Brantly International Inc B-2B, VH-BHY, Raymond Island, Vic, 2 March 2000

1. The pilot planned the flight using a fuel consumption rate that was significantly less than the actual consumption.
2. There was no logging of fuel usage for the helicopter that would have alerted the pilot to the greater than planned consumption rates.
3. The pilot did not check the actual fuel consumption.

The circumstances leading to the loss of engine power were consistent with fuel exhaustion. The same consumption rate achieved on the flight from Bankstown to Moruya would have used all the helicopter's useable fuel in the elapsed flight time from Moruya to the accident site at Raymond Island.

The lack of any recorded fuel consumption checks meant that actual fuel consumption rates were not readily available to pilots flying the helicopter. This meant significant differences between planned and actual fuel consumption rates remained undetected. However, the quantity of fuel added at Moruya was greater than the planned fuel burn-off and should have alerted the pilot to the need for a check of the helicopter's actual fuel consumption. The remaining useable fuel at Moruya represented the minimum recommended allowance of 20 minutes fixed reserve. Any attempt to fly a greater distance under those conditions would have only been achieved by reducing the reserve fuel allowance.

The fuel consumption rate may have been masked by the reported anomalous fuel quantity indication. The reported 1/4 indication on the fuel gauge prior to the loss of engine power was just greater than the quantity that the pilot would have expected at his planned consumption rate. This may have reinforced his assessment of the actual fuel status and caused him to doubt the veracity of the low fuel warning.

Pilots of single-engine aircraft should always consider the possibility of an in-flight engine failure and its consequences. The engine failure occurred over water and at an altitude that did not permit an unpowered descent to a suitable land emergency landing site. This meant that the pilot was not in a position to conduct a forced landing without risk of damage to the helicopter and possible injury to its occupants. Evidence at the accident site suggested that contact with the tree canopy was not consistent with an autorotation landing that would have achieved minimum forward speed and rate of descent as recommended in the flight manual. Consequently, the attempted landing into the tree canopy did not achieve optimum conditions for survival.

Witnesses immediately initiated search and rescue action. However, had the helicopter not been seen just before descending into the trees, as might have been the case in more remote parts of the island, the consequences of not carrying an ELT may have been crucial to the survival of both the pilot and passenger.

History of the flight

The pilot and passenger were making a private flight in a
Brantly two-place helicopter in accordance with the visual flight
rules (VFR) from Bankstown to Lilydale with planned fuel stops at
Moruya and Orbost. They departed Bankstown at 1100 ESuT and,
following an uneventful flight to Moruya, refuelled the helicopter
to full tanks at 1313. While on the ground at Moruya the pilot
telephoned the fuel distributor at Orbost to confirm the
availability of Avgas and was told that they did not hold any Avgas
drum stock. The distributor suggested that he try Bairnsdale where
Avgas was readily available. The pilot then elected to fly the
extra distance to Bairnsdale after having determined that it was
within the safe range of the helicopter and overfly Merimbula where
fuel was readily available. At 1412 he departed Moruya with a
planned endurance of 2 hours and 50 minutes.

The pilot monitored the progress of his flight by comparing the
10-minute time increments he had marked on his charts against an
electronic timer attached to the instrument panel. The passenger
reported that as they were approaching Bairnsdale she saw the low
fuel warning light begin to flicker. The fuel gauge showed just
above one quarter full. Shortly after, she saw the needle of the
fuel gauge drop below the quarter full mark and the low fuel
warning light stopped flickering and remained on. A few moments
later the engine began to run roughly.

The pilot reported that soon after he saw the low fuel warning
light illuminate, the engine lost power. He was flying at
approximately 1,500 ft over water and turned toward Raymond Island,
7 NM east of Bairnsdale. He elected to land on the tree-covered
shore rather than attempt to ditch the helicopter, which was not
equipped with flotation gear or life jackets. He could not recall
actioning any emergency drills.

At 1640 witnesses on Raymond Island reported seeing a helicopter
approaching the southern shore of the island at low altitude with
its engine running roughly and intermittently. As it passed low
over bushland the engine was heard to cut out and the helicopter
descended out of sight behind trees. A few seconds later witnesses
heard the sound of two distinct impacts. They immediately commenced
a search of the area and after 10 to 15 minutes located the
wreckage of the helicopter in the undergrowth. The seriously
injured occupants were administered first aid. Rescue and emergency
personnel reported that there was no smell or evidence of fuel at
the accident site and the injured passenger had told them the
helicopter had run out of fuel.

Examination of the wreckage

The helicopter entered the tree canopy at moderate forward speed
and travelled through the light timber and scrub for nearly 30
metres before contacting the ground, pitching forward and coming to
rest inverted. Although damaged, one of the three main rotor blades
was still attached to the rotor hub. The other two blades were
shattered outboard of the secondary hinge and the fragments
dispersed. Damage to the transmission and main rotor was consistent
with no power being delivered to the rotor system. Examination of
the wreckage and subsequent testing of components did not reveal
any defect that would have contributed to the accident. The upper
fuel cell was perforated during the accident sequence and the fuel
plumbing damaged. The fuel system was drained and a small quantity
of Avgas, approximately 50 mL, was found. The accuracy of the low
fuel warning system could not be determined.

