Airbus is developing a retrofit to reduce the risk of system logic weaknesses that played a role in the SmartLynx A320 touch-and-go accident at Tallinn last year. While performing touch-and-go circuits for student pilots, the aircraft lost elevator control just after landing, a situation which the crew only discovered as the jet accelerated towards rotation again. It became airborne as a result of the horizontal stabiliser setting before bouncing heavily on the runway and entering a sharp climb with its engines damaged and elevators inoperable. Estonian investigation authority OJK found that, during each landing, the instructor pilot had been grasping the trim wheel to prevent the stabiliser from returning to neutral, in order to maintain a take-off setting. This action would have been observed as a discrepancy between the stabiliser's actual and commanded positions. In order for this situation not to be interpreted as a runaway, an override mechanism is designed to detect manual takeover, disengage the pitch-trim actuator and trigger three microswitches. But the inquiry found that the wrong sort of oil – with twice the viscosity of the oil required – was used in the override mechanism, resulting in a "non-standard" friction curve of the mechanism's clutch, and incorrect microswitch activation. Maintenance documentation does not require any test of the override during regular checks, it adds, and "could have contributed" to the wrong oil being left unnoticed. OJK says the instructor's manual grasping of the stabiliser trim wheel was not registered correctly by the override, generating erratic microswitch triggering and the loss of elevator aileron computer control. At the moment of the touch-and-go incident on 28 February last year, this sequence had rendered both elevator aileron computers unavailable. Airbus is developing a software modification for this computer, intended to "mitigate the consequences" of a failure to detect manual takeover of the horizontal stabiliser through the trim wheel, it adds. Certification of this upgrade and global retrofit is planned for mid-2020. When neither elevator aileron computer is available the system logic shifts pitch control to the spoiler elevator computer. But OJK also found that a "design flaw" allowed a single event – a shallow rebound during the landing – to trigger a consolidation logic discrepancy between the spoiler elevator computer's two channels, with one computing elevator orders in 'flight' law and the other computing orders in 'ground' law. It resulted in the loss of control of both elevators by both spoiler elevator computers, and subsequently to the elevators' moving and locking in the neutral position – setting up the failure to rotate when the A320 accelerated for take-off. Airbus has initiated developed of a modification which, the inquiry says, will improve the weakness in the consolidation logic and increase robustness of the spoiler elevator computer against landing-gear bounce. All seven occupants of the A320, including four student pilots, survived after the instructor and a safety pilot managed to use thrust from the damaged engines and horizontal stabiliser trim to return to Tallinn for an emergency landing. Both engines failed before the aircraft touched down and the jet was subsequently written off.

Source: FlightGlobal

Indian authorities have instructed the country's Airbus A320neo operators to replace the Pratt & Whitney PW1100G engines on the type with an upgraded version of the powerplant by the end of January 2020. IndiGo and GoAir each have the PW1100G on their A320neo fleets. Civil aviation regulator DGCA issued a directive a week ago requiring the two carriers to have at least one modified engine on aircraft with more than 2,900h. The airlines were given up to 19 November to meet this requirement. But on 1 November, the regulator ordered the carriers to ensure that all their A320neos have both powerplants modified with new third-stage low-pressure turbines, by 31 January next year. IndiGo says it has already modified about 45% of its A320neo engines, and is confident that it will be able to meet the deadline A year ago, a spate of aborted take-offs and in-flight engine shutdowns led to the grounding of 11 A320neos. Two key parts of the engine, its third-stage low-pressure turbine and gearbox, had to be replaced. The revised requirements come after IndiGo suffered another series of engine shutdowns, its latest taking place on 1 November. The airline confirmed the engine issues in a stock exchange disclosure. “We are working with both P&W and Airbus on mitigation so that we have enough modified spare engines by January 31, 2020,” the airline adds, pointing out that its schedules "remain intact”. GoAir has yet to respond to FlightGlobal requests for comment. In late August, the DGCA stated that it was keeping a close watch on the PW1100G engine performance. It imposed directives on IndiGo and GoAir, including restricting them from accepting leased engines, or engines from MROs, without modified parts. IndiGo was an early operator of the PW1100G-powered A320neo and suffered some of the engine’s early reliability issues. Most recently at the Paris Air Show, the airline pivoted away from P&W engines to the rival CFM International Leap-1A to power 280 A320neos on order. Cirium’s fleets data indicates GoAir operates 38 A320neos while IndiGo has 91 A320neos powered by PW1100G engines.

Source: FlightGlobal

Avianca has confirmed that it is no longer interested in buying Mexican regional operator Aeromar, as the Colombian carrier focuses on executing a strategic plan to restore profitability within its core business in its home country and Central America. German Efromovich, Avianca's previous controlling shareholder, had embarked on an ambitious international expansion strategy under which airlines operated under the Avianca brand in Ecuador, Peru, Brazil and Argentina. However, Avianca Brasil and Avianca Argentina both filed for bankruptcy and went into liquidation while Avianca Peru pulled out of most domestic markets. Mexico was the latest territory Avianca intended to conquer by acquiring a majority stake in ATR turboprop operator Aeromar. However, Avianca's new chief executive Anko van der Werff, formerly Aeromexico's commercial chief, makes clear that expanding into Mexico through an Avianca-controlled local carrier is no longer an option. "I never considered [acquiring Aeromar] a good idea [for Avianca] nor is this going to happen with the current leadership team," says van der Werff. "We already have a codeshare agreement with Aeromexico, which is much larger and offers more frequencies. Investing in Aeromar would not give us any benefits," he argues.

Source: FlightGlobal