CAAF in its document titled ‘State Safety Programme Fiji’ in Paragraph 2.1 under ‘safety policy’, referred to ‘a continuous flow and exchange of safety management data between CAAF and operators/service providers.’
However, this did not occur with regards to the risks of tropical low-pressure trough systems and mountain flying.
With respect to this accident, CAAF was unable to provide the safety oversight mentioned in the ‘SSP Fiji’ document says the Civil Aviation Authority of Fiji’s own Cessna 172R Aircraft Accident Report.
The PFS Safety Management System was unable to identify the risks of low-pressure weather trough systems and mountain flying which contributed to this accident.
The CAAF SMS and ATIC audits of early 2017 did not identify these omissions in the PFS documentation. Nor did the audits express any findings or comments in relation to the risk assessment of cross-country flight training in bad weather and over mountainous terrain.
The items that were identified in the audits did not relate directly to bad weather risks or mountain flying and are therefore unlikely to be relevant to this accident.
Unlike New Zealand, CAAF had not been able to identify mountain flying risks and had not followed New Zealand’s guidelines in addressing them.
Although New Zealand does not experience tropical low-pressure trough systems, its mountain flying training does consider similar consequences of bad weather such as turbulence and weather entrapment, when addressing mountain flying risks.
None of the CAAF Aviation Safety Bulletins between 2012 and 2018 identified the risks of low-pressure weather troughs and mountain flying.
CAAF did not address the ‘local needs’ that are mentioned in the executive summary of the ‘SSP Fiji’ document. These include the needs to identify and manage the risks of LP weather troughs which are peculiar to Fiji and other South Pacific countries near the SPCZ, and mountain flying risks.
The accident aircraft, a Cessna 172R registered as DQ-FTR and operated by the Pacific Flying School (PFS) departed Nadi at 7:03 am on the morning of Monday the 26th of February 2018 with a flight instructor and student on board. Its flight plan showed it flying on Visual Flight Rules (VFR) to Labasa, Savusavu and Nausori before returning to Nadi.
The flight was a 300 nautical mile cross country training flight as part of the student’s Commercial Pilot Licence (CPL).
After landing at Labasa at 8:40 am, the weather deteriorated and it began to rain. The pilots waited for the weather to improve before departing for Savusavu at 11:37 am.
Cloud satellite and rain radar imagery showed that as or shortly after the aircraft departed Labasa, the weather deteriorated and closed in on the accident aircraft, entrapping it without any escape route. This together with ADS-B surveillance data showed that in likely poor visibility and in Instrument Meteorological Conditions (IMC) for which the pilots had only received limited training, the aircraft entered a mountain valley before impacting steep mountainous terrain at an altitude of 2,600 feet near Mt Delaikoro, killing both occupants. The crash occurred shortly after 12:00 o’clock midday.
At the time of departing Labasa, it is likely that the weather was sufficiently adequate to comply with that required for flight under VFR. The pilots had probably complied with all the procedures and requirements specifically required of them by PFS.
The weather system that covered Vanua Levu that day was a tropical low-pressure trough system that progressed in a combination of bands and patches and probably originated from the South Pacific Convergence Zone (SPCZ) to the North of Vanua Levu.
These systems are difficult to properly characterise using formal aviation weather systems and are also difficult to forecast. Moreover, they are not fully understood by the international aviation community. In these circumstances rapid changes in visibility can occur over relatively large areas and this is difficult for pilots to manage.
The aviation safety risk of these conditions is magnified by mountainous terrain which can not only generate high turbulence including strong downdrafts, but can also further reduce visibility by causing condensation in the form of dense cloud, mist and heavy rain. The pilots did not fully understand how to manage these risks.