Airport Engineering MCQ Quiz in मराठी - Objective Question with Answer for Airport Engineering - मोफत PDF डाउनलोड करा

Concept:

Wind Cover: The percentage of time in a year during which the cross wind component of wind is within permissible limit of 25 kmph

Wind Rose: is a graphical representation of the direction, intensity, and duration of wind is called wind rose and is used to the find the orientation of the runway

The wind data should usually be collected for a period of at least 5 years and preferably of 10 years so as to obtain an average data with sufficient accuracy

Head Wind: The runway is oriented in the direction of the prevailing winds. It helps in the landing of vehicles by causing a breaking effect and during takeoff, it provided lift on the wings of the aircraft.

Cross Wind: Component of wind perpendicular to the runway. It abrupts the landing and takeoff of aircraft.

Concept:

Airport reference temperature (ART) \(= {T_a} + \frac{{{T_m} - {T_a}}}{3}\)

Where,

Ta = monthly mean of the average daily temperature for the hottest month of the year

Tm = monthly mean of the maximum daily temperature for the same month

Calculation:

Ta =  30°C

Tm = 45°C

\(ART = 30 + \frac{{45 - 30}}{3}\)

∴ ART = 35 ° C

Actual Runway length calculation as recommended by ICAO (International Civil Aviation Organization) includes two corrections as follows:

Correction for Elevation: 7% increase per 300 m

Correction for Temperature:

Airport reference temperature (ART),

\({\rm{ART}} = {T_a} + \frac{{{T_m} - {T_a}}}{3}\)

T­_a = Monthly mean of the average daily temperature of the hottest month.

T_m = Monthly mean of the maximum daily temperature of the hottest month.

For every 1° C rise of ART, Standard Airport Temperature (SAT) length will be increased by 1%.

FAA (Federal Aviation Administration) also recommends correction for Gradient as follows:

Correction for Gradient:

For every 1% effective gradient, runway length will be increased by 20%.

Explanation:

Correction for basic Runway length (I)

1) Correction for elevation

ICAO recommends that basic runway length should be increased at the rate of 7% per 300 m rise in elevation above mean sea level.

2) Temperature correction

Airport reference Temperature (ART)

\(T_a + {1\over3}(T_m-T_a)\)

Tm = Monthly mean of the maximum daily temperature of the hottest month.

Ta = Monthly mean of the average daily temperature of the hottest month

Rise in temperature = ART - SAT

Where,

SAT is Standard Atmospheric Temperature

NOTE: Due to the elevation, there is a decrease in standard temperature at the rate of -6.50 c per 1000 m rise.

As per ICAO, Basic runway length after correction for elevation should be further increased at the rate of 1% for every 1° C rise of the airport reference temperature

Correction for temperature

Note: As per ICAO, the cumulative connection for elevation and temperature Cumulative (%) correction together should not be ≯35%

If exceeds modify, I2 = 1.35 x I

3) Gradient correction

For every 1% effective gradient, runway length will be increased by 20%

\(Gradient = {Elevation \space difference\over Original \space length \space of \space runway}\)

Concept:

Correction for basic Runway length (l)

i) Elevation correction

For every 300-meter rise above MSL, the length will be increased by 7%

Corrected length \(\Rightarrow {{\rm{l}}_1} = {\rm{l}} + \left( {\frac{{\rm{x}}}{{300}} \times \frac{7}{{100}}} \right) \times {\rm{l}}\)

ii) Temperature correction

Airport reference Temperature (ART)

\({\rm{T}} = {{\rm{T}}_{\rm{a}}} + \frac{{{{\rm{T}}_{\rm{m}}} - {{\rm{T}}_{\rm{a}}}}}{3}\)

Tm → monthly mean of maximum daily temp of hottest month

Ta → monthly mean of average daily temp of hottest month

For energy 1°C rise of ART above (SATx i.e. Standard Airport Temperature) length will be increased by 1%

Corrected length \( \Rightarrow {{\rm{l}}_2} = {{\rm{l}}_1} + \left( {\frac{{{\rm{\Delta T}}}}{{100}}} \right){{\rm{l}}_1}\)

Note: As per ICAO, the cumulative connection for elevation and temperature together should not be ≯ 35%.

