Hg67 Aviation Management : Encyclopedia Assessment Answers

Answer:

Task 1

Introduction:

Gyroscopes entail the instruments which are available in aircraft systems and they are basically used for the purposes of controlling the turning, attitude and direction of an aircraft and they encompass devices such as rotor and wheel that are significant in providing the precision and rigidity of the aircraft. The gyroscope system is fitted with a device known as a gyro that primarily provides the gyroscope with vast degrees of freedom. There are various. The movement of the gyroscope system is achieved by different mechanisms including electrical mechanism, pneumatic mechanisms or even vacuum mechanisms. As described below, there is the difference between these mechanisms (Gupta, 2009).

Vacuum driven gyroscope

This system comprises a vacuum pump that is attached to the engine which avails electric power to the system. The vacuum pump obtains its power from the engine of the aircraft. Besides, they also encompass suction connectors that link the vacuum pump to the gyroscope system thereby allowing the sucking of air from the openings available in the instrument (Tischler, 2009). Upon generating of the sucked air into the system, the air gets pushed and it is accelerated towards the tiny pockets that are present in the wheel of the gyroscope. Attached to the gyroscope system are two gimbals which are basically used in the control of height and maintenance of the index bank. Also, a tiny sized regulator is present in the vacuum drove gyroscope that takes control of the suction pressure into the system. The speed of the gyroscope is taken care of by the presence of calibrated regulators while air from the gyroscope is allowed back into the atmosphere via an outlet (Barreveld, 2015).  Nevertheless, this mechanism exhibits some properties including;

The gyroscope system has a low responding characteristic hence at low speeds there is a resultant effect of lads produced on the indications

Besides, higher speeds create an excessive reaction of the gyroscope thereby promoting early wearing off of the gyroscope and tentatively a reduced lifespan (Bennett, 2009).

Limitation

• This kind of mechanisms can be applied in high altitude aircrafts since this may result in an overall reduction in the efficiency of the instrument .below is a diagram of the instrument

Pneumatic driven gyroscope

 The mechanism used in the powering of this instrument here is similar to the vacuum drove system such that both of the systems utilize the vacuum pumps .the only difference is that for the pneumatic systems, the pump is primarily used for the purposes of minimizing the air pressure that passes through the gimbals. This pump takes in air from the cabin that has been filtered into the gyroscope then push it towards the gimbals thereby making them turn. Below is a diagram of the pneumatic system (Bennett, 2010).

Limitation

• The set back that arises with this kind of power is that it is prone to errors emanating from the pressure drops as a reduction of the speed of the rotor.
• Additionally, this system cannot be applied in high altitude aircrafts since the efficiency of the pump may be reduced and causing subsequent effects.  

Electrically powered gyroscope

These type of mechanism operates on the same principle as an electric motor. The spinning of the gyroscope is similar to the spinning of the motor armature. This system is connected to an inverter that helps in converting direct current to an alternating current that consequently aids in powering the gyroscope (Bennett, 2012).

 Characteristics

• The gyroscope has a constant speed of 8000 revolutions per minute
• Their constant speed makes them suitable to be used in high altitude aircrafts.

Limitations

• This system is prone to an electrical failure or faults
• There is also the possibility of the precision being influenced by the presence of, moisture and dust(Bennett, 2011).  

Task two

The modern flight instrumentation uses the gyroscope system purposefully for the provision of rigidity and precision. The ability of the gyroscope to offer some level of resistance to any kind of force which attempts to displace the plane of its position provides the rigidity whereas precision is attained by the ability of the gyroscope to distribute any kind of force in a perpendicular manner to the rotation of the instrument thereby manifesting the force 90 degrees further (Parr, 2011).

Modern air flights such as Boeing and Airbus has both the vacuum and the electrically driven gyroscopes for the precision and rigidity .the vacuum gyroscopes help in attaining the attitude indication while the electric gyroscopes help in turning motion (Brownell, 2009). Both of Boeing and Airbus aircrafts have their vacuum gyroscopes that continue to operate even when the other system gyroscopes have halted. This is because of the significant role that the vacuum system gyroscope plays in the provision of reference to the pilot. This is always enabled by the altitude indicator by remaining at a constant altitude with respect to the horizon thus achieving the aspect of rigidity. The two attached gimbals in the modern aircrafts help in achieving this by controlling the height and the maintenance of the banking index (Crolla, 2015).

Moreover, the electrically powered gyroscope system in the modern aircrafts such as the Airbus and the Boeing holds a significant role by providing the information with data and information concerning its turning rate and the banking information. Upon starting to turn, the electrically powered gyroscope systems provide a signal that the banking is underway and when the turning is over, the rate at which the turn was is indicated. Besides, this device helps in ensuring the level and height of the flight by exploiting the aspect of precision since as the aircraft turns, a force that is perpendicular is being felt by the gyroscope. This force makes the banking action whose information and data is availed by slightly canting the plane and hence stopping the rotation of the gyroscope with respect to its rotational axis (Bryson, 2014).

However, there are some shortcomings that are being experienced with the magnetic compass. These limitations may include;

The magnetic compass cannot isolate the magnetic field of the earth form the other fields.

The magnetic compass mostly provides an indication of the magnetic north contrary to the expectation of the true north (Russell, 2001).

Besides, even after performing compensation on the magnetic compass, some elements of the residual error can still be noticed (Corda, 2017) 

Thus there is need to replace the magnetic compass with one which will minimize some of the challenges that are being realized by the magnetic compass. A perfect replacement is an electro-mechanical gyrocompass. Despite being complex and expensive, this device has many benefits that will ease the provision of indications in a precise manner (Filippone, 2009). For instance

• They consume less amount of power
• They have no friction or any form of wear
• They have a self-correcting mechanism
• They provide a standardized output in a digital manner.

