105 - Speed Assignment Flashcards
Glossary > Indicated Airspeed
The uncorrected reading on the airspeed indicator.
Glossary > TAS (True Airspeed)
The airspeed of an aircraft relative to undisturbed air. It is used primarily in flight planning and the enroute portion of flight. When used in pilot/controller communications, it is referred to as “true airspeed” and not shortened to “airspeed.”
Glossary > Mach Number
The ratio of the speed of an object to the local speed of sound.
TC AIM RAC 11.1 Adherence to Mach Number
Within CDA, aircraft shall adhere to the Mach number assigned by ATC, to within 0.01 Mach, unless approval is obtained from ATC to make a change or until the pilot receives the initial descent clearance approaching destination. If it is necessary to make an immediate temporary change in the Mach number (e.g. because of turbulence), ATC shall be notified as soon as possible that such a change has been made.
If it is not possible to maintain the last assigned Mach number during en route climbs and descents because of aircraft performance, pilots shall advise ATC at the time of the climb/descent request.
Mental Math > Miles Per Minute
60 mph = 60 miles/1 hour = 60 miles/60 minutes = 1 mile per minute
60 mph = 1 mile per minute
120 mph = 2 miles per minute
180 mph = 3 miles per minute
240 mph = 4 miles per minute
270 mph = 4.5 miles per minute (270/6 = 4.5; .5 = 5/10 of a minute or 30 sec)
480 mph = 8 miles per minute
Separation Basics > Requirements to Have Multiple types of Separation
If the type of separation or the minimum used to separate aircraft cannot be maintained, take action to ensure that another type of separation exists, or another minimum is established, before the current separation becomes insufficient.
For example, if two aircraft are on converging tracks, ensure that vertical or longitudinal separation exists before lateral separation is lost.
When to Use Speed Assignments
If required to achieve or maintain required spacing or to minimize vectoring, instruct a pilot to adjust the aircraft’s speed.
Avoid repetitive and constant speed changes unless they are required because of traffic flow, traffic levels, pilot workload, or airspace design.
Speed Assignments > Expression of Speed Adjustments (Knots vs Mach)
Express the speed adjustment using either of the following methods:
* As a multiple of 10 knots, based on IAS
* If the aircraft is a turbojet operating in high-level airspace, as a Mach number
Table: Speed Adjustment Guidelines > Minimum Assignable Speeds
*20 miles or more distance to destination
> 10000 ASL and above > 250 IAS
> Below 10000 ASL > 210 IAS
*Less than 20 miles distance to destination
> Turbojet > 150 IAS (Use only when required for spacing on final approach) / 160 IAS (Preferred when assigning a speed to cross the final approach fix)
> Propeller > 120 IAS
Speed Assignments > Airspeed Limitations
Do not approve a speed over 250 knots IAS below 10000 feet above sea level, but acknowledge a pilot who informs you of a requirement to operate above the CARs-regulated speed limitations for minimum safe speed requirements.
If a pilot reports or operates at a speed over 250 knots below 10000 feet above sea level and does not state that it is for minimum safe speed, inform the operations duty manager.
TC AIM RAC 2.5.2 Aircraft Speed Limit Order
According to CAR 602.32, no person shall operate an aircraft in Canada;
(a) below 10 000 ft ASL at more than 250 KIAS; or
(b) below 3 000 ft AGL within 10 NM of a controlled airport and at more than 200 KIAS, unless authorized to do so in an air traffic control clearance.
Exceptions
(a) A person may operate an aircraft at an indicated airspeed greater than the airspeeds referred to in (a) and (b) above where the aircraft is being operated in accordance with a special flight operations certificate – special aviation event issued under CAR 603.
(b) If the minimum safe speed, given the aircraft configuration, is greater than the speed referred to in (a) or (b) above, the aircraft shall be operated at the minimum safe speed.
Speed Assignments > Speed Assignment Phraseology
When assigning speeds, use positive speed control by issuing any of the pilot instructions indicated the following sections.
(Use of the word TO in speed assignments may be omitted where it is redundant or could be mistaken for the number TWO).
Avoid ambiguous phraseology such as MAINTAIN BEST FORWARD SPEED or KEEP THE SPEED UP.
(Ambiguous speed assignments may lead to unexpected speeds being flown by a pilot).
Speed Assignments > Speed Reductions and Slower Speed Ranges
You may instruct a pilot to fly at slower speeds. Do not specify the minimum aircraft speed when a higher speed would suffice.
Speed Assignments > Speed Increases and Faster Speed Ranges
You may instruct a pilot to fly at faster speeds.
Speed Assignments > Issuing Speed Reductions and Simultaneous Descents
A simultaneous descent and speed reduction can be a difficult manoeuvre for some types of turbojet aircraft. It may be necessary for the pilot to level off temporarily and reduce speed prior to descending. Specifying which action is to be accomplished first removes any doubt the pilot may have concerning controller intent or priority.
“Reduce [speed] [to] (number) knots [or less], then descend [to] (altitude).”
“Descend [to] (altitude), then reduce [speed] [to] ((number) knots / mach (number)) [or less].”
“Descend [to] (altitude), then reduce [speed] by ((number) knots / mach (number)) [or less].”
