Boeing is developing updated software for 787s to correct an erroneous localiser mode behaviour during ILS approaches. The US FAA is advising operators of the three 787 variants to notify crews about potential failure by the autopilot flight-director system to capture the localiser, notably during intercept of the localiser at angles of 40° or more. Several incidents have occurred involving 787s flying approaches to Hong Kong from the east, and the FAA says operators should incorporate "at the earliest opportunity" actions outlined in an operations manual bulletin. Flight data from the incidents shows that flight-director system guidance partially reduced the intercept angle to the localiser, with the aircraft initially turning towards the localiser heading but then stopping short and flying a constant heading. This resulted in the aircraft intercepting the runway axis at an angle of 20-30°, says the FAA in a 24 September bulletin. "Airplanes continued through the localiser at a heading not aligned with the runway centreline," it says. Both localiser and glideslope modes were engaged, and the flight-mode annunciator on the primary flight display continued to show the active roll mode as ‘LOC’ – for ‘localiser’ – without any indication of capture failure. The flight-director system provided guidance to descend on the glideslope, which meant the aircraft continue to deviate from the centreline and descend on the wrong heading. In all the events the deviation from the localiser was accurately shown by both the localiser pointer and scale on the primary flight display as well as the aircraft symbol on the navigation display. Boeing has previously issued, in December last year, an operations bulletin on the issue and operating instructions for the autopilot flight-director system during ILS, reinforcing procedures and training. Hong Kong authorities had also warned 787 operators of possible adverse autopilot behaviour during localiser capture, notably on approach to runways 25R and 25L. The anomaly, they stated, could result in aircraft flying in proximity to high terrain, and that crews should climb back to minimum sector altitude and conduct a missed approach if in doubt. Air Canada, Virgin Atlantic, Ethiopian Airlines, and Etihad Airways have all experienced 787 misbehaviour during ILS approaches to the Asian hub.

Source: Cirium

IATA will move its annual general meeting — traditionally the biggest event in the airline calendar — online, as the coronavirus outbreak continues to preclude large scale physical meetings. The airline trade body had initially rescheduled the meeting, to be held in Amsterdam and hosted by KLM, from June to November, in light of the pandemic. Says IATA director-general Alexandre de Juniac: “When we postponed this year’s AGM from June until November, it was with the expectation that government restrictions on travel would have been sufficiently eased to enable a physical meeting. That now seems unlikely and alternative plans for a virtual event are being activated.” IATA has also cancelled this year’s edition of the World Air Transport Summit that accompanies the AGM. Despite the change in plans, de Juniac says the meeting is still an important one, given how the industry is in turmoil. “This will be one of our most important AGMs. The industry is in the deepest crisis in its history. And it is more important than ever for the industry to have this meeting serve as a rallying call of resilience as we find solutions to safely open borders and re-establish global connectivity, ensure vital cargo lanes; and build a sustainable future from the destruction of the virus,” he adds.

Source: Cirium

UK cockpit crew representatives are seeking assurances on several aspects of the Boeing 737 Max’s redesign, including scenarios relating to the angle-of-attack sensors and the potential need for two pilots to turn the trim wheel if the jet is out of trim. Pilots union BALPA has formally responded to a US FAA notification detailing proposed changes to the Max intended to address design weaknesses linked to the fatal Lion Air and Ethiopian Airlines accidents, weaknesses which subsequently led to the type’s grounding last year. Sourcing both angle-of-attack sensors, rather than one, to activate the MCAS system – which automatically pushes the nose down to avoid a high angle-of-attack situation – is “clearly an improvement”, says the union. But it argues that Boeing ought to have pursued a “preferable” three-sensor system, as used by Airbus A320s, which allows a computer to compare sensor data and eliminate, by ‘voting out’, a spurious sensor reading that does not match the other two. The Max redesign prevents activation of MCAS if the two angle-of-attack sensors disagree, but the union queries how the aircraft would respond if both sensors produced erroneous – yet insufficiently different – readings. “Is this viewed as an extremely improbable event?” it asks. One aspect which emerged during the inquiry into the Ethiopian accident was the crew’s difficulty in correcting the aircraft’s out-of-trim condition using the trim wheel at high airspeed. The FAA’s notification states that a revised checklist for manually trimming the horizontal stabiliser will note that a “two-pilot effort” may be used. “Requiring both crew members to turn the trim wheel simultaneously in a non-normal scenario is extremely undesirable,” says BALPA, adding that it “goes against all philosophies” of having flying pilot operating the controls and a non-flying pilot reading the quick-reference handbook. The union points out that the Max has a smaller-diameter trim wheel, which enables larger display screens in the cockpit, and wants “assurance” that a single pilot can still turn the wheel at airspeeds of perhaps 40kt beyond the maximum operating limit speed. It also suggests that Boeing should revisit procedures such as the “rollercoaster” manoeuvre to mitigate significant retrimming problems. This manoeuvre involves trimming nose-up by repeatedly pulling on the control column until the nose is far above the horizon, and trimming as column back-pressure is released – a similar principle to easing pressure on a fishing line while rapidly winding the reel in order to maintain a pull on the catch. BALPA uses the British Midland Boeing 737-400 accident at Kegworth in 1989 to underline some of its remarks about the Max redesign, notably regarding the reduced certification scrutiny associated with derivative developments. The Kegworth accident resulted from the crew’s responding to an engine failure by inadvertently shutting down the wrong engine. UK investigators noted the modernised aircraft featured solid-state electronic engine indicators, rather than the previous electromechanical hybrid displays, and remarked that the change would have required “different techniques” to interrogate the information – skills the pilots might not have acquired before being subjected to a stressful emergency in the cockpit. “It is strongly felt that all future substantial aircraft design changes should result in certification as a new type with a commensurate level of training required for pilots,” says BALPA in its comments to the FAA. The union adds that the Kegworth investigation highlighted the “importance of an ‘attention-getting’ facility”, and BALPA wants clarification as to whether Max pilots will receive an automated call-out alerting them to activation of MCAS, ensuring that they are aware of its being triggered. BALPA also says it “strongly supports” the proposed mandating of an ‘angle-of-attack disagree’ alert on the 737 Max, and argues that the optional angle-of-attack gauge should be a standard fit on the type.

Source: Cirium