 
 
 
 INSIGHTi  
Boeing 737 Max to Fly Again, Clouded by 
Certification Concerns 
December 7, 2020 
On November 18, 2020, the Federal Aviation Administration (FAA) issue
d an order rescinding it
s March 
2019 order that had grounded the Boeing 737 Max passenger jet for nearly 20 months. Congress 
continues to debate legislation 
(H.R. 8408, S. 3969, a
nd S. 3866) seeking to reform aircraft certification in 
an effort to avoid future safety stand-downs of this magnitude involving the design of highly  complex 
transport aircraft.
 
Two high-profile fatal accidents, the crash 
of Lion Air flight 610 in October 2018 and the crash of 
Ethiopian Airlines  flight 302 in March 2019, prompted the unprecedented worldwide grounding of the 
737 Max as investigators and engineers sought to identify and remedy a common set of causes. Both 
accidents were linked to an automated flight control system feature cal ed t
he Maneuvering 
Characteristics Augmentation System (MCAS). The design of the 737 Max included larger engines than 
earlier versions of the 737. Under certain circumstances, these engines could cause an unintended pitch up 
of the airplane’s nose. MCAS was instal ed to automatical y  compensate for this undesirable tendency. In 
both accidents, MCAS activated repeatedly, resulting in extreme nose-down pitching. Analysis after the 
accidents revealed that MCAS relied on a single sensor that was reportedl
y prone to damage, and that the 
aircraft lacked safeguards to prevent its activation if that single sensor failed. The two crashed airplanes 
had no cockpit indicators to notify pilots of a possible sensor failure, and Boeing had not advised airlines 
to train pilots about the existence and functioning of MCAS or proper procedures to override or disable it 
if necessary.
 
Design Certification Probed 
The crashes triggered a number of investigations and reviews of FAA’s procedures for certifying the 
safety of the 737 Max in particular and of passenger aircraft more broadly. FAA joined with aviation 
authorities from other countries and the European Union to complete a comprehensi
ve technical review of 
the Boeing 737 Max flight control system design and certification. The Department of Transportation 
independently convened 
a special committee to review the certification of the Boeing 737 Max, which 
urged FAA to require aircraft manufacturers to implement Safety Management Systems (SMS) like those 
alrea
dy required of airlines.  While FA
A initiated rulemaking back in 2014 to comply with international 
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Congressional Research Service 
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standards requiring SMS at aircraft design and manufacturing organizations, FAA and industry had settled 
on voluntary implementation of an SMS standard rather than a mandatory requirement. 
A House Transportation and Infrastructure Committee investigative report found, in addition to faulty 
design and performance assumptions specific to the Boeing 737 Max, a “culture of concealment” at 
Boeing  that contributed to withholding critical details from FAA, airlines, and pilots. It concluded that 
FAA had insufficient oversight over the aircraft’s development after delegating significant aspects of 
certification to Boeing itself under t
he Organization Designation Authorization (ODA) program. The 
report also concluded that schedule, cost, and production pressures at Boeing further compromised safety. 
Grounding Order Lifted 
FAA’s November 18 order requires Boeing 737 Max operators in the United States to take certain 
corrective actions detailed i
n Airworthiness Directives to address identified MCAS flaws before the 
airplanes can return to service. It also requires airlines to develop FAA-approve
d pilot training regarding 
the MCAS system and its functionality, including flight simulator training to help pilots respond to 
MCAS failures. American Airlines reportedly
 plans to resume some 737 Max flights by late December 
2020, while United Airlines  and Southwest Airlines reportedly plan to reintroduce the jet in early 2021. 
Air safety agencies in some other countries and the European Union grounded the 737 Max prior to 
FAA’s action in 2019, leading to speculation that they might impose stricter conditions than FAA before 
al owing the aircraft to reenter service. However
, the European Union Aviation Safety Agency (EASA), 
along with its counterparts in Canada and Brazil, has reportedly mostly harmonized with FAA in setting 
conditions for returning the 737 Max to service, al aying concerns over potential y lengthy disagreements 
among international regulators. It remains to be seen whether foreign regulators wil  scrutinize aircraft 
certification more closely in the future and rely less on FAA’s determinations. 
Legislation Seeks Certification Reforms 
On November 17, 2020, the House passed the Aircraft Certification Reform and Accountability Act 
(H.R. 
8408). The bil  would require each aircraft manufacturer to develop and implement an FAA-approved 
SMS that includes a confidential, nonpunitive safety reporting program for employees to voice safety 
concerns and to follow a code of ethics setting safety as the company’s top priority. It would also order an 
expert review of al  ODA holders that manufacture transport category airplanes. The review would assess 
the extent to which those manufacturers have implemented a safety culture, the effectiveness of measures 
implemented to prioritize safety, and each company’s capability to make reasonable and appropriate 
decisions regarding certification functions delegated by FAA under ODA. 
Similarly, the Aircraft Safety and Certification Reform Act of 2020 
(S. 3969) would mandate changes to 
the aircraft certification process, the ODA program, and FAA oversight of that program. The bil  would 
mandate implementation of FAA-approved SMS for aircraft manufacturers. It would additional y require 
that FAA review and approve al  personnel assigned to an aircraft manufacturer’s ODA unit, and would 
increase FAA involvement with and oversight of ODA activities. The bil   would direct FAA to convene an 
expert panel to review ODA best practices and to address the panel’s findings and recommendations. It 
would also require FAA to review and update existing requirements and guidance regarding human 
factors and human systems integration, particularly those related to aircraft-pilot interfaces. A separate bil  
under consideration in the Senate, the Aircraft Safety Improvement Act of 2020
 (S. 3866), would 
similarly  require aircraft manufacturers to implement SMS, and would require FAA to identify and 
implement ODA best practices and address human factors considerations in the design of aircraft 
automation. 
  
Congressional Research Service 
3 
Author Information 
 Bart Elias 
   
Specialist in Aviation Policy  
 
 
 
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