to a southerly
heading in the vicinity of Washington National Airport, and
continued along a route consistent with Route 4, on the Washington,
D.C. Helicopter Route Chart, towards the Woodrow Wilson Bridge.
A review of the NOAA Chart revealed that it depicted a maximum
altitude restriction of 200 feet north of the Woodrow Wilson
Bridge, and a maximum altitude restriction of 300 feet, south of
the Woodrow Wilson Bridge.
Preliminary radar data provided by the Federal Aviation
Administration (FAA) revealed the helicopter flew southbound
(180-degree flightpath) along the Potomac River, at an altitude of
200 feet. At 2311, the helicopter was observed just south of the
Woodrow Wilson Bridge, maintaining its southbound heading and
200-foot altitude. Four seconds later, the helicopter was observed
on an approximate 190-degree heading, and an altitude of 100 feet.
The next and last recorded radar hit, was 5 seconds later, on an
approximate 200-degree heading, at an altitude of zero feet.
A Safety Board investigator interviewed the flight nurse in the
hospital. According to the flight nurse, he was seated in the left
front (copilot) seat, the pilot was in the right front (pilot)
seat, and the flight medic was seated immediately behind the flight
nurse, in the left-side, aft-facing seat.
As the helicopter approached the Woodrow Wilson Bridge from the
north, it passed abeam Washington National Airport at a "lower than
normal altitude," but climbed 200 to 300 feet before reaching the
Wilson Bridge. About 1 mile prior to the bridge, the helicopter
appeared to be at the same, or higher altitude, than the marking
lights on the cranes, which were positioned near the bridge. The
flight nurse "called the lights," on both sides of the river, and
the pilot acknowledged him.
As the helicopter climbed, the flight nurse noticed an airplane
descending towards Washington National Airport, and wondered if
there would be a conflict, or a wake turbulence hazard.
Additionally, he stated he was not sure what the relationship was
between the helicopter and the airplane, as the airplane passed
The flight continued along the river close to the Maryland
shoreline; however, as the helicopter approached the bridge, the
pilot maneuvered the helicopter to cross over the mid-span of the
inner loop (westbound) bridge.
The flight nurse remembered being over the outer loop
(eastbound) span of the bridge, and then being submerged in the
water with his seatbelt on, and his helmet off. He stated, "I don't
remember striking something, but my initial reaction was that we
must have hit something."
The flight nurse also stated that at no time did the Master
Caution lights, or the panel segment lights illuminate. He also did
not hear any audio alarms sound. The helicopter was neither high
nor low, but "on altitude," relative to other flights which he had
been on in the past.
The pilot did not perform any evasive maneuvers, and did not
communicate any difficulties either verbally or nonverbally in the
vicinity of the bridge. The flight nurse did recall observing a
large white bird fly up from the lower left towards the helicopter,
but made no mention of striking it. When asked what he thought
might have caused the accident to occur, the flight nurse stated,
"We must have hit an unlit crane."
The helicopter came to rest in the Potomac River about 0.5 miles
south of the Woodrow Wilson Bridge.
The pilot held a commercial pilot certificate with ratings for
airplane single and multiengine land, rotorcraft-helicopter, and
instrument helicopter. His most recent second-class FAA medical
certificate was issued on May 28, 2004.
According to records maintained by the operator, the pilot was
hired in June 2004, at which time he reported 2,750 hours of total
flight experience, 2,450 of which were in helicopters.
Examination of maintenance records revealed that the helicopter
was being maintained in accordance with an FAA Approved Aircraft
Inspection Program (AAIP). The last AAIP 50-hour inspection was
performed on the helicopter on December 17, 2004. The last 100-hour
inspection was performed on November 23, 2004, at an aircraft time
of 94.5 total flight hours. The maintenance log indicated that the
radar altimeter was inoperative and included a listing of the
malfunction in the Approved Minimum Equipment List (MEL) record. As
of January 10, 2005, the helicopter had accumulated 166.6 total
Weather reported at Washington National Airport, at 2251,
included calm winds, 10 miles visibility, broken clouds at 13,000
feet, broken clouds at 20,000 feet, temperature 45 degrees
Fahrenheit, dew point 35 degrees Fahrenheit, and altimeter setting
30.25 inches of Hg.
