Cessna Aircraft Company 421C, HB-LRW

Sequence of events¹

On 30 August 2004, shortly before 1200 Western Standard Time,
the owner-pilot of a twin-engine Cessna Aircraft Company 421C
Golden Eagle (C421) aircraft, registered HB-LRW, commenced his
takeoff from runway 32 at El Questro Aircraft Landing Area (ALA).
The private flight was to Broome, where the pilot intended resuming
the aircraft delivery flight from Switzerland to Perth. The
available documentation indicated that the flight segments en route
to Australia had all been to international or major aerodromes.

The pilot of a Cessna Aircraft Company 210 (C210) and his two
passengers in the runway 32 parking area witnessed the takeoff.
Those witnesses reported that the C421 pilot carried out a
pre-flight inspection of the aircraft prior to boarding for the
takeoff. During that inspection, he was observed preparing for, and
conducting a fuel drain check under the left wing, and to have
removed some weed-like material from the right main wheel. He then
loaded a small amount of personal luggage into the aircraft cabin,
before he and the sole passenger boarded.

The C210 pilot witness, who reported having observed a number of
twin-engine aircraft operations at another aerodrome, did not
comment on the nature of the pilot's start and engines run-up
checks. The passenger witnesses reported that the pilot of the C421
made a number of unsuccessful attempts to start the left engine,
before reverting to starting the right engine. He then started the
left engine and moved the aircraft clear of the C210 in order to
conduct his engine run-up checks. The passenger witnesses reported
that during those checks they heard a 'frequency vibration' as the
C421 pilot manipulated the engines' controls.

The witnesses at the parking area reported that the C421 pilot
taxied the aircraft onto the runway and applied power to commence a
rolling takeoff.² They, together with
a hearing witness³ located to the
north of the ALA indicated that the engines sounded 'normal'
throughout the takeoff. Witnesses who observed the takeoff reported
that the aircraft accelerated away 'briskly'. The pilot witness
stated that the take-off roll and lift-off from the runway appeared
similar to other twin-engine aircraft takeoffs that he had
observed.

The witnesses at the parking area also stated that, shortly
after lift-off from the runway, the aircraft banked slightly to the
left at an estimated 10 to 15 degrees angle of bank and drifted
left before striking the trees along the side of the runway and
impacting the ground. There was no report of any objects falling
from the aircraft, or of any smoke or vapour emanating from the
aircraft during the takeoff. The aircraft was destroyed by the
impact forces and post-impact fire. The pilot and passenger were
fatally injured.

Personnel information

The 60 year old pilot was appropriately licensed and held the
relevant aircraft and other endorsements to conduct the flight. It
was reported that the pilot had accumulated more than 975 hours
experience flying the Cessna 421 B and C model aircraft over the
preceding 10 year period and had at least 2,100 total flying hours.
The pilot had flown about 50 to 60 hours in the aircraft since
March 2004 and held a valid Class 2 medical certificate. He last
underwent an electro cardiogram examination (ECG) in support of the
revalidation of his medical certificate, on 22 September 1999. That
included an annotation by the consulting doctor that the ECG was
'normal'. The pilot's family indicated that the pilot's personal
logbook would have been in the aircraft at the time of the
accident.

The passenger had accompanied the pilot for the majority of the
flight from Switzerland to Australia, but was reported to have been
a little nervous about takeoffs and landings.

The pilot and passenger arrived at the El Questro ALA at about
1330 on 28 August 2004 and landed on runway 14. They were reported
to have spent the next two days relaxing in the tourist resort and
homestead. During that time, the pilot was observed by staff to
have retired for bed by about 2200 and appeared from his room by
about 0930 each day. During his stay the pilot ate regularly, drank
alcohol only socially, and recounted many of his experiences during
the delivery flight to staff and other guests. That did not include
the discussion of any difficulty starting the aircraft engines, of
any anomalies during the after-start checks and procedures, or
during the flight to El Questro. The pilot was reported to be fit
and well and in good spirits on the morning of the accident.

Aircraft information

General information

All of the aircraft's original maintenance documentation was
reported to be on board the aircraft for the flight to Australia
and was subsequently destroyed in the post-impact fire. The loss of
the aircraft's maintenance documentation and historical records
precluded a thorough review of the aircraft's documentation
concerning compliance with applicable airworthiness directives and
service bulletins. Aircraft and engine maintenance and
airworthiness-related issues were reconstructed from available
secondary documentation, including: pilot and other relevant party
e-mails and facsimile messages, and data from international
regulatory and other agencies.

