Beach nourishment involves pumping sand onto beaches to improve their health. Beach nourishment is common for major beach cities around the world; however the beaches that have been nourished can still appear quite natural and often many visitors are unaware of the works undertaken to support the health of the beach. Such beaches are often not recognized by consumers as artificial. A famous example of beach nourishment came with the replenishment of Waikīkī Beach in Honolulu, Hawaii, where sand from Manhattan Beach, California was transported via ship and barge throughout most of the 20th century in order to combat Waikiki's erosion problems. The Surfrider Foundation has debated the merits of artificial reefs with members torn between their desire to support natural coastal environments and opportunities to enhance the quality of surfing waves. Similar debates surround beach nourishment and snow cannon in sensitive environments.
During hot calm seasons, a crust may form on the surface of ocean beaches as the heat of the sun evaporates the water leaving the salt which crystallises around the sand particles. This crust forms an additional protective layer that resists wind erosion unless disturbed by animals, or dissolved by the advancing tide. Cusps and horns form where incoming waves divide, depositing sand as horns and scouring out sand to form cusps. This forms the uneven face on some sand shorelines. White sand beaches look white because the quartz or eroded limestone in the sand reflects or scatters sunlight without absorbing other colors.
A beach is an unstable environment that exposes plants and animals to changeable and potentially harsh conditions. Some animals burrow into the sand and feed on material deposited by the waves. Crabs, insects and shorebirds feed on these beach dwellers. The endangered piping plover and some tern species rely on beaches for nesting. Sea turtles also bury their eggs in ocean beaches. Seagrasses and other beach plants grow on undisturbed areas of the beach and dunes.
On November 27, 2007, Hawaiian Airlines signed a MOU (Memorandum of Understanding) with Airbus for 24 long-range jets priced at $4.4 billion. The order included six Airbus A330-200s with a further six purchase rights and six Airbus A350-800s with a further six purchase rights - plans to fly to Paris and London were discussed. Deliveries for the A330s began in 2010 while the first A350 was to be delivered in 2017.
All inter-island passengers on Hawaiian Airlines should check-in at least 90 minutes prior to scheduled departure. Passengers should plan to check-in for trans-pacific flights between Hawaii and US mainland cities two-and-a-half hours prior to departures and three hours prior to departure for international flights. Inter-island check-in closes 30 minutes before departure, and all other flight check-in options close 45 minutes before departure. Online check-in is available 24 hours before departure and closes 90 minute beforehand.
Hawaiian began acquiring Boeing 717 aircraft for operation on the Neighbor Island network in February 2001. On June 4, 2008, the airline announced that it had agreed to lease an additional four 717 airplanes to meet demand due to the shutdown of Aloha Airlines' passenger operations and the closing of ATA Airlines, with deliveries between September and the end of 2008.
If a particular city has two or more airports, market forces will tend to attract the less profitable routes, or those on which competition is weakest, to the less congested airport, where slots are likely to be more available and therefore cheaper. For example, Reagan National Airport attracts profitable routes due partly to its congestion, leaving less-profitable routes to Baltimore-Washington International Airport and Dulles International Airport.
Often the companies combine IT operations, or purchase fuel and aircraft as a bloc to achieve higher bargaining power. However, the alliances have been most successful at purchasing invisible supplies and services, such as fuel. Airlines usually prefer to purchase items visible to their passengers to differentiate themselves from local competitors. If an airline's main domestic competitor flies Boeing airliners, then the airline may prefer to use Airbus aircraft regardless of what the rest of the alliance chooses.