Originally Posted by
jimjim1
Here are pages 11-16 for your convenience. Fancy slides all gone, raw text all here, nearly.
Return to Service - EASA conditions p 11
Letter sent to the FAA on April 01, 2019.
4 conditions:
1. Design changes proposed by Boeing are EASA approved (no delegation to
FAA)
2. Additional and broader independent design review has been satisfactorily
completed by EASA
3. Accidents of JT610 and ET302 are deemed sufficiently understood
4. B737 MAX flight crews have been adequately trained
EASA design review p 12
Objective: to ensure that no similar weaknesses in the design are present in
the other (safety critical) areas of the 737 MAX design.
Activities are being carried out on the Flight Control System and all
associated functions/systems including but not limited to the following:
displays, alerting system, autopilot and air data system.
- Review of Functional Hazard Assessments and Safety Analysis
- Review of Development Assurance process
- Review of Flight Controls and Autopilot architecture and logics
- Review of Human Factors aspects
- Review of the methodology applied for the assessment of the Crew Training
needs
EASA activities p 13
EASA PROPRIETARY – Do not disclose without EASA consent
- Unprecedented level of effort, involving around 20 multi-disciplinary
experts, including test pilots and engineers, 2-3 weekly web- based meetings
with Boeing, review of 500+ documents and actions
- EASA requirements for flight/Simulator evaluation communicated on May 22.
70 test points requested to be evaluated, covering:
- Normal operations (identification of MCAS operation)
- Abnormal operations (AoA failures, stabiliser runaway, MCAS inoperative,…)
- Simulators evaluation performed in June and July.
EASA findings p 14
Significant technical issues:
- Lack of exhaustive monitoring of the system failures resulting in a
stabiliser runaway
- Too high forces needed to move the manual trim wheel in case of a
stabiliser runaway
- Too late disconnection of autopilot near stall speed (in specific
conditions)
- Too high crew workload and risk of crew confusion in some failure cases,
especially Angle of Attack single failure at take-off
Findings communicated to Boeing and FAA in July 2019
p 15 in image below
Next major milestones p 16
EASA PROPRIETARY – Do not disclose without EASA consent
- Safety assessment of the new design changes proposed by Boeing, including
operational procedures
- Human factor evaluation and functional tests of the new software
- Flight tests on a modified B737 max [one full week - at Boeing Flight Test Center]
-- MCAS operations (nominal behavior)
-- Flight without MCAS (including high speed turns and stall)
-- Scenario of stabiliser runaway (uncommanded MCAS activation, manual trim wheel forces)
-- Approach to stall with autopilot engaged
- Crew Training requirements, in particular using Computer Based Training or Simulator
- Coordination with EASA Member States on Return to Service actions
Flight tests on a modified B737 max [one full week - at Boeing Flight Test Center]
- MCAS operations (nominal behavior)
- Flight without MCAS (including high speed turns and stall)
- Scenario of stabiliser runaway (uncommanded MCAS activation, manual trim wheel forces)
- Approach to stall with autopilot engaged