FAA Order 8130.34D — OPA / OPA-UAS Operating Limitation B-3
Appendix B · p. B-1
The OPA system may only be engaged or used while the aircraft is at or above (altitude) feet above ground level (AGL). The system must be turned off or otherwise rendered inoperative below (altitude) feet AGL.
The applicant should propose the altitude limits for this limitation and provide justification during the safety evaluation. After completion of successful flight testing above the altitude restriction, the operator may provide the FAA with a flight test plan to lower the altitude restriction. Lower altitudes may be incrementally approved to include automatic takeoff and/or landing operations. If automatic takeoff and/or landing operations were not discussed during the original safety evaluation, a supplemental safety evaluation will be held. If approved, this limitation will be rewritten to permit the OPA system to be engaged during automatic takeoff and/or landing operations.
Verify it yourself: the eyeball above opens the exact page of Order 8130.34D with this limitation highlighted.