Abstract
On 7 February 2003, a Raytheon (Beech Aircraft Corporation) BE76 Duchess aircraft, registered VH-JWX, was being flown for the purpose of an initial-issue multi-engine command instrument rating flight test. A Civil Aviation Safety Authority (CASA) designated Approved Testing Officer (ATO), who was also the pilot in command of the flight, was to conduct the test. The other pilot was the flight test candidate who was flying in a 'dual' capacity because he was not yet qualified to conduct the flight. The candidate had to demonstrate to the ATO a number of manoeuvres in order to pass the flight test. Some of these manoeuvres included a demonstration of aircraft handling during a simulated engine failure. One manoeuvre required a demonstration of handling the aircraft when an engine failure was simulated during or after a takeoff. The candidate reported that he and the ATO had agreed, prior to the flight, that simulated engine failures would not be conducted below a height of 500 ft above ground level (AGL).
The candidate had planned the flight to depart from Bankstown, NSW, and fly via Wollongong and Camden before returning to Bankstown. The planned departure time was 1915 Eastern Summer Time, however the aircraft did not depart Bankstown until 2038, which was 16 minutes after the end of daylight.
During interview, the candidate advised that they had conducted instrument airwork at Wollongong, including procedures with simulated engine failures, before they flew on to Camden.
At 2134, the candidate made two broadcasts on the Camden mandatory broadcast zone (MBZ) frequency, announcing that he was in the circuit area at Camden and intending to conduct an approach to runway 06 for a touch-and-go. Soon after takeoff from the touch-and-go, a witness observed the aircraft flying at a low height and parallel to the runway, with the landing gear retracted. Another witness reported hearing two loud impacts. That witness observed that the aircraft had impacted the ground and had caught fire, beyond the departure end of the runway and to the right of the runway 06 extended centreline. The candidate and the ATO received severe burns as they evacuated the aircraft. The ATO died during the following morning.
The candidate stated during interview that, shortly after takeoff from the touch-and-go, as he was handling the landing gear retraction switch, the ATO simulated a failure of the right engine. The candidate said that he continued to retract the landing gear and manoeuvred the aircraft to maximise its climb performance, but did not handle the engine controls. He reported that because the aircraft was not achieving satisfactory performance, he called for the ATO to apply full power. He said that soon after this call, there was a loud impact noise. Moments later, the aircraft collided with the ground.
An examination of the accident site revealed that the aircraft's right wing had contacted a large tree approximately 296 m beyond, and 133 m right of, the runway 06 extended centreline. The aircraft had climbed approximately 50 ft from where the witness saw the aircraft flying parallel to the runway to the point where the aircraft collided with the tree. The aircraft then appeared to have descended slightly into rising terrain, before it collided with the ground approximately 210 m beyond the tree. Score marks on the ground from the propellers and flaps indicated that the aircraft had impacted the ground at a high angle of attack, with both engines operating at a high power setting, and at a groundspeed of about 55 kts. The aircraft collided with steel and concrete structures as it slowed to a stop, however the cockpit area remained intact. Both wing fuel tanks were ruptured during the impact sequence and an intense post-impact fire erupted, consuming the cockpit area and right engine nacelle.
The weather was reported as being fine, with a light north-east wind and overcast cloud at 5,000 ft. Some illumination was provided by ground lighting from Sydney that was reflected from the base of the cloud.
The candidate reported that the aircraft had been operating normally throughout the flight. A post-accident review of medical history indicated that there were no physiological or psychological factors for either crewmember that may have affected the flight crew's performance prior to, or during the accident.
Aircraft performance
The Duchess was required under Civil Aviation Order 20.7.4 (8) to have a climb capability under defined conditions in the event of an engine failure1. Typically, a light twin such as the Duchess loses much of its ability to climb with one engine inoperative, with the aircraft configured with the propeller of the inoperative engine feathered and the landing gear retracted. An aircraft's windmilling2 propeller creates significantly more drag than a feathered propeller and, as a consequence, the Duchess would not have had the capability to accelerate or climb on one engine, with a windmilling propeller.
