Local safety action
The Sports Aircraft Association of Australia (SAAA) announced in
July 2003 that it is scoping the development and implementation of
a four-stage flight safety assistance program for members. The
program adopts some of the existing programs run by the association
and will develop into a broader program incorporating aspects not
currently covered.
The intention is to encourage members to sign onto the total
program while still giving them the choice under the experimental
rules.
During July /August 2003, the Association's technical
coordinator travelled overseas to meet with United States of
America Experimental Aircraft Association officials to discuss that
organisation's flight advisor program.
An outline of the SAAA intended program was introduced to SAAA
members in October 2003.
The Association will also include a note and link to this report
on its website www.saaa.com.
Planned activities on the 9 December 2002 flight had indicated
that the aircraft became laterally unstable as the aircraft
approached the stall speed. Recorded flight data indicated that the
aircraft also entered a stall during the flight on 9 December, even
though this was not planned. It is possible that this stall was an
unplanned activity. There was no evidence that any of the
aircraft's performance and handling characteristics encountered in
this unplanned stall, such as stalling airspeed, were considered
when preparing for the flight when the accident occurred, when
stalls were part of the test program.
Lateral instability, as the aircraft speed approached the stall
speed, had been experienced and noted in a previous flight. The
test flight program did not include a lateral stability test for
the flight and the recorded aircraft data did not indicate that a
lateral stability test had been undertaken on the flight. It is
possible that the notes referred to a tendency for the aircraft to
drop a wing as it approached the stall, or stalled, as similarly
experienced during the accident flight.
During the flight when the accident occurred, the aircraft
departed controlled flight from a deliberately induced stall during
a test flight. The aircraft then descended rapidly, at an airspeed
that was not consistent with a stalled or spinning
configuration.
The aircraft instruments displayed a stall speed that was
significantly below the actual stall speed in that configuration.
It is possible that the stall occurred before the flight crew
expected it.
The aircraft was based on an established aircraft design, but
had significant design changes from the original. Those design
changes were likely to have changed the performance and handling
characteristics of the aircraft and the cumulative effect of those
changes would have been hard to predict.
The test flight program had been developed in accordance with
some of the approved advisory material. The advisory material gave
detailed guidance on what was to be done, and how it should be
done. It did not give detailed guidance on defining what should be
expected during the test program, and what to do if something
unexpected occurred during the program. As an example, a particular
aircraft design is normally expected to stall at a particular
airspeed for a given configuration and flight condition. The
particular handling characteristics as the aircraft approaches and
passes through a stall should also be predictable and expected.
When these characteristics are examined during a test flight, they
would be expected to fall within a defined range. The guidance
material did not detail what to do if any of the performance or
handling characteristics were outside the expected ranges.
There was no evidence of a significant risk management process,
other than preflight briefings conducted by the pilot of the first
two flights, throughout the design, construction, or test flight
program development for the aircraft. Such a program could have
assisted in identifying hazards and their attendant risks, and for
managing them appropriately from initial construction though to
certification. While there was no requirement for an owner/builder
to have a risk management process, such a process would have been
prudent considering the significant changes made to the
aircraft.
The test program did not incorporate flight instrument
calibration and therefore the accuracy of the flight instruments
was unknown. It would not have been possible to confidently
establish the exact speeds at which the aircraft's handling and
performance were assessed.
The test flight program only required one person on board the
aircraft for test flights. The investigation was not able to
identify an operational reason for the owner/builder to be on board
the aircraft.
History of the flight
The Lancair, registered VH-CIV, was a homebuilt aircraft
operating under an experimental certificate of airworthiness. The
owner had recently built the aircraft and had commenced a test
flight program. The aircraft departed with a test pilot occupying
the pilot seat, and the owner/builder occupying the right seat.
Witnesses reported seeing the aircraft flying in the Drysdale area
before descending steeply. It subsequently impacted the ground and
the two occupants were fatally injured.
The pilot departed from Point Cook and flew along the coast,
southwest of Point Cook aerodrome, at altitudes between 3,000 ft
and 4,000 ft. After crossing Port Phillip Bay to the Bellarine
Peninsula the pilot climbed the aircraft to between 5,000 ft and
6,000 ft. Recorded flight data indicated that the aircraft was
slowed, and stalled at an altitude of 5,200 ft. The pilot recovered
from the stall, but the aircraft entered another stall during the
recovery at 4,950 ft. The pilot recovered the aircraft from that
stall, and then repositioned it and entered a third stall at an
altitude of 6,200 ft. The aircraft rolled at the initiation of the
stall, and continued to roll as it then descended rapidly,
accelerating to approximately 150 kts at an angle of approximately
40 degrees from the horizontal, with low engine power. The engine
power increased shortly before the aircraft impacted the
ground.
The aircraft impacted the ground upright, with the wings level,
at a pitch angle of 40 degrees nose down. The landing gear was
retracted at the time of impact, and the flaps were either
completely or nearly retracted. There was no indication of any
mechanical failure prior to impact. The accident was not
survivable.
