N2

N₂ English Noun en 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, often expressed as a percentage of a certain reference rotational speed. en 3 February 1971 w:National Transportation Safety Board Aircraft Incident Report: American Airlines, Inc., Boeing 747-121, N743PA, San Francisco, California, September 18, 1970 Analysis and Conclusions https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR7107.pdf https://web.archive.org/web/20220705102355/https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR7107.pdf 5 July 2022 5 July 2022 12 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 increase of EGT and fuel flow while N2 showed a progressive decrease over the same period of time. en 9 January 2007 w:National Transportation Safety Board Aircraft Accident Report: Crash of Pinnacle Airlines Flight 3701, Bombardier CL-600-2B19, N8396A, Jefferson City, Missouri, October 14, 2004 1.16.3 Engine Tests https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR0701.pdf https://web.archive.org/web/20220705100709/https://www.ntsb.gov/investigations/accidentreports/reports/aar0701.pdf 5 July 2022 5 July 2022 27 A test to evaluate the slight increases (25 to 30 pounds per square inch gauge [psig]) in core-driven hydraulic pump pressure indications showed that hydraulic pump pressure would begin to indicate on the FDR with about 35 rpm of core rotation. Another test showed that N2 signals would begin to indicate on the FDR and in the cockpit with about 70 rpm of core rotation. en N₂. Coordinate terms en N1 en N3