question: What type of aircraft can be used in congested or isolated areas and is used at Langley Regional Airport?
answer: Helicopter
context: Title: Langley Regional Airport
  Passage: Langley Regional Airport (IATA: YLY, ICAO: CYNJ) is located in Langley Township, British Columbia, Canada.  The airport serves mostly general aviation, and also provided scheduled passenger service to the Victoria Airport Water Aerodrome via Harbour Air Seaplanes before service was ended on May 20, 2011.  Helicopter operations are a major part of Langley Airport's traffic; the airport has 3 helipads.
  Title: Papuan mythology
  Passage: The Papuans are one of four major cultural groups of Papua New Guinea.  The majority of the population lives in rural areas.  In isolated areas there still remains a handful of the giant communal structures that previously housed the whole male population, with a circling cluster of huts for the women.  The Papuan people are Melanesian people composed of at least 240 different peoples, each with its own language and culture.  Sago is the staple food of the Papuan supplemented with hunting, fishing and small gardens.
  Title: Canadian Museum of Flight
  Passage: The Canadian Museum of Flight (formally the Canadian Museum of Flight Association since 1998) is an aviation museum at the Langley Regional Airport in Langley, British Columbia, Canada.  The museum has over 25 civilian and military jets, piston driven engine aircraft, gliders, and helicopters on display, six of which have been restored to flying condition.  Other displays include an aviation art gallery and aviation artefacts.
  Title: Forests in Odisha
  Passage: There are two basic kinds of forest here; in the northeast region of the state the forest is classified as the tropical-moist-deciduous type, blanketing hills, plateaus and other high-altitude isolated areas; in the southwest the tropical-dry-deciduous variety dominate.
  Title: Destin–Fort Walton Beach Airport
  Passage: Destin–Fort Walton Beach Airport (IATA: VPS, ICAO: KVPS, FAA LID: VPS) is an airport located within Eglin Air Force Base, near Destin and Fort Walton Beach in Okaloosa County, Florida.  No private aircraft are allowed, so Destin Executive Airport is used instead for non-commercial operations by general aviation and business aircraft.  The airport was previously named Northwest Florida Regional Airport until February 17, 2015 and Okaloosa Regional Airport until September 2008.
  Title: Helicopter
  Passage: A helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors.  This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward, and laterally.  These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL (vertical takeoff and landing) aircraft cannot perform.
  Title: Winmor
  Passage: WINMOR is a radio transmission protocol intended to be used in the Winlink 2000 Global Radio E-mail System by amateur radio operators, marine radio stations, and radio stations in isolated areas.  WINMOR will complement the PACTOR modes in the high frequency portion of the Winlink system.  WINMOR debuted at the 2008 ARRL / TAPR Digital Communications Conference.  Unlike PACTOR II & III, only a simple computer soundcard-to-radio interface is required, as compared to PACTOR's relatively expensive external terminal node controller.  It has two modes, either 500 or 1600 Hertz in bandwidth, and provides ARQ speeds ranging from 67 to at least 1300 bits per second, similar to PACTOR's various modes.  It is fully documented and without restrictions or license issues preventing anyone from using the protocol in other software.  WINMOR supports both connected (ARQ) and FEC (broadcast) modes.
  Title: Flora and fauna of Odisha
  Passage: The flora and fauna of Odisha, a state in eastern India, is extremely diverse and gives the state a reputation for abundance of natural beauty and wildlife.  The districts in the interior are thickly covered by forests both of the tropical moist deciduous type as well as tropical dry deciduous.  The hills, plateaus and isolated areas of the northeastern part of the state are covered by the tropical moist deciduous forests whereas the second types of the forests are located in the southwest region of the state.  Some of the trees which grow in abundance in Odisha are bamboo, teak, rosewood, sal, piasal, sanghvan and haldi.  There are 479 species of birds, 86 species of mammals, 19 species of amphibians and 110 species of reptiles present in Odisha.  The state is also an important habitat for the endangered olive ridley turtles and Irrawaddy dolphins.  Koraft district of southern Odisha has been identified by Food and Agriculture Organisation (FAO) of UN as Global Agricultural Heritage site which is among only other three sites in the world.Other sites are in Peru, China and Philippines.
  Title: PACTOR
  Passage: PACTOR is a used by amateur radio operators, marine radio stations, and radio stations in isolated areas to send and receive digital information via radio.  A robust network of PACTOR stations has been established to relay data between radio stations and the Internet, extending Internet access to sea based and other isolated users.  PACTOR utilizes a combination of simple FSK modulation, and the ARQ protocol for robust error detection and data throughput.  Generational improvements to PACTOR include PACTOR II, PACTOR III, and PACTOR IV which are capable of higher speed transmission.  Pactor modes other than level 1 (P1) are not open source and therefore cannot be decoded by anyone who hasn't invested in a proprietary modem.
  Title: Landing fee
  Passage: A landing fee is a charge paid by an aircraft to an airport company for landing at a particular airport.  Landing fees can vary greatly between airports, with congested airports, ones where most of the landing slots are held by airlines being able to charge premium prices because of supply and demand, while less congested airports charge less because the demand is not as high.  The money generated by landing fees is used to pay for the maintenance or expansion of the airport's buildings, runways, aprons and taxiways.
citations: Helicopter Langley Regional Airport