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Tue Nov 25 20:05:24 GMT 2008

Cases where medical helicopters had problems with off-airport landings per
the NTSB:
*
12/1/2007  Talladega, AL*
The pilot performed an off-airport landing in the helicopter, to pick up a
patient for transport to a nearby hospital. During the subsequent takeoff,
the helicopter's tail rotor struck a wire that was located about 30 feet
above the ground, oriented perpendicular to its flight path. The pilot
immediately landed without further incident. Neither the pilot, nor the crew
were previously informed of the wire, which was not observed until just
prior to contact. The helicopter sustained damage to the tail rotor,
vertical stabilizer, and left aft storage compartment door.

*8/9/2007  Ridgeville, SC*
The pilot said that upon landing at the scene he kept the helicopter
operating with him at the controls, while the medical crew attended to the
patient. After loading the patient into the helicopter, the paramedic did a
walk around inspection, entered the helicopter, and called out the
before-takeoff-checklist, while voicing an alert to the pilot concerning
overhanging trees on the port side of the helicopter. The pilot
acknowledged, and told the crew that he intended to pick the helicopter up
into a hover, slide to the right, and then perform a left pedal turn to exit
the scene to the west. The pilot said that while performing a left pedal
turn at a hover, a vibration occurred throughout the airframe, and he
immediately set the helicopter back on the ground, facing west. An EMS
technician on the ground who had been observing the helicopter, stated that
after the patient had been loaded into the helicopter, the helicopter was
lifted into about a 3-foot hover, and then began to rotate and face into the
direction of the light wind, coming from the west. After the helicopter
completed the rotation into the wind, the EMS technician stated that it then
began to increase altitude, and as the altitude increased the tail rotor
struck a small pine tree limb that stuck out about 1 to 2 feet into, and
over the westbound traffic lane closest to the median. He said he heard the
change in pitch to the sound of the helicopter's engine, and also saw the
tail rotor begin a slight "wobbling." At this point the EMS technician said
the helicopter was about 6 to 8 feet off the ground, and he believes that
the pilot sensed that something was wrong with the helicopter, and set the
helicopter down firmly on the curbside lane, facing west. An examination
reveal no evidence of a preaccident mechanical failure or malfunction to the
helicopter or any of its systems.

*21 February 2005  Gentry, Arkansas*    (Patient killed in crash)    The
setting and wind conditions contributed to the crash because it reduced the
effectiveness of the tail rotor.

*14 July 2004   Lake Louie, ID *

After the medical evacuation flight arrived at its designated landing zone
(6,500 feet mean sea level/MSL), an out-of-ground-effect hover was
accomplished to verify the aircraft's performance. The power check was good
and a positive rate of climb was noted. After landing and the crew had
exited the aircraft, the pilot departed the area to locate a landing zone
closer to the pickup point of the crew and patient. A landing zone at the
6,600 foot level (MSL) was located 3/8 of a mile closer to the patient
pickup point. While waiting to load the patient the pilot determined a
takeoff could be made based on his review of the aircraft's takeoff
performance data. After completing an in-ground-effect power check and
initiating a vertical climbout, the pilot confirmed the helicopter would
clear a 100 foot tree line as it began to transition forward. After clearing
the tree line the pilot detected the aircraft lose all lift as the
helicopter began to settle toward the approaching trees. Applying the
remaining power, the RPM warning sounded, prompting the pilot to reduce
collective, but only to realize that he was descending into approaching
obstacles. Right pedal was applied in an attempt to return to the original
point of departure, however, the rotor RPM had still not completely
recovered and the aircraft continued to descend. The aircraft impacted a
boulder, and with the RPM now fully recovered, the helicopter jumped back
into the air. The aircraft then rotated 180 degrees before the pilot
performed a hover autorotation. During the maneuver the tail rotor had
impacted a tree branch which resulted in an 8 inch chord wise gash to one of
the tail rotor blades. The pilot felt that as the helicopter was clearing
the tree line it entered a downwind condition, a condition which he didn't
anticipate, resulting in a reduced power margin with which to overcome the
loss of lift. A weather reporting station located 7 miles west-northwest of
the accident site reported the wind was variable at 3 knots. The density
altitude was calculated to be 8,898 feet. The pilot did not assert that any
mechanical malfunctions precipitated the accident.

