Quantitative evaluation of upper limb (UL) kinematics in children with unilateral cerebral palsy (uCP) remains challenging for researchers and clinicians, especially during bimanual situations. This study proposed a new 3D bimanual protocol dedicated to children with uCP, called "Be an Airplane Pilot" (BE-API protocol) and assessed its reliability for typically developing children (TDC).this protocol is composed of four bimanual tasks that allow the exploration of all degrees of freedom of the hemiplegic/non-dominant UL. Twenty TDC (mean age 11.9 ± 3.4) carried out three protocol sessions. Reliability was investigated through three kinematic parameters: angular waveforms (WAVE) using the coefficient of multiple correlation (CMC), range of motion (RoM) and maximum angles (MAX) both using the intra-class correlation coefficient (ICC) and the standard error of measurement (SEM).A very good reliability was observed for the three kinematic parameters in most cases (WAVE: CMC ≥0.90, RoM & MAX: ICC ≥0.81, SEM ≤5.0°).the very good reliability can be partly explained by the high level of rigor of the protocol. Such promising results open the door to validation tests on children with uCP. The BE-API protocol could pretend to support clinical decisions by objectively assessing the efficiency of therapeutics, e.g. injection of botulinic toxin.