The Civil Aviation Safety Authority today removed the restrictions on Bristell LSAs that prevented them from being used in stall training.
CASA issued a ban on stall training in Bristells in July 2020, stating that they had not received sufficient assurance from BRM Aero that the aircraft complied with the standard for light sport aircraft (LSA), a contention that the manufacturer has disputed consistently.
CASA today revoked the instrument, stating that they had now received more information from independent bodies about the stall testing done on the Bristell and BRM Aero's notification to owners about the centre of gravity arms.
"[Today] CASA revoked the regulation 262APA(4) operating limitations following receipt of new compliance information from BRM Aero Ltd and fundamental corrections having been made to the Aircraft Operating Instructions (AOI)," CASA says.
"On 9 March 2021, BRM Aero Ltd provided to CASA further information as to compliance of Bristell LSA with ASTM 4.5.9 spin requirements by two specialist organisations as to spin compliance and the scope of the LSA self-certification scheme.
"In addition, CASA had information that BRM Aero Ltd had recently made and distributed to aircraft owners, important corrections to the centre of gravity calculations for the affected aircraft. The corrections were required to be incorporated into the AOI.
"CASA is reasonably satisfied that the corrections made to the AOI have adequately mitigated the safety related concerns held by CASA, such that all participants are meaningfully aware of these corrections and importantly, how they change the loading requirements of the aircraft.
"Provided operators of the aircraft only operate the aircraft in compliance with the corrected AOI data, CASA considers that the potential for inadvertent operation of the aircraft at or outside the centre of gravity limits is substantially reduced."
In light of the corrections to the AOI, CASA has issued the following recommendations.
- CASA recommends that pilots and operators of the affected aircraft ensure they are familiar with the effect of the revised AOI corrections, as there may now be a significant change to the way the aircraft is permitted to be loaded and there may now be restrictions upon operating the aircraft in certain configurations.
- Pilots and operators should pay particular attention to the corrected arm associated with the pilot and passenger row. The correction to the AOI has adjusted the arm for the pilot and passenger significantly further rearward.
- Pilots and operators should pay particular attention to the aft movement of the centre of gravity with fuel burn. Dependant on the empty weight and empty CoG of each aircraft, the corrected arm and the effect of an aft moving CoG with fuel burn, may significantly change the revised permitted loading of the aircraft, when compared to previous loading of the aircraft.
- Pilots should check that the loading of the aircraft is within the published limits, both at the proposed take-off weight and also at a zero-fuel or minimum fuel weight.
CASA applied the restrictions after a number of Bristell accidents around the world including two in Australia where the stall recovery characteristics were brought into question. The regulator then stated they were not satisfied with undertakings from the manufacturer that the aircraft complied with the stalling requirements of the ASTM standard.
According to CASA. it was the investigation into a fatal crash in Ireland in June 2019 that exposed the CoG problem, when investigators found the moment arm was longer than that specified in the weight and balance documents. An interim report was issued last week.
The UK Light Aircraft Association also completed work late last year that supported the findings of the Irish investigation.
BRM Aero worked through Australian agent Edge Aviation on the matter, which has resulted in CASA being referred to the Commonwealth Ombudsman over their conduct in dealing with BRM Aero and local dealer Anderson Aviation.