Night asymmetric flight
Asymmetric flight at night was not precluded by regulation. However, guidance provided to pilots contained in the Aeronautical Information Publication (AIP) stated that simulated asymmetric flight at night must not be conducted below 1,500 ft AGL. Civil Aviation Advisory Publication (CAAP) 5.23-1 (0) provided guidance on a syllabus of training, which included night asymmetric circuits. A note in that publication reminded the reader that the condition in AIP, which effectively precluded these operations from the circuit area at night, applied. However, no guidance was given on how to reconcile the conduct of asymmetric night circuit operations with the height limitation in AIP.
Previous accident review
A night asymmetric training accident involving a SA227-AC Metroliner, VH-NEJ, at Tamworth on 16 September 1995 (Occurrence report BO/199503057), was investigated by the then Bureau of Air Safety Investigation (BASI), which issued the following interim recommendation on 01 May 1996:
'IR 950224
The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority amend the Civil Aviation Regulations and the Civil Aviation Orders to ensure that when a provision of the Aeronautical Information Publication specifically prohibits certain manoeuvres and procedures, then this prohibition has legal force which is reflected in relevant Civil Aviation Regulations and Civil Aviation Orders.
The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority take appropriate steps to inform and educate the industry on the hazards involved in asymmetric training operations in conditions of low visibility and at night.'
The Civil Aviation Safety Authority responded to the recommendation 01 August 1996, stating:
'I refer to your interim recommendation IR950224 concerning the accident involving SA227 AC, VH NEJ at Tamworth on 16 September 1995. I apologise for the delay in forwarding the following comments.
The Regulatory Structure and Validation Project (RSVP), which is the first stage of a two stage review of existing civil aviation regulations, is currently being finalised by CASA. The RSVP will, inter alia, rectify the problems identified in the first paragraph of the BASI recommendation. In addition, CASA endorses the recommendation in the second paragraph of IR950224 and will produce an article in the summer issue of the Flight Safety Australia magazine on the hazards of asymmetric training operations in conditions of low visibility and at night.'
Following the response from CASA, BASI classified the recommendation as 'Closed - Accepted'.
An article appeared in the March/April 2002 edition of Flight Safety Australia entitled 'Even Worse than the Real Thing'. Mention was made of performing the EFATO manoeuvre in visual flight conditions, but it did not emphasise the hazards of conducting 'engine failure after take off' (EFATO) manoeuvres at night or night asymmetric training.
To date, the issue identified in the first paragraph of the Bureau's 1996 recommendation has not been rectified. Accordingly, the ATSB has amended the status of the recommendation to 'Monitor' pending evidence of the proposed action being taken by CASA.
Role and function of an Approved Testing Officer
The candidate was being tested for a flight qualification that is awarded and administered by CASA. CASA delegated the conduct of most flight tests to Approved Testing Officers (ATOs), who are authorised to conduct flight tests on behalf of CASA.
A flight test is used to demonstrate a pilot's competence in a particular aviation operating environment, to a defined level. Normally, a pilot is not qualified to conduct that type of flight until the flight test has been passed. The test officer is the competent pilot for the flight and is responsible for maintaining the safety of the flight.
A flight test explores the limits of the operating environment that is being examined, even though the limits of that environment will not normally be used while exercising the privileges of the qualification. For example, it is not normal to conduct asymmetric multi-engine operations, except during training, during a flight test, or in the event of an actual engine failure.
Categorisation of flight test operations
There are many similarities between flight training and flight test operations. In both cases:
- the pilot in command is responsible for the safety for the flight. However, the pilot in command does not normally manipulate the controls for most of the flight, although they are entitled to resume control of the aircraft to maintain the safety of the flight.
- the limits of a defined flight envelope are explored, to ensure that the student or candidate is capable of operating the aircraft safely throughout that defined envelope.
- the pilot in command is normally paid for his or her services.
Irrespective of any legislative or regulatory requirement, the nature of both types of operation, and the risks associated with both types of operation are very similar. If a similar risk level is to be expected from both types of operation, it would be reasonable to expect similar defences against those risks to exist in both types of operation.
