Business aircraft are amazing. They are capable of speeds approaching that of sound, range exceeding that of most airliners, and comfort and convenience that make every trip productive and restful.  But there are limitations that must be respected and followed.

Limitations on aircraft extend to more than just the laws of physics or the bounds of engineering. Here in the US, the Federal Aviation Regulations (FARs) establish a set of safety parameters in an effort to balance what the aircraft (and crew) are capable of achieving with what is prudent from an approach to safety. Furthermore, there are multiple levels of safety, and what was acceptable last week may not be acceptable today just because of how the aircraft is being operated or who is in control..

The FARs do not assume a uniform standard of safety. They are designed to let those with the most responsibility and authority have the most leeway in the operation of the aircraft. The FARs also make some judgments as to the ability of the passenger to control the flight. Underlying all these boundary conditions is the rule that the pilot in command is the final authority regarding the safe operation of the aircraft.

At the most restrictive level is the scheduled air carrier. The airline passenger has no control over the aircraft.  He or she cannot schedule a trip, change the destination or hire the pilots. The paying passenger is under no obligation to understand any of the FARs. The only rule the paying passenger must know is the 3-1-1 rule by TSA! Under air carrier operations, the FARs absolve the passenger from all responsibility as to the safe conduct of the flight. In return, the FARs place the most restrictive level of safety on the aircraft and crew as to how the aircraft is operated. Things like weather requirements for take-off, approach and landing, the length of a crew’s work-day, and what must be functioning on the aircraft for it to be dispatched are all tightly controlled by the FARs.

The next basic safety level also covers paying passengers, but it applies to on-demand charter (FAR 135). The charter regulations also state that the paying passenger has no responsibility for the safe conduct of the flight. Unlike the airline passenger, however, the charter passenger does have the ability to schedule a trip, change the itinerary and state who else flies on the aircraft.  The charter passenger is assumed to have more “knowledge” of the flight. Within that, the FARs allows a bit more leeway in terms of how the aircraft can be operated. It is still restrictive of things like weather requirements, crew duty day, etc. but not to the same level of the scheduled air carrier.

The most flexible level of safety lies with the owner, or owner-operator. This individual does not buy a ticket, but has a significant level of authority over selecting the aircraft, hiring the pilots and deciding how the aircraft is to be operated. The FAR covering these operations are called FAR Part 91. FAR 91 covers a wide range of not-for-hire flying, including the private pilot flying a small plane to her favorite airport lunch-spot on a sunny afternoon to the global business jet carrying executives to far flung locales. While the operations under FAR 91 can differ considerably, they all confer the responsibility for the flight to the owner and operator.

This regulation is the most flexible in what the pilot(s) are allowed to do. One example of this is a “zero-zero” take-off. This means the aircraft can take off with zero forward visibility and zero-feet cloud height. There are aircraft with that capability! There are also considerable levels of risk in the event things go wrong. If the aircraft and crew are capable of such a feat, then FAR 91 may allow it. Please note that even if FAR 91 allows a certain privilege, the prudent  pilot may not elect to pursue such a course of action.

The big restriction under FAR 91 is compensation. Yes, you can buy a business aircraft and hire pilots to fly it for you, but you cannot offer your aircraft and pilots to others outside the owner’s responsibility for a fee. FAR 91 does allow some sharing of expenses – think of it as chipping in for gas—but  it is very clear that in order to maintain the flexibility of the regulations, there is no commercial for-hire activity.

Where this aspect of the FARs can be a source of confusion lies in the fact that on a given day, the same trip may be flown under different regulations. Yesterday, your own business aircraft may have safely and successfully flown on a trip that you specify. Today, your aircraft is not available. You may schedule a charter aircraft of the same type as your own aircraft. The weather and conditions may be exactly the same, but you may be told that you can’t fly the trip that you just flew yesterday. The for-hire charter flight is different from the private flight in your company aircraft, so different regulations apply.

The FARs are designed to protect the “flying public.”  As such, the same aircraft can have different “capabilities” depending on how it is being operated.