4.5 Time Measurement and Evidence

4.5.1 Time measurement

Time data requirements may be fulfilled by any of the following measuring methods:

a. By direct observation from the ground by an observer with direct access to approved time measuring equipment (e.g. a synchronised timepiece). If a timepiece displaying only minutes is used, 59
seconds is to be added to each duration measured to allow for the possibility that the reading was taken just before the minute changeover. Pilots and OOs should use timing devices with outputs in seconds whenever possible.

b. With a barograph, to measure time differences (except for speed flights),

c. With a time camera, to measure time differences (except for speed and duration flights),

d. A recording device with correct real time input, such as a flight recorder.

4.5.2 Time evidence

a. Evidence of timing and time recording of flights must be under the control of an OO. Time recording equipment carried on board a glider must be capable of being physically or electronically sealed and, where a human action is required, shall be sealed and unsealed only by the OO.

b. The equipment must be positioned so that the time parameters cannot be altered by the pilot or passenger during the flight.

c. If a means is provided for the pilot to make inputs into a device for remote recording of flight events, such inputs must be confined to functions not critical to the validation of the flight.

For example, it is permissible for a pilot to make a mark on the time base to register an event such as a particular position, or in GNSS systems to change the sampling rate in flight.

4.5.3 Night flight

A flight which continues beyond the hours of legal daylight in the country concerned shall not be validated, except where the glider and pilot comply with the laws of that country for night flight.