E-mail correspondence from the pilot dated 16 September 2003
indicated that the aircraft was equipped with the Robertson Short
Takeoff and Landing (R-STOL) Kit. That kit included the following
changes to the configuration of the aircraft:

• Replacement of the existing trailing-edge split flaps with
  R-STOL slotted flaps for use with the flaps extended 10°. The
  effect was to reduce the aircraft stall speed and the best
  single-engine climb speed.
• Introduction of a scissors-type aileron bell crank that allows
  symmetrical aileron droop with extension of the flaps. This had the
  effect of further reducing the aircraft stall speed.
• Introduction of a spring/cable flap/elevator interconnect to
  minimise pitch trim changes with flap extension or retraction.

In this instance, and as discussed in the wreckage examination
discussion at page 13, and the asymmetric or 'split' flap
discussion at page 19, the aircraft flaps were retracted. In that
case, the R-STOL kit would have had no effect on the aircraft
take-off performance, and the aircraft's performance would have
been in accordance with a standard C421C in a flaps retracted
configuration.

The aircraft's take-off weight and centre of gravity were
estimated by the investigation to be within the limits published in
the C421C's Pilot's Operating Handbook (POH). The POH also included
a Normal Takeoff Distance prediction chart. Application of the
estimated aircraft take-off weight and reported ambient conditions
for a normally configured C421C to that chart resulted in a
predicted take-off roll that approximated the estimated take-off
distance reported by the witnesses located at the runway 32 parking
area.

Aircraft history

The aircraft was manufactured in the United States (US) and was
US-registered until 1992, when it was exported to Switzerland. It
was operated in Switzerland in the private category until purchased
by the pilot in December 2003. E-mail correspondence from the pilot
and dated 4 December 2003 indicated that a Swiss maintenance
organisation would commence a 'new annual/200-hours check' on 10
December 2003. The available aircraft maintenance records indicated
that the total aircraft flight hours were 3,192 hours 40 minutes as
at 10 December 2003. That corresponded with the initial entry made
by the pilot in the aircraft maintenance record after a flight in
the aircraft on 2 March 2004. The last entry in the aircraft's
maintenance record, that was available to the investigation, was a
total of 3,233.6 aircraft flight hours at Ahmedabad, India on 9
August 2004.

A number of aircraft anomalies or maintenance requirements
needed resolution while the aircraft was en-route from Switzerland
to Australia. They included:

• In Malta, where an approved maintenance facility:
• replaced leaking right engine push rod tube seals
• replaced a faulty left engine vacuum pump
• identified a leaking right main landing gear oleo and
  disassembled the landing gear oleo and installed new packings and
  'o' ring seals before reinstalling the oleo on the aircraft.
• In Cyprus, where a crack was discovered in the right engine
  crankcase that necessitated the replacement of that engine.
• In the United Arab Emirates and Oman, where a number of
  attempts were made by local engineering companies to resolve a
  problem with the operation of the aircraft's landing gear. That
  ultimately required the replacement of a selector valve and
  hydraulic line.

In addition, the pilot established communications with a
twin-engine Cessna owners group in an effort to fault analyse
ongoing problems with:

• the left and right hydraulic pumps that supplied the necessary
  hydraulic pressure to extend and retract the landing gear, and
• the right alternator warning light, which was reported to
  commence flickering after about 30 minutes flight time. That
  anomaly was reported to have commenced in July 2004.

The resolution or otherwise of those two anomalies was not
documented by the pilot.

On arrival in Australia, a 50-hourly inspection of the aircraft
was carried out by a Broome aircraft maintenance company on 26
August 2004. The total airframe hours at the time of that
inspection were not noted on the inspection work sheet. At the
conclusion of the inspection, a company engineer carried out a
ground run of the engines with the pilot accompanying him in the
right front seat. The engineer reported that during that ground
run, both engines started on the first attempt and ran normally
without any anomalies being noted.

Engines and propellers

The aircraft engine details were as follows:

The available right engine documentation indicated that it had
been certified by a US Federal Aviation Administration-approved
maintenance organisation. In addition, the documentation confirmed
that the engine complied with all of the engine manufacturer's
service bulletins and service letters that affected the engine up
to and including 17 May 2004.

