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AIM 

6/17/21 

aircraft by the certification authority of the country of 
registry. A pilot must maneuver the aircraft within the 
circling approach protected area (see FIG 5

4

29) to 

achieve the obstacle and terrain clearances provided 
by procedure design criteria. 

b. 

In addition to pilot techniques for maneuvering, 

one acceptable method to reduce the risk of flying out 
of the circling approach protected area is to use either 
the minima corresponding to the category determined 
during certification or minima associated with a 
higher category. Helicopters may use Category A 
minima. If it is necessary to operate at a speed in 
excess of the upper limit of the speed range for an 
aircraft’s category, the minimums for the higher 
category should be used. This may occur with certain 
aircraft types operating in heavy/gusty wind, icing, or 
non

normal conditions. For example, an airplane 

which fits into Category B, but is circling to land at 
a speed of 145 knots, should use the approach 
Category D minimums. As an additional example, a 
Category A airplane (or helicopter) which is 
operating at 130 knots on a straight

in approach 

should use the approach Category C minimums. 

c. 

A pilot who chooses an alternative method 

when it is necessary to maneuver at a speed that 
exceeds the category speed limit (for example, where 
higher category minimums are not published) should 
consider the following factors that can significantly 
affect the actual ground track flown: 

1. 

Bank angle. For example, at 165 knots 

groundspeed, the radius of turn increases from 
4,194 feet using 30 degrees of bank to 6,654 feet 
when using 20 degrees of bank. When using a 
shallower bank angle, it may be necessary to modify 
the flightpath or indicated airspeed to remain within 
the circling approach protected area. Pilots should be 
aware that excessive bank angle can lead to a loss of 
aircraft control. 

2. 

Indicated airspeed. Procedure design criteria 

typically utilize the highest speed for a particular 
category. If a pilot chooses to operate at a higher 
speed, other factors should be modified to ensure that 
the aircraft remains within the circling approach 
protected area. 

3. 

Wind speed and direction. For example, it is 

not uncommon to maneuver the aircraft to a 
downwind leg where the groundspeed will be 
considerably higher than the indicated airspeed. 

Pilots must carefully plan the initiation of all turns to 
ensure that the aircraft remains within the circling 
approach protected area. 

4. 

Pilot technique. Pilots frequently have many 

options with regard to flightpath when conducting 
circling approaches. Sound planning and judgment 
are vital to proper execution. The lateral and vertical 
path to be flown should be carefully considered using 
current weather and terrain information to ensure that 
the aircraft remains within the circling approach 
protected area. 

d. 

It is important to remember that 14 CFR 

Section 91.175(c) requires that “where a DA/DH or 
MDA is applicable, no pilot may operate an aircraft 
below the authorized MDA or continue an approach 
below the authorized DA/DH unless the aircraft is 
continuously in a position from which a descent to a 
landing on the intended runway can be made at a 
normal rate of descent using normal maneuvers, and 
for operations conducted under Part 121 or Part 135 
unless that descent rate will allow touchdown to 
occur within the touchdown zone of the runway of 
intended landing.” 

e. 

See the following category limits: 

1. 

Category A:  Speed less than 91 knots. 

2. 

Category B:  Speed 91 knots or more but less 

than 121 knots. 

3. 

Category C:  Speed 121 knots or more but 

less than 141 knots. 

4. 

Category D:  Speed 141 knots or more but 

less than 166 knots. 

5. 

Category E:  Speed 166 knots or more. 

NOTE

 

V

REF

 in the above definition refers to the speed used in 

establishing the approved landing distance under the 
airworthiness regulations constituting the type certifica-
tion basis of the airplane, regardless of whether that speed 
for a particular airplane is 1.3 

V

SO,

 1.23 

V

SR,

 or some 

higher speed required for airplane controllability. This 
speed, at the maximum certificated landing weight, 
determines the lowest applicable approach category for 
all approaches regardless of actual landing weight. 

f. 

When operating on an unpublished route or 

while being radar vectored, the pilot, when an 
approach clearance is received, must, in addition to 
complying with the minimum altitudes for IFR 
operations (14 CFR Section 91.177), maintain the 
last assigned altitude unless a different altitude is 

Arrival Procedures 

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