Request for clarification to the applicability section concerning Part 91 Ferry flights.

117.1 Applicability.

(a) This part prescribes flight and duty limitations and rest requirements for all flightcrew members and 

certificate holders conducting passenger operations under part 121 of this chapter.

(b) This part applies to all operations directed by part 121 certificate holders under part 91, other than 

subpart K, of this chapter if any segment is conducted as a domestic passenger, flag passenger, or supplemental 

passenger operation.

(c) This part applies to all flightcrew members when participating in an operation under part 91, other than 

subpart K of this chapter, on behalf of the part 121 certificate holder if any flight segment is conducted as a 

domestic passenger, flag passenger, or supplemental passenger operation

(d) Notwithstanding paragraphs (a), (b) and (c) of this section, a certificate holder may conduct under part 

117 its part 121 operations pursuant to 121.470, 121.480, or 121.500.

Under section (b) the specific clause ‘if any segment is conducted as a’ seems ambiguous.

It is fully understood when operations within the same FDP or TRIP contain any part 121 conducted under part 117 

operation, that the part 91 operation must also be conducted under part 117.

This interpretation was covered under:

FNPRM preamble, 

III. Discussion of Public Comments and Final Rule

A. Applicability (Ref: discussions with UAL and NJASAP).
General questions to be resolved

The problem seems to arise when a flightcrew member has a ‘mix’ of operations within the schedule, eg) part 91 

ferry trip preceding/following a part 121 / part 117 trip.

(1) What determines the ‘break’ of a series of flight segments between part 91 ferry to/from part 121 

conducted under part 117? 

(2) Is it a rest period in accordance to all provisions of 117.25?

117.25 Rest period.

(a) No certificate holder may assign and no flightcrew member may accept assignment to any reserve or 

duty with the certificate holder during any required rest period.

(b) Before beginning any reserve or flight duty period a flightcrew member must be given at least 30 

consecutive hours free from all duty in any 168 consecutive hour period.

(c) If a flightcrew member operating in a new theater has received 36 consecutive hours of rest, that 

flightcrew member is acclimated and the rest period meets the requirements of paragraph (b) of this section.

(d) If a flightcrew member travels more than 60o longitude during a flight duty period or a series of flight 

duty periods that require him or her to be away from home base for more than 168 consecutive hours, the 

flightcrew member must be given a minimum of 56 consecutive hours rest upon return to home base. This rest 

must encompass three physiological nights’ rest based on local time.

(e) No certificate holder may schedule and no flightcrew member may accept an assignment for any 

reserve or flight duty period unless the flightcrew member is given a rest period of at least 10 consecutive hours 

immediately before beginning the reserve or flight duty period measured from the time the flightcrew member 

is released from duty. The 10 hour rest period must provide the flightcrew member with a minimum of 8 

uninterrupted hours of sleep opportunity.

(f) If a flightcrew member determines that a rest period under paragraph (e) of this section will not 

provide eight uninterrupted hours of sleep opportunity, the flightcrew member must notify the certificate 

holder. The flightcrew member cannot report for the assigned flight duty period until he or she receives a rest 

period specified in paragraph (e) of this section.

(g) If a flightcrew member engaged in deadhead transportation exceeds the applicable flight duty period in 

Table B of this part, the flightcrew member must be given a rest period equal to the length of the deadhead 

transportation but not less than the required rest in paragraph (e) of this section before beginning a flight duty 

period.
Specific scenarios to be resolved

Initial Situation – Part 91 ferry to part 117.

Suppose a crewmember is assigned to part 91 ferry trip, the first flight is DEN to SFO for maintenance, the second 

is a part 91 ferry SFO to DEN for positioning, after which the crewmember is released from duty.

The question is how long must the crewmember be released from duty, before that crewmember may be assigned 

to a FDP that contains part 117 operations?

A) Is it just 10 hours with an 8 hour sleep opportunity?

B) Is it 30 hours?

C) Is it any of the rest requirements contained in 117.25?

Reverse Situation – Part 117 to part 91 ferry 

Suppose a crewmember is assigned to part 117 FDP. 

The question here is how long must the crewmember be released from duty before a part 91 ferry assignment may 

be assigned so that the part 91 ferry flights are not subject to the flight / FDP limitations contained in part 117?

A) Is it just 10 hours with an 8 hour sleep opportunity?

B) Is it 30 hours?

C) Is any of the rest requirements contained in 117.25?

Issues that are understood

Given the provision in 117.25 (a) above, a part 91 ferry flight would not be allowed to be assigned during a 

required rest period, thereby, the only legal occurrences of a part 91 ferry flight assigned to a flightcrew member 

should the applicable provisions of 117.25 (b) through (e), are appropriately applied.

