Difference between revisions of "1972: Autogyros"
(Undo revision 154936 by 126.96.36.199 (talk) Obviously not a food reference; the statement is more directly factual than that.)
(→Flown without a license)
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===Flown without a license===
===Flown without a license===
''Can often be flown without a license''
''Can often be flown without a license''
Revision as of 14:20, 28 March 2018
| This explanation may be incomplete or incorrect: Have created sections for explaining each of the statements, but they need to be expanded. Do NOT delete this tag too soon.|
If you can address this issue, please edit the page! Thanks.
Randall states that an autogyro is nothing like a helicopter (which it looks like), nothing like a plane (but flies like one) and works like a powered parachute or paraplane (which it might kind of look like except without a parachute). He continues to make a total of 12 statements which will be explained individually below.
The final statement at the bottom right is the punch line of how strange these flying machines are, because they are safe, as long as you do not do what a pilot instinctively would do in a plane in case of a stall, because if you do so the autogyros will crash immediately... See the explanation below. That sentence is almost rendered unnecessary by the one above it that states that autogyros never stalls!
Randall's conclusion is clear: Autogyros are weird.
In the title text Randall continues on the last statement by saying that today autogyros are much more stable. Which must refer to that this was not always the case. And this new stability probably means that a stall situation is much less likely and the last statement is then not so relevant anymore.
Randall then goes on to suggest that the autogyro people will be angered by this comic, which impugns (i.e. attacks) the safety of their beloved machines. But he keeps on mocking them. In fact, he states that they will come after him, once they have finished building the autogyros they have been working on in their garage for the last 10 years. By this, he implies that the people who work on them do this as a home garage project so they will never get them finished and able to fly. Thus, they will probably never come after him.
- Below each of the statements in the comic are explained
- The optimal reading order is to read them in the four columns they are arranged in:
- The left with four, the two single in the middle and the six on the right.
Nothing like a helicopter
Looks like a helicopter, but is nothing like a helicopter
It is like a helicopter in the sense that a horizontally spinning fan provides the lift. It is unlike a helicoper because A) the fan is not powered, B) the fan does not provide forward propulsion, C) it is incapable of hovering, or moving in any other direction than forward.
Nothing like a plane
Flies like a plane but is nothing like a plane
Its flight pattern resembles a plane in that it can only move forward, turns by banking, and needs to maintain forward velocity in order to create lift. However, unlike a plane it has no wings to generate that lift.
Sort of like a powered parachute
A powered parachute, also referred to as a PPC or paraplane, is a similar design except instead of a freely-rotating blade they are attached to a large parachute that acts like an airplane wing. As long as there is thrust the parachute will fill with air and maintain its wing-like characteristics, with the advantage of acting like a real parachute in the event of a loss of thrust (i.e. engine dies) wherein they come floating down at a speed significantly slower and more survivable than freefall. A single-seater can often be flown without a license and can be as inexpensive as $5,000 USD in parts.
Rare in the US
Rare in the US, usually homemade. Common in Europe.
Big blade on top
Big blade on top is not powered and spins freely
Flown without a license
Can often be flown without a license Autogyros are frequently built as ultralights, and that group of aircraft are a special case where licenses are not needed. (Ultralights, in the US, are aircraft that weigh less than 254lbs, carry less than 5 gallons of fuel, stall at less than 24kts, have a maximum speed less than 55kts, and carry only the pilot.)
Helicopters are notorious for being extremely expensive to operate. At a typical general aviation service in the US, a two-seat aircraft may rent for under $100/hr, while a helicopter runs over $200/hr. Similarly, a small used helicopter may cost almost $200,000 while a small new autogyro may cost under $25,000. Since many people home-build their autogyros, it would often be even cheaper.
Needs a runway to take off
Needs a runway to take off, but not a long one
Can land vertically
An autogyro can land vertically: for that matter, so can any airplane. What matters isn't ground speed but airspeed, and as long as there's as much headwind as the landing airspeed of the aircraft, it will land vertically. Now, with fixed wing airplanes the landing speed is at least 40-50 mph, and you don't often find headwinds like that. The much lower landing airspeed of an autogyro makes vertical landings feasible.
True hovering would require the rotor to be powered. However, an autogyro must be moving forward relative to airspeed in order for the rotor to generate lift.
Most conditions that would cause a stall in a fixed wing airplane such as low speeds, high-G maneuvers, and gusty winds don't apply to autogyros. The rotor in an autogyro is in equilibrium, the inner, slower part is stalled, the middle part makes it spin and the outer, faster part slows down the rotor and provides lift. As the angle of attack increases, a fixed wing aircraft would stall, however, on an autogyro, it will just make the lift-generating area smaller, causing the rotor to automatically spin faster and the equilibrium is restored.
This is not entirely correct however. If you reduce the forward speed of an autogyro, the rotor slows down, reducing lift so the autogyro will descend. Under most circumstances, this would lead to a controlled landing. However, if it happens at high altitude, you can run out of lift completely while still high above the ground causing a stall. This is more likely to happen if there is a strong tailwind.
Extremely safe, unless you do the one thing you instinctively do to escape a stall in a normal airplane, in which case it will crash immediately
Autogyros are considered safe due to their slow landing speed, which is important in emergency landings, their forgiving behavior in windy conditions and the fact they are almost impossible to stall. This is thanks to the freely spinning rotor. Unfortunately, as soon as the rotor stops spinning, the whole aircraft falls like a brick and the rotor may be impossible to restart in flight. This is a situation that should be avoided at all costs.
Normally it is not a problem since the weight of the aircraft keeps the rotor spinning. However, if the weight becomes too low or even negative, the angle of attack will become negative, and the rotor will slow down and eventually stop. It can happen when the pilot "pushes on the stick" and dives.
Unfortunately, "pushing on the stick" is also how you escape a stall in a fixed wing (normal) airplane as it is a way to regain airspeed. This is actually a counter-intuitive maneuver but because a stall is an emergency, pilots are trained to do it instinctively. It can trick a pilot trained in fixed wing aircraft into doing the one thing that shouldn't be done on a gyro.
- [A picture of Megan wearing aviator goggles, sitting in an autogyro and holding the control stick. The autogyro is surrounded by sentence fragments, explaining characteristics of it. The one above the blade that concerns the blade has an arrow pointing from the text to the blade. The sentences in columns from the left (i.e. first four sentences to the left, then two above the autogyro's body, and finally six sentences to the right):]
- Looks like a helicopter, but is nothing like a helicopter
- Flies like a plane but is nothing like a plane
- Sort of like a powered parachute
- Rare in the US, usually homemade. Common in Europe.
- Big blade on top is not powered and spins freely
- Can often be flown without a license
- Needs a runway to take off, but not a long one
- Can land vertically
- Cannot hover
- Never stalls
- Extremely safe, unless you do the one thing you instinctively do to escape a stall in a normal airplane, in which case it will crash immediately.
- [Caption below the panel:]
- Autogyros are weird.
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