.  
Includes errors or failures in software and database systems.

.  
Includes non-powerplant parts or pieces separating from an aircraft.

.  
For unmanned aircraft, includes failure or malfunction of ground-based, transmission, or aircraft-based communication systems or components –or– datalink systems or components.

.  
Includes failures/malfunctions of ground-based launch or recovery systems equipment.

.  
Includes all failures/malfunctions, including those related to or caused by maintenance issues.

SYSTEM/COMPONENT FAILURE OR MALFUNCTION (POWERPLANT) (SCF–PP)
Failure or malfunction of an aircraft system or component related to the powerplant.
.  
If the failure renders the aircraft uncontrollable it is coded as SCF–PP only, not as loss of control (LOC–I or LOC–G). However, if the failure does not render the aircraft uncontrollable, but leads to a loss of control, code the event under both SCF–PP and LOC–I or LOC–G, as appropriate.

.  
Includes failures or malfunctions of any of the following: propellers, propeller system and engine gearbox, reversers, and powerplant controls.

.  
Includes powerplant parts or pieces separating from a powerplant.

.  
Includes all failures/malfunctions, including those related to or caused by maintenance issues.

.  
Rotorcraft main rotor and tail rotor system, drive system and flight control failures or malfunctions are coded as non-powerplant failures (SCF–NP), not SCF–PP. 

.  
The following fuel-related powerplant problems are coded under the category FUEL, not under the category SCF–PP: fuel exhaustion; fuel starvation/mismanagement; fuel contamination; wrong fuel; carburetor and induction icing. 

NOTE: For sub-categorization of SCF–PP, a separate taxonomy has been developed and can be found on the CICTT website.

TURBULENCE ENCOUNTER (TURB)

Usage Notes:
.  
Includes encounters with turbulence in clear air, mountain wave, mechanical, and/or cloud-associated turbulence.

.  
Wake vortex encounters are also included here. 

.  
Flights into wind shear or thunderstorm-related turbulence are coded as WSTRW.

.  
Includes turbulence encountered by aircraft when operating around or at buildings, structures, and objects.

 UNDERSHOOT/OVERSHOOT (USOS)

A touchdown off the runway/helipad/helideck surface. 
Usage Notes:
.  
An undershoot/overshoot of a runway/helipad/helideck occurs in close proximity to the runway/helipad/helideck and includes offside touchdowns and any occurrence where the landing gear touches off the runway/helipad/helideck surface. 
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：AVIATION OCCURRENCE CATEGORIES DEFINITIONS AND USAGE NOTES(14)