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Boeing defends its MAX situation

B737 MAX airliners continue to accumulate at Boeing Field while the type remains grounded.

Last month Boeing hit back strongly in comments about industry criticism on the AOA (angle of attack) disagreement information. “On every aircraft delivered to our customers, including the MAX, all flight data and information needed to safely operate the aircraft is provided in the flight deck on the primary flight deck displays. This information is provided full-time in the pilots’ primary field of view, and it always has been,” said the manufacturer.

“Airspeed, attitude, altitude, vertical speed, heading and engine power settings are the primary parameters the flight crews use to safely operate the aircraft in normal flight. Stick shaker and the pitch limit indicator are the primary features used for the operation of the aircraft at elevated angles of attack.

“All recommended pilot actions, checklists, and training are based upon these primary indicators. Neither the angle of attack indicator nor the AOA Disagree alert is necessary for the safe operation of the aircraft. They provide supplemental information only, and have never been considered safety features on commercial jet transport aircraft.”

The Boeing design requirements for the B737 MAX included the AOA Disagree alert as a standard, standalone feature. In 2017, within several months of beginning B737 MAX deliveries, engineers at Boeing identified that the B737 MAX display system software did not correctly meet the AOA Disagree alert requirements. The software delivered to Boeing linked the AOA Disagree alert to the AOA indicator, which is an optional feature on the MAX and the NG. Accordingly, the software activated the AOA Disagree alert only if an airline opted for the AOA indicator. 

When the discrepancy between the requirements and the software was identified, Boeing followed its standard process for determining the appropriate resolution of such issues. That review, which involved multiple company subject matter experts, determined that the absence of the AOA Disagree alert did not adversely impact aircraft safety or operation. Accordingly, the review concluded, the existing functionality was acceptable until the alert and the indicator could be delinked in the next planned display system software update.

Senior company leadership was not involved in the review and first became aware of this issue in the aftermath of the Lion Air accident.

About a week after the Lion Air accident, on 6 November 2018, Boeing issued an Operations Manual Bulletin (OMB) which was followed a day later by the FAA’s issuance of an AD. In identifying the AOA Disagree alert as one among a number of indications that could result from erroneous AOA, both the OMB and the AD described the AOA Disagree alert feature as available only if the AOA indicator option is installed.

Boeing is issuing a display system software update to implement the AOA Disagree alert as a standard, standalone feature before the MAX returns to service. All MAX production aircraft will have an activated and operable AOA Disagree alert and an optional angle of attack indicator. All customers with previously delivered MAX aircraft will have the ability to activate the AOA Disagree alert. 

Media are now reporting the changes are looking acceptable to airline operators. Airline Ratings says, in a major endorsement of the B737 MAX changes, that the world’s largest pilots’ union will not ask the FAA to require additional mandatory simulator training on the MCAS scenarios before pilots can fly the aircraft again.

According to Aviation Week, ALPA will just recommend scenario training as part of routine recurrent training and that ALPA “will make its views known in comments on a draft of proposed minimum B737 MAX training standards out for public comment. The Flight Standardization Board (FSB) draft report does not recommend simulator sessions as part of transition training for B737 Next Generation pilots upgrading to the B737 MAX, opting for less costly computer-based training instead.”…

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Auckland Is wreckage recovered

The Marine Countess has landed the wreckage of the BK117 which crashed just off Enderby Island on 22 April during a medical evacuation. The wreckage is now stored in a secure facility at Bluff Harbour and will soon be conveyed to Wellington for examination by officials from TAIC.

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Sweeping changes proposed

The New Zealand government proposes sweeping changes to the country’s aviation sector regulations, ranging from damaged or lost luggage compensation, drug and alcohol management and the assessment of airline alliances to making it an offence to harm or assault an aviation security officer’s dog

The overhaul is part of a new Civil Aviation Bill announced on 10 May by Transport Minister Phil Twyford. The current bill, which seeks to combine the Airport Authorities Act 1966 and the Civil Aviation Act 1990 and currently runs to about 400 clauses, is expected to be introduced to Parliament within the next 12 months and passed in mid-to-late-2020.

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AOA sensor grounds Cirrus jets

The FAA last month grounded all 117 Cirrus Vision SF50 jets through an emergency AD prompted by Cirrus reporting three incidents on its Model SF50 of the stall warning and protection system (SWPS) or electronic stability and protection (ESP) system engaging when not appropriate.

Cirrus senior vice president of sales and marketing, Ben Kowalski, said the manufacturer immediately began working with the FAA and the company’s internal teams to determine the root cause of the problem.

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Bombardier consolidates

Two state-run Chinese firms, the Aviation Industry Corporation of China (AVIC) and the Commercial Aircraft Corporation of China (COMAC), are vying to purchase Bombardier’s Northern Ireland facility as the Canadian aircraft builder consolidates its operation to one facility in Canada.

Montreal-based Bombardier Group, one of the biggest employers in Northern Ireland with a workforce of 3600, is selling not only its Belfast operation but also its Newtownabbey, Newtownards and Dunmurry operations and its Moroccan facility as Bombardier continues to consolidate all its aerospace assets into a single streamlined and fully integrated business

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