Airlines, unions and regulators are working to understand the 737 Max's flight systems while unions uncover seeming errors in emergency "runaway stabiliser" checklists.

The work comes amid reports that the US industry was unaware Boeing had equipped the 737 Max with a new system that has been linked to the 29 October crash of a Lion Air 737 Max 8.

"We are working at an extraordinarily positive pace to share information," says a spokesperson for the Allied Pilots Association (APA), which represents pilots at American Airlines, a 737 Max operator.

"We are looking at differences between the Max and the non-Max aircraft" in an effort to understand nuances in stall prevention and notification systems, the union adds.

Bombardier has disclosed that it is selling its Dash 8 turboprop programme to a subsidiary of Longview Aviation Capital Corporation for $300 million.
Longview is a holding company which includes Viking Air, the manufacturer of the revived DHC-6 Twin Otter programme.
Bombardier says the sale includes the Q400 programme, as well as all assets and intellectual property for other Dash 8 models – comprising the -100, -200 and -300.
It also involves divesting the related aftermarket operations.
Bombardier says the transaction will close by the second half of next year. It expects net proceeds of $250 million.
Having already sold the CSeries twinjet programme to a partnership controlled by Airbus, Bombardier has been left with the CRJ regional jet as its primary commercial air transport product.
Bombardier says it will give its “full attention” to the CRJ programme.
It says it will also “explore strategic options” for the CRJ, while focusing on reducing costs and increasing volumes, as well as “optimising” the aftermarket for the fleet of 1,500 CRJs in service.

European safety regulators have warned of a potentially unsafe condition with the tail rotor assemblies of Leonardo Helicopters AW169 and AW189 rotorcraft.
Although the move follows the fatal crash of an AW169 in Leicester, UK on 27 October, the emergency airworthiness directive stresses the root cause of that accident "has not been identified".

The Leicester crash occurred "while the helicopter was on a take-off phase at low forward speed" and "a loss of yaw control was observed".
Footage of the AW169's take-off shows its pilot performing a vertical departure before the helicopter develops an uncontrollable spin and crashes to the ground.
Issued by the European Aviation Safety Agency, the directive stipulates that operators of both types must, within five flight hours or 24h, inspect the tail rotor servo-actuator installation.

On 6 November, the manufacturer issued an emergency service bulletin advising operators of the AW169 to check the installation and functioning of the same component.
"Incorrect installation may lead to loss of tail rotor control which, depending on the flight condition, could lead to loss of control of the aircraft," the bulletin warns.

No safety issues have so far been detected with the larger AW189 super-medium-twin, but EASA notes that it is included in the directive as its tail rotor control system is "of a similar design" to that on AW169.
The UK Air Accidents Investigation Branch has yet to release any information related to the cause of the Leicester crash.

Leonardo Helicopters describes the service bulletins for both types as "precautionary", adding that "any hypothesis on the cause of the accident is premature at this time and the AAIB investigation continues".