| The first practice flight models took to the air in the | | | | creating a mess of oil from engine exhaust, and the |
| early 20th century. Progress in the performance of | | | | engines are very noisy. |
| these devices depends on the technology. All flight | | | | Over the past five years, electric motors have literally |
| models must be constructed of light, strong materials | | | | taken over as the best source for model airplanes. A |
| to fly properly, and require some form of power to | | | | chance of convergence of technologies - small, |
| achieve flight. | | | | lightweight and inexpensive system for monitoring the |
| Twisted elastic are a form of lightweight and | | | | radio, the efficiency of rechargeable batteries and |
| inexpensive power for model aircraft, and are still used | | | | brushless electric motors - has helped to revolutionize |
| today in some areas of free flight. As the models | | | | the model airplane hobby. Many of today, control |
| have increased in size and weight, small gas engines | | | | aircraft radio modelers have anything stolen, but |
| became the means to feed the vast majority of flights. | | | | electric RC airplanes and have never even started a |
| Gas engines are a lot of power, but require strong and | | | | small gas engine. |
| heavy structures of the cell to handle engine vibration, | | | | |