Task three

Direct reading compasses

Card type compasses, which are designed for mounting on an instrument panel o, indicate magnetic heading by means of a graduated card affixed to the magnet system and registering against lubber line in the front of the bowl.

Grid steering type compasses, employ a needle and filament type magnet system which is referenced against a grid-ring located over the compass bowl. The grid-ring, which may be rotated and clamped in any position, has a graduated scale and two pairs of parallel grid wire.

Compass construction

The aircraft's magnetic compass is a simple, self-contained instrument. it consists of a sealed outer case within, which is located, a pivot assembly and a float containing two or more magnets. A compass card is attached to the float with the cardinal headings shown by corresponding letters. Between the Cardinals heading each 30 degrees increment is shown as a number with the last zero removed.  

The case is filled with an acid-free white kerosene that helps to dampen oscillations of the float and also to lubricate the pivot assembly. The pivot assembly is spring-mounted to further dampen aircraft vibrations so that the compass heading may be read more easily.

Location considerations

The location of a compass or detector unit is important. The location is determined during the aircraft's design stage and should not be altered. Where practicable, magnetic steel parts, especially movable parts, should not be positioned near the compass. Electrical cables carrying uni-directional current produce a magnetic effect and should be positioned at least 2 feet away from the compass.

Errors

The errors in aircraft's main and standby compass system are caused by external magnetic fields as well as errors within the direct reading compass systems. The errors within the direct reading compass systems include turning and acceleration errors alongside minor errors which include;

• scale error
• alignment error
• centering error
• parallax error

Analysis of deviation

In an analysis of deviation, a deviation card may be used. The deviation card should be compiled to show the deviations which are related to standard headings at intervals of 45 degrees and should be kept in a place next to the respective compass. The card readings are those which the compass must indicate to fly the aircraft on the correct magnetic headings, for example, to fly on a magnetic heading 000 north the compass must indicate 002 degrees.

Compensation

A special calibration procedure called swinging is carried out so that adjustments can be made to compensate for the deviations. This is done to determine what amount compass readings are affected by hard and soft iron magnetism. These adjustments may be affected by the compensator or a corrector magnet devices which, in the case of direct-reading compasses, always relate only to deviation coefficients.

Task 4 (the operation of a typical magnetic heading reference system)

Synchronous data transmission systems – these systems are generically introduced and comprises of transmitting and receiving elements .they are utilized in the engine systems, analog data computers and remote indicating compasses.

Synchro types

Usually, they are four. I.e. control, torques, resolver and differential. The torques are obtained from the input of the transmitting element while the control obtained from the servomechanism. It provides amplification signals.

Flux valves

Is a magnetic sensory device which electrically transmits information to an aircraft compass system m regarding the orientation relative to the earth magnetic field? It helps in generating a visual indication of the flight crew regarding the heading of the aircraft relative to the magnetic north.

Operating Modes

Are usually two, the magnetic slaved information mode that is applied when the heading references are reliable and the directional mode which is used when the heading reference is not reliable?

Deviating compensation

During the deviation compensation. The aircraft first gets aligned to the  magnetic north the n-s compensating magnet is adjusted to eliminate one half of the south error and finally, the aircraft to point the magnetic west an then adjusted the east-west magnetic to remove the one half error

Integration with radio and inertial systems

These are reckoning device which is self-contained i.e. computer platform or module with many devices which are usually independent of their environments.

References:

Administration, A., 2009. Pilot's Handbook of Aeronautical Knowledge. 2nd ed. Manchester: Skyhorse Publishing Inc.

Barreveld, D., 2015. modern inertial technology - Inadvertent In-Flight Slat Deployment. 2nd ed. London: Lulu.com.

Bennett, S., 2011. Large Aircraft Systems. 2nd ed. Carlisle: Cengage Learning.

Brownell, T., 2009. Aircraft generators. 1st ed. London: Motorbooks International.

Bryson, E., 2014. Control of Spacecraft and Aircraft. 6th ed. Leicester: Princeton University Press,

Corda, S., 2017. Introduction to Aerospace Engineering with a Flight Test Perspective. 2nd ed. Carlisle: John Wiley & Sons,

Corke, C., 2008. The design of Aircraft. 4th ed. New York: Prentice-Hall,

Corolla, D., 2015. Encyclopedia of Automotive Engineering. 4th ed. Westminster: John Wiley & Sons.

Murali, L., 2015. A New Self-Contained Electro-Hydraulic Brake System. 3rd ed. New York: University of Waterloo.

Filippone, A., 2007. Flight Performance of Fixed and Rotary Wing Aircraft. 5th ed. New York: Elsevier,

Johnson, J., 2012. Introduction to Fluid Power. 4th ed. New York: Cengage Learning,

Parr, A., 2011. Hydraulics and Pneumatics: A Technician's and Engineer's Guide. 4th ed. Carlisle: Elsevier,

Pascoe, D., 2013. Aircraft. 2nd ed. Chicago: Reaktion Books.

Russell, J., 2010. Performance and Stability of Aircraft. 2nd ed. Carlisle: Butterworth-Heinemann.

Schmidt, L., 2008. Introduction to Aircraft Flight Dynamics. 1st ed. Chicago: AIAA.

Tischler, B., 2009. Advances In Aircraft Flight Control. 3rd ed. Chicago: CRC Press.