Class 'A' Airspace: ATC Controlled airspace in which IFR aircraft only are permitted. Mode-C equipped transponders are mandatory. Usually this airspace is from FL180 up to FL600.
Class 'B' Airspace: ATC Controlled airspace in which IFR and CVFR aircraft are permitted. Mode-C equipped transponders are mandatory. Usually this airspace is from 12,500' to (but not including) 18,000'.
Class 'C' Airspace: ATC Controlled airspace in which IFR and VFR aircraft are permitted. Mode-C equipped transponders are mandatory. Usually this airspace surrounds an airport with significant traffic volumes, such as Ottawa and Montreal. A clearance is required for VFR aircraft to enter Class 'C' airspace.
Class 'D' Airspace: Controlled airspace in which IFR and VFR aircraft are permitted. Often Mode-C transponders are required (when the airspace is classified as Transponder Airspace). A clearance is not required to enter Class 'D' airspace, but two-way communications must be established with the appropriate ATC unit before entering the airspace.
Class 'E' Airspace: Controlled airspace in which IFR and VFR aircraft are permitted. Often Mode-C transponders are required (when the airspace is classified as Transponder Airspace). A clearance is not required to enter Class 'E' airspace. There are no special requirements for VFR aircraft, however two-way communications should be established with the appropriate ATC unit before entering the airspace.
CVFR: Controlled Visual Flight Rules. A VFR aircraft with specific ATC clearances.
DME: Distance Measuring Equipment.
FMS: Flight Management Computer
GPS: Global Positioning System. An onboard receiver determines exact position via a constellation of satellites.
INS: Inertial Navigation System. Gyroscopes in all three axes combined with computers can compute acceleration and therefore position over the earth.
TCA: Terminal Control Area. The volume of airspace controlled by the local terminal air traffic controllers.
Transponder: An aircraft instrument that enhances Air Traffic Control's (ATC) radar reflection from your aircraft, and simultaneously provides squack code and altitude data to ATC in Mode-C operation. Mode-A operation only provides enhanced radar reflection and a squack code.
SID: Standard Instrument Departure. A set of departure routings pilots can use that provides accurate transitions from the IFR airport departure portion to the enroute portion of an IFR flight. SIDs come in basically two flavours, FMS and non-FMS. Non-FMS SIDs use external navigational aids such as VOR/DME radials/distances and specific headings to fly the SID. FMS SIDs use internal navigational equipment such as INS and GPS to fly the SID.
STARs: Standard Terminal Arrival Routings. A set of arrival routings pilots can use that provides accurate transitions from the enroute portion of an IFR flight to the IFR approach portion of an IFR flight. STARs come in basically two flavours, FMS and non-FMS. Non-FMS STARs use external navigational aids such as VOR/DME radials/distances and specific headings to fly the STAR. FMS STARs use internal navigational equipment such as INS and GPS to fly the STAR.
Squack Code: A four digit code set on a transponder by the pilot. The code can only be digits between 0 and 7. Example: 1234, 4366, 7777, 0000, etc. Some codes are reserved for generic or special use. VFR aircraft not under Air Traffic Control should set code 1200, where an aircraft declaring an emergency should set 7700 if able. If under Air Traffic Control, the ATC controller may ask the pilot to set a specific code to better identific the pilot's aircraft from others around it.
Vector: An ATC assigned heading flown
VOR: VHF Omnidirectional Range. A radio signal emitted by a ground station that provides radial and distance information to an aircraft and displayed on an instrument.