(e)  
Class E airspace Controlled airspace within which both IFR and VFR flights are permitted, but VFR flights do not have to establish two-way communications with the appropriate ATC agency prior to entering the airspace. ATC separation is provided only to IFR aircraft. All high level controlled airspace above FL 600 within the SCA, NCA and ACA is Class E airspace. Also, low level airways, low level fixed area navigation (RNAV) routes, control area extensions, transition areas, or control zones established without an operating control tower may be classified as Class E airspace.

(f)  
Class F airspace Special-use airspace that may be a restricted area, an advisory area, military operations areas or danger areas and can be controlled airspace, uncontrolled airspace or a combination of both. It is described in terms of horizontal and vertical dimensions, effective for a specified period of time. Although both IFR and VFR flights are permitted in Class F airspace, restricted-airspace access is not authorized without the approval of the user/controlling agency, and advisory-area access is normally reserved for participating aircraft. Non-participating flights should avoid flight within advisory areas, and ATC will not clear non-participating IFR aircraft into an active advisory area. Rules for special-use airspace are as specified in the DAH, and, if not specified, or when the area is not active, the appropriate rules for the surrounding airspace apply.

(g)  
Class G airspace
Airspace within which IFR and VFR flights are not subject to control. Airspace shall be
classified as Class G if it has not been designated as A, B, C, D, E or F.

Note: A poster entitled “Canada’s Airspace” (TP 6010) provides a graphic presentation of airspace structure.
Fr: classification de l’espace aérien
airspace structure The structure that defines the physical dimensions of the elements into which the airspace is divided, such as control zones (CZ), terminal control areas (TCA), control area extensions (CAE) and airways. The dimensions of airspace structure elements are described in the Designated Airspace Handbook (DAH). Note: A poster entitled “Canada’s Airspace” (TP 6010) provides a graphic representation of airspace structure. Fr: structure de l’espace aérien
airspeed Other expression for: indicated airspeed (IAS)
airstart
The starting of an aircraft engine while the aircraft is airborne.
Fr: démarrage en vol
air taxi
U.S. and Canada: The movement of a helicopter or vertical takeoff and landing aircraft (VTOL) above the surface of an aerodrome but normally not above 100 ft AGL. The aircraft may proceed via flight at airspeeds of more than 20 kt. 
. see also: hover taxi
Note: One of the two terms encompassed by ICAO’s term air-taxiing

Fr: circulation en vol
air-taxiing ICAO: Movement of a helicopter/VTOL above the surface of an aerodrome, normally in ground effect and at a ground speed normally less than 37 km/h (20 kt). Note ICAO: The actual height may vary, and some helicopters may require air-taxiing above 8 m (25 ft) AGL to reduce ground effect turbulence or provide clearance for cargo slingloads.