Since medical helicopters, police helicopters, traffic/news helicopters and private helicopters are all taking off from their own little heli-pads, often at an un-scheduled time, how do they keep clear of each other? Look through the windshield, or is it more complicated?
And, bonus question - what about blimps? I assume their take-off time is pretty well scheduled but if you’re shooting a game, there’s no way to know when it will end and you return back to the blimp hangar. Do they fly at the same height as helicopters?
It is the same as small planes. The short answer is that each flight will be categorized as Visual Flight Rules (VFR) or Instrument Flight Rules (IFR). VFR flight can only be conducted in certain airspace and weather conditions (no flying through clouds for example). The pilot is responsible for maintaining separation from other aircraft visually although they may also request assistance (flight following) from nearby Air Traffic Control as well. The pilot can generally fly wherever they want as long as it doesn’t violate any other airspace regulations.
IFR flight has a much more strict set of rules and requires an IFR rating. Air Traffic Control dictates the routing and aircraft separation for IFR flight although the pilot always has to keep a lookout as well and always has the option of taking emergency evasive action if necessary but that would be very unusual. During normal IFR flight operations, the controllers separate the planes for optimum sequencing to their destination.
For medical evacuation and police helicopters, it isn’t very important that they are scheduled in advance or not. The important part is the type of air space they are flying in and how much maneuvering they will need to do to complete their mission. For a helicopter taking off in New York City for example, they will always need to be under control of the New York air traffic controllers unless they just want to fly through the tiny VFR corridor along the Hudson River.
The rules for slow moving craft like blimps are similar to maritime rules. The slower moving and less maneuverable craft like blimps and hot air balloons have the right of way over airplanes and helicopters because they can’t get out of the way very quickly.
The advanced scheduling aspect isn’t as important as you think it is. What is important is whether a given flight operates under VFR or IFR flight rules. For some VFR flight, you can just take off in your personal plane/blimp/helicopter, buzz around for a while and then land without asking anyone for permission or even talking to anyone.
However, that isn’t common for any semi-populated area if you are taking off and landing from anything but your personal airstrip in the middle of nowhere. You generally have to broadcast your intentions to someone (or even blindly) even for VFR flight and you may have to talk to Air Traffic Controllers as well in busier areas. However, you alone are responsible for making sure you don’t hit any other aircraft (or anything else).
IFR flight requires an IFR flight plan but those can be filed quickly on demand especially in the case of police or medical evacuation helicopters (or so I am told; I am not an IFR pilot). The whole Air Traffic Control system is dynamic and built to deal with very fast changes. It is a miracle that it works at all but it does and it does it well.
It does especially for police and medical evacuation flights. Air space charts are complicated and strictly enforced but the best way to visualize them is like a giant ice-cream cone coming up from ground level where the bottom tip is generally a large airport or a restricted air space.
You can fly VFR (weather permitting) over the vast majority of the U.S. by land area at lower altitudes (a few thousand feet or less) but it becomes more complicated as you approach a congested airspace area.
There are procedures to keep helicopters and fixed-wing aircraft separated in congested areas, since they travel at very different speeds. They are also a hazard to each other - helicopters are much harder to see, and even airplanes are harder to see in the air than you might think. All the air a helicopter sucks downward is dangerous to aircraft above it (Sen. John Heinz was killed in such an accident).
At non-towered airports, helicopters using runways often have traffic patterns on the opposite side of the runway, for separation. Tower controllers will separate them directly. In larger urban areas, with Class B airspace under direct ATC, there may also be helicopter routes defined, to limit ground noise - typically they run directly over freeways.
Many small planes and helicopters can fly quite high in theory but tend to fly much lower in practice (a few thousand feet above ground level but it depends on the surrounding terrain and the purpose of the flight). Common small planes like a Cessna 152 have a service ceiling that is roughly equivalent to two seat helicopters like a Robinson R-22. They both have a service ceiling a little over 14,000 ft which is plenty in Nebraska but not so good if you need to fly across the tallest peaks in the Rockies.
More exotic (and expensive) small planes can go even higher. A Mooney M-20 for example has a service ceiling greater than 25,000 feet. High attitude flying introduces some complications. Supplemental oxygen is required any time a pilot flies over 12,500 feet for more than 30 minutes and at all times over 14,000 feet. Few small planes are pressurized so that means donning an oxygen mask to prevent the insidious onset of hypoxia. Another issue is that airspace between 18,000 and 60,000 ft is Class A airspace and controlled by ATC everywhere in the U.S. You have to have an IFR rating, an IFR equipped plane and file a flight plan to fly into it.
In other words, many small planes can fly a lot higher than they usually go. Altitudes between 2,000 and about 8,000 feet above ground level (AGL) are much more common in small planes than altitudes above 12,000 feet. Helicopters tend to stay even closer to the ground because of the things they are used for (sightseeing, search and rescue, surveying etc).