The details of the propellers, including their relationship to
their respective engines, were determined from examination of the
pilot's e-mail correspondence and the aircraft sales brochures, and
included:

Meteorological information

A Bureau of Meteorology (BoM) post-accident assessment of the
wind at the ALA at the time of the accident was that it would have
been a light southerly at around 5 kts. An estimation of the
ambient temperature and humidity at the ALA was not included in the
BoM assessment. The BoM indicated that any difference between the
BoM estimation of the prevailing wind and that reported by any
witnesses could have been due to local topographical effects at the
site. The BoM advised that a possible influencing factor on the
aircraft's takeoff could have been the presence of a dust
devil⁹, but that the presence of that
phenomenon would also require confirmation by any witnesses at the
scene of the accident.

The witnesses at the landing area estimated that the wind
affecting the runway was south-easterly at 5 to 10 kts at the time
of the takeoff. There were no dust devils reported in the vicinity
of the runway at that time, and another pilot who was conducting
charter work in the vicinity of the landing area indicated that
there was minimal thermal activity.

Aerodrome and communications information

Aerodrome

The El Questro ALA, designation YEQO, is located at 16°00.5'S,
127°58.5'E and is at an elevation of 300 ft above mean sea level.
The dirt runway is aligned south-east (runway 14) to north-west
(runway 32) and is 1,400 m long and about 15 m wide. Wind socks are
located at the northern side of the threshold to runway 14 and at
the tourist resort homestead, which is located about 1 km
south-east of the landing area.

The manager of the tourist resort indicated that when making
bookings with the resort, visiting pilots generally included that
they were 'self-fliers'. That was the case with the occurrence
pilot. In addition, it was reported that the pilot telephoned the
resort manager on the morning of 28 August 2004 and nominated a
SARTIME¹⁰ for his arrival at El
Questro. During that call, the pilot confirmed that he was
comfortable with the location and details of the ALA. Other
twin-engine aircraft of similar size to the C421 Golden Eagle were
reported by the resort manager to have operated to, and continue to
operate to, the El Questro ALA.

It was reported that in mid March each year, just prior to the
commencement of each tourist season, resort staff conducted a
routine inspection of the runway and environs. As a result of those
inspections, any newly-growing vegetation was cleared from the
runway and its surrounds, runway markers were repainted as required
and other actions were undertaken by resort staff as and when
required. In addition, the resort manager stated that he routinely
consulted with aircraft operators who regularly fly to the resort,
in order to confirm the ongoing suitability of the ALA for aircraft
operations.

Communications

The charter pilot indicated that just prior to 1200, he
exchanged a number of radio transmissions with the pilot of an
unknown aircraft on frequency 126.7 Mhz in order to coordinate that
pilot's takeoff from the ALA. The charter pilot reported observing
a plume of smoke from the vicinity of the ALA shortly thereafter,
and that he did not hear a distress radio transmission. There was
no facility at the ALA to record pilots' radio transmissions.

Wreckage information

The impact forces and post-impact fire sustained by aircraft
structures in occurrences of this type can result in erroneous
control position indications. In general, the position of the
flight controls after impact cannot be relied upon as evidence of
the aircraft's pre-impact configuration.

Overview of accident site and aircraft wreckage

The accident site was located on level ground, alongside a dry
creek bed about 106 m to the left of the runway centreline and
abeam a point on the runway about 888 m from the runway 32
threshold. A photograph of the general location of the accident
site is at Figure 1. Groupings of rocks were located about the site
and the surrounding light scrub was interspersed with isolated
larger Boab and other trees.

Figure 1: General location of the accident
site

A number of trees to the left of the runway were struck by the
aircraft before it impacted the ground. Those trees were oriented
along a line at about 15° to the left of the runway heading. Laser
range equipment was used to measure the distances of those tree
strikes from the aircraft wreckage. Trigonometry was then applied
to the laser ranges in order to estimate the height of the strikes
above ground level as follows:

• The initial tree strike was to a tree located about 66 m to the
  left of the runway centreline and at an estimated height of about
  8.2 m (27 feet (ft)).
• The final tree that was struck prior to ground impact was
  located about 97 m from the runway centreline. That tree was struck
  at an estimated height of about 10.7 m (36 ft). The location of the
  left wing tip and remnants of the left navigation light in the
  immediate vicinity of that tree indicated that tree strike had been
  by the left wing.

