(CNN)We're flying more than ever.
At any one time, the skies are buzzing with activity -- air traffic measured in Revenue Passenger Kilometers has grown 85% in the past 15 years and Airbus's Global Market Forecast 2015 predicts it will grow 145% by 2034.
The air traveler of today has a wide spread of frequencies, connections and types of service available to them -- but there's one area where choice has narrowed.
Growing consolidation in the aircraft manufacturing industry, driven by its huge capital requirements and massive economies of scale, means we're flying in an increasingly narrower range of airliner types.
While there's much to admire in the most recent aircraft models, those looking for unconventional flying experiences will have to try harder.
Here, in part one of our selection of iconic aircraft today's aviation enthusiast may still be able to fly in, are 20 of our favorite planes from the last 50 years.
de Havilland Canada DHC-6 Twin Otter
First flight: 1965
Often used as a commuter aircraft providing service to small communities, the Twin Otter is a small, solid aircraft that's nevertheless capable of the most incredible landings.
For example, it provides service to the Caribbean island of Saba -- which has the shortest commercial landing strip in the world -- as well as nearby Saint Barts, where pilots must undergo special training before they're permitted to land.
Flying into any of these airports on a DHC-6 is an experience no aviation enthusiast will want to miss.
First flight: 1967
This aircraft is surely familiar to today's frequent flyer. The Boeing 737 is the best-selling airliner of all time.
Some 9,000 of them, which come in many variants, have been built since 1967, making it ubiquitous in all corners of the globe.
Which means you're unlikely to run out of opportunities to fly in a Boeing 737 anytime soon.
As it approaches its 50th anniversary, the Boeing 737 is still going strong: the updated MAX version first flew in January 2016 and already has an order book numbering in the thousands.
First flight: 1969
Few aircraft have achieved the iconic status of the Boeing 747, commonly known as the Jumbo Jet.
Its easily recognizable shape, with two decks on the forward section, helped it gain popularity, but the Jumbo is impressive for other reasons as well.
Its capacity, reach and reliability have made it a "queen of the skies" for over four decades.
Despite the fact that its latest iteration, the Boeing 747-8, hasn't been a huge commercial success and many airlines have started to withdraw earlier versions of the type, there are still so many Jumbos in service that opportunities to fly on a Boeing 747 will be around for decades to come.
Some of the largest operators right now include major airlines such as British Airways and Lufthansa.
First flight: 1971
Although its primary role since entering service with the Soviet Air Force in 1974 has been military transport, the Il-76 is capable of performing a multitude of other roles, from firefighting to passenger service.
The Il-76 is a reliable, solid, four-engine aircraft, able to operate from unpaved, short runways or drop paratroopers or supplies in war zones. It's still in production, although very few of them are in service as civilian airliners.
Short of joining the Russian army, the easiest way to fly on an Il-76 is to go on a North Korean aviation tour or get in touch with Alrosa, a Russian airline that still operates the type.
It's also possible to book zero gravity flights on an Il-76 MDK out of Moscow Star City.
An Il-76 MDK was the setting of a recent music video by band OK Go, known for their viral hits.
First flight (An-72): 1977
First flight (An-74): 1983
This is possibly one of the weirdest-looking aircraft out there. The An-72 and its later version, the An-74, are nicknamed Cheburashka because the engine configuration, with two jet engines mounted on top of the fuselage, makes it look like a popular Soviet cartoon character of the same name.
You can fly on one as part of a tour to polar research station Barneo, built every year near the North Pole by the Russian Geographical Society.
Camp supplies are delivered by An-74 that lands on drifting ice.
Flights are usually operated by Russian airline UTair Cargo.
Several tour operators offer trips to the Barneo polar station, including Polar Cruises.
BAe 146/Avro RJ
First flight (BAe 146): 1981
First flight (Avro RJ): 1992
This British short-haul airliner and its later derivative, the Avro RJ series, feature a very distinctive design, with a high-cantilever wing and four engines underneath it.