FAA interpretations that are currently being applied

If we follow the interpretation for 121 subpart Q (see enclosed letter to James Johnson, 2003 from Donald Byrne), 

we would see that a part 91 ferry flight would require compliance with subpart Q when that specific flight 

precedes a subpart Q flight within 24 hours.

johnson 2003.rtf
Quote from section Analysis:

We view the safety logic to protect subsequent air transportation flights as being equally important in the 

application of the §121.471 rest rules when a ferry flight that is the last flight of a duty day is scheduled: 1) to

precede §121.471 air transportation flights that are scheduled to be performed the following day; 2) the end-ofduty-day ferry flight and the subsequent day's §121.471 flights are scheduled to be performed in a 24-consecutivehour period;25 i

and 3) all such flying will be performed by the same pilot for the same certificate holder.

Therefore, as to Example No. 1(a), the answer is that the certificate holder was required to provide the pilot 

before Day 3's flying either an 11-hour minimum lookback rest period pursuant to § 121.471(b)(3), or a planned 

minimum reduced lookback rest of no less than 9 hours pursuant to §121.471(c)(3) to be followed by 12 hours of 

compensatory rest starting no later than at 1500 hours on Day 3. The 1 hour and 59 minutes ferry flight at the 

end of duty Day 2 precedes §121.471 flying on duty Day 3, and is within the 24-consecutive-hour period from 

1230 hours on Day 2 to 1230 hours on Day 3 in which § 121.471 and ferry flying total 9 hours and 4 minutes 

scheduled flight time. The end-of-duty-Day 2 scheduled ferry flight time must be counted in the total scheduled 

flight time that determines the amount of lookback rest or planned reduced lookback rest with planned 

compensatory rest.

For Example No 1(b), the answer to `Question a' is that even though the pilot was entitled to the same amount of 

lookback rest preceding duty Day 2's flying (i.e., a minimum of 9 hours), whether the 1 hour and 59 minutes of 

ferry flight time is added to duty Day 2's 6 hours of §121.471 flight time or not, because the 1 hour and 59 

minutes ferry flight at the end of duty Day 2 is scheduled to precede §121.471 flying in a 24-consecutive-hour 

period, that ferry flight time must be counted to designate the amount of lookback rest for Day 2's flying; and the 

reduction of lookback rest to 8 hours and 31 minutes at the ferry flight's actual expected completion triggers 

receipt of at least 10 hours of compensatory rest. The answer to `Question b' is that the 10-hour compensatory 

rest triggered by the actual expected completion of the ferry flight at the end of duty Day 2 and the already 

scheduled 11-hour lookback rest to precede Day 3's flying may be served concurrently, provided that the 

compensatory rest starts on time and the pilot receives a total rest period of 1126 hours.

The answer to `Question a' of Example 1(c) is that we not consider the 3-hour scheduled ferry flight time following 

duty Day 2's scheduled §121.471 flights in determining compliance with paragraph (a)(4)'s flight time limits. Thus, 

we do not consider that the flight time limits of paragraph (a)(4) have been violated. The answer to `Question b' is 

that the certificate holder was required to provide the pilot before Day 3's flying either a minimum 11-hour 

lookback rest period under §121.471(b)(3), or a planned minimum 9-hour reduced lookback rest under 

§121.471(c)(3) to be followed by 12 hours of compensatory rest starting no later than at 1500 hours on Day 3. The 

3-hour ferry flight at the end of duty Day 2 precedes §121.471 flying on duty Day 3, and is within the 24-

consecutive-hour period from 0600 hours on Day 2 to 0600 hours on Day 3 in which §121.471 flying and ferry flying 

total 10 hours and 59 minutes of scheduled flight time. The end-of-duty-Day 2 scheduled ferry flight time must be 

counted in the total scheduled flight time that designates the amount of lookback rest or planned reduced lookback 

rest with planned compensatory rest.

Garret Healy

Sr. System Programmer

Jeppesen Commercial & Military Aviation | New York

ph: 212.478.1259 | fax: 212.725.0327 garret.healy@jeppesen.com

381 Park Avenue South | New York, NY 10016 USA| www.jeppesen.com

 

i

25iSee generally 50 Fed. Reg. 29306, at 29311 for an explanation (text and Figure 1) of the mechanics of scheduling a pilot to 

fly in excess of 8 hours within a 24-consecutive-hour period

26See supra notes 18 and 19. Note again that footnote 19 discusses a situation in which the already scheduled 11-hour 

lookback rest period is reduced to 10 hours.