1,000 feet not true — over open water it is 500’ for airplanes.
Helicopters have no minimum altitude restrictions unless it’s over an open air assembly of people.
Common sense is to stay 5 miles away from active airports and don’t fly above 400’ or outside line of sight.
Sorry but you are incorrect regarding open water. Any aircraft over open water away from a structure or boat or people can fly right down as low as they want to above the water, though this is not a safe thing to do. In manned flying, altitude is safety in case you have an engine out.
As for open ground away from towns etc. you can again fly right down to the deck if you wish, that is the law. An airliner will approach to land at a 3 degree slope, into the intended arrival airport. Small aircraft will be flying in the pattern around an airport, remote or tower controlled at anywhere from 500ft to the standard 1,000ft AGL. The general safety rule is that you fly at an altitude in the pattern that will allow you to glide to the runway, in the event of an engine out. So think of it as a giant V shape all around the airport runway. The further out you are, the higher you will be, the closer, in the lower in the pattern you will be.
As for the Piper Cub, there is a new category or class, of aircraft called Light Sport Aircraft, and the Piper Cub now falls into that weight category. Many of these light (weight) aircraft may fly at lower altitudes in the pattern and closer in because their speed range is lower than many of the heavier faster GA aircraft, like a Mooney, for example. A GA aircraft does not generally come in to land at a 3 degree approach angle like a commercial airliner does, but they often like to do shallow approaches to work their speed off easier than dropping in high with the resultant airspeed associated with such an approach. Often a small biz-jet, like a Falcon or Lear, for example, may do a straight in approach from 10 miles out, at those smaller uncontrolled airports and that would be at a shallow approach angle.
Best just not to mix in with traffic that close to an airport. Go and take a flight lesson one day and you may have a better appreciation for manned flight and all that there is to do and look out for when in the pattern, either close in or further out. I fly both and understand the feelings on both ends of the spectrum but would never go flying around an airport just 1.5 miles away.
Don't get it into your mind that a manned aircraft must be 1,000ft above the ground, because that is simply not true. They are required to avoid, as in fly around, someone or a building on the ground when out in open land or down on the water, but they are allowed to be what ever altitude they wish, when out over open ground away from everywhere.