Cumulative (%) correction \(= \frac{{{{\rm{l}}_2} - {{\rm{l}}_1}}}{{\rm{l}}} \times 100 \not > 35\% \)

If exceeds modify, l2 = 1.35 × l

iii) Gradient correction

For every 1% effective gradient, runway length will be increased by 20%

\({\rm{Final\;length\;}}\left( {{{\rm{l}}_3}} \right) = {{\rm{l}}_2} + \left( {20 \times \frac{{{{\rm{G}}_{{\rm{effective}}}}}}{{100}}{\rm{\% }}} \right){{\rm{l}}_2}\)

\({{\rm{G}}_{{\rm{effective}}}}\left( {\rm{\% }} \right) = \frac{{{\rm{R}}{{\rm{L}}_{{\rm{highest\;point}}}} - {\rm{R}}{{\rm{L}}_{{\rm{lower\;point}}}}}}{{{\rm{Runway\;unit\;}}\left( {{{\rm{l}}_2}} \right)}}\).

Explanation

As the airport is at MSL and the airport temperature is the same, the elevation and temperature correction is zero.

Along the runway the gradient is different, Determining the entire gradient correction 

Gradient correction:

Effective rise or fall

\( = \frac{1.2}{{100}} \times 300 - \frac{{0.7}}{{100}} \times \left( {600 - 300} \right) + \frac{{0.6}}{{100}} \times \left( {1100 - 600} \right) - \frac{0.8}{{100}} \times \left( {1400 - 1100} \right) - \frac{{1.0}}{{100}} \times \left( {1700 - 1400} \right)\)

 = 3.6 - 2.1 + 3 - 2.4 - 3

= - 0.9

 ∴ Cumulative rise/fall is - 0.9 m 

\(Effective\;gradient = \frac{{Maximum\;Difference\;in\;level}}{{Total\;Length}}\)

\( = \frac{{4.5 - \left( { - 0.9} \right)}}{{1700}} \times 100 = 0.3176\;\% \)

∴   The effective gradient is 0.3176 %

Concept:

Explanation:

Given

1. Basic runway length = 2000 metres

2. Elevation of airport site = 600 metres

Elevation correction is 7% increase per 300 m rise.

Hence correction \(= \frac{7}{{100}} \times \frac{{600}}{{300}} \times 2000 = 280m\)

Corrected length = 2000 + 280 = 2280 m

Concept:

Wind Rose Diagram

• A wind rose is a graphic tool used by meteorologists to give a succinct view of how wind speed and direction are typically distributed at a particular location.
• Historically, wind roses were predecessors of the compass rose (found on charts), as there was no differentiation between a cardinal direction and the wind which blew from such a direction.
• Using a polar coordinate system of gridding, the frequency of winds over a time period is plotted by wind direction, with color bands showing wind speed ranges.
• The direction of the longest spoke shows the wind direction with the greatest frequency. 
• The wind rose diagrams help you visualize wind patterns at a site. Use them to better inform your design decisions, but be aware of unique microclimates and site considerations that wind rose intensity blows from the respective direction.
• The procedure for determining the orientation of the runway from this type of wind rose is described below. Draw three equispaced parallel lines on a transparent paper strip in such a way that the distance between the two nearby parallel lines is equal to the permissible crosswind component. 
• The best direction of runway is along the direction of the longest line on the windrose diagram.

Explanation:

1. Yellow:
   • ​​ Yellow lights are used to indicate a cautionary status in many applications, but they're not typically used for runway threshold lights.
2. White:
   • ​​White is used along the length of the runway to guide the plane's path for taking off or landing but not specifically for the threshold.
3. Red:
   • ​​Red is often used in aviation to indicate danger or areas that should not be entered, usually situated at the end of the runway to indicate its limit from the opposite landing direction.
4. Green:
   • Green lights are used for threshold lighting. According to the International Civil Aviation Organization (ICAO) Annex 14, runway threshold lights should be green.
   • They indicate the start of the runway that is available for landing when seen from the air.