(n) :
(aviation) The rotational speed of the high-pressure spool of a two-spool gas turbine engine or the intermediate-pressure spool of a three-spool gas turbine engine, expressed as a percentage of a certain reference rotational speed.
(n) :
(aviation) The rotational speed of the high-pressure spool of a two-spool gas turbine engine or the intermediate-pressure spool of a three-spool gas turbine engine, expressed as a percentage of a certain reference rotational speed.