Flight crew
The pilot was an experienced ex-military pilot with 6,500 hours
total aeronautical experience, including experience over many years
in aircraft with a wide range of performances.
The owner/builder had a Commercial Pilot (Aeroplane) Licence
issued 16 October 2001. He had 352 hours total aeronautical
experience in a range of general aviation aircraft with a level of
complexity and performance up to four-seat single-engine aircraft,
with a constant speed propeller and retractable landing gear.
Aircraft
The aircraft was originally being constructed to comply with the
requirements of Civil Aviation Safety Authority (CASA) Civil
Aviation Order (CAO) 101.28. During construction, the experimental
designation concept was developed and the aircraft construction was
subsequently changed and completed in accordance with the
experimental designation under Advisory Circular (AC) 21.4(2)
issued September 2000. The certification requirements in the
experimental category were less prescriptive than those in CAO
101.28 as experimental aircraft are not type-certificated.
'Experimental' is not a category but rather a designation. It is
also important to note that an experimental certificate does not
attest to an aircraft being fully airworthy (Civil Aviation Safety
Authority Advisory Circular 21.1(1) - Aircraft Airworthiness
Certification Categories and Designations Explained - Revised
December 2000).
The aircraft was based on a Lancair IV-T kit plane that was
originally designed to use a high-performance piston engine. The
owner/builder decided to replace the engine with a turbo-propeller
engine and sought assistance from a number of people to redesign
the aircraft to accommodate the new engine.
Documentation indicated that during construction, numerous
changes had been made to the original design, including the engine
type and the design of the aircraft from the firewall forward. The
propeller had been modified by removing 20 cm of the propeller
tips. No evidence was found to indicate that any form of risk
assessment had been undertaken to consider the safety implication
of these aircraft design changes. A risk assessment was not
required for aircraft constructed under the experimental
designation.
Aircraft equipment
The aircraft was equipped with an integrated electronic flight
information system (EFIS) comprised of a number of data acquisition
units and three liquid crystal multi-function display (MFD) units,
that could be configured to present operational information in
different ways. The instrumentation system received data from a
variety of sources, and integrated that data to present operational
information to the pilot. Each MFD also contained a memory unit
that recorded information that was sent to it. This information was
used by the ATSB to determine the flight profile prior to the
accident.
The MFDs could be selected by the pilot to display primary
flight information, navigation information, or engine system
information. The primary flight information consisted of an
electronically generated artificial horizon display upon which a
number of other information displays were overlayed. Indicated
airspeed (IAS) was also displayed on the left side of this display.
The IAS was presented as a vertical tape display of airspeed with a
range of approximately 100 kts, in increments of 10 kts. The actual
airspeed was also displayed numerically on the left side of the
artificial horizon display, adjacent to the IAS speed tape display.
The airspeed tape display contained a number of coloured regions to
indicate various speed ranges and included the stall speed of the
aircraft. The stall speed was dynamically generated and changed
with varying flight loads on the aircraft. The displayed stall
speed was known as the G-corrected stall speed. The EFIS derived
the G-corrected stall speed from the aircraft's static 1G stall
speed. The 1G stall speed had to be manually entered into the EFIS.
The aircraft instrumentation system had been programmed with a 1G
indicated stall speed of 69 kts with flaps and landing gear
retracted.
The aircraft was also equipped with a video camera mounted on
the ceiling just behind the two front seats, which was aimed at the
instrument panel. This camera operated for some of the test
flights, and some of the recordings were recovered from the camera
after the accident.
The original aircraft design (with a piston engine) had a
declared indicated stall speed of 84 mph, or 73 kts with flaps and
landing gear retracted. The Comparative Aircraft Flight Efficiency
(CAFE) foundation test flight of this version of the aircraft type
recorded a stall speed of 78 kts with flaps and landing gear
retracted. That test flight was conducted with a calibrated
pitot/static boom, so the indicated airspeed would have been
accurate in that instance. A theoretical aerodynamic calculation
for the accident aircraft indicated a stall speed of 82 kts.
Recorded information indicated that the aircraft stalled at 82 kts
at the commencement of the accident sequence.
A flight path marker symbol, in the centre of the primary flight
display, indicated the current pitch attitude of the aircraft. At
an airspeed of 20 kts above the G-corrected stall speed, an amber
pitch limit indicator symbol appeared above the flight path marker.
The pitch limit indicator symbol moved down toward the flight path
marker symbol as the airspeed decreased towards the stall speed. At
5 kts above the stall speed, the pitch limit indicator symbol
turned red. At the point of stall, the pitch limit indicator symbol
overlayed the flight path marker symbol. Coincident with the pitch
limit indicator symbol changing to red, an aural annunciator would
repeat a voice warning of 'stall' and a red stall flag symbol would
display in the bottom left corner of the primary flight
display.
The aircraft was also equipped with an angle of attack sensing
device that used pressure information from two ports on the upper
and lower sides of the left wingtip to derive the angle of attack.
