3 Performance trials

 For craft intended to be controlled by the operator when on the ground, the following criteria should be met:

• .1 The craft should demonstrate a stable attitude on flat ground when manoeuvring on its undercarriage. The limit of gradient up or down which the craft may safely be manoeuvred should be established.

• .2 The craft should not show any tendency to spin horizontally in cross winds up to the designed maximum wind velocity.

• .3 Operation of wheel brakes, if fitted, should not cause the craft to pitch nose down or spin horizontally.

 The following tests should be conducted to establish and/or confirm craft performance parameters in displacement mode:

• .1 Establish that the craft freeboard meets design and regulatory specifications.

• .2 Propulsion systems: Tests should be conducted to confirm that procedures for starting, engaging, disengaging, stopping are safe and effective.

• .3 Establish maximum safe operating speeds in both normal and worst intended conditions.

• .4 Determine turning radius and rate of turn.

• .5 Establish and confirm stopping distance and procedures in both normal and emergency situations.

• .6 Confirm berthing and anchoring procedures can be performed safely.

• .7 Establish/confirm the effects of failures as described in 4.3, appropriate for the displacement mode, and procedures to deal with failures.

 The following tests should be conducted to establish and/or confirm performance parameters as the craft moves from displacement to planing mode:

• .1 Establish the speed at which the craft transits to planing mode in the range of configurations and conditions described in 2.5 and 2.6.

• .2 Confirm that the craft is stable and controllable during transition.

• .3 Determine procedures for safe transition to planing mode.

• .4 Establish/confirm the effects of failures as described in 4.3, appropriate for the transition mode, and procedures to deal with failures.

 The following tests should be conducted to establish and/or confirm performance parameters for craft in planing mode:

• .1 Establish the range of speeds at which the craft will operate in planing mode in both normal and worst intended operating conditions.

• .2 Determine the range of loading conditions for which the craft displays a safe and stable condition.

• .3 Establish maximum velocity of 90° cross wind in which craft is controllable.

• .4 Determine maximum rate of turn and minimum turn radius in both normal and worst intended operating conditions.

• .5 Confirm that water spray does not impair operator visibility.

• .6 Establish/confirm procedures for safe operation of the craft in planing mode.

• .7 Establish/confirm the effects of failures as described in 4.3, appropriate for the planing mode, and procedures to deal with failures.

 The following tests should be conducted to establish and/or confirm craft performance parameters during take-off:

• .1 Establish the speeds at which the craft takes off over the range of load configurations in normal and worst intended conditions.

• .2 Determine the distance, from rest, to achieve take-off in the range of conditions described in 3.5.1.

• .3 Confirm that craft is aerodynamically stable and controllable during take-off.

• .4 Confirm that surface impacts during take-off do not cause horizontal or vertical accelerations that are likely to have more than a minor effect on craft or personnel.

• .5 Establish/confirm maximum velocity of 90° cross wind in which craft can safely take-off.

• .6 Confirm that water spray does not impair operator visibility.

• .7 Establish/confirm operating procedures to ensure a safe take-off manoeuvre is performed.

• .8 Establish/confirm the effects of failures as described in 4.3, appropriate for the take-off mode, and procedures to deal with failures.

 The following tests should be conducted to establish and/or confirm craft performance parameters in ground effect:

• .1 Determine the range of loading conditions for which the craft is stable about its three primary axes.

• .2 The following control criteria must be demonstrated when the craft is flight-trimmed in ground effect mode:

  • .1 Elevator controls should have the following characteristics for all speeds within the craft's normal ground effect speed range:

  • A push on the elevator control should cause the craft to flight-trim forward and increase speed from its previous flight-trim angle and speed. A pull should have the opposite effect. Airspeed and flight-trim angle should return to within 10% of original flight-trim speed and angle when the elevator control pressure is released.

  • .2 Longitudinal control must be demonstrated as follows:

  • The elevator control force/speed curve must have a stable slope at all speeds within a range which is the greater of 15% of the flight-trim speed plus the resulting free return speed range, or 50 knots plus the resulting free return speed range, above and below the flight-trim speed (except that the speed range need not include speeds below minimum normal ground effect speed or greater than maximum safe speed, nor speeds that require an elevator control force of more than 20 kg), with;

  • .2.1 the centre of gravity in the most adverse position;

  • .2.2 the most critical weight between the maximum take-off and maximum landing weights;

  • .2.3 75% of maximum continuous power for reciprocating engines or for turbine engines, the maximum cruising power selected by the applicant as an operating limitation, except that the power need not exceed that required at maximum normal safe ground effect speed; and

  • .2.4 the craft flight flight-trimmed for level flight with the power required in .2.3.