The aircraft impacted the ground about 33 m beyond the last
tree, in a left wing low attitude and cartwheeled
counter-clockwise. The right wing and tail then struck the ground.
During the impact sequence, the right engine separated from the
airframe mounts and was thrown about 26 m from the main wreckage
and the tail section separated from the aircraft. The main wreckage
came to rest upright, with the nose of the aircraft facing
south-east. All structural components and flight control surfaces
were accounted for in the vicinity of the impact point. A severe
post-impact fire destroyed the majority of the aircraft's fuselage,
wings, tail section, cockpit and cabin, and damaged the left
engine. The right engine sustained minor fire damage from a scrub
fire that was started by the aircraft fire. A photograph of the
aircraft wreckage is shown at Figure 2.

Figure 2: Aircraft wreckage

Wreckage examination

The investigation conducted a post-accident inspection of runway
32 from the threshold of the runway to a point on the runway abeam
the ground impact point. That inspection found no evidence of any:
bird or other animal remains; gouges, scrapes or other abnormal
ground marks; or the presence of any detached aircraft items or
components.

Very few ground impact scars or marks were able to be examined
at the accident site due to them having been partially obliterated
by the vehicles and personnel involved in the initial fire-fighting
and rescue response. However, a number of rocks located in the dry
creek bed had evidence of propeller impacts at substantial
propeller revolutions per minute (RPM).

Both wing structures were destroyed by the fire. The right wing
forward attachment point was intact and the aft spar was fractured
in overload consistent with upward loads in excess of design
limits. The left wing structure had separated at the wing spar
outboard of the engine nacelle, having also failed in overload due
to the ground impact.

The fire severely damaged the aircraft fuel system. Both wing
tanks were destroyed and their associated auxiliary pumps were
severely damaged. The left and right over-wing filler caps were
secure. Damage during the impact, and the post-impact fire
precluded the recovery of a fuel sample from the wreckage.

Both of the engines' air boxes and both turbocharger compressor
turbines, together with their associated valves were fire-damaged.
On-site examination of the turbochargers did not reveal any
anomalies, or foreign object, or other damage that might have
adversely affected their operation. Deformation damage to the right
engine's exhaust system was consistent with engine operation at
ground impact. The left and right engines were recovered from the
accident site and transported to an authorised overhaul facility
for subsequent inspection under the supervision of the Australian
Transport Safety Bureau (ATSB).

All six propeller blades separated from their respective hubs
during the ground impact. Four intact propeller blades and segments
from the remaining two blades were recovered from the accident site
for subsequent technical examination.

Both engine propeller hubs flanges displayed indications of
rotation at high RPM at the time of ground impact and were
recovered from the accident site for subsequent technical
examination. Severe impact damage to the propeller static stops
prevented any determination of the propeller pitch settings at the
time of ground impact. All of the propeller counterweights were
recovered and examined on site. That examination identified
overload of the threaded inserts, to the extent that a number of
the counterweights had separated from their housing. That
corroborated the earlier evidence of high engine RPM at the time of
ground impact.

All of the cockpit and cabin seats and structures, along with
the seat belts and their attachments, were destroyed by the fire.
Most of the cabin fittings and cockpit, including instrumentation
and switches were also destroyed. The nature of the damage to the
switches was such that their position prior to the ground impact
could not be ascertained. The control columns and flap actuator
were destroyed in the fire and the engine controls, and the cockpit
instruments and radios were severely damaged. While that prevented
the examination of most of the instruments, the attitude indicators
and annunciator panel were recovered for subsequent technical
examination.

Pre-impact flight control continuity was confirmed for the
elevator and rudder control surfaces. Flight control continuity was
evident for the ailerons, from the cockpit controls aft to the
point where the wing impact damage occurred. A continuity check of
the engine controls was not possible as a result of the fire
damage. The nature of the damage to the right flap indicated that
it was retracted at the time of ground impact. The more extensive
damage to the left flap precluded a definitive assessment of its
position at ground impact. The landing gear was fully extended. The
tyres were destroyed by the fire. The severe disruption of the tail
structure rendered the determination of the aircraft trim
measurements inconclusive.

Examination of components recovered from the wreckage

The left and right engines were disassembled and inspected at an
authorised overhaul facility under the supervision of the ATSB and
with the engine manufacturer's representative in attendance. That
inspection found no evidence of internal mechanical failure within
either engine, or of their associated accessories or components
that would have prevented the normal operation of either engine
prior to the accident.

Technical examination of the propellers and propeller segments
indicated multiple high-energy hard object impact signatures on all
blade surfaces. Several of those impacts were of sufficient force
to have caused ductile shear of the outer airfoil sections. In
addition, there was backward curling or loss of material from the
blades' leading edges, with associated chordwise scoring and
gouging across the airfoil sections. That was consistent with each
propeller being actively driven by a comparable amount of power
from within the respective engine's upper operating range at the
time of ground impact.

