Whirlybird Wonder

I have been a helicopter pilot for over ten years and I am still amazed by the capabilities of these aircraft and the roles they play in modern civilization.  Take a look around while walking on campus or downtown and you will likely see at least one helicopter serving a purpose that will improve someone's day.  For example, you may see a news chopper watching traffic or a sightseeing tour over the city.  Significantly more important, are the helicopters that are assisting police with a bird's eye view or transporting a critically injured patient to a trauma center in the heart of a congested, building riddled city.  With so much versatility, it may seem surprising that helicopters comprise a very small segment of aviation.  In fact, the costs associated with helicopters make them a very large pill to swallow for all except those with a specific need.  Cost, noise, and component life-cycle all work to reduce the appeal of owning or operating helicopters.  The Advanced Rotorcraft Driveline initiative, by Bell Helicopters, aims to reduce some of those costs.

The driveline of a helicopter must withstand tremendous forces and loads, at incredible speeds, to move the wings (rotor blades) fast enough to generate lift.  In addition to generating lift, the driveline must allow for provisions to move the blades independently to allow for directional control.  This adds up to a costly, noisy, fault prone system that is overcome with large budgets, hearing protection, and constant component replacement.  The Advanced Rotorcraft Driveline (ARD), is a study conducted by Bell to dramatically improve the materials and components to reduce the negative characteristics associated with making a chopper go.  Improvements in materials, gear geometry, and optimization of cooling/lubrication systems all lead to a better system.

Lower cost.  Reduction in costs can be a competitive advantage for Bell Helicopters as new technology will allow for higher margins or a lower price for customers.  With a cost reduction of up to 35%, the volume of aircraft ordered and sold will likely increase due to a more attractive price point.  Cost reductions will propagate through the aircraft life cycle (many aircraft are decades old and still flying) and provide a reduction in lifetime costs

Quieter.  Many helicopter applications would benefit from lower noise.  Gears moving at those speeds tend to create a very high pitched whine.  The ARD estimates that up to 18 dB.  Though this may seem like a very small decrease, especially in the presence of a turbine engine with main and tail rotors churning through the air, this can be a dramatic reduction if in a certain frequency range.  There are some pilots that suffer high frequency hearing loss (they can hear most sounds just fine, but have lost the ability to perceive certain frequencies due to prolonged exposure).

Fault detection.  Most importantly, the ARD hopes to realize a 90% fault detection capability.  Sensors located throughout the drive system will be able to provide information about temperatures, stresses, and loads.  The information is used to monitor the system and detect faults within the system and predict impending failure.  The system will also be capable of monitoring lubricants for debris (engine wear causes metallic particles to be dispersed through the oil) and moisture, to warn maintenance of a component or lubricant change.  This drastically increases passenger and pilot safety and is far more accurate than simple visual inspection and replacement.  Furthermore, the data gathered can be used to continually compare component life cycle prediction with actual wear.

If the ARD is able to live up to expectations, it will mean an improvement in ease of use, lower purchase and maintenance cost, and a better product to meet the critical needs of the current helicopter fleet.  When a fire is burning out of control, or a patient is critically injured at a remote location, these improvements raise the likelihood that a helicopter is there to respond.