Flight Time

Definition of Flight Time

The time value relevant to pilot experience is flight time. This time is entered by the pilots in their logbook and fully counted towards his experience. Depending on the aircraft category, it is defined differently:

• (FCL.010): for aeroplanes, touring motor gliders and powered-lift aircraft
  the total time from the moment an aircraft first moves for the purpose of taking off until the moment it finally comes to rest at the end of the flight;
• (FCL.010): for helicopters
  the total time from the moment a helicopter's rotor blades start turning until the moment the helicopter finally comes to rest at the end of the flight, and the rotor blades are stopped;
• (SFCL Part-DEF 16.a) for self-launch sailplanes and touring motor gliders
  the total time from the moment an aircraft first moves for the purpose of taking off until the moment it finally comes to rest at the end of the flight;
• (SFCL Part-DEF 16.b) for sailplanes
  the total time from the moment the sailplane commences the ground run in the process of taking off until the moment the sailplane finally comes to a rest at the end of flight;
• (BFCL Part-DEF 11.a) for balloons
  the total time from the moment the basket leaves the ground for the purpose of taking off until the moment it finally comes to a rest at the end of the flight.

Block Time

The term block time goes back to the securing of the aircraft on the ground with so-called roll-away locks (chokes). Before the flight can begin, the ground crew must remove them from the tyres; and when the aircraft is parked, these are put back in place.

So the aircraft first goes "off blocks" and then back "on blocks".

The time in between is called block time. The block time is pretty much the same as the definition of flight time for aircraft, since the removal of the blocks usually happens a few seconds before the push-back and after the standstill, respectively, and the flight time is recorded in hours and minutes, but not in seconds. The block time is always greater than the Airborne Time and less than the engine running time.

Rotor Turning Time (RTT)

The flight time for helicopters corresponds to the time during which the rotor blades turn. The term rotor turning time is therefore simply more precise than the general definition of flight time and is therefore often used. Analogous to the block time in aircraft, the RTT is always greater than the Airborne Time and less than or equal to the engine running time.

Airborne Time

For both aircraft and helicopters, this term is used to refer to the effective time in the air, i.e. from the time of take-off to the time of touchdown.

Hobbs Time

The Hobbs Counter is part of the aircraft, measures its operating time and normally displays hours and tenths of hours. There are different counting methods depending on the design. It can be triggered by the electrical main switch, the oil pressure or even the retraction of the landing gear or an airspeed sensor. In contrast, the tachometer (speedometer) measures the engine speed and provides a better indicator of engine wear.