What is "ifr"

IFR is instrument flight rules, rules for when flight by outside visual reference is not safe.

IFR may also refer to:

• Ideal Final Result, an engineering design goal
• In-flight refueling
• Institute of Food Research, an agricultural and food science research institution
• Integral Fast Reactor, a nuclear reactor design
• International Federation of Robotics
• International Fleet Review
• instantaneous wave-free ratio (iFR), a diagnostic medical test used in coronary artery stenosis assessment