There is no 14 hour duty day limit under Part 135.  None.

There is a look back requirement for 10 hours of rest in the last 24 hrs at the completion of the planned Part 135 flight (not the duty thereafter).

That's were people get it wrong, thinking there is a 14 hr duty day limit.

You can be on duty forever.   But, to PIC an aircraft under Part 135, you have to show you had a 10 hr rest period looking back 24 hrs.   If not, your rest clock has not reset.   You also have to show at least 13 rest periods of at least 24 consecutive hours each in each calendar quarter.   Not "days off" but 24 hour periods (i.e, free from all duty).

The notion of a 14 hour duty day limit is born from fiction and peddled by the ignorant

we know. 

But you also could not accept a flight after being on duty for 15 hours. So being on duty "forever" wouldn't make sense

There's no 14 hour duty day, you just need to have a 10 hour rest period every 24 hours! So maximum duty is ACTUALLY... wait...

Can you describe one of these scenarios where you're on duty over 14 hours yet still have to show up to at your assigned time to fly Part 135 the next day?

Like I said, perpetuated by the ignorant!

You are not limited to 14 hours of duty.   There, that is the example!

Under FAR 135.267(b), you can be on duty 20 hours with your company, but must look back 24 hrs from the planned completion of the flight for a Part 135 flight, but not for a Part 91 flight.  You can get off, go home for 8 hours and return to fly Part 91, duty time for your company, but not violating Part 135.   You won't be able to show a 10 hr rest period in 24 though, so you can't fly Part 135.  Your duty is not limited to 14 hours ever because I can end my duty at the 14th hour and still not get 10 hours of rest before coming back for the next Part 135 flight.

The regulation is not a duty time limitation!  It is a rest requirement!

So then the FAA didn't intend to say there is a 14 hour limit??...

§ 135.267 Flight time limitations and rest requirements: Unscheduled one- and two-pilot crews.

(c) A flight crewmember's flight time may exceed the flight time limits of paragraph (b) of this section if the assigned flight time occurs during a regularly assigned duty period of no more than 14 hours

You do not have a regularly assigned duty schedule!   Unless, of course, you are ALWAYS on day shifts, or night shifts.   If you flip-flop between them (as ALL do), you do not operate under (c).

Check your GOM for details!

How can you be so insanely wrong about something? Are you sure you're even in an aviation career? I guess under 61.123 I got my commercial pilot cert by just being operating under (a), none of the other sections apply huh?

This board is insane. No wonder you don't understand how 24 - 10 = 14.

https://drs.faa.gov/browse/excelExternalWindow/FAA000000000LEGALINTPR2013049PDF.0001

Your notion that all of it is applicable, it isn't.  Either your certificate holder is operating under a regularly assigned schedule scheme, or it is not.   If the pilot's duty start times vary over the course of a month (4 weeks), then they are NOT operating under (c) because their schedule is not considered a regularly assigned schedule.

Cut and past the following link into your browser's url:

https://drs.faa.gov/browse/excelExternalWindow/FAA000000000LEGALINTPR2009008PDF.0001

You still need 10 hours of rest before taking any Part 135 flight and thus within the period of a 24 hour lookback can only have a maximum duty day time of 14 hours which can only be extended due to unforseen circumstances which also requires additional rest time.

There is no duty time limitation!   It is a rest requirement!   It doesn't force the operator to release you from duty at 14 hours!

If you are on a regularly assigned schedule, you can gain the flight time advantages of (c), but if you aren't on a regularly assigned schedule, you have to use (b)

The regulation does not limit duty time to 14 hours.   It just tells you which subparagraph to use to determine FLIGHT TIME limitations!

Refers to the conditions required to exceed FLIGHT TIME limitations, my dude.

If you are not exceeding flight time limits (8/10 flight hours), 135.267 is moot.

A flight crewmember's flight time may exceed the flight time limits of paragraph (b) of this section if the assigned flight time occurs during a regularly assigned duty period of no more than 14 hours and—

But, when you're on a daily rotation, starting one duty day after another, exceeding 14 hours means you don't come in until the 10 hours, plus, is complete.

That's just one reality.  You figure the rest.

Be careful with all that.  Check with FAA Legal in DC, they're not inaccessible.  There's more to the story which one must be careful.  At some point, yeah, subjective, one can enter "careless and reckless" potential given excessive hours of wakefulness.  Don't think the Feds will agree with you just because you discover interpreting regulations with, potentially, blinders on.

Wrong.  Look at the FAQ section of FAA Legal in DC.  

https://www.faa.gov/faq?combine=duty&field_faq_category_target_id=All

                         What are the crewmember flight and duty time and rest requirements?                      

General aviation operations conducted under 14 CFR Part 91 are not subject to flight and duty time and rest requirements, except flight instruction (14 CFR Section 61.195) and fractional ownership operations (14 CFR Part 91 Subpart K).

Commercial crewmember flight time and duty period limitations and rest requirements are described in 14 CFR Part 135 Subpart F or 14 CFR Part 121, Subpart Q, Subpart R, or Subpart S, depending on the type of operation.

Certificated air carriers and operators should contact their FAA principal inspector for further questions about flight and duty time and crew rest.

you screw up every post. if you weren't alone in ma's basement, I'd say have somebody else read it first bro

8 hour shifts , I'll think about coming back

A certificate holder is operating under 135.267 [d]; not 135.267 [c].  135.267 [c] actually specifies "a regularly assigned duty period of no more than 14 hours."   135.267 [d] applies to a flight crew member who, as an example, is on call or similar and is not on a regularly assigned duty schedule. Those two cannot be conflated into one revolving or interchangeable set of scheduling methods simultaneously by the operator.  Only one can apply for the operator.  Read them closely.

