To read the full opinion of the interpretation, 
click here.

It is the FAAís policy, under the commonly referred to "one phone call exception," that a rest period is not viewed as interrupted if the air carrier makes contact with the pilot one time by telephone, pager or the like.1 Once the contact is made, it cannot, however, be made again without interrupting the rest period.

To reemphasize - under no circumstances is a pilot obligated to answer the telephone if the pilot is considered to be on rest. It appears that some people overlook the voluntary nature of receiving phone calls. Thus, if the pilot seeks to have an uninterrupted rest period, the pilot certainly can take measures to prevent being contacted by the carrier, e.g., if the pilot is staying at a hotel, the front desk can hold any incoming calls; or if the pilot is at home, the telephone ringer can be turned off and an answering machine can pick up calls. Further, a flight crewmember can provide written notification to the air carrier of his or her desire not to be contacted while on rest periods (or the conditions under which contact should not be attempted). If an air carrier receives such a "do not call" letter from a flight crewmember, then the carrier is on actual notice that its attempts to contact the pilot during the rest period could disrupt the pilotís attempts to sleep. In such a situation, unlike the situations summarized in footnote 1, even one phone call from the carrier to the pilot is evidence that the carrier has broken the pilotís continuous rest period, and the rest period must begin anew before the carrier could use the pilot in part 121 domestic operations.

At the same time, however, an air carrier should consider the consequences of repeatedly trying to reach a pilot who is on rest (assuming the pilot has not explicitly provided the air carrier a "do not call" letter). For example, if a pilot must report for duty by 7 a.m., he or she is likely sleeping during the hours of midnight to 5 a.m.; or if a pilot is on an 8 hour rest period, he or she is likely asleep 4 hours into the period. Therefore, the air carrier should assume that any attempts to contact the pilot during those periods of sleep would disturb the pilot. Perhaps, the pilot hears the repeated rings of the telephone but has chosen not to answer or is too disoriented from being roused from sleep to do so (there is no obligation to do so). Repeated attempts by the air carrier to contact the pilot during these hours would not be reasonable. While these "interruptions" do not meet the legal standard for breaking a continuous rest period as interpreted by the FAA (because contact has not been made), these circumstances do raise serious concerns about potential pilot fatigue and the possibility of a careless or reckless operation of the aircraft (i.e., by pilot and certificate holder) contrary to 14 CFR 3 91.13 (a).

1 Note that the Federal Aviation Regulations do not explicitly allow "one phone call" from the carrier during a pilotís rest period. However, the FAA established the "one phone call" policy based on certain narrow conditions and the fact patterns presented to us. Generally speaking, an air carrier can initiate a phone call and a pilot can - on his or her own volition - receive one call from an air carrier without the phone call being viewed as disruptive and, breaking the continuous rest period.