ASSIGNMENT #3.6 : HELICOPTER from INVENTOR'S SPECIFICATION

 Suppose you are the inventor of a new device called helicopter. By describing the functional  characteristics of the machine, list some of the social needs that it is expected to satisfy. Which of these have come to fruition, and which have not?

                                                           HELICOPTER

The modern world nowadays has enabled various air transportations to be invented. One of them is a device called helicopter. Helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors.  It is maintained in the air by a variety of forces and controls working in opposition to each other. Helicopter is able to take off and land vertically as well as flies forward, backward, hover for extended period of time. Figure 1 below shows the helicopter controls system from top view:

Helicopter wider usage has made it one of the important transportation today. It is used as a part of defense, medical, tourism, construction and many more. As the inventors of the brand new helicopter, we have figured out the customer’s social needs as they ride this transport. Among the social needs that are expected are: Safety, Comfort, Fast Travel, Longer Travel, High Load Capacity, Special Function and Eco-Green Design.

          Base on the social needs stated above, some of them can be fruition and some of them are not. As we discovered those needs must equivalent with the helicopter functional characteristics itself. So, below are several social needs that can be meet base on functional characteristics of the helicopter:

1). Safety

          Helicopter is exposed to danger especially during the times when it flies. Among the factor contribute is the vibration. The higher vibration will cause the helicopter to shake itself apart especially in the air. So by adding stabilizer bar above and cross the main rotor helps in dampen unwanted vibration and directly stabilizes the craft in all flight condition. Thus, this social need can be achieved.

2). Comfort

The inside space of the helicopter will determine the comfort ability of the passengers.  Big spaces will cause passengers to sit comfortably. The enlargement of the cabin can be prepared on certain parameter according to its function. Apart from that, less noisiness inside helicopter also will increase tranquility of the passengers. Base on functional characteristic of helicopter, the tail rotor which is recessed into fairing of the tail reduces the noise level. This type of rotor may have 8 to 12 blade that can increase the frequency of the noise and then weakening by the atmosphere. Thus, these social needs can be accomplished since the helicopter much quieter than conventional one.

3). Fast Travel

Helicopter is always known for low travel speed. This characteristic in influenced by several factors in its design. However, the travel speed can be improved by using powerful rotor blade which suitable according to power weight ratio. Other alternatives might be using lighter material in the helicopter body. Composite materials are extensively used in the structure of the main rotor blade in order to realize the weight distribution for a low vibration design, and to reduce weight and manufacturing costs.

4). Longer Travel and Ship Landing Assist System (SLAS)

The ability to travel in longer distance travel also becomes the priority for customer. This specification is highly demanded for customers who wishes to have private helicopter which can take them anywhere without short distance limit. However, this kind social need difficult to justify as the cost spending is too much. Only certain type of helicopter can fulfill such need.

Ship Landing Assist System (SLAS) has the function of automatically carrying out operations of the approach of the aircraft to the base ship, automatic entry, and hovering and landing on the flight deck. Major aims of this system are to reduce the pilot workload and to improve a flight safety at nighttime and stormy weather. Thus, by adopting the SLAS Ship Guidance Sensor (SSGS) using laser and infrared radiation it can measure the relative distance and azimuth/elevation from the ship to the aircraft, by tracking the marker and reflecting a laser beam emitted from the sensor off the reflector.

5). High load capacity

The increase load usually influenced by the increase in the number of passenger and things. This specification is possibly implemented by using the powerful rotor blade which blade has a unique blade tip shape with dihedral and anhedral angle and swept back angles which provides excellent aerodynamic characteristics during hovering flight. This design makes it possible to increase the maximum gross weight without increasing the rotor diameter.

6). Special functions

            Rescue

The special design for rescue helicopter maybe is needed by special agencies such as Health Administration, Red Crescent Society, Fire and Rescue Department and many more. This helicopter will be equipped by rescuing parts such as ropes, water shuttle tanks and others.

            Attacking Weapon

The attacking weapons can also be installed to the helicopter. This special design might be used for the defense department such as Police and Army.

7). Eco-Green Design

It is found that helicopter produce carbon dioxide (CO2) gas which will cause pollution. The CO2 emission rate is three times the amount produce by the van. Thus, the new design of helicopter which equipped with eco-green characteristics is need to be invented to help minimizing the environment pollution rate.   

Conclusion

Helicopter has variety in preference. It all depends on customer's priorities and every single helicopter compromises of size, capacity, costs (both initial and running), comfort, speed and versatility. Hence, all basic functional characteristics of helicopter should be identified in order to meet the social needs or specification.