The helicopter was recovered from approximately 5 feet of water
in the Potomac River. Debris from the helicopter was recovered
along a wreckage path oriented on a southbound heading, consistent
with the helicopter's flight path prior to the Wilson Bridge.
The main fuselage section was separated into the lower cockpit
area and upper cockpit area. The lower cockpit area contained the
flightcrew floorboard section, anti-torque pedals, forward skid
frame, and fragments of the ruptured fuel tank. The upper cockpit
area contained the flight control tubes, the center electrical and
flight control structure (broom closet), the upper flight control
deck, the main rotor gearbox, rotor head, and engines.
The mechanical flight control system was assisted by hydraulic
actuators and an automatic flight control system (AFCS). The system
was controlled by two dual controllable pilot cyclics and
collectives. For the EMS mission, the co-pilot controls had been
removed. The anti-torque pedals were routed to the tail rotor servo
via a Teleflex cable. The cyclic and collective controls were
routed through mechanical linkages to an upper deck dual hydraulic
servo control system, which controlled lateral, longitudinal, and
The cyclic, collective, and yaw controls were examined for
evidence of malfunctions or pre-impact failures. Continuity could
not be established due to breaks in the system and missing portions
of the push-pull tubes; however, the breaks were matched and
examined for evidence of pre-impact malfunction or failure.
Examination of the breaks revealed no pre-impact mechanical
malfunctions, and the fractures were consistent with overload
fractures and water impact.
The main rotor mast was in place and intact in the main
transmission. All four main rotor blades remained attached to their
respective mounting areas, which bolted directly to the mast. Three
out of four of the pitch change links were integral to their two
attach points, the fourth (red) pitch change link was fractured in
the middle. The fracture was consistent with compression bending
The root ends of all four main rotor blades remained attached to
the main rotor hub. Portions of all four main rotor blade tips were
accounted for, and matched to their respective blades. All four
main rotor blades contained overload fractures between 6-12 inches
from the blade hub, and chordwise scoring on the lower blade skin
in the same area. The main rotor blades contained fractures along
the span of the blade, consistent with impact damage. No
indications of an object or bird strike were noted along the
The main gearbox remained attached to the center section of the
upper airframe structure. All four mounting points were intact. The
main transmission turned freely, no chips were found on the
detectors, and the transmission appeared intact and functional.
Both engines remained attached to
the upper fuselage section. Both engines sustained relatively minor
damage, and their N1 and N2 sections rotated freely.
The main fuselage was separated from the tail boom section at
the aft fuselage frame. The tail section included the tail gearbox,
the tail rotor assembly and the complete fenestron assembly.
The tail rotor driveshaft was shifted about 1.5 inches forward.
The aft portion of the driveshaft (carbon composite) was found
fractured and torsionally cracked and deformed. The tail rotor
blades remained complete and attached to the fenestron structure. A
rotational scrape was noted on the fenestron shroud structure at
the 5 o'clock position corresponding with the blade width.
Several of the helicopter components were retained for further
Safety Board investigators examined sites along the Potomac
River that matched the coordinates recorded by ATC radar data and
the operator's flight-following GPS. The projected track along
these locations toward the accident site was about 300 feet from
the nearest crane, and no additional obstructions were observed
along the track.
Five of the closest cranes along the Potomac River, near the
Wilson Bridge construction project (Maryland side) were examined,
and no structural damage or aircraft strike indications were
A Maryland Department of Transportation traffic surveillance
video was secured and sent to the Safety Board's Video Laboratory
for examination. Preliminary examination revealed an aircraft
flying, and then descending, over the bridge about the time of the
accident. According to the video, the aircraft passed above and
beyond the cranes prior to beginning its descent.
Examination of additional ATC radar data revealed that a
70-passenger Canadair Regional Jet 700 (CRJ-7), passed over the
Woodrow Wilson Bridge about 1 minute and 45 seconds before the
accident helicopter passed over the bridge. The radar data
indicated that the helicopter passed 900 feet directly beneath the
flight path of the CRJ-7, while heading in the opposite