Verification of the actual fuel quantity during pre-flight
inspection would have alerted the pilot to the amended state of
fuel quantity on board the accident aircraft. CASA produced an
Advisory Circular in September 2001 on fuel planning as guidance
for operators and pilots to help ensure correct pre-flight planning
procedures and that aircraft carry sufficient fuel to safely
complete each flight.
The fitment of upper body restraints to the passenger seat belt
systems may have reduced the exposure to some of the serious
injuries incurred in this accident. Recommendation R19980281
arising from occurrence 199802830, dated 26 July 1998, was
previously made to CASA to address this perceived deficiency with
regard to upper body restraints. In response to this
recommendation, CASA issued a Discussion Paper `Proposed
Airworthiness Directive, General Series - Upper Torso Restraints
for Occupants in Small Aircraft' explaining the intention to
introduce such a requirement and inviting comment by the industry.
The public comment period closed 01 March 2002 and CASA is now
considering these comments prior to promulgation of the AD.
The Bureau's response to that action was RESPONSE STATUS:
MONITOR. The ATSB will continue to monitor the CASA action and any
further correspondence will be published on the ATSB website
www.atsb.gov.au.
Fuel quantity calibration and indication
Although the aircraft fuel gauges differed between left and
right tanks for a given scale marking, this was compensated for by
having a calibration correction card fitted to the aircraft. It is
not uncommon to have such discrepancies between multiple gauges in
the same aircraft and should not have been a factor in this
accident.
As a back up measure the aircraft also carried a dipstick, which
was usually locally manufactured by the maintenance organisation.
It could be used by the pilot to verify the actual fuel quantity on
board before or between flights. The dipstick found at the crash
site, although not calibrated specifically for the accident
aircraft, should have given a reliable enough reading to alert the
pilot to the 80L discrepancy in the fuel quantity on board; if it
had been used. Passengers did not see the pilot verify the fuel
quantities at Rawlinna, either visually or by using the dipstick.
It could not be determined if the pilot verified the actual fuel
quantity on board, visually or by dipstick prior to departing
Kalgoorlie but, considering the incorrect trip log annotation of
160L in each tank, it is unlikely that he did.
The fuel that rescuers observed leaking onto the front seat
occupant and which had pooled under the aircraft, probably came
from the disrupted fuel lines around the fuel tank selector in the
first instance and later augmented by the right door pillar supply
line from the right tank that was severed during the rescue. As the
residual fuel in the left tank was not able to feed to the fuel
selector supply lines, the fuel remaining in the left tank only
approximated to the unusable amount, as published in the POH, for
that tank.
The selected position of the yellow segment of the auxiliary
fuel pump switch as observed at the accident site, was consistent
with emergency checklist action following an inflight engine power
loss or vapour purge.
The fuel selector was found selected to the right tank. The fuel
pump switch and fuel selector position observations were considered
in conjunction with the pilot's trip log notes showing that the
flight immediately prior to the power loss was conducted on the
left tank. If the pilot had conducted the emergency checklist
actions, as seems likely based on the auxiliary fuel pump switch
selection, then he had selected the fuel selector to the opposite
tank. The evidence was consistent with a power loss while operating
from the left fuel tank and a probable attempted engine re-start
after changing fuel tank selection to the right tank.
In flight engine restart
The radio call made by the pilot gave the aircraft height of
about 800ft above ground level (AGL) at the time the engine lost
power. This would have provided gliding time of approximately one
minute in the flaps up configuration recommended by the POH; and
used by the pilot. This short interval after the engine power loss
may have been insufficient for the pilot to successfully complete
an in flight engine re-start drill.
Fuel tank exhaustion - fuel supply
starvation
The aircraft fuel usage annotations recorded in the trip fuel
log by the pilot showed that he had started his fuel calculations
with 80L more fuel than was on-board. The annotations also showed
that the left tank had been used for taxi and take off on both
flight sectors that day. Take-offs were the periods of highest fuel
demand by the engine and in accordance with the POH, should have
been conducted from the fullest tank. The trip fuel log showed
that, on departure from Rawlinna, the right tank contained the most
fuel and, therefore, should have been used for that take off.
Whether prolonged taxi or extended use of climb power using the
left tank took place could not be verified and the possibility of
additional fuel usage from the left tank during these periods could
not be ruled out.
The pilot's fuel usage annotations showed that he calculated the
aircraft had used approximately 69L from the left tank and 70L from
the right tank in total for both sectors that day, up to the last
hand written entry for the fuel tank selection change at 1345.
Using the operator's average fuel consumption figure for this
aircraft, a further 28L needed to be used from the left tank by the
time that the engine lost power; approximately 1413. If the tank
selections were correctly carried out as annotated by the pilot,
the total fuel burn from the left tank would have been around 97L,
which should have left approximately 23L remaining in that tank.