The National Transportation Safety Board determines the probable cause(s) of
this accident as follows:
The failure of the pilot to maintain rotor rpm and his inadequate recovery
from a bounced landing. Factors contributing to the accident included the
tailwind condition and the tree.
*
16 March 2003   Highland, Michigan*
On March 16, 2003, at 2015 eastern standard time, a Bell 430 helicopter,
N431UM, piloted by an airline transport pilot, was substantially damaged
when the tail rotor impacted a roadway sign during an aerial taxi. The
accident occurred on Highway M-59, east of US Highway 23, near Highland,
Michigan. Visual meteorological conditions prevailed at the time of the
accident. The medical evacuation flight was operating under the provisions
of 14 CFR Part 135 and was not on a flight plan. The pilot was the sole
occupant at the time of the accident. He reported no injuries. The flight
departed the University of Michigan Medical Center Heliport (MI32), Ann
Arbor, Michigan, at 1959 est, with the intention of returning to MI32 after
picking up a patient.

According to the pilot's statement, he overflew the area from west to east
to review the landing site. He stated that he reversed course and approached
the landing site from the east. Prior to touchdown the pilot reported he
rotated the aircraft and landed on an easterly heading, at which point the
medical crew departed the helicopter.

The pilot decided to reposition the aircraft to face west for departure.
After notifying local authorities and clearing the helcopter, he reported he
began to taxi to the east. He stated he "cleared the tail to move left into
the turn around along M-59. I started to move the aircraft which now was
facing south into M-59 ... when the tail rotor hit a steel reflector post.
The aircraft became airborne to around five or six feet when I lowered the
collective and rolled the throttles to idle to stop the aircraft rotation."
The aircraft impacted on the left rear skid first and came to rest
one-hundred eightly degrees from its initial heading.

A post-accident examination revealed the tail rotor and gearbox had departed
the helicopter. The pilot reported there were no mechanical malfunctions
with the helicopter prior to the accident.

*18 August 2001  Vinton, CA*

The pilot of the med-vac helicopter reported that, during liftoff at the
remote site, he encountered a loss of visual reference due to a "brown out"
condition created by blowing dust at 3 feet agl. He then attempted to land
the helicopter without any visual reference; however, the right skid
contacted the ground first. A rolling motion to the left was created and,
after the left skid contacted the ground, a dynamic rollover ensued. The
helicopter came to rest on its left side.

The National Transportation Safety Board determines the probable cause(s) of
this accident as follows:
The pilot's selection of an unsuitable landing site, which caused
"brown-out" conditions during departure liftoff and resulted in loss of
control of the helicopter.

*
14 October 2001  Grand Canyon, AZ*

During the aeromedical evacuation of a seriously injured patient, the
helicopter pilot attempted to takeoff from a clearing surrounded by trees
and high elevation terrain. Also on board the helicopter were a paramedic
and a flight nurse. The crewmembers indicated that no tree branches were
closer than 8 to 20 feet from the helicopter as it gained between 80 and 100
feet above the terrain. As the pilot turned into the light wind, the tail
rotor lost effectiveness and the helicopter started yawing uncontrollably in
a clockwise direction. Due to the lack of climb performance in the high
density altitude (approximately 8,850 feet) and heavy weight condition, the
pilot made a forced landing in the underlying terrain during which it
impacted trees.

The National Transportation Safety Board determines the probable cause(s) of
this accident as follows:
The pilot's in-flight loss of control during liftoff due to his improper
planning and decisions. Related factors were the high density altitude and
helicopter weight condition, and the lack of a suitable takeoff area.

