question: Ridley Park, Pennsylvania is home of a Boeing division that produces a helicopter model developed by what company?
answer: Vertol
context: Title: Ridley Park, Pennsylvania
  Passage: Ridley Park is a borough in Delaware County, Pennsylvania, United States.  The population was 7,002 at the 2010 census.  Ridley Park is the home of The Boeing Company's CH-47 Chinook helicopter division.
  Title: Ridley Park station
  Passage: Ridley Park station is a station along the SEPTA Wilmington/Newark Line and Amtrak Northeast Corridor.  Amtrak does not stop here; only SEPTA serves this station.  It is located at Hinckley & Morton Avenues in Ridley Park, PA, and contains a one-story station house similar to that of Media Regional Rail Station built into the embankment next to a platform, as well as a passenger drop-off area at Hinckley Avenue and Lincoln Street.  Another platform also exists on the opposite side of the tracks on Ridley & Morton Avenues.  Access between the two platforms is available from the nearby Ward Street Bridge just west of the station.
  Title: Boeing CH-47 Chinook
  Passage: The Boeing CH-47 Chinook is an American twin-engine, tandem-rotor, heavy-lift helicopter developed by American rotorcraft company Vertol and manufactured by Boeing Vertol (later known as Boeing Rotorcraft Systems).  The CH-47 is among the heaviest lifting Western helicopters.  Its name, "Chinook", is from the Native American Chinook people.
  Title: Supply-chain operations reference
  Passage: Supply-chain operations reference (SCOR) model is a process reference model developed and endorsed by the Supply Chain Council as the cross-industry, standard diagnostic tool for supply chain management, according to the APICS Dictionary (14th ed.) .  The SCOR model describes the business activities associated with satisfying a customer's demand, which include plan, source, make, deliver, and return.  Use of the model includes analyzing the current state of a company's processes and goals, quantifying operational performance, and comparing company performance to benchmark data.  SCOR has developed a set of metrics for supply chain performance, and Supply Chain Council members have formed industry groups to collect best practices information that companies can use to elevate their supply chain models.
  Title: Boeing Rotorcraft Systems
  Passage: Boeing Rotorcraft Systems (formerly Boeing Helicopters and before that Boeing Vertol) is the former name of a US aircraft manufacturer, now known as the Mobility Division of Boeing Military Aircraft, a division of Boeing Defense, Space & Security.  The headquarters and main rotorcraft factory is in Ridley Park, Pennsylvania, a suburb of Philadelphia.  Production of Apache attack helicopters in Mesa, Arizona, formerly part of Rotorcraft Systems, is now under the Global Strike Division of Boeing Military Aircraft.
  Title: Boeing Model 360
  Passage: The Boeing Model 360 was an American experimental medium-lift tandem rotor cargo helicopter developed privately by Boeing to demonstrate advanced helicopter technology.  The aircraft was intended as a technology demonstrator, with no plans to put the type into production, and many of its design features were carried onto other programs including the RAH-66 Comanche and V-22 Osprey.  The sole prototype now resides at the American Helicopter Museum in West Chester, Pennsylvania.
  Title: Wilkie investment model
  Passage: The Wilkie investment model, often just called Wilkie model, is a stochastic asset model developed by A. D. Wilkie that describes the behavior of various economics factors as stochastic time series.  These time series are generated by autoregressive models.  The main factor of the model which influences all asset prices is the consumer price index.  The model is mainly in use for actuarial work and asset liability management.  Because of the stochastic properties of that model it is mainly combined with Monte Carlo methods.
  Title: Ridley School District
  Passage: Ridley School District is a large, suburban public school district in southeastern Delaware County, Pennsylvania in the United States.  It serves the residents of Ridley Township, and the boroughs of Ridley Park and Eddystone.  Ridley School District encompasses approximately 8 square miles.  According to 2000 federal census data, Ridley School District served a resident population of 40,429.  In 2009, the district residents’ per capita income was $21,563, while the median family income was $56,201.  In the Commonwealth, the median family income was $49,501 and the United States median family income was $49,445, in 2010.  Per Ridley School District officials, in the school year 2007–08, Ridley School District provided basic educational services to 5,775 pupils.  The district employed: 443 teachers, 430 full-time and part-time support personnel, and 28 administrators.  Ridley School District received more than $18.8 million in state funding in school year 2007–08.
  Title: Crum Lynne station
  Passage: Crum Lynne station is a station on the SEPTA Wilmington/Newark Line.  Though the station sits along the Northeast Corridor, it is not served by any Amtrak intercity services.  The station, located at Chester Pike (US 13) & West Ridley Avenue in Ridley Park, PA, is actually northeast of the community the station is named for.  It includes a 14-space parking lot, and sheltered platforms on both West Ridley Avenue and Chester Pike.
  Title: DICE model
  Passage: The Dynamic Integrated Climate-Economy model, referred to as the DICE model or Dice model, is a computer-based integrated assessment model developed by William Nordhaus that “integrates in an end-to-end fashion the economics, carbon cycle, climate science, and impacts in a highly aggregated model that allows a weighing of the costs and benefits of taking steps to slow greenhouse warming."  Nordhaus also developed the RICE model (Regional Integrated Climate-Economy model), a variant of the DICE model that was updated and developed alongside the DICE model.  Others who collaborated with Nordhaus to develop the model include David Popp, Zili Yang, Joseph Boyer, and other colleagues.
citations: Boeing CH-47 Chinook Ridley Park, Pennsylvania