14 CFR § 60.23 - Modifications to FSTDs.
(a) Description of a modification. For the purposes of this part, an FSTD is said to have been modified when:
(1) Equipment or devices intended to simulate aircraft appliances are added to or removed from FSTD, which change the Statement of Qualification or the MQTG; or
(2) Changes are made to either software or hardware that are intended to impact flight or ground dynamics; changes are made that impact performance or handling characteristics of the FSTD (including motion, visual, control loading, or sound systems for those FSTD levels requiring sound tests and measurements); or changes are made to the MQTG. Changes to the MQTG which do not affect required objective testing results or validation data approved during the initial evaluation of the FSTD are not considered modifications under this section.
(b) FSTD Directive. When the FAA determines that FSTD modification is necessary for safety of flight reasons, the sponsor of each affected FSTD must ensure that the FSTD is modified according to the FSTD Directive regardless of the original qualification standards applicable to any specific FSTD.
(c) Using the modified FSTD. The sponsor may not use, or allow the use of, or offer the use of, the FSTD with the proposed modification for flight crewmember training or evaluation or for obtaining flight experience for the flight crewmember to meet any requirement of this chapter unless:
(1) The sponsor has notified the responsible Flight Standards office and the TPAA of their intent to incorporate the proposed modification, and one of the following has occurred;
(i) Twenty-one days have passed since the sponsor notified the responsible Flight Standards office and the TPAA of the proposed modification and the sponsor has not received any response from either the responsible Flight Standards office or the TPAA;
(ii) Twenty-one days have passed since the sponsor notified the responsible Flight Standards office and the TPAA of the proposed modification and one has approved the proposed modification and the other has not responded;
(iii) Fewer than twenty-one days have passed since the sponsor notified the responsible Flight Standards office and the TPAA of the proposed modification and the responsible Flight Standards office and TPAA both approve the proposed modification;
(iv) The sponsor has successfully completed any evaluation the responsible Flight Standards office may require in accordance with the standards for an evaluation for initial qualification or any part thereof before the modified FSTD is placed in service.
(2) The notification is submitted with the content as, and in a form and manner as, specified in the applicable QPS.
(d) User notification. When a modification is made to an FSTD that affects the Statement of Qualification, the sponsor must post an addendum to the Statement of Qualification until such time as a permanent, updated statement is posted.
(e) MQTG update. The MQTG must be updated with current objective test results in accordance with § 60.15(h) and (i) and appropriate objective data in accordance with § 60.13, each time an FSTD is modified and an objective test or other MQTG section is affected by the modification. If an FSTD Directive is the cause of this update, the direction to make the modification and the record of the modification completion must be filed in the MQTG.