N2s

Noun

N2 (plural N2s)

1. 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, often expressed as a percentage of a certain reference rotational speed.
   • The inputs into the computerized JT9D condition monitoring program for this engine from September 10 through 16 likewise reflected adverse changes in trends of vital operating parameters which were indicative of the possibility of a serious engine malfunction. These data points showed a progressive...1971 February 3, National Transportation Safety Board, “Analysis and Conclusions”, in Aircraft Incident Report: American Airlines, Inc., Boeing 747-121, N743PA, San Francisco, California, September...