Boeing has formally requested an exemption from the Federal Aviation Administration (FAA) regarding certain stall management and yaw damper (SMYD) system regulations for its 737 MAX 7 and 737 MAX 10 aircraft. These models have yet to receive certification, and Boeing argues that a time-limited exemption until October 31, 2028, would allow them to proceed with certification and deliveries while retrofitting aircraft later to meet full compliance.
Why Boeing Needs the Exemption
On January 21, 2024, the FAA published Boeing’s request, which cites two Code of Federal Regulations (CFR) provisions that the 737 MAX 7 and MAX 10 SMYD systems currently do not meet. Boeing contends that these issues stem from post-certification updates across the 737 MAX family, including the Enhanced Angle of Attack (EAOA) system meant to improve safety following the 737 MAX 8 crashes in 2018 and 2019.
By granting the exemption, Boeing claims:
- The SMYD system will be upgraded in compliance over time.
- Deliveries of the 737 MAX 7 and MAX 10 can proceed without further delays.
- Already-delivered aircraft can be retrofitted to meet full certification requirements.
Understanding the SMYD System
The Stall Management Yaw Damper (SMYD) system is a critical component in Boeing’s aircraft, providing:
- Stall warning and identification
- Yaw damper functions (helping stabilize the aircraft)
Boeing modified the 737 MAX 9’s SMYD software for the 737 MAX 7 and similarly adapted the 737 MAX 7’s software for the 737 MAX 10, ensuring consistent performance despite differences in fuselage length.
The new Enhanced Angle of Attack (EAOA) safety feature was added to improve system integrity and reduce pilot workload in case of air data or angle of attack (AOA) failures—which were major factors in the Lion Air Flight 610 and Ethiopian Airlines Flight 302 crashes.
What Has Changed?
- No hardware changes were made; updates are software-based.
- Less than 10% of SMYD code was modified, mainly to integrate the EAOA feature.
- Extensive simulator and testing evaluations confirmed no adverse effects on flight stability.
FAA Certification Hurdles
A key issue for Boeing is that SMYD certification requirements have changed over time. Historically, the 737 Next Generation (NG) and earlier MAX models were certified under “Level B” safety standards, but a new assessment now requires “Level A” (DAL A) certification, which Boeing has not yet met.
To resolve this, Boeing plans to:
- Complete full DAL A certification as part of post-certification work.
- Upgrade the SMYD system on existing aircraft after deliveries begin.
Boeing’s Justification for the Exemption
Boeing argues that granting the exemption is in the public interest because:
- It allows 737 MAX aircraft with EAOA safety features to be delivered sooner.
- Delays in certification could stall critical safety improvements for the MAX fleet.
- The 737 MAX family has a strong safety track record, with no major yaw damper failures reported in Boeing’s Continued Operational Safety Program (COSP) database.
Additionally, Boeing highlights the economic and environmental benefits of the 737 MAX, including improved fuel efficiency and operational capability for airlines.
Boeing’s History of Exemption Requests
This is not the first time Boeing has sought an exemption from the FAA.
- November 2023: Boeing requested an exemption for eight CFR provisions related to the engine nacelle inlet and engine anti-ice system on the 737 MAX 7.
- January 2024: Following the Alaska Airlines 737 MAX 9 door plug incident, Boeing withdrew the exemption due to political and regulatory pressure.
Despite these setbacks, Boeing remains confident that the 737 MAX 7 and 737 MAX 10 will be certified in 2025, pending FAA approvals.
Boeing’s request for an FAA exemption on SMYD certification is critical to moving forward with 737 MAX 7 and MAX 10 deliveries. While the company assures that safety enhancements will not be compromised, regulators and lawmakers may scrutinize the exemption request, given Boeing’s history with the 737 MAX crisis. The FAA’s decision will determine whether these models can enter service soon or face further delays.