Additionally, a lot of individuals seem to believe duty time may be extended.  Again, please read the entire 135.267 section.  Only "Flight Time" may be extended explicitly by this section.  There is no reference to duty time extensions under Part 135.267.  That's the reason some operators [notwithstanding 135 Subpart L] allow the legs following passenger drop-off to be conducted under Part 91.  The Part 135 requirements stop when the paying passenger is dropped off [135.85].

As cynical as this sounds, there will most likely be a lot of down-votes.  The regulation is specific and is contexed explicitly.  Not to be insulting or condescending, but the down-voters may want to do further research for clarification.  

V/r

If your schedule changes regularly within a month, like from day shifts to night shifts, or 0700 this time and 0800 another, then you cannot use (c).

(c) is not a duty time limitation of 14 hours.   It's just saying that if a pilot's schedule can't be held within a regurlarly assigned duty 14 hour schedule,  you cannot take advantage of the flight time benefits of (c), and must use (b)/(d).

There is no 14 hour duty time limitation in Part 135

simply to ensure (b)/(d) is followed, if he's not following a regularly assigned schedule start times and end times vary or exceed 14 hrs.

And it must be within the rest requirements and flight time limitations.  The above poster is correct in that no 14 hour duty day is established.  It is the rest requirements which must be met for Part 135 [or 121, as appropriate].

V/r

My GOM says “Twelve scheduled consecutive hours that may be continued to 14 hours.”  

I also have a regular scheduled shift so (c) applies. Max of 14 duty day. 

What type of operation are you referring to?  I am in HAA. 

HAA, News, Pipeline, GOM, on-call Charter, etc?

If you are like any other HAA operator, you switch from day shifts to night shifts over the course of a month.   Some, 3 (or 4) days, then 4 (or 3) nights, then off, do it again.  Others, 7 days, 7 off, 7 night, 7 off.  Or some regularly rotating schedule like that!   Even if 14 and 14, changing each from day to night.

If you are on one of those type of schedules, you are not operating under a regularly assigned schedule, there the start and finish times are the same.   That means, you don't operate under (c), but (b), and will have to be able to show (documented) the assigned 10 hours rest in the 24 hours look back as required under (d).

HAA operators would be KRAZY to think they can operate under (c)!

If you’re on a standard schedule, why are you saying (c) does not apply?

in any 24 hour period defines the 14 hour duty day.

Ours does. And then it immediately provides guidance on how to exceed that 14 hour limit in the next paragraph.

Clowns.

it doesn't cap you at 14, what's the point of putting it in the gom

 your gom says you can’t work past 14 but then tells you that you can lol

never heard that before

135.267(c) - A flight crewmember's flight time may exceed the flight time limits of paragraph (b) of this section if the assigned flight time occurs during a regularly assigned duty period of no more than 14 hours and--

135.267(d) - Each assignment under paragraph (b) of this section must provide for at least 10 consecutive hours of rest during the 24-hour period that precedes the planned completion time of the assignment.

So (c) explicitly says 14 hours duty day and (d) tells you that you need 10 hours of rest under (b) thus limiting you to 14 hours.

So duty day limit is 14 hours extendable due to unforeseen circumstances via (e) but that includes even more rest.

you can use for FLIGHT TIME limits

(b)(1) or (c)(2)(i).

Also, note the name of the Section:

§ 135.267 Flight time limitations and rest requirements: Unscheduled one- and two-pilot crews.

Don't see it called "Duty Limitations"!

regularly assigned duty period of no more than 14 hours

Then my duty day limit is 14 hours!

as you want or as your employer wants.   You will need a 10 hr rest before you do PIC a Part 135 flight though!

There is no 14 hour duty time limitation under Part 135 or Part 91.  There is a rest requirement looking back 24 hrs from the reasonably planned completion time of that flight assignment.

A flight crewmember's flight time may exceed the flight time limits of paragraph (b) of this section if the assigned flight time occurs during a regularly assigned duty period of no more than 14 hours and—

"if,..."   if you can't, then (b).  It is not a limitation!   IF you have a regularly assigned duty period of no more than 14 hours, then you can use the flight time provisions, IF you can't, then use (b).

That is not a limitation!!  literally!!

Refers to the conditions required to exceed FLIGHT TIME limitations, my dude.

If you are not exceeding flight time limits (8/10 flight hours), 135.267 is moot.

A flight crewmember's flight time may exceed the flight time limits of paragraph (b) of this section if the assigned flight time occurs during a regularly assigned duty period of no more than 14 hours and—

really need to learn how to read regulations in context of others with influence.  It all starts with a sound understanding with definitions.  

14 hour duty day?  Yeup, it's real.

That is incorrect. Better read the following FAA Legal Interpretation: Triponey_2018_Interpretation. It's all about a 14 duty day

You'd be better off to read FAA General Council's letter to New (2013) because that will clearly tell you that nobody in HAA is operating under 135.267(c)!

missing the point.  Just because "14 hour duty day" is not written as such you must read the regs in-total to get the idea as to what is, and isn't.  The rest periods required establish a defacto 14 hour duty day - talk to FAA Legal and you'll get the little string of logic you need to understand this.  

Ur arguing a totally moot point and indicating the fact you are not reading the regs as an intertwined body, which is what almost all law happens to be.  One statement affects others, which is why writing new regs is not a simple chore.

Nowhere in your 2013 reference does it say that an HAA is not operated under (b) or (d).  That reference is for an on call HAA operation.  

I have a regular start time and end time. Regular shift.  I know what my schedule is a year from now.  How is that not a regular schedule?

I have a max of 14.  

In the course of a month?   Nothing but days?   Nothing but nights??

One of these guys… can’t fly worth d#%m but wants to find all kinds of stupid loop holes to complain about. Go home.

Said!