In February 2016, the EASA certified the MAX with the expectation that pilot procedures and training would clearly explain unusual situations in which the seldom used manual trim wheel would be required to trim the plane, i.e. adjust the angle of the nose; however, the original flight manual did not mention those situations.[86] The EASA certification document referred to simulations whereby the electric thumb switches were ineffective to properly trim the MAX under certain conditions. The EASA document said that after flight testing, because the thumb switches could not always control trim on their own, the FAA was concerned by whether the 737 MAX system complied with regulations.[87] The American Airlines flight manual contains a similar notice regarding the thumb switches but does not specify conditions where the manual wheel may be needed.[87]