Acronym Glossary

This section has a list of important acronyms and their definitions.

Acronym	Definition
2FA	Two-Factor Authentication
AFT	Average Flight Time
ATA	Air Transport Association
BIT	Built In Test
BOM	Bill of Materials
CAS	Continued Airworthiness System
CFR	Code of Federal Regulations
CS	Certification Specification
EASA	European Aviation Safety Agency
EF	Environmental Factor
EPRD	Electronic Part Reliability Data
FAA	Federal Aviation Administration
FEC	Failure Effect Categorization
FM	Failure Mode
FMEA	Failure Mode and Effects Analysis
FMECA	Failure Mode, Effects and Criticality Analysis
FMES	Failure Modes and Effects Summary
FoS	Factor of Safety
FR	Failure Rate
FRACAS	Failure Reporting, Analysis, and Corrective Action System
FT	Fault Tree
FTA	Fault Tree Analysis
JARUS	Joint Authorities for Rule-making on Unmanned Systems
MCS	Minimal Cut Sets
MIL-HDBK	Military Handbook
MSG-3	Maintenance Steering Group 3
MSI	Maintenance Significant Items
MTBF	Mean Time Between Failures
MTBUR	Mean Time Between Unscheduled Removals
MTTR	Mean Time to Repair
NATO	North Atlantic Treaty Organization
NPRD	Non-Electronic Parts Reliability Data
NSWC	Naval Surface Warfare Center
OT	Operation Time
PN	Part Number
RAMS	Reliability, Availability, Maintainability, and Safety
RPA	Reliability Prediction Analysis
SCM	Scheduled Maintenance
SN	Serial Number
SPF	Single Point of Failure
SSI	Significant Structural Item
TBD	To Be Defined
ZSA	Zonal Safety Assessment