The tank was observed, at the accident site, to contain
approximately half a litre of (unusable) fuel. It could not be
positively determined why only unusable fuel remained in the left
fuel tank.
The previous accident in 1995 demonstrated, that on at least one
other occasion, this aircraft's left fuel tank contents could be
exhausted after one hour and 40 minutes of operation from a `tabs
level' fuel quantity. Flight time of the Kalgoorlie accident
flight, while operating on fuel supplied only from the left tank,
was estimated to have totalled approximately one hour and 37
minutes. It was therefore possible that the contents of the left
tank may have also been exhausted on the Kalgoorlie, Rawlinna,
Kalgoorlie flight in this period of time.
Operations with low-fuel quantity
The trip fuel log revealed that the pilot would have expected to
have 40L more fuel remaining in each tank at the time the engine
lost power. Consequently, he may not have considered a low fuel
state as a possible cause for the engine power loss.
Flying in turbulence with a low fuel state can also lead to
uncovering of the fuel outlets in the fuel tanks. If the pilot had
correctly carried out the tank changes noted in the trip log, the
left tank should have had approximately 23L of fuel remaining when
the engine lost power; which equated to about an eighth of a tank.
If such a quantity was present in the reported turbulent
conditions, then the possibility of unporting the fuel outlets
could not be ruled out.
Summary
The low fuel-state of the left tank alone, or in combination
with the forecast turbulence, probably caused the engine to lose
power.
In the absence of evidence of a mechanical failure leading to
engine loss of power, the most likely cause of the engine loss of
power was associated with fuel supply starvation or exhaustion.
The presence of a vehicle on the road appeared to have caused
the pilot to initiate a sudden pull back on the flight controls
that led to a loss of control and subsequent impact with the
ground.
The pilot of a Cessna 210 Centurion was tasked to fly three
passengers from Kalgoorlie WA to Rawlinna WA and return.
The aircraft departed Kalgoorlie at 0804 Western Standard Time
for Rawlina with the flight proceeding without incident. The trip
fuel log showed that the pilot believed that the aircraft arrived
in Rawlinna with approximately 106L remaining in the left tank and
130L remaining in the right tank. The aircraft was not refuelled at
Rawlinna.
Two passengers watched the pilot prepare for the return journey
from Rawlinna. They reported that the pilot appeared to do a walk
around the aircraft and one passenger stated that although he saw
the pilot `check things at the front, wingtips and tail', the pilot
did not check the fuel tanks in the wings. At approximately 1250,
the flight departed for Kalgoorlie. One of the passengers recalled
that, shortly after reaching a cruise altitude of about 4,000ft,
the pilot appeared to become agitated and was checking something on
the floor between the seats. This concerned the passenger, but
after a few minutes, the pilot settled down and the passenger
assumed that whatever had been a concern, was resolved. The fuel
selector is located on the floor between the two front seats.
One passenger with recollection of the remainder of the flight
from Rawlinna, stated that it appeared routine up until the engine
lost power while the aircraft was approaching Kalgoorlie. (Due to
the serious nature of the head injuries sustained in the accident
by all of the passengers, their recollections of the flight prior
to the engine power loss were very fragmented.)
At approximately 1413, the pilot was heard to broadcast a
distress call including the aircraft altitude of 2,000 ft above sea
level and his intention to land on a road. During the landing
attempt, the passenger in the right front seat observed a car
appear in the landing path. The passenger reports of what occurred
after the car appeared were consistent with the pilot attempting to
climb the aircraft to avoid the car and subsequently losing control
of the aircraft during the manoeuvre.
The driver of the car and his wife saw the aircraft pass
silently overhead as it crossed the road in a southerly direction.
When it impacted the ground, the car driver's wife said that it
appeared to `really bury in' before it was obscured by a large
cloud of dust.
The driver immediately called emergency services and then he and
his wife attempted to render assistance to the occupants. The pilot
was fatally injured while the passengers were seriously
injured.
Wreckage information
The aircraft impacted the ground in a left wing low, nose-down
attitude. Examination of the aircraft found the left and right fuel
tanks intact, but the fuel system plumbing was disrupted by cabin
distortion at the fuel tank selector valve under the floor. The
fuel line to the firewall mounted filter strainer and engine was
broken and the strainer was destroyed during the accident impact
sequence. The forward door pillar had been severed on the right
side of the aircraft by hydraulic cutters used during the rescue
effort to free the trapped front seat passenger. The examination of
the fuel tank selector revealed that the right fuel tank was
selected at impact.