Believe it or not, that would be completely legal over most of the U.S. A lawn chair/balloon rig would be classified as a ultralight and they are almost completely unregulated in the U.S. and do not require any license at all to fly. The only reason that Larry Walters got into trouble for his was that he launched close to Los Angeles and penetrated LAX airspace. As long as you take off and land without busting any controlled airspace, you can take your own joy ride without a worry (other than the fact you may kill yourself).
I realise that I know nothing about radar capabilities on aircraft. I just sort of unconsciously assumed that some of them at least must have radar, but I have no knowledge of it. The responses on the thread make it seem as though small planes don’t have radar. What about big ones? Military ones? Small expensive private ones? What about helicopters?
I always heard of controlled airspace better described as an upside-down wedding cake - radius expands at certain intervals.
There are basic rules, even for VFR. IIRC, after take-off and landing, en route should travel at 1000 feet levels for one half of the compass and 500 feet above that for the other half, thus negating the risk of head-on or that stupid “which way do I turn” dance. (I’ve forgotten my ground school from 1977 - turn right?) I know at uncontrolled airports small planes announce processes - “on runway 14”, or “joining circuit”, approaching from northeast at 2000 feet", etc. I imagine helicopters probably do the same from their pads. There is a standard channel for en-route radio in uncontrolled airspace so others can hear you.
So it’s not total chaos - some basic rules apply.
When I took a helicopter tour of New York a few years ago, they mentioned Manhattan over central park was out of bounds due to noise complaints; but we did go up the length of the Hudson and then circled Yankee Stadium.
Plus, IIRC, if you go near controlled airspace nowadays you MUST(?) have a transponder to ID you by location and altitude and your own code number to air traffic control. It’s not just passive radar.
Just to mention - Apart from urban areas and airports, there are often military installations that a person on the ground may not even be aware of. Overflying a military base is strictly a no no, in every country in the world.
If they don’t want you flying over something, it will be noted on the air sectional charts or if temporary, in NOTAMs and such advisories. Active pilots in the area will likely be well aware of restrictions (i.e. there’s an airshow, keep out of this area). If you are flying through, you need to check the NOTAMs and plot the course on a chart to see what you encounter. That’s more applicable to small planes than to helicopters that (AFAIK) rarely stray more that 100 miles from base, typically do local trips.
A military airport will be controlled airspace. Other bases will be marked. There’s an exclusion zone, IIRC, for quite a ways around the White House and other areas of Washington. If you don’t know about these things, you deserve to lose your pilot’s license - because what else will you fly into that you don’t know, like smaller airport flight paths? Skydiving areas? Firing ranges?
There’s a defined VFR corridor with IIRC a 1000’ ceiling, through New York airspace, down the Hudson River, exactly for that purpose, and to let non-IFR traffic transit the area. A set of special self-reporting rules apply, including for separating airplanes and helicopters at the Statue of Liberty (IIRC, airplanes go clockwise and between 500-1000’, helicopters CCW and lower).
Depends on the airspace. The bigger controlled airports (Class B or C) have a “Mode C Veil” at a 30 nautical mile radius, within which you need an operating Mode C transponder to fly (unless you request and receive permission). There is no veil around smaller towered airports (Class D) or nontowered airports or elsewhere.
My recollection (from a very, VERY limited exposure to flying lessons, so I apologize if this is inaccurate) is that private aircraft CAN be outfitted with a couple of different systems that alert you to other aircraft in the area, but that those other aircraft also have to be using the same system in order to be identified, so it wasn’t the same thing as having radar.
Within airport airspace helicopters are directed by the tower, or coordinate on unicom just like airplanes. Helicopters are to operate so as not to interfere with fixed-wing traffic. Outside of that airspace, helicopter pilots are expected to give periodic position reports. These reports are generally made where they are most useful. For example, ‘Four-Zero-Zero-Zero-Niner, northbound, Newhall Pass, two-point-four.’ (i.e., ‘This is N40009, northbound through the Newhall Pass at two thousand four hundred feet.’) Reports are made on the common helicopter frequency. In addition, we generally ‘keep right’. Helicopters frequently follow freeways, train tracks, rivers, and such, and you fly to the right of them.
Right. There are a number of different types of Traffic Advisory and Collision Avoidance systems for aircraft both large and small but they are uncommon on smaller planes partly because of the high cost and most of them don’t use radar at all. Some of them just use a passive strategy to intercept transponder returns from initiated by more sophisticated equipment located elsewhere so they can’t always give a complete picture of all possible traffic. They are a supplement to a pilot’s own eyes and ATC but they do not replace it in any way.
Commercial airliners commonly have limited range collision avoidance systems that can prevent a collision when all else fails but even those don’t typically display the level of information the controllers can see for the whole area. However, they can and have prevented a few major accidents at the last second when they sounded a potential collision alarm with emergency avoidance instructions.