Unlike formal flight training, flight tests conducted by ATOs were not prescribed as commercial operations. Civil Aviation Regulations (CAR) did not define flight tests as private operations, however they generally referred to private operations as operations in which the operating crew received no remuneration for the flight. In accordance with standard practice, the candidate and the ATO had made a commercial arrangement in that the candidate was to pay the ATO a fee for his flight test services.
A commercial flight operation, as defined under Civil Aviation Regulations3, had to be conducted under the management of a commercial air operator whose activities had to be managed, and the management process had to be approved and monitored by CASA.
Commercial operators who are required, under CAR (1988) 217, to conduct training and checking also conduct similar types of flight test. Those organisations are required to conduct this type of flight test in accordance with the requirements of an Air Operator's Certificate and the Check and Training procedures appended to that Air Operator's Certificate. This provides the opportunity for CASA to authorise the testing process and to ensure that procedures for risk mitigators, such as minimum operating altitudes, are formally maintained. There were no such requirements for flight tests conducted as private flights.
CASA provided guidance to ATOs on the conduct of flight tests in the form of a 'Flight Crew Licensing Industry Delegate's Handbook'. This document described the procedures surrounding a flight test and defined what was to be tested. The handbook did not provide guidance on the conduct or management of a flight test, or the precautions necessary to ensure the safety of a flight test.
Analysis
The ATO commenced a simulated engine-failure exercise from a position where a subsequent safe flightpath could not be assured. The aircraft deviated from the extended runway centreline track and collided with a tree. The ATO and candidate were not able to ensure that the likely flightpath was free from obstacles, so the safety of the flight could not be assured following a simulated engine-failure from this position in the flight. The aircraft's flightpath and normal operating procedures for a simulated engine-failure exercise make it likely that an engine failure was simulated, and then full power was returned to that engine without that propeller being feathered, or any other power adjustments being made.
A flight test is used to examine a pilot's competence throughout a flight envelope that is defined by the requirements for the flight test. A flight test will therefore normally operate nearer the edges of its defined flight envelope than other types of flight. The test officer is the competent pilot on board, and is therefore responsible for the safe operation of the aircraft. The safety buffer inherent from operating within a defined flight environment does not exist when a flight operates outside that environment. That was no different from the flight training regime where an instructor and student are performing the same manoeuvre.
The candidate pilot, who had not yet been deemed competent to fly in the defined flight envelope for the flight test, would normally be the handling pilot. The test officer would therefore be responsible for the safety of a flight being flown by a pilot who might not be competent, while operating at the edge of the defined safe envelope. These conditions remove some of the inherent defences that would make a normal flight safer. This higher risk situation is necessary for the effective conduct of a flight test. In the case of a multi-engine command instrument rating flight test, any abnormal operation of the aircraft, such as asymmetric flight therefore has an element of risk not present in normal operations. Setting safe speed margins and imposing altitude restrictions for the conduct of simulated emergency manoeuvres can mitigate that risk. Using experienced pilots as Approved Test Officers may also mitigate that risk.
Asymmetric flight with one engine failed degrades this aircraft type's ability to climb to a negligible quantity under optimal conditions. It is also normal to expect a minor change in direction as a change to an asymmetric condition is managed. This change in the aircraft's flightpath from two-engine flight to asymmetric flight should be taken into consideration when planning and managing asymmetric flight.
Planned low-level asymmetric flight at night is considered to be an unacceptable risk because, unlike daylight conditions, the pilot may neither know about, nor be able to see, any obstacles in the aircraft's changed flight path in order to take avoiding action.
The flight was a commercial operation, in that the ATO was entitled to charge for his services for the flight test, in the same way that a student pays for the services of a flight instructor when being trained. Because the operation was conducted as a private flight, it did not have similar risk mitigators that are inherent in the required organisational structure for a commercial flight, as happens with flight tests conducted through a Civil Aviation Regulations (1988), Regulation 217 (CAR 217) approved organisation. The ATO was conducting a flight test in accordance with the test requirements set by the CASA, and while acting as a delegate of the authority. CASA provided neither guidance nor prescriptive requirements to ATOs to ensure the consistent, safe conduct of flight tests.