Both engine propeller hubs sustained similar multiple fractures
to their aluminium alloy housings that was consistent with ductile
overload during the accident sequence. There was no indication of
any pre-impact cracking or manufacturing defects. The propeller
hubs were exposed to gross bending loads through the blade sockets,
which was assessed as being consistent with the magnitude of the
impact forces that damaged the propellers.

The technical examination of the primary attitude indicator
proved inconclusive due to the extensive heat damage to the
instrument. There was evidence of rotational scoring to the inside
of the secondary attitude indicator's instrument case and to the
gyro armature, which indicated that pneumatic drive was available
to the aircraft's vacuum instruments at the time of ground
impact.

The filaments from the annunciator panel globes were distorted
and encased in molten glass as a result of the fire. That prevented
the analysis of whether any of those lights had been illuminated at
the time of ground impact.

Medical and pathological information

A review of the pilot's aviation-related medical records and the
results of the pilot's post mortem examination found no evidence of
any pre-existing medical disease, sudden illness or incapacitation
that may have affected his ability to control the aircraft.

Fire

There was no report by the witnesses to the takeoff, or
evidence, of an in-flight fire. The tourist resort volunteer
fire-fighting crew responded to the accident site and scrub
fires.

The source of the intense post-impact fire was fuel that had
spilled from the ruptured wing fuel tanks. The ignition source of
the fire could not be confirmed, but was likely the hot engine
exhausts.

Survival aspects

The emergency locator transmitter (ELT) was destroyed in the
post-impact fire. There was no report from the charter pilot, or
from the search and rescue authorities to indicate that the ELT had
activated on ground impact.

The destruction of the cockpit and cabin from the combined
effects of the impact forces and fire rendered the accident
non-survivable.

Tests and research - aircraft fuel

The last recorded refuel of the aircraft was the addition of 594
litres of aviation gasoline 100 at Broome on 27 August 2004. It was
reported that the pilot refuelled the aircraft's tanks to capacity.
The investigation team quarantined a sample of that fuel for
subsequent analysis by an approved National Association of Testing
Authorities facility. That analysis indicated that the fuel:

• was clear and bright
• was free from water and sediment
• conformed to specification for aviation gasoline 100.

Examination of the Broome fuel supplier's records confirmed that
18 other aircraft were refuelled from that source after the
occurrence aircraft on that day. There were no reports from the
pilots of those aircraft of any fuel-related problems.

There were no aircraft refuelling facilities at El Questro.

Additional information

Use of aerodromes

Civil Aviation Regulation 92 places responsibility for ensuring
that an aircraft landing area is suitable for landing or takoff
with the pilot in command. In addition, the regulation requires the
pilot to have regard to the prevailing weather conditions and other
circumstances affecting the proposed landing or takeoff. The
determination by a pilot of which other circumstances should be
considered is not stated in that regulation.

Civil Aviation Advisory Publication (CAAP) 92-1(1):
Guidelines for Aeroplane Landing Areas includes guidance
on the factors that may be considered by a pilot when determining
the suitability of a potential landing area. While there was no
evidence that the pilot had considered the requirements of the CAAP
prior to planning his arrival at the El Questro ALA, the
investigation applied the minimum landing area physical
characteristics recommended by the CAAP to the pilot's takeoff from
runway 32 until the point at which the aircraft first struck a tree
to the left of the runway. That examination determined the
following relevant recommended parameters for the takeoff:

• minimum runway width - 15 m
• required runway length - about 624 m
• suitable lateral transitional slope, which the CAAP notes could
  allow for a desirable area of increased lateral clearance during
  the takeoff and may reduce wind shear if near tall trees - maximum
  obstacle height of about 7.2 m at 66 m from the runway
  centreline.

The pilot's family indicated that the pilot had operated at a
gravel airstrip in the south-west of Western Australia on a number
of occasions over the previous 3 years. In addition, the family
reported that the pilot drove to El Questro in June 2003 and,
during that visit, most likely observed the ALA.

Preparation for flight

The pilot submitted a flight notification to Airservices
Australia on the morning of the accident, for a 2 hours 15 minutes
flight under the Visual Flight Rules from El Questro to Broome. The
investigation estimated that 740 lbs of fuel remained after the
reported 2 hour flight from Broome to El Questro, and the POH
stated that 50 lbs of fuel was required for 'taxiing for takeoff'.
That, and the endurance nominated by the pilot in the flight
notification, indicated that sufficient fuel was carried for the
planned flight to Broome.

