Rationale

This standard is being revised to clarify that during the test, force and moment measurements can be made from all test stations simultaneously, or from one or more test stations at a time. The current published version of the standard states in 13.4, “On each station, all force and moment measurements should be made either simultaneously from all stations or in a sequence, one test station at a time, for a duration of five test cycles.” This could be interpreted as a requirement that the measurements be made at the same time or sequentially, with no other options (e.g., taking measurements from two stations at a time). However, this is not mandatory, and it is acceptable to take measurements from all stations simultaneously or from one or more test stations at a time. Additionally, this standard is being revised to replace references to ISO 4287 and ISO 4288 (withdrawn) with references to the new versions of these standards, ISO 21920-2 and ISO 21920-3, respectively.