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ATC procedures permit ILS/RNAV/GLS 

instrument approach operations to dual or triple 
parallel runway configurations. ILS/RNAV/GLS 
approaches to parallel runways are grouped into three 
classes: Simultaneous Dependent Approaches; Sim-
ultaneous Independent Approaches; and 
Simultaneous Close Parallel PRM Approaches. 
RNAV approach procedures that are approved for 
simultaneous operations require GPS as the sensor 
for position updating. VOR/DME, DME/DME and 
IRU RNAV updating is not authorized. The 
classification of a parallel runway approach 
procedure is dependent on adjacent parallel runway 
centerline separation, ATC procedures, and airport 
ATC final approach radar monitoring and commu-
nications capabilities. At some airports, one or more 
approach courses may be offset up to 3 degrees. ILS 
approaches with offset localizer configurations result 
in loss of Category II/III capabilities and an increase 
in decision altitude/height (50’). 


Depending on weather conditions, traffic 

volume, and the specific combination of runways 
being utilized for arrival operations, a runway may be 
used for different types of simultaneous operations, 
including closely spaced dependent or independent 
approaches. Pilots should ensure that they understand 
the type of operation that is being conducted, and ask 
ATC for clarification if necessary. 


Parallel approach operations demand height-

ened pilot situational awareness. A thorough 
Approach Procedure Chart review should be 
conducted with, as a minimum, emphasis on the 
following approach chart information: name and 
number of the approach, localizer frequency, inbound 
localizer/azimuth course, glideslope/glidepath inter-
cept altitude, glideslope crossing altitude at the final 
approach fix, decision height, missed approach 
instructions, special notes/procedures, and the 
assigned runway location/proximity to adjacent 
runways. Pilots are informed by ATC or through the 
ATIS that simultaneous approaches are in use. 


The close proximity of adjacent aircraft 

conducting simultaneous independent approaches, 
especially simultaneous close parallel PRM ap-

proaches mandates strict pilot compliance with all 
ATC clearances. ATC assigned airspeeds, altitudes, 
and headings must be complied with in a timely 
manner. Autopilot coupled approaches require pilot 
knowledge of procedures necessary to comply with 
ATC instructions. Simultaneous independent ap-
proaches, particularly simultaneous close parallel 
PRM approaches necessitate precise approach course 
tracking to minimize final monitor controller 
intervention, and unwanted No Transgression Zone 
(NTZ) penetration. In the unlikely event of a 
breakout, ATC will not assign altitudes lower than the 
minimum vectoring altitude. Pilots should notify 
ATC immediately if there is a degradation of aircraft 
or navigation systems. 


Strict radio discipline is mandatory during 

simultaneous independent and simultaneous close 
parallel PRM approach operations. This includes an 
alert listening watch and the avoidance of lengthy, 
unnecessary radio transmissions. Attention must be 
given to proper call sign usage to prevent the 
inadvertent execution of clearances intended for 
another aircraft. Use of abbreviated call signs must be 
avoided to preclude confusion of aircraft with similar 
sounding call signs. Pilots must be alert to unusually 
long periods of silence or any unusual background 
sounds in their radio receiver. A stuck microphone 
may block the issuance of ATC instructions on the 
tower frequency by the final monitor controller 
during simultaneous independent and simultaneous 
close parallel PRM approaches. In the case of PRM 
approaches, the use of a second frequency by the 
monitor controller mitigates the “stuck mike” or other 
blockage on the tower frequency. 



AIM, Chapter 4, Section 2, Radio Communications Phraseology and 
Techniques, gives additional communications information. 


Use of Traffic Collision Avoidance Systems 

(TCAS) provides an additional element of safety to 
parallel approach operations. Pilots should follow 
recommended TCAS operating procedures presented 
in approved flight manuals, original equipment 
manufacturer recommendations, professional news-
letters, and FAA publications. 

Arrival Procedures