This instrument could have indicated when the aircraft was
approaching a stall. The investigation did not determine if it had
been calibrated before the accident flight.
During a test flight on 9 December 2002, the test pilot had
decelerated the aircraft until it was approaching the stall as a
part of the test flight program. Written records from that flight
noted:
'A/c [aircraft] becomes laterally unstable below 80
Kts.'
Recorded flight data indicated that the aircraft stalled three
times during this flight, from speeds of 72, 75 and 76 kts. The
test pilot had also noted:
'Close to stall at 75 Kts with 10 [degrees] flap
Close to stall at 72 Kts with full flap'.
Video recordings from the flight indicated that the aircraft had
stalled, and rolled 45 degrees to the left, and then 45 degrees to
the right of horizontal during the recovery from the stall. Stalls
were not a part of the test flight program for the flight.
Test program
A friend of the owner/builder developed a program for the flight
testing of the aircraft. That program followed the guidelines in
the Federal Aviation Administration (FAA) Advisory Circular 90-89A
- Amateur-built Aircraft and Ultralight Test flighting Handbook.
The CASA Advisory Circular 21.4(2) - Amateur Built Experimental
Aircraft - Certification, advised that CASA:
'...most strongly urges [Amateur-built experimental
aircraft builders] to make detailed reference to [this document],
prior to their flight programs commencing, and [to] follow the
guidance provided.' (section 14.4).
The test flight program was detailed, and was clearly developed
in accordance with the recommendations of Advisory Circular 90-89A.
Neither the advisory material, nor the test flight program
considered action to be taken if aircraft handling or performance
produced unexpected results.
CASA Advisory Circular 21.4(2) stated:
'14.5 Those undertaking test flight programs may also
derive benefit in consulting the following additional references,
as applicable to the class of aircraft involved:
'(a) CAA publication dated January 91, Flight Test Guide for
Certification of CAO 101.28 Category Aeroplanes...'
This document recommended calibration of aircraft flight
instruments, so that the limits of the flight envelope could be
accurately determined. The test flight program for the accident
aircraft did not include the in-flight calibration of aircraft
flight instruments, including the airspeed indicator. Comparison of
the recorded airspeed from the satellite navigation system, fitted
to the aircraft as apart of the EFIS, with the recorded airspeed
from the pitot/static system showed no inaccuracy in airspeed
indication.
There was no evidence that any significant risk assessment was
undertaken during construction of the aircraft and in the
development of the test flight program. Such a risk assessment
could have examined the planned activities and considered any
potential hazards for their likely impact on the aircraft's safety
during test flights.
The friend who developed the test program stated that he
conducted the first two flights of the aircraft, but subsequently
did not participate any further in the test program. Prior to those
initial flights, he conducted an operational pre-flight briefing
with the owner. These briefings included hazards and potential
actions. The investigation did not determine whether the test pilot
for the accident flight conducted similar operational pre-flight
briefings for subsequent flights.
There was no evidence that any significant re-evaluation of risk
was done during the subsequent conduct of the test flight program.
Such a risk assessment process could have examined the results of
test flights for hazards that became apparent from analysis of
observations and data from each flight. This could have allowed for
a considered assessment of any risk mitigators for their likely
impact on the aircraft's safety during subsequent test flights, as
the aircraft flight envelope was expanded. For example, if
unexpected handling characteristics had been encountered during a
stall sequence, then previously identified mitigation procedures,
such as moving the centre of gravity forward, could have been
considered.
Aircraft design
An aircraft operated as an experimental aircraft does not have
to comply with any specific design. Builders may comply exactly
with a design, or may deviate from that design as much as they
wish, or may build an aircraft independent of any previously
developed design.
If an aircraft is built mainly in accordance with an established
design, but with some design differences, then it may perform
differently from an aircraft built exactly in accordance with that
established design. If design differences are incorporated one at a
time, then it is possible to measure the effect of any single
design difference. If many design differences are incorporated at
one time, the effect of a single design difference on the behaviour
of the aircraft may be impossible to predict due to the compounding
effect of other incorporated design differences. The accident
aircraft had been constructed with many differences compared with
the original Lancair IV-T design.
Required persons on board during test
flights
A CASA delegate had issued a special certificate of
airworthiness authorising flight in accordance with the test flight
program. The approval included operating limitations for the test
flight program, such as geographical limitations, minimum weather
conditions for flight and the maximum number of persons to be on
board the aircraft.
Test flights are hazardous compared with normal flight.
Accordingly, there is normally a requirement for only operational
persons to be on board an aircraft during a test flight. The
special certificate of airworthiness under which the accident
flight was made stated 'Only personnel essential for the conduct of
the testing may fly on board the aircraft. The carriage of
passengers is prohibited.'
This aircraft type was normally flown as a single crew
operation, and the cockpit of this aircraft was configured for
single crew operation. There was no evidence that the test
flighting required two persons on board.