Fuel had poured on to the right front seat occupant during the
rescue and had continued for a considerable amount of time after
the accident. No fuel remained in the right tank when it was
examined by the investigation team on site. The rescuers said that
they had not observed fuel to leak from the left wing onto the
ground at any time. The aircraft's left wing low attitude uncovered
the engine fuel supply lines at the inboard end of the tank and, as
a result prevented the remaining left tank contents escaping
through the damaged connections to the fuel selector. Less than
half a litre of clean fuel remained in the outboard section (lowest
point) of the left tank compartment and was considered to
approximate the unusable amount for the tank. A sample of the
Avgas, which was normal green colour, was taken from the aircraft
and inspected at the accident site. It was free of any water or
particles in suspension and visible contaminants. The fuel uplift
for the flight was from the Kalgoorlie aerodrome. This fuel supply
was tested by the supplier and found to be within correct
specification.
The left wing vent line was also clear of the remaining contents
and did not appear to have been capable of allowing the remaining
contents to drain off through the left wing tip vent due to the
syphon effect. The fuel contractor's log showed that there were
multiple deliveries from the same batch of fuel to other aircraft
operating from Kalgoorlie airport coincident with the delivery to
VH-LMX. The bureau found no reports of fuel related problems with
any of these other aircraft.
The fuel system components were bench tested and found to be
capable of normal operation within the manufacturer's parameters.
The wreckage, engine and component examinations found no evidence
of pre-existing mechanical defects with the aircraft or its
systems, that would have prevented normal operation of the aircraft
prior to the accident.
Fuel pump switch
The auxiliary fuel pump switch is a two-segment split rocker
type mechanism. The right half was colour-coded yellow and the left
half red. The yellow half was marked START, with the upper position
as ON and was used for normal start and some minor vapour purging
if required. It was usually selected OFF for normal flight. In the
event of an engine driven fuel pump failure in cruise flight, the
yellow switch selected to ON should have provided, through a
micro-switch arrangement, sufficient fuel for normal engine
operation. The red half of the switch was marked EMERG (emergency)
with its upper position marked as HI. This red switch was used in
the event of an engine driven fuel pump failure during takeoff or
high power operation and also extreme vapour purging. When the
auxiliary fuel pump switch was removed and examined the yellow
segment was found in the ON position.
A fuel dipstick with graduated markings on it was found in the
baggage compartment of the aircraft. It was marked C210M VH-WXC and
had the following graduations: LEFT FULL, 140, 100, 60, 30 with
identical graduations and the word RIGHT on the reverse side of the
stick. A check of the type certificate data sheet revealed that the
C210N (accident aircraft) was fitted with identical type and
capacity fuel tanks to the C210M.
Emergency locator transmitter
The aircraft was fitted with an emergency locator transmitter
that activated upon impact. The transmission was received and
logged by the Australian search and rescue organisation (AUSSAR)
for 2hrs 39 mins before local police disabled the transmitter.
Pilot information
The pilot held a valid Australian commercial pilot licence and
command instrument rating. He held a valid Class 1 medical
certificate and did not require vision correction while operating
an aircraft. At the time of the accident the pilot had accrued a
total of 1,087 hours flying experience with 317.5 hours on the
Cessna 210. From interviews and post mortem results, no evidence
was found that the pilot had any personal or medical problems that
may have adversely impinged on his ability to conduct the
flight.
Survival
The nose-down, left wing low attitude of the aircraft as it
impacted the ground exposed the left front seat occupant (the
pilot) to the full force of the impact.
The passengers sustained numerous serious injuries in the form
of fractures to legs, upper bodies and heads as well as injuries to
internal organs. The leg injuries probably occurred when the floor
was forced in an upward direction during the impact sequence. The
floor movement also released the anchor points for the front seats.
The middle row right seat remained fixed to its mounts. The middle
left seat remained fixed by its rear mounts and forward left mount
but with the front right mount partially released. There were no
upper body restraint systems fitted to the passenger seat row
positions in the aircraft, nor were any required to be. The upper
body and head injuries sustained by all occupants were probably due
to upper torso flailing contact with interior structure and
objects. The front seat positions were fitted with upper body
restraints. The effectiveness of the front seat restraint systems
was compromised by the loss of integrity of the seat to floor
attachments. The rearward movement of the engine firewall during
the impact sequence may also have reduced the front seat survival
space between front seat occupants and control panel structures;
which would have increased exposure to injury.
Weather
The weather forecast for the day was for fine conditions, but
with thunderstorm activity expected in the Kalgoorlie area during
the afternoon after the flight. Other pilots reported experiencing
some heavy turbulence in the area during the day and the operator's
Chief Pilot remarked it was, `the first really rough day of the
season'. The passengers recalled that, for the portions of the
flight that they could remember, there was some turbulence but
remarked that it was not unusually rough.
