Neither the regulation nor the FAA provide any obligation to an employer to provide rooms on, or off OE.

While the FAA uses the phraseology "during s regularly scheduled duty day of no more than 14 hours" (14 CFR 135.267(c)), the FAA doesn't actually specify that 14 hours is a duty limit, but rather specifies a look-back rest period. This means that in a given 24 hour day, if a pilot must look back at any given moment and find ten consecutive hours rest in the prior 24 hours, the requirement of the regulation is met. If one looks back at the end of 14 hours and finds ten hours of rest, then all that can be had for duty is 14 hours, which is where the 14 hour duty "limit" comes from. It's not a duty limit, but a rest requirement, and that's an important distinction pointing to the rational and basis of the regulation. The FAA doesn't care about your duty. The FAA cares about your rest.

Having said that, your question seems to focus on rest, and rest interruptions. The FAA is very specific about rest. It must be known prospectively, meaning defined and established in advance, or before the rest begins. The employer cannot ever look back, say you didn't fly, and call it rest, if it wasn't a known rest period to you before the rest began. Emloyers have been "backdating" rest periods from 10 hour blocks to the requisite "1-in-7" for decades, and the FAA is very clear that this does not fly. Not only can the employer get violated for doing this, but the pilot will absolutely be the subject of administrative action (violation) if discovered. The FAA and FAA Chief Legal Counsel, has been very clear about this, for a very long time.

A rest period must be known in advance, and it must be free of all obligation to act for the employer during the term of the rest period. The Whitlow letter, many years ago, stated that a single phone call does not interrupt rest, and many have taken that to mean that an employer is allowed one phone call. This is not correct, and the FAA has clarified that in subsequent letters of interpretation. What the intent of Whitlow, as written, stated, was that a pilot who accepts a call doesn't necessarily need to re-start the rest period. Whitlow does not grant authorization to an employer to interrupt a pilots rest, and if an employer assigns duty (availability to act, or acting on behalf of the employer in any capacity), then it's not rest. The FAA has been very clear, and consistent about this, too. Rest then, must be known in advance, and must be free of all responsibility to act for the employer.

There are a lot of expressions out there defining rest, such as "if you can't have a beer, it's not rest," which have no legal basis, but if you understand that you must know of the rest in advance, and that you have no obligation to act for the company during the rest period, then you'll have a good handle on your rights, and the company's limitations with respect to rest. The company doesn't have to provide a room for your rest. That agreement is between you and the employer, and the FAA does not get involved. While the employer must provide a rest period, the employer is not required to provide rest facilities. A pilot does have a legal obligation to have rest, however, just as an employer has an obligation to allow for rest.

If you choose to silence your phone during a rest period, the employer will have a difficult time explaining to the FAA why you are punished for failure to respond. You can accept a call, or email or text advising of a flight assignment to take place after the rest period has ended, but if the employer assigns duty during the rest period, then it's not rest.

It is possible to end a duty period, and not be in rest, but also not be on duty. An example of this might be a flight to a destination with a long interval getting to a hotel. Duty may end shortly after the flight, but rest may not begin at that time. Many employers presume that the moment official duty ends (eg, typically 1/2 hour after the flight blocks in, etc), rest begins. I've run into this many times under 135 and 121, and have made a point to get to my hotel or to a place or point where rest is possible, or get into rest, and advise that rest begins NOW...to make clear that it didn't end when the official duty ended. Likewise, transportation to a location to work may not be duty, but also isn't rest. The employer has a super cub broken down, with a passenger, in a field on a mountainside. I get flown to the mountainside with a part to install, and then I need to fly that passenger and cub off the mountain. I'm necessarily on duty on the flight to the mountain, as I'm riding in another cub on the way. When I get there, I'm not on duty as a pilot, as I'm installing that part, and I eventually put on my pilot duty hat and fly off the mountain...I don't have 14 hours of duty available at that point, because I can't look back and find 10 hours of rest. I may not have 14 hours of duty available, and the company can't assign me to 14 hours of duty, but they must allow me to look back and find the necessary rest, and I can't operate unless I can do that. It may seem like semantics, but you can see that it's an important distinction, duty vs. rest, and that rest is the key to determining what you can or can't do for that employer under Part 135.

Now, having said that, if you're going to act in a capacity other than 135 for that employer (you're not performing as a crewmember under Part 135), then those rest limitations don't apply. If your employer wants you to operate under Part 91 (go fly the boss to church in his airplane, or ferry the airplane for maintenance), and prior to that interrupts your rest with a request for a bologna sandwich and to pick up his daughter at preschool, then you're not in violation. At some point, you'll need to consider how this impacts your safety, and you're very much responsible for that, just as you are for adhering to any regulation (always remember, Careless and Reckless operation applies everywhere...so flying tired still counts. 14 CFR 91.13 is the catch-all regulation).

There's a popular notion about "behind the door," which is not regulatory, and is meaningless when considering the regulation. When the regulation states 10 hour rest, for example, it doesn't state how many hours must be "behind the door." You can be standing on your head in a field of barley, and the FAA doesn't care, so long as you have no obligation to act for the employer, and you knew about the rest period in advance.


https://www.ecfr.gov/current/title-1...-135/subpart-F

https://www.ecfr.gov/current/title-1.../section-91.13