Safety margins for the conduct of multi-engine instrument renewal flight tests are prescribed in the approved training manuals of training and checking organisations. However, when such a flight test is performed outside the oversight of a CAR 217 training and checking organisation, the safety margins can only be determined by the testing pilot and may vary depending on the experience and competency of both the testing pilot and the candidate. This means that the safety standards for the conduct of these flight tests are not consistent across Australian civil aviation.
This was the ATO's first flight with the candidate. Although some asymmetric flying was reported to have been performed earlier in the flight, it was possible that the ATO had determined that the candidate was capable of handling a simulated engine failure just after takeoff from runway 06 at Camden. The simulated engine failure was contrary to the preflight briefing and may have been initiated at that point to negate the candidate's anticipation of a predetermined simulated engine failure at the briefed altitude.
The maximum groundspeed at impact was determined to be about 55 kts. In the light wind conditions at the time, the airspeed would have been approximately 60 kts, slightly above the aircraft's stalling speed in that configuration. It is unlikely that the aircraft would have been able to climb or accelerate significantly with only one engine operating while the landing gear was still retracting and the right propeller was windmilling.
The ATO was responsible for the safety of the flight. That responsibility included ensuring that the speed and altitude at which simulated emergency procedures were initiated provided adequate safety margins for the manoeuvres being attempted. The simulated engine failure just after takeoff did not provide those adequate margins, especially at night, with inadequate visual reference to ensure obstacle clearance. It was likely that the ATO may not have been aware that the aircraft was not climbing and had drifted well right of the runway toward obstacles and higher ground. Although he reapplied full power to the simulated 'failed' engine at either the candidate's expressed concern or out of his own concern, the response was not timely enough to avoid a collision with the tree or the ground.
The risks associated with low level asymmetric operations at night were identified and addressed in May 1996 in Interim Recommendation IR19950224. Regulatory and education action that was addressed by CASA in its response to the recommendation in August 1996 has yet to be fully implemented.
Significant Factors
A simulated engine failure was initiated from a point where a safe outcome could not be assured.
Safety Action
CASA safety action
CASA is involved in a regulatory reform programme and is leading the development of new regulations which are proposed to be made by government. Some of those proposed regulations, as detailed below, impose new requirements on persons conducting flight tests.
The proposed new Civil Aviation Safety Regulations 1998, Part 91.305, is expected to incorporate a requirement that no planned asymmetric operations are initiated below the circuit height or 1,000 ft above the ground at night, or below a minimum en-route altitude or instrument initial approach altitude in instrument meteorological conditions.
The proposed new Civil Aviation Safety Regulations 1998, Part 61.220, is expected to change the conditions under which flight tests may be carried out. The present draft will require flight tests conducted by 'flight examiners' (those who conduct flight tests) to be booked through a flying training organisation, and that flight examiners must comply with the manual of standards (MOS) associated with Part 61. This MOS will specify what is to be assessed in each type of flight test, and will also specify that other things are not to be tested during the flight test.
The proposed new Civil Aviation Safety Regulations 1998, Part 141, is expected to require the operator to specify through their operations manual the procedures for the conduct of flight tests, and the responsibilities of the flight examiner for the safety of operations during the flight test. These procedures in the operations manual are expected to include the operator's specific requirements and methods for simulating emergencies and the evolutions necessary for the conduct of specific flight tests. Operators will need to be able to demonstrate to CASA that they are operating in compliance with their operating manual.
1 In order to operate under Instrument Flight Rules (IFR), this aircraft type was required to have demonstrated that it could climb at a 1% gradient with its critical engine inoperative, at an altitude of 5,000 ft in an International Standard Atmosphere (ISA). This equated to an indicated altitude of 5,000 ft on an altimeter with a subscale setting of 1013.25 hPa, and an atmospheric temperature of +5C.
2 'Windmilling' is the term used to describe a rotating propeller being driven by the airflow rather than by engine power.
3 Civil Aviation Regulations 1988, regulation 206 defined categories of commercial flight operations.
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