Pilot qualifications and experience

The pilot held a Special Pilot (Helicopter) Licence and a valid
Class 1 medical certificate. The special licence validated his
United States of America, Federal Aviation Administration (FAA)
Commercial Helicopter Licence. He also held a United Kingdom Civil
Aviation Authority Private Pilot's Licence (Helicopters). His total
flying experience was 262 hours helicopter flight time of which 100
hours were on type. Prior to this flight, all but 10 hours of
flight time on this type had been undertaken in the United
Kingdom.

Fuel consumption and flight planning

A fuel gauge and engine instrumentation provided pilots with
fuel flow information. Apart from this the only fuel consumption
data provided to pilots was on a specification sheet published by
the manufacturer of the helicopter. This listed a normal cruise
fuel consumption of between 38 and 42 Litres per hour (LPH) at a
power setting of 75 percent. The engine manufacturer's charts gave
fuel consumption rates for the equivalent power from a lean limit
of 43 LPH up to a "suggested high limit" of 52 LPH. The reason for
the apparent difference in quoted fuel consumption rates was not
able to be determined. The fuel consumption rate for the flight
from Bankstown to Moruya was calculated to have been between 46 and
47 LPH. This was based on the flight time of 2 hours and 13
minutes. An accurate average fuel consumption rate for the
helicopter was not possible because flying times and fuel records
were incomplete. Only one pilot had established a consumption rate,
reported to have been 48 LPH. Other pilots reported they had
conservatively flown the helicopter for periods less than two hours
and although they were unsure of actual consumption rates they
thought that it was greater than 40 LPH.

The pilot had planned this flight using a fuel consumption rate
of 40 LPH, a figure he had used for all his previous flying on the
type. The flight from Bankstown to Moruya was the first extended
flight he had undertaken in Australia. He had not checked the fuel
consumption after refuelling at Moruya and used the same flight
planned fuel consumption rate in his fuel calculations for the
flight to Bairnsdale.

The helicopter was fitted with a manually operated vernier
mixture control. The fuel flow gauge was graduated in US gallons
per hour with a corresponding non-linear outer scale for the
manifold air pressure (MAP) setting. The pilot reported that he had
used a MAP setting of 21 inches of mercury and had adjusted the
mixture in accordance with the flight manual procedure. The
corresponding fuel flow indication for this power setting equated
to 41.7 LPH. In contrast the estimated consumption rate of 47 LPH
was equivalent to a MAP setting of 22.5 inches of mercury.

Fuel quantity indications and warnings

The helicopter had an electrically powered fuel gauge with
graduations for each quarter of tank capacity. The calibration card
showed that the 1/4 capacity graduation corresponded to a quantity
of 29 L. Other pilots who had flown the helicopter reported that
the gauge readings appeared to be inconsistent with fuel usage and
that at lower fuel quantities they thought the gauge over-read.

A warning light provided the pilot with a low fuel quantity
warning. The system was pneumatically operated and was independent
of the fuel quantity indication system. The low fuel quantity
warning light was designed to flash as the fuel level approached
the 10 minute reserve. The length of flash became progressively
longer until finally a steady red light appeared when approximately
5 minutes of flight time remained. The aircraft Flight Manual
stated that flight should not be attempted beyond the first
indication of the low fuel warning light. A few pilots reported
that on occasions the low fuel warning light had illuminated
intermittently during manoeuvring and in turbulence with low fuel
quantities.

Autorotation technique

Autorotation facilitates a controlled descent and landing when
engine power to the rotor system is removed, such as when an engine
fails. The technique normally requires the helicopter to be flared
toward the end of the approach in order to arrest its forward speed
and use the energy stored in the rotor system to reduce the
vertical speed and cushion the helicopter's touchdown. The flight
manual recommended a speed of 48 kts for a power-off approach. It
also stated that in the event of an engine failure over rough
terrain "Increase angle of flare to reduce airspeed to near zero
ground speed and allow helicopter to settle vertically".

Search and rescue

The pilot had not lodged flight details or nominated a Sartime,
but had arranged for an operator at Bankstown to provide a
SARWATCH. Although the pilot had nominated carriage of an Emergency
Locator Transmitter (ELT) on his flight plan the aircraft was not
equipped with one, nor had he carried a portable unit. Civil
Aviation Regulation (CAR) 252A required the carriage of an ELT for
this flight. The pilot later reported that he thought the aircraft
had an ELT installed. An entry on the Maintenance Release stated
"Carriage of ELT in accordance with CAR 252A - As Required".