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Section 4.  Two-way Radio Communications Failure 



1.  Two-way Radio Communications 



It is virtually impossible to provide regulations 

and procedures applicable to all possible situations 
associated with two-way radio communications 
failure. During two-way radio communications 
failure, when confronted by a situation not covered in 
the regulation, pilots are expected to exercise good 
judgment in whatever action they elect to take. 
Should the situation so dictate they should not be 
reluctant to use the emergency action contained in 
14 CFR Section 91.3(b). 


Whether two-way communications failure 

constitutes an emergency depends on the circum-
stances, and in any event, it is a determination made 
by the pilot. 14 CFR Section 91.3(b) authorizes a 
pilot to deviate from any rule in Subparts A and B to 
the extent required to meet an emergency. 


In the event of two-way radio communications 

failure, ATC service will be provided on the basis that 
the pilot is operating in accordance with 14 CFR 
Section 91.185. A pilot experiencing two-way 
communications failure should (unless emergency 
authority is exercised) comply with 14 CFR 
Section 91.185 quoted below: 

1.  General. 

Unless otherwise authorized by 

ATC, each pilot who has two-way radio communica-
tions failure when operating under IFR must comply 
with the rules of this section. 

2.  VFR conditions. 

If the failure occurs in 

VFR conditions, or if VFR conditions are encoun-
tered after the failure, each pilot must continue the 
flight under VFR and land as soon as practicable. 



This procedure also applies when two-way radio failure 
occurs while operating in Class A airspace. The primary 
objective of this provision in 

14 CFR Section 

91.185 is to 

preclude extended IFR operation by these aircraft within 
the ATC system. Pilots should recognize that operation 
under these conditions may unnecessarily as well as 
adversely affect other users of the airspace, since ATC may 
be required to reroute or delay other users in order to 
protect the failure aircraft. However, it is not intended that 
the requirement to “land as soon as practicable” be 
construed to mean “as soon as possible.” Pilots retain the 
prerogative of exercising their best judgment and are not 

required to land at an unauthorized airport, at an airport 
unsuitable for the type of aircraft flown, or to land only 
minutes short of their intended destination. 

3.  IFR conditions. 

If the failure occurs in IFR 

conditions, or if subparagraph 2 above cannot be 
complied with, each pilot must continue the flight 
according to the following: 

(a)  Route. 


By the route assigned in the last ATC 

clearance received; 


If being radar vectored, by the direct 

route from the point of radio failure to the fix, route, 
or airway specified in the vector clearance; 


In the absence of an assigned route, by 

the route that ATC has advised may be expected in a 
further clearance; or 


In the absence of an assigned route or a 

route that ATC has advised may be expected in a 
further clearance by the route filed in the flight plan. 

(b)  Altitude. 

At the HIGHEST of the 

following altitudes or flight levels FOR THE ROUTE 


The altitude or flight level assigned in 

the last ATC clearance received; 


The minimum altitude (converted, if 

appropriate, to minimum flight level as prescribed in 
14 CFR Section 91.121(c)) for IFR operations; or 


The altitude or flight level ATC has 

advised may be expected in a further clearance. 



The intent of the rule is that a pilot who has experienced 
two-way radio failure should select the appropriate 
altitude for the particular route segment being flown and 
make the necessary altitude adjustments for subsequent 
route segments. If the pilot received an “expect further 
clearance” containing a higher altitude to expect at a 
specified time or fix, maintain the highest of the following 
altitudes until that time/fix: 

(1)  the last assigned altitude; or 
(2) the minimum altitude/flight level for IFR 


Upon reaching the time/fix specified, the pilot should 
commence climbing to the altitude advised to expect. If the 

Two-way Radio Communications Failure