A U.K. government commission exploring short- and long-term plans to increase capacity at the country’s airports is now preparing to narrow down its list of submissions, which it made public Wednesday.

Led by Sir Howard Davies, the Airports Commission has received around 120 submissions from varying parties examining a wide range of approaches to building airport capacity. Some 70 of the submissions discuss how airports should make best use of their existing facilities in the short term, while another 50 have proposed long-term ideas for expansion. These include submissions from the owners of Heathrow, Gatwick and Stansted, the three main London airports.

“The proposals that we have received and that we have published today demonstrate imaginative and thoughtful responses to the challenges that the Airports Commission has set, but also show clearly the wide spectrum of views that exist on these issues,” Davies commented.

With a deadline of December to examine the short-term options, Davies said the timetable for comments on the proposals was “tight” and he urged interested parties to “move quickly to winnow down the options” to reduce the uncertainty for communities which may be affected by the changes.

Long-term submissions range from developing a new hub airport in the Thames estuary—an idea suggested by London Mayor Boris Johnson—to several options for new runways at Heathrow, including those submitted by Heathrow Holdings, the owners of the airport, on July 17.

Other submissions include detailed plans for a new airport in Oxfordshire, some 40 mi. to the west of London. Another company is even suggesting what it calls a “hybrid runway” using electromagnetic catapults to launch aircraft at greater speed. The Exhaustless submission claims that its facility would require about half the length and one-fifth the width of a traditional runway, using national grid electricity to assist takeoffs rather than aircraft engine power. Exhaustless says it could further develop the idea with the assistance of £200 million ($310 million) of government funding.

Short-term options are also aimed at reducing noise and pollution, and include suggestions such as restructuring air traffic control systems to allow steeper approaches and climb-out, improved management of approaching flights into London airspace and even a return of slot allocation to government control. Others suggest reducing the number of slots at a constrained Heathrow in order to boost the airport’s resilience in the event of an incident or poor weather, especially since such disruptions usually result in cascading delays which can take hours or days to clear.

Improvements in ground transportation access and reducing the levels of air passenger duty levied on airline passengers will also be considered.

Interested parties have an opportunity to comment on the published documents until September 27. The Airports Commission will report on the short-term options, such as raising existing runway capacity in the next five years, by the end of this year. The body will report on the long-term submissions in the summer of 2015, after the next general election.