Definition
A Global Positioning System receiver that has been certified by the FAA under TSO-C129, TSO-C145, or TSO-C146 (and installed per an approved airworthiness process) as meeting the accuracy, integrity, and reliability standards required for use as a primary navigation source under Instrument Flight Rules. Such a receiver may be used for IFR en route, terminal, and approach phases according to its certification class.
Plain English
A GPS unit that the FAA has officially certified as accurate and reliable enough to be used for navigation in instrument weather conditions, not just for reference in good weather.
Context Anchor
Seen in instrument procedure and equipment discussions, especially when deciding whether the airplane’s GPS can be used to fly a published instrument approach.
Derivation
IFR stands for Instrument Flight Rules, the rules used when a pilot flies mainly by instruments instead of outside visual references. GPS stands for Global Positioning System, the satellite-based system the receiver uses to determine position. The word “approved” is the key part: it means the unit and installation are accepted for a specific IFR use, not merely that the GPS can receive satellite signals.
Why Pilots Care
Only an IFR-approved receiver may be used as the primary navigation source under instrument rules; using a non-approved unit is both illegal and unsafe.
Intuition Check
Do not assume “IFR-approved” means any GPS that works in cloudy weather. It means the receiver, its installation, and its allowed uses meet FAA requirements for instrument flying.
Example Sentence 1
Before filing the flight plan with a GPS approach at the destination, she confirmed the aircraft had an IFR-approved GPS receiver and a current navigation database.
Example Sentence 2
The approach plate required an IFR-approved GPS receiver for the LNAV minimums.