  • .3 Lateral-directional control

  • The rudder control force/speed curve gradient must meet requirements through the speed range between maximum normal ground effect speed and maximum safe speed, except that the dihedral effect (aileron deflection opposite the corresponding rudder input) may be negative, provided the divergence is gradual, easily recognised, and easily controlled by the operator.

  • .4 Any short period oscillation about any single axis, which occurs within the normal ground effect speed range, must be substantially dampened with the primary controls both free and in a fixed position.

  • Any combined lateral-directional oscillation, which occur within the normal ground effect speed range must be positively dampened with the controls free and must be controllable with the primary controls without requiring exceptional operator skills.

• .3 Determine the controllability of the craft when out of flight-trim in accordance with:

• From an initial condition with the craft flight-trimmed within normal ground effect speed range the craft must have satisfactory manoeuvring stability and controllability with the degree of out-of-flight-trim in the craft nose-up direction which results from the greater of:

  • .1 a three-second movement of the longitudinal flight-trim system at its normal rate for the particular flight condition with no aerodynamic load (or an equivalent degree of flight-trim for craft that do not have a power-operated flight-trim system), except as limited by stops in the flight-trim system; and

  • .2 the maximum flight mis-flight-trim that can be sustained by the autopilot, if fitted, while maintaining level flight in the high-speed ground effect condition.

• .4 Craft speed

  • .1 Determine the range of safe operating speeds at which the craft will operate in ground effect mode in both normal and worst intended conditions.

  • .2 Investigate relationship between craft speed and altitude in ground effect mode.

  • .3 The following speed increase and recovery characteristics must be met:

    • .1 Operating conditions and characteristics likely to cause inadvertent speed increases (including upsets in pitch and roll) must be simulated with the craft flight-trimmed at any speed within the normal ground effect speed range. These conditions and characteristics include gust upsets, inadvertent control movements, low control force gradient in relation to control friction and passenger movement.

    • .2 Allowing for operator reaction time after effective inherent or artificial speed warning occurs, it must be shown that the craft can be recovered to a normal attitude and its speed reduced to maximum normal ground effect speed, without:

    • .2.1 exceptional operator strength or skill;

    • .2.2 exceeding the absolute maximum craft speed or its structural limitations; and

    • .2.3 buffeting that would impair the operator’s ability to read the instruments or control the craft for recovery.

    • .3 With the craft flight-trimmed at any speed up to maximum normal ground effect speed, there must be no reversal of the response to control input about any axis at any speed up to maximum safe speed. Any tendency to pitch, roll, or yaw must be mild and readily controllable, using normal operating techniques. When the craft is flight-trimmed at maximum normal ground effect speed, the slope of the elevator control force/speed curve need not be stable at speeds greater than maximum safe speed, but there must be a push force at all speeds to absolute maximum craft speed and there must be no sudden or excessive reduction of elevator control force as that speed is reached.

• .5 Turning

• Determine the following characteristics in normal and worst intended operating conditions:

  • .1 maximum safe angle of bank;

  • .2 maximum rate of turn; and

  • .3 minimum turn radius.

• .6 Confirm that the maximum change of lateral or longitudinal centre of gravity that may be caused by the movement of passengers or cargo, is able to be counteracted with operator control input.

• .7 Establish/confirm the effects of failures as described in 4.3, appropriate for the ground effect mode, and procedures to deal with failures.

 The following tests should be conducted to establish and/or confirm craft performance parameters during landing:

• .1 Determine the minimum distance required in normal and worst intended conditions to perform the landings specified below. The distance should be measured from the point of touchdown to the position of the craft when stopped:

  • .1 normal landing;

  • .2 emergency landing; and

  • .3 power-off landing.

• .2 Confirm that the craft is stable and controllable throughout the landing phase.

• The elevator control force/speed curve must have a stable slope, and the force may not exceed 35 kg, through the range of speeds specified as acceptable for landing with:

  • .1 maximum landing weight;

  • .2 power or thrust off on the engines; and

  • .3 the craft flight-trimmed for minimum normal ground effect speed with power or thrust off.

• .3 Confirm that surface impacts during landing on flat water do not cause horizontal or vertical acceleration that are likely to have more than a minor effect on the craft or personnel.

• .4 Perform a "hands-free" landing to simulate total loss of ability to manipulate control surfaces.

• .5 Establish/confirm maximum velocity of 90º cross wind in which the craft can land safely.

• .6 Confirm that spray does not impair operator visibility.

• .7 Establish/confirm operating procedures for normal emergency and power off landing.

• .8 Establish/confirm the effects of failures as described in 4.3, appropriate for the transition mode, and procedures to deal with failures.