All tests shall be performed with the active elements of the system designed to operate during rear impact set to their operation condition (e.g. Active head restraint, Seat belt pre-tensioner). The time to fire (TTF) required for a specific element of the active head restraint shall be specified by the vehicle manufacturer.

3.2.2. Acceleration Sled

3.2.2.1. The parts of the vehicle structure considered essential for the replication of the vehicle rigidity regarding the seat, its anchorages, the safety-belt anchorages and the head restraints shall be secured to the sled.

It shall be so constructed that no permanent deformation appears after the test. Where the upper anchorage has an adjustable height position, it shall be set nearest to the mid-range position permitted by the design

3.2.2.2. The sled shall be capable of accommodating, in an appropriate manner, such equipment as may be specified by the manufacturer as necessary for the correct functioning of advanced head restraint systems (active head restraints). 3.2.2.3. A toe board comprising a horizontal section and a forward facing section oriented at 45 º from the horizontal shall be provided. 3.2.2.4. Some sled motion is allowed at the initiation of the test (T=0) however, the dummy’s head, T1 vertebra, and the sled should have the same velocity ± 0.1m/s at T=0. The back of the dummy’s head and T1 vertebra should be in the same position (± 5mm) relative to the head restraint at T=0 as the initial test set-up.

3.2.3. Mounting the seat on the sled.

3.2.3.1. Mount the seat, including all of its adjustment mechanisms and hardware that normally connect it to the vehicle floor on the sled platform so that the seat’s orientation relative to the horizontal is the same as it would be in the vehicle. The gap between the front of the seat and rear of the toe board shall be no more than 100 mm. Instrument the platform with an accelerometer mounted such that its sensitive axis is parallel to the direction of test platform travel.

3.2.4. Seat Adjustment

3.2.4.1. The seat shall be set as specified by the manufacturer, with regard to both the design position of the seat back (see paragraph 3.4. of this Regulation) and the position of the seat itself. This position shall be the one where the H-point coincides with R -point. 50 In the absence of any specification declared by the manufacturer, the procedures of paragraphs 3.2.4.2. to 3.2.4.6. of this Annex shall apply. 3.2.4.2. Where adjustment is not specified, the seat shall be adjusted to its mid- position in both the horizontal and vertical directions.

If an adjustment position does not exist midway between those positions, place the seat midway between the most forward and most rearward position. The closest adjustment position to the rear of the midpoint shall be used.

3.2.4.3. Where a cushion adjustment is not specified, and where the seat cushion is adjustable independently of the seat back, adjust the seat cushion inclination to its mid-position. All other cushion adjustments shall be in a fully retracted position, with the exception of cushion side bolsters which shall be set to their widest position. 3.2.4.4. Any adjustable lumbar supports shall be positioned so that the lumbar support is in its lowest retracted or deflated position. Arm rests shall be set in the stowed position.