What if they charge some amount per hour, then is it for hire?.....I guess im just trying to find any differences between an FBO aircraft rental and a private individual renting their aircraft out.......
Doesnt sound like its for hire since you are paying your share of the operating expenses. How bout the question though, is it considered compensation if someone lets you use their airplane for free and you get to log the flight hour in exchange for something? Because you need that flight hour, so it seems like it may be compensation.
"For Hire" - aircraft and pilot/instructor provided TOGETHER at cost to another party
For Hire-Your flight school provides students with airplanes and instructors
Not For Hire-You rent an airplane and bring an instructor with you
(here, your instructor is HIRED by you...the FBO is not providing a service FOR HIRE)
For Hire-You charge people to fly in your plane on local sight-seeing flights (within 25 SM of departure airport)...this is a legal 91 operation
Not For Hire-Your friend owns a plane and asks you to fly him 300 miles away to a meeting (here, again, you can be HIRED for your services as a commercial pilot...and this is a legal 91 operation since you did not provide the plane and pilot FOR HIRE)
So, in answer to your question, you can be HIRED to fly your friend's plane, but the operation would not necessarily be FOR HIRE. On the other hand, if this friend charges another acquaintance to ride along with you piloting the aircraft (he HIRED you and provided the pilot and plane to another party at cost), then the flight is FOR HIRE.
If a person seeking transportation from point A to point B approaches a flight school and says "I want to rent an airplane, pilot XYZ will be flying it", this is a legal operation as long as the plane and the pilot are paid for completely seperately. Also, the pilot that will be flying the plane can in no way be employed or affiliated with the flight school/FBO from which they are renting the plane. A CFI who works for the flight school in this situation could not legally pilot the plane being rented (IMO).
In addition, the pilot and flight school would be wise to have the renter sign some kind of written agreement of understanding that the flight is being operated under part 91, that the renter is responsible for the plane, yadda yadda yadda. This is not considered holding out, and is therefore legal.
Is simply renting an airplane to someone considered an operation for hire? Not to my knowledge. It becomes "for hire" when you're paying someone to be in the airplane with you.
I think we're confusing the issue here. The original poster asked if you borrow someone's aircraft and pay for the fuel, is the aircraft considered to be "for hire". The conversation has mutated to a discussion of whether the operation is Part 135 or not. Clearly just renting aircraft and flying them for your own personal and business use is not 135. I think the question revolves more around, does it need a 100 hour, landing light (for night VFR) and will the insurance cover it?
As far as the 100 hour inspection and night flight landing light, the FARs refer only to hire, not "compensation or hire" In interpretations where the FARs have used the word compensation as well as hire, the FAA interprets the word compensation VERY broadly. The use of only the word "hire" probably indicates that at least an attempt to be operating for profit or using the aircraft to make money would have to be made. One guy borrowing an aircraft and paying for the fuel would most likely not be considered "for hire"
Having said that, you can never be too sure. I do not have any FAA interpretations on this issue, so I cannot say what they have done in the past, but since the phrase "for hire" is vague, it is open to a wide variety of interpretation.
As for the insurance company, you would have to read the policy very carefully. At the very least you would either have to meet the policy's Open Pilot Warranty minimums, or be listed on the policy as an approved pilot. Again, what an insurance company thinks is "for hire" is very much open to interpretation as well. Bear in mind that insurance companies will do whatever they can to get out of paying a claim, so they would (in the event of a claim being made) probably try to deny a claim on the basis that it was for hire....at least initially.