According to International Civil Aviation Organization (ICAO) standards, which two units of measurement are recognized for expressing horizontal navigation distances?
Answer
Nautical miles and kilometres
Explanation
The material identifies nautical miles and kilometres as the basic horizontal-distance units. Feet and metres are commonly used for vertical measurements, while statute miles are not the standard pair given here. **Key takeaway:** Recognize NM and km as horizontal navigation units. **Glossary:** **NM**: Nautical mile; **km**: Kilometre.