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Pitch & Roll Limitations for Helicopters

Helicopters are perhaps the most complex flying machines in creation. Like the bumblebee, their appearance is not in accord with the breathtaking maneuverability and fancy feats of flight they are capable of. Renaissance artist Leonardo Da Vinci was the first person to imagine the aviation possibilities inherent in the form of the helicopter. Since the acclaimed Italian first created his rudimentary designs for a helicopter in the late 15th century, the unique flying capabilities of the affectionately named 'choppers' has outgrown all expectations. Although they easily rival and out maneuver their fixed wing counterparts in certain areas, helicopters are still susceptible to limitations in pitch and roll.

How A Helicopter Flies
- Compared with the airplanes, helicopters are more mechanically complex, harder to maintain, and less fuel effective. However, helicopters possess a quirky and individualistic charm which planes do not. Perhaps it's all to do with the way they fly. To become airborne, the helicopter's blades, or rotor disc, spin, and like a fan, generate enough air to give it what is termed "lift." As the helicopter travels upwards, the rotor disc is tilted through the "cyclic" or the "stick" and converts some of the upward force into going forward, rear, left or right. What the helicopter gains in direction, it loses in altitude. To counter this the rotor disc is leveled again, or the overall power of the blades is increased.
What Is Pitch?
- A helicopter's blades are angled or pitched in various ways for direction of movement. When all the angling of blades are at the same degree it is called collective pitch. Without this helicopters would not vertically rise. Cyclic pitch is dependent on the individual angling of the blades as they revolve. It affects the roll of the helicopter as it tilts upwards, downwards and from side to side. Differential collective pitch controls the left and right turning movement of the helicopter.
What Is Roll?
- When taking off, helicopters are susceptible to a lateral rolling tendency named dynamic rollover. The process occurs because helicopters naturally lift on one skid. If the pilot is inexperienced and slides the helicopter too much in the direction of that skid, dynamic rollover occurs. Once it has began the process is difficult to stop. Only by applying collective thrust on full power can an accident be averted.
Limitations
- The high speeds at which a plane can travel are limited in helicopters because of the discordant symmetry between collective pitch (lift) and cyclic pitch (direction). A pitch will only work to its full potential at the detriment of the other. Because they require so much power and fuel for lift, helicopters are also limited in the ranges they can travel without refueling. Their tendency to roll when hovering makes them prone to crashing, especially in severe winds.

Aviation