The answer depends on what you mean by "fly." There's no limit to the amount of cash you can carry onto a commercial flight domestically or internationally, according to common knowledge. However, declaring large sums of cash is crucial for customs and tax reasons.
Flying with Cash
- Domestic and International Flights: You can carry any amount of cash on a plane, but you should be prepared to declare it to customs officials if it exceeds a certain threshold (which varies by country). [Source: People often ask: How much cash can you carry on a plane for a domestic or international flight? The short answer is “there is no limit to how much cash you can bring to the airport for a domestic or intentional flight.”]
- Example: Someone flying to Las Vegas with $5,000 in cash for gambling would be allowed to do so, but should be aware of declaration requirements. [Source: Traveling With About $5000 in Cash - FlyerTalk Forums]
Flying in an Aircraft at 5000 Feet
This question refers to the altitude of a flight.
- Commercial Airliners: While commercial airliners can fly at 5,000 feet, it's not typical for a significant portion of the flight. They usually fly at much higher altitudes for efficiency. The maximum speed at this altitude depends on the specific aircraft model but is typically around 350 knots. [Source: What is the maximum speed a passenger airliner can fly at 5,000 feet]
- Private Jets: Some private jets, like the Bombardier Global 5000, have a range that allows them to fly long distances. This jet, for example, can travel 5,200 nautical miles. [Sources: What Is A Bombardier Global 5000 Jet? - BLADE; Bombardier Global 5000 Private Jet] Note that this refers to the distance, not necessarily the cruising altitude. Many long-range private jets operate at altitudes higher than 5000 feet for optimal fuel efficiency. [Source: Ultra Long-Range Private Jets]
Hypoxia at 5000 Feet
- Hypoxia Risk: While hypoxia (lack of oxygen) effects are generally felt at higher altitudes (6,000-10,000 feet), it's still possible to experience milder effects at 5,000 feet. [Source: Can you get hypoxia at 5000? : r/flying]