*17 November 1999   Neihart, MT*

The pilot reported that, due to trees directly in front of him for the
departure from a remote site located near ski lift towers, he elected to
turn the nose of the helicopter 45 to 50 degrees to the left, hover over to
an open area, and depart downslope building airspeed and altitude. After the
helicopter moved to the left about 20 to 30 feet, the pilot felt the tail of
the helicopter rotate abruptly to the left. The pilot applied left pedal
which slowed, but did not stop the rotation. The pilot applied cyclic
control to return to the landing zone. During the maneuver, the helicopter
drifted over to one of the ski lift towers, striking the tail rotor on the
tower. The rotation increased, and the pilot closed the throttle and
utilized collective to cushion the landing which was hard. The pilot
reported that there were no mechanical failures or malfunctions with the
helicopter at the time of the accident. Shortly after the accident, as the
pilot was waiting for company personnel to arrive, he noted that at 10 to 15
minute intervals, the wind gusts would become stronger for a short period of
time, then die down. The pilot reported that the wind was from 180 degrees
at five knots, gusting to 15 knots.

The National Transportation Safety Board determines the probable cause(s) of
this accident as follows:
Clearance from an object was not maintained. Gusting wind conditions was a
factor.

*13 February 1999   Hockley, Texas*

The helicopter impacted power lines while departing from an automobile
accident scene. The helicopter was part of a two aircraft team dispatched to
the scene of the automobile accident. During the landing approach, the pilot
noticed the power lines running parallel to the road; however, he did not
consider them to be an unusual hazard at the time. After the passengers were
loaded into the helicopter, the pilot took off, drifted toward the wires,
and impacted the power lines. The pilot then landed the helicopter in an
adjacent field. The pilot stated that at the time the helicopter impacted
the wires 'the sun was shining directly into the aircraft' and that 'trash
was blowing around.' Another helicopter was dispatched to the scene of the
accident to transport the patients to the hospital.

The National Transportation Safety Board determines the probable cause(s) of
this accident as follows:
The pilot's failure to maintain clearance with the power lines. A factor was
the sunglare reducing the pilot's visibility.

*29 November 1998   Idaho City, Idaho*

The McDonnell Douglas MD-900 medevac helicopter was dispatched to a car
accident at a site characterized by high terrain and high trees. Prior to
landing, the pilot requested information about wires and was advised by
ground personnel that 'there were none.' Subsequent to landing, the pilot
examined the landing site and proposed departure route for wires, and
reportedly observed none. The departure from the site was conducted under
dusk to dark night conditions. While climbing out vertically due to the
narrow canyon conditions at the site, the helicopter struck unmarked
transmission lines approximately 150 feet above ground. The pilot then
determined that the helicopter was controllable and displayed no unusual
flight characteristics, and chose to proceed to his destination. Post-flight
examination revealed crazing of the windscreen and damage to four of the
five main rotor blades requiring major repair/replacement.

The National Transportation Safety Board determines the probable cause(s) of
this accident as follows:
The pilot-in-command's not obtaining/maintaining clearance with the unmarked
transmission lines. Contributing factors were environmental (dusk)
conditions, the transmission lines, and both the pilot-in-command and the
ground personnel not identifying the existence of the hazardous condition
(high wires).

===========================
Those are the cases that I found in a quick review of the past 10 years
worth of crashes.  Luckily there was only one fatality as a result of these
crashes, but still there are lessons to be learned here.  There are numerous
additional cases where helicopters not on medical flights have had accidents
under similar circumstances and we would be well advised to include those in
the review of whether off-airport landings are really a good idea,
especially given the minimal benefit offered to patients by helicopter
transport in most circumstances.

This list is also limited to the Part 135 operations- in other words, which
for the most part are only those where there was a patient on board at the
time of the incident. This list also excludes those incidents where the
primary cause was a mechanical problem (either immediately after departing
an improvised LZ or on approach to one) and the lack of suitable area to put
the helicopter down in contributed to the problem. I will put together a
list of the Part 91 incidents which include those incidents where there was
no patient on board, but this may take a few days as there are far more
cases of helicopter crashes to go through and I am moving tomorrow back to
Indiana.

-- 
Stephen L. Richey, CRT
Aviation Injury Research Project Leader
Saginaw Valley State University
Work E-mail: slrichey at svsu.edu
Home Office Phone: 248-366-4452

"Hier stehe ich. Ich kann nicht anders. Gott helfe mir. Amen."- Martin
Luther, before the Diet of Worms, 16. April 1521

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