Aircraft fuelling
The afternoon before the charter flight, the aircraft operator
requested the fuel contractor to fill the aircraft tanks (capacity
160L in each of two tanks) `to the tabs', which equated to a fuel
quantity of approximately 120L in each fuel tank. The fuel request
form was normally faxed to the fuel depot during the afternoon, but
as no request had been received by the time he was due to commence
fuelling tasks, the fuel contractor obtained the request sheet by
walking to the aircraft operator's office and retrieving the
original. The contractor noted that the sheet had been amended by
the use of white-out correction fluid and that the original request
entered had been for full tanks. It could not be positively
determined if the pilot had sighted this fuel quantity request
sheet.
Company pre-flight briefing
Some months after the accident, a director of the company stated
that he spoke to the pilot in the afternoon prior to the accident
flight. This conversation covered the task briefing for the
following day and included the fuel load as being `to the tabs'. If
this was so, the weight and balance calculations made by the pilot
for the flight, in which a `full fuel' quantity was used and showed
that the aircraft was close to maximum take off weight, did not
reflect any knowledge that he had received the `fill to tabs' fuel
information. The director could not confirm whether the pilot
assimilated this information at the time he talked to him.
Aircraft service history
The aircraft had been maintained in accordance with the relevant
Civil Aviation Regulations and Orders. The aircraft had a valid
maintenance release at the time of the accident with no maintenance
overdue. Because a fuel quantity system calibration was required by
the Civil Aviation Safety Authority (CASA) every three years as
part of an airworthiness directive (AD), a calibration had been
carried out six months prior to the accident in accordance with the
AD. The gauge calibration results recorded in the aircraft logbook
were as follows:
Left 10/46, 20/83, 30/117, 40/167, F/169
(Gallons/Litres)
Right 10/38, 20/65, 30/100, 40/145, F/164 (Gallons/Litres)
The aircraft fuel gauges, calibrated in US Gallons, were within
the required parameters but the quantities differed between the
left and right tanks for a given scale marking. This was
compensated for by having a calibration correction card fitted to
the aircraft. The calibration recordings in the logbook did not
include a value for E (empty). However the calibration card fitted
to the aircraft stated that for E indication on the gauge, the
tanks were to be read as empty.
A review of the aircraft's history revealed that, when being
operated by its previous owner on the east coast, it had been
involved in a similar accident in 1995 when it was force landed due
to engine power loss. The aircraft had also taken off with the fuel
tanks filled `to the tabs', and on that occasion it was estimated
that the pilot had operated the aircraft for approximately 1 hour
and 40 minutes when the engine lost power. The left fuel tank was
used for the entire flight and when examined at the accident site,
it was found to be empty.
Flight trip log
A company trip fuel log for the flight was found at the accident
site. This log was being used by the pilot to record flight times
and fuel usage from each tank for the flight. It had the following
annotations:
| Place | Time | Left | Right |
|---|---|---|---|
| KG | 0804 | 160 | 160 |
| 34 | 130 | 160 | |
| 04 | 130 | 130 | |
| RAW | 0928 | 106 | 130 |
| RAW | 1250 | 106 | 130 |
| 05 | 91 | 130 | |
| 1345 | 91 | 90 |
The trip fuel log noted that the fuel tanks contained 160L in
each tank on departure from Kalgoorlie.
The takeoff from Kalgoorlie had been conducted using fuel from
the left tank. The trip fuel log indicated that the aircraft had
consumed 54 litres from the left tank and 30 litres from the right
tank during the flight to Rawlina. Additionally the log indicated
that the pilot elected to remain on the left tank for the taxi,
pre-takeoff checks, takeoff and departure from Rawlinna thereby
carrying out both takeoffs using fuel from the left tank. The pilot
recorded an initial use of 15L from the left tank on departure from
Rawlinna, followed by 40L from the right. At 13:45 WST he changed
the selection to the left tank. About 28 minutes later, the engine
lost power.
Pilots Operating Handbook (POH)
The aircraft was fitted with a placard that provided information
in the form of a checklist in the event of major fuel flow
fluctuations and/or engine power surges. Additionally the POH
provided expanded procedures for inflight engine restarts and
excessive fuel vapour in the fuel system. The POH also noted that
if the propeller is windmilling, the engine will start
automatically within a few seconds. If the propeller has stopped
(possible at lower speeds), turn the ignition switch to START,
advance the throttle slowly from idle, and (at higher altitudes)
lean mixture from full rich.
The POH went on to indicate that with fuel quantities of less
than a quarter tank, prolonged uncoordinated turns or slips should
be avoided as it might uncover the fuel tank supply outlets and
starve the engine of fuel.
Engine out glide distance
The MAYDAY transmission made by the pilot placed the aircraft at
a height of 800 ft above ground level. This height, according to
the Maximum Glide graph in the POH, equated to approximately 1.2
NM, or approximately one minute of glide time from the time at
which the engine lost power to the impact point.