Safety Advisory Notice SAN19980212

Safety Advisory Notice issued to: Operators of regional airlines

Recommendation details
Output No: SAN19980212
Date issued: 02 November 1998
Safety action status: Closed



Between October 1995 and July 1997, the Bureau of Air Safety Investigation undertook a study of the safety of Australian regional airlines. The objectives of this study were to:

(a) identify safety deficiencies affecting regional airline (operations in Australia; and
(b) identify means of reducing the impact on safety of these deficiencies.

For the purpose of the survey, regional airlines were grouped according to the number of passenger seats fitted to the largest aircraft operated by that airline in January 1997. The groups are defined as follows:

(a) Group 1: 1-9 seats;
(b) Group 2: 10-19 seats: and
(c) Group 3: more than 20 seats.

The study involved analysing data obtained from:

(a) responses to a survey of Australian regional airline employees;
(b) discussions with Australian regional airline employees and managers;
(c) air safety occurrence reports involving regional airlines over a 10-year period (1986-1995) from the BASI database.

This Safety Advisory Notice addresses one of the safety deficiencies identified as a result of this study.


Some asymmetric training is being conducted in a manner or under conditions where the risk involved is not commensurate with the training value gained.


Survey results

Pilots were asked to outline any flying training exercises that caused them concern. Sixty-nine pilots (18%) responded to this question. The most common responses were as follows:

Forty-seven pilots (68% of those answering this question) were concerned about the dangers of asymmetric training in general. The most common concern was that simulated asymmetric flight (flight with one engine set at or near a zero-power setting) was being conducted close to the ground, or in aircraft configurations or flight conditions that increased the risk of an accident.

Twenty-three of the respondents who commented on the danger of asymmetric training, said that "V1 cuts" (simulated failure of an engine at V1 speed) were excessively dangerous due to the marginal performance of the aircraft on one engine, or due to the manner in which this exercise was practised. Five respondents cited examples of V1 cuts being practiced at night and one described a V1 cut while the pilot was wearing "foggles" (devices to restrict the pilot's view to the instrument panel). Many pilots felt that V1 cuts should only be practised in flight simulators.

Examples of survey responses

"During a twin engine, full flap go-around, [the training captain simulated] an engine failure when power [was coming] up, leaving the aircraft hanging on one engine low to the ground. With or without the [landing] gear, the aircraft will not climb [on one engine] with full flap selected."
- Pilot, respondent 465

"[I am concerned about] Vmc demonstrations and practice. [They are] all very dubious demonstrations at this level of operation and definitely a safety hazard in practice for no gain in safety."
- Pilot, respondent 472

"[I am concerned about simulated] engine failures at Vr (rotate speed) at night. Besides being a breech of the operations manual and CAOs, there is no margin for error in such an exercise."
-Pilot, respondent 493

Asymmetric training and checking requirements

Asymmetric training is a significant aspect of the multi-engine training syllabus and flight test. Pilots are also required to undergo training and demonstrate proficiency in asymmetric flight to obtain and renew multi-engine instrument ratings in addition to other required periodical flight checks.

Aircraft performance

Many of the aircraft types used by regional airline operators demonstrate limited performance during asymmetric operations and do not have to meet the "one engine inoperative" performance requirements that must be met for certification of larger transport-category aircraft. This effectively means that there is an accepted period of risk during the take-off and the initial climb phases of flight. If an engine failure were to occur during this phase of flight, climb performance would not be guaranteed. Notwithstanding, and as part of training and checking activities, pilots are expected to demonstrate proficiency in asymmetric operations during all phases of flight, including takeoff and initial climb.

Related occurrence and safety action

An accident, in which two pilots were killed in a Fairchild Metro II during a night training exercise at Tamworth, highlighted the hazards associated with the conduct of some asymmetric training exercises, particularly V1 cuts below 1,500 ft AGL at night. The Bureau issued two interim recommendations as a result of that accident which highlighted similar safety concerns that have emerged from the Regional Airlines Safety Study.

Interim Recommendation 950224, issued on 29 April 1996, stated that CASA should amend the Civil Aviation Regulations and Civil Aviation Orders to ensure that "when a provision of the Aeronautical Information Publication specifically prohibits certain manoeuvres and procedures, then the prohibition has legal force which is reflected in relevant Civil Aviation Regulations and Civil Aviation Orders". BASI also recommended that CASA 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". CASA indicated that the Regulatory Structure Validation Project would rectify the problems identified in the BASI recommendation and that an article would be produced and included in the CASA Flight Safety Australia magazine. To date, BASI has not been notified of any action taken in response to this recommendation.

Interim Recommendation 960035, issued on 29 July 1996, stated that CASA should "address the issue of endorsement training requirements for aircraft above 5,700 kg MTOW where a simulator is not available". BASI also recommended that the review of the multi-engine training syllabus should cover the possible difference in flight training when a simulator is used for training and for the conduct of emergency procedures. CASA has since issued Civil Aviation Advisory Publication 53.1-(0) which provides detailed guidance on the conduct of multi-engine endorsement training and reiterates that multi-engine training at night should be conducted in accordance with Aeronautical Information Publication OPS-77. In its response to the interim recommendation, CASA stated that while it had no legislative power to mandate the use of simulators, the new syllabus encouraged the use of an approved type simulator for the conduct of endorsement training. CASA added that the need for different training requirements, depending on the availability of a simulator, was currently under review. However, CASA indicated that it would prefer to have a generic syllabus for multi-engine training.


Most asymmetric training conducted by regional airline operators must be undertaken in aircraft as flight simulators are currently available for only a few of the regional airline aircraft types. In addition, many regional airline aircraft demonstrate limited asymmetric performance, even at training weights. Therefore, asymmetric training can be a potentially hazardous activity if it is not conducted in accordance with accepted safe practices that are reflected in Australian and international regulations and guidance material.

While there is some benefit in presenting a realistic scenario when conducting asymmetric training, the risks must be weighed up against the training benefits. There may also be insufficient allowance being made for the difference between flight manual performance expectations and the aircraft's actual performance. Consideration should be given to conducting the same training at a height above ground level that would provide a greater margin for error in those cases when aircraft may be operated inappropriately or when aircraft performance does not meet expectations.

The reports provided in the survey suggest that some training and checking pilots may be presenting unrealistic asymmetric scenarios during training and checking exercises. Such an approach further diminishes the safety margins available as well as the capacity of training and check pilots to recognise and recover from developing unsafe situations.

Output text

Operators of regional airlines should note the safety deficiency identified in this document and take appropriate action.

Initial response
Date issued:
Response from: Regional Airlines
Action status: Not Required
Response text:
Last update 01 April 2011