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6/17/21 

AIM 

c. 

Without such actions as leading a turn, aircraft 

operating in excess of 290 knots true air speed (TAS) 
can exceed the normal airway or route boundaries 
depending on the amount of course change required, 
wind direction and velocity, the character of the turn 
fix (DME, overhead navigation aid, or intersection), 
and the pilot’s technique in making a course change. 
For example, a flight operating at 17,000 feet MSL 
with a TAS of 400 knots, a 25 degree bank, and a 
course change of more than 40 degrees would exceed 
the width of the airway or route; i.e., 4 nautical miles 
each side of centerline. However, in the airspace 
below 18,000 feet MSL, operations in excess of 
290 knots TAS are not prevalent and the provision of 
additional IFR separation in all course change 
situations for the occasional aircraft making a turn in 
excess of 290 knots TAS creates an unacceptable 
waste of airspace and imposes a penalty upon the 
preponderance of traffic which operate at low speeds. 
Consequently, the FAA expects pilots to lead turns 
and take other actions they consider necessary during 
course changes to adhere as closely as possible to the 
airways or route being flown. 

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6.  Changeover Points (COPs) 

a. 

COPs are prescribed for Federal airways, jet 

routes, area navigation routes, or other direct routes 
for which an MEA is designated under 14 CFR 
Part 95. The COP is a point along the route or airway 
segment between two adjacent navigation facilities or 
waypoints where changeover in navigation guidance 
should occur. At this point, the pilot should change 
navigation receiver frequency from the station 
behind the aircraft to the station ahead. 

b. 

The COP is normally located midway between 

the navigation facilities for straight route segments, 
or at the intersection of radials or courses forming a 
dogleg in the case of dogleg route segments. When 
the COP is NOT located at the midway point, 
aeronautical charts will depict the COP location and 
give the mileage to the radio aids. 

c. 

COPs are established for the purpose of 

preventing loss of navigation guidance, to prevent 
frequency interference from other facilities, and to 
prevent use of different facilities by different aircraft 
in the same airspace. Pilots are urged to observe COPs 
to the fullest extent. 

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7.  Minimum Turning Altitude (MTA) 

Due to increased airspeeds at 10,000 ft MSL or above, 
the published minimum enroute altitude (MEA) may 
not be sufficient for obstacle clearance when a turn is 
required over a fix, NAVAID, or waypoint. In these 
instances, an expanded area in the vicinity of the turn 
point is examined to determine whether the published 
MEA is sufficient for obstacle clearance. In some 
locations (normally mountainous), terrain/obstacles 
in the expanded search area may necessitate a higher 
minimum altitude while conducting the turning 
maneuver. Turning fixes requiring a higher minimum 
turning altitude (MTA) will be denoted on 
government charts by the minimum crossing altitude 
(MCA) icon (“x” flag) and an accompanying note 
describing the MTA restriction. An MTA restriction 
will normally consist of the air traffic service (ATS) 
route leading to the turn point, the ATS route leading 
from the turn point, and the required altitude; e.g., 
MTA V330 E TO V520 W 16000. When an MTA is 
applicable for the intended route of flight, pilots must 
ensure they are at or above the charted MTA not later 
than the turn point and maintain at or above the MTA 
until joining the centerline of the ATS route following 
the turn point. Once established on the centerline 
following the turning fix, the MEA/MOCA deter-
mines the minimum altitude available for 
assignment. An MTA may also preclude the use of a 
specific altitude or a range of altitudes during a turn. 
For example, the MTA may restrict the use of 10,000 
through 11,000 ft MSL. In this case, any altitude 
greater than 11,000 ft MSL is unrestricted, as are 
altitudes less than 10,000 ft MSL provided 
MEA/MOCA requirements are satisfied. 

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8.  Holding 

a. 

Whenever an aircraft is cleared to a fix other 

than the destination airport and delay is expected, it 
is the responsibility of ATC to issue complete holding 
instructions (unless the pattern is charted), an EFC 
time and best estimate of any additional en 
route/terminal delay. 

NOTE

 

Only those holding patterns depicted on U.S. government 
or commercially produced (meeting FAA requirements) 
low/high altitude en route, and area or STAR charts should 
be used. 

b. 

If the holding pattern is charted and the 

controller doesn’t issue complete holding instruc-
tions, the pilot is expected to hold as depicted on the 

En Route Procedures 

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