The FAA and Boeing both refuted media reports describing MCAS as an anti-stall system, which Boeing asserted it is distinctly not.[31][32][33] The aircraft had to perform well in a low-speed stall test.[34] The Joint Authorities Technical Review "considers that the STS/MCAS and elevator feel shift (EFS) functions could be considered as stall identification systems or stall protection systems, depending on the natural (unaugmented) stall characteristics of the aircraft".