Turbojet operations have a built‑in safety margin for landing performance. FAR 135.375–135.399 require that you cannot depart unless you can land within 60% of the available landing distance on both the destination and the alternate airports. In other words, the estimated landing distance must be no more than 60% of the effective runway length (the usable landing distance) for each airport. This ensures you have adequate margin for braking and contingencies, given the higher performance and stopping characteristics of turbojets. For example, if the destination runway provides 5,000 feet of usable landing distance, you must be able to land in 3,000 feet or less. The same 60% rule applies to the alternate as well. This rule is not about dry versus wet runways and it is not a blanket “no restriction” situation, nor is it about a 70% limit. The requirement is specifically that the landing distance must fit within 60% of the available runway at both the destination and the alternate.

During single-point fueling, there are hazards such as fuel spills, fumes, and static that require supervision by trained crew. If passengers are onboard, the operation is permitted only when at least one crewmember is onboard to monitor. This provides a person who can watch for any abnormal conditions, ensure cabin safety procedures are followed, and coordinate with the fueling team if anything needs attention. The other options are too absolute or miss the key control: you don’t automatically remove all passengers, the status of the main cabin door isn’t the deciding factor, and you don’t categorically prohibit fueling with passengers onboard when a crewmember is present to monitor.

A T1 controller is the person who has direct operational control over a Part 135 flight—the one who can authorize and direct flight operations and ensure the operation stays in compliance with the regulations. That authority typically rests in the leadership or official flight-operations chain, such as the President (owner/operator) who has ultimate responsibility, the Director of Operations who oversees the operation’s day-to-day control, and the Chief Pilot who ensures pilots and flights meet the required standards and procedures. A Flight Attendant, while essential to the crew, does not hold authority to release or direct flights or make regulatory compliance decisions, so they are not a T1 controller.

Class C airspace is designed as two layers around a towered airport: a core and a surrounding shelf. The core is a 5 NM radius that extends from the surface up to 4,000 ft above the airport’s elevation. The outer shelf reaches out to a 10 NM radius and extends from roughly the floor up to the same top of 4,000 ft above the airport elevation. In practice, when the airport sits near sea level, this tops out around 4,000 ft MSL, so you commonly see it described as from the surface to about 4,000 ft with 5- and 10-mile radii. This structure means entry requires two-way radio communication with ATC and a discrete transponder code (Mode C generally, when available). The other options describe different airspace configurations: one is far taller and larger (more like Class B), another uses a very small radius not characteristic of Class C, and the last describes high-altitude airspace that isn’t Class C.