Explain why operational delays occur at airports even when the demand is less than the airfields capacity.

answer the following questions using complete 2-3 sentences EACH. Thank you

1)Since 2003, major carriers have been required to report the course of delays and cancellations to the Bureau of Transportation Statistics. Why are weather delays NOT reported as a single number?
2)Airline flight schedules have built-in-delay time. From an AIRLINEs PERSPECTIVE, what are the advantages and disadvantages of this practice?
3)Why has the proposal to implement a minimum aircraft size at LaGuardia been met with opposition?
4)Explain why operational delays occur at airports even when the demand is less than the airfields capacity.
5)What measures have airlines taken since the great recession of 2008-2009 to enable them to be profitable?
6)Capacity of airfield or airways is dependent upon many factors, including the available technology and installed equipment n the aircraft or at the airport. Describe an example of technology and installed equipment that can be used to increase capacity of an airfield.
7)How does fleet mix of aircraft operating at an airfield impact capacity?
8)What is meant by term practical capacity of an airfield? How is it determined?
9)What factors do the FAA approximation charts consider in estimating an airfields capacity?
10)What are the typical hurdles that must be overcome in having an airport expansion proposal approval?
11)In theory, why is the use of differential pricing, or the marginal cost approach, preferred over the average cost pricing method, in calculating landing fees?
12)Why were the airlines and the Port Authority of New York and New Jersey opposed the DOTs proposal of slot auctions at the NYC airports? What alternative approach(es) would they prefer to see implemented to reduce congestion?
13)Why was the cumulative metric (DNL) created to measure human response to noise?
Added on 17.05.2016 00:07
please answer the questions using 2-3 complete sentences each. Do not copy and paste.