The POH stated that the aircraft equipment included a control
column lock that restricted control column movement and held the
ailerons in a neutral position and the elevators at about 10°
trailing edge down. The aircraft manufacturer indicated that the
design of the control column lock was such that, if inadvertently
left engaged by a pilot, the aircraft would be unable to takeoff.
The available documentation indicated that an optional rudder gust
lock was also included in the aircraft equipment. The POH stated
that engagement of that lock required the rudder to be centralised
and the elevators to be moved to the fully 'down' position.
Disengagement of the rudder lock was possible either manually
during the aircraft pre-flight, or automatically as the elevator
was moved up through the 6° 'down' position. Due to the damage to
the aircraft, the investigation was unable to confirm the position
of these locks.

Manufacturer data

The POH promulgated the necessary checks to be carried out by
the pilot when operating the aircraft. That included confirmation
of the selection of the left and right engines to the left and
right main fuel tanks respectively as part of the following checks:
before start, before takeoff and during the descent. In addition,
the POH stated that:

A takeoff with one main tank full and the opposite tank low on
fuel creates a lateral unbalance. This is not recommended since
gusty air or premature lift-off could create a serious control
problem.

The published take-off technique included the requirement for
the pilot to raise the nose wheel at 95 kts indicated air speed
(KIAS) and lift the aircraft from the runway at 100 KIAS. In
addition, the POH included a description of the aircraft stall
including that:

• the stall characteristics are conventional
• there is an aural stall warning device that operates at 5 to 10
  KIAS above the stall in all configurations
• the stall is preceded by a mild, aerodynamic buffet, which
  increases in intensity as the stall is approached
• the power-on stall occurs at a very steep pitch angle, either
  with or without flaps extended
• it is difficult to inadvertently stall the aircraft during
  normal manoeuvring.

Stall speeds were published in the POH for a number of aircraft
configurations. None of those configurations reflected the
aircraft's takeoff configuration. At the estimated aircraft weight
and with wings level, the maximum stall speed for the published
configurations was calculated as 83 KIAS. The increase in stall
speed at 15° angle of bank for all published configurations was
about 2 KIAS.

The manufacturer's Pilot Safety and Warning Supplements
identified a rare, but potentially serious problem known as 'split
wing flaps'. Split or asymmetric wing flaps may result from a
mechanical failure in the flap system and cause the flap position
on one wing to differ from that of the opposite wing flap. The
result is a tendency for the aircraft to roll in the direction of
the retracted flap. Depending on the experience and proficiency of
a pilot, the manufacturer indicated that any rolling tendency
caused by a split flap situation may be controlled with opposite
aileron. In addition, there was the potential for a pilot to apply
differential power in a multi-engine aircraft to assist in managing
the condition. This is discussed further in the Analysis under
'Takeoff'.

1. Only
   those investigation areas identified by the headings and
   subheadings were considered to be relevant to the circumstances of
   the occurrence.
2. A
   takeoff commenced by a pilot without pausing an aircraft in a
   stationary position on a runway, or decreasing the speed of an
   aircraft on arriving at a runway intended for use for a
   takeoff.
3. A
   witness that heard, but did not observe the takeoff.
4. On 14
   November 2003, the pilot submitted an application to the Australian
   Civil Aviation Safety Authority (CASA) to reserve an Australian
   aircraft registration in anticipation of registering the aircraft
   in Australia. That reservation was granted by CASA.
5. Based
   on the 50-hourly inspection that was carried out in Broome on 26
   August 2004 being conducted within the potential 10-hour extension
   period that had been authorised by the Swiss regulatory
   authorities. That was between 50 and 60 hours after an annual/200
   hours check that was reported as being commenced in Switzerland on
   10 December 2003, and included the 2.0 hour flight to El Questro
   ALA.
6. Derived
   from e-mail correspondence from the pilot dated over the period 16
   September 2003 to 24 August 2004 and the available aircraft and
   engine documentation.
7. Derived
   from the right engine Export Certificate of Airworthiness of 19 May
   2004 and e-mail correspondence from the pilot dated 29 July to 19
   August 2004.
8. Precise
   date not available.
9. A
   miniature whirlwind with the potential to be of considerable
   intensity, and to pick up dust and perhaps other items and carry
   them some distance into the air.
10. The
    time nominated by a pilot for the initiation of Search and Rescue
    action if a report has not been received by the nominated
    unit.