Some versions were called Jumbolino because of its four engines and wide cabin, both unusual in a regional airliner.
Although its global fleet has been dwindling since production stopped in 2003, there are still a good number of them around, with Swiss, Brussels Airlines and CityJet being the primary operators.
The most glamorous role for the type, however, has been service with the RAF Royal Squadron.
First flight: 1984
What Airbus is to jets, ATR is to smaller, turboprop aircraft.
In the early 1980s French firm Aerospatiale (now part of Airbus) and Alenia, of Italy, joined forces to design a regional propeller aircraft.
The result was the ATR 42 and, later on, its larger derivative, the ATR 72, both wildly successful in their market niches.
Several airlines fly the ATR 42. Among the largest operators are Aeromar in Mexico and HOP!, Air France's regional subsidiary.
First flight: 1987
If the Boeing 737 is included in this list, the Airbus A320 has to be here too.
Although it first flew in 1987 -- two decades later than its archrival -- the A320 has managed to catch up with the Boeing 737 and even outsell it.
"The A320 was Airbus' response to the Boeing 737 and, with its fly-by-wire and side stick controls, pioneered a new approach to commercial aircraft," said Andy Foster, senior lecturer in Air Transport Management at Cranfield University,
The A320 has spawned a whole family of aircraft, from the smaller A318 and A319 to the stretched A321, which gives airlines plenty of flexibility when planning their fleets without sacrificing the efficiency gained from sharing a common technology.
As is the case with the Boeing 737, the A320 is still an evolving aircraft. Deliveries of its latest iteration, the re-engined A320neo, are just starting.
First flight: 1988
Because of the buzz it generates, you may be forgiven for thinking that the Airbus A380 is the largest aircraft in the world.
In fact, that honor belongs to the Antonov An-225 Mriya.
This six-engined giant was originally designed to carry the Soviet space shuttle on its back but was later converted to airlift cargoes that no other aircraft is capable of carrying -- a job it still performs to this day.
No wonder the only An-225 in existence becomes an immediate sensation with plane-spotters wherever it lands.
The bad news is that getting to fly in it is a challenge. You'll need to convince Ukrainian cargo operator Antonov Airlines to give you a lift.
First flight: 1988
The swan song of the Soviet civilian manufacturing industry, this long-range, four-engined wide-body airliner first flew when the USSR was in its last throes.
It entered service with Aeroflot, the flag carrier of the new Russian state, in 1992.
One of the most notable features for passengers is the cabin's unusually high ceiling.
Although technically still in production, only 29 of them have ever been built.
Aeroflot stored its Il-96 fleet in 2014, leaving Cubana de Aviacion as the sole operator of the type.
First flight: 1991
The A340 is a four-engined long-haul airliner that was designed by Airbus in the 1980s to challenge the American-made models that dominated the market at the time.
Typically flown in configurations ranging from 260 to 350 seats, it competed in a segment between the larger Boeing 747 and the smaller Boeing 767.
It was produced in several versions. The A340-600, for example, is a sight to behold, with its long, slender fuselage, while the A340-500 specialized in super long-haul routes, such as Singapore to New York.
The A340 fell out of favor because twin-engine jets such as the Airbus A330 or the Boeing 777 could do the same job while consuming less fuel.
Many airlines have been phasing them out but there are still more than 200 crisscrossing the globe.
First flight: 1991
This aircraft family has made a big contribution to the popularization of the regional jet concept.
Canadian manufacturer Bombardier has developed different sizes of this stylized aircraft, from the 50-seat to the 100-seat categories.
The planes are marketed as CRJ and include a number that designates their capacity -- CRJ700 for the 70-seater, CRJ900 for the 90-seater and so on.
Hundreds of CRJs are currently flying, with the type being particularly popular among feeder airlines across North America and Europe.
First flight: 1994
Typically carrying between 300 and 450 passengers over long distances, lots of superlatives can be used to describe the Boeing 777 (or Triple Seven as it's popularly known): first commercial airliner to be 100% digitally designed, airliner with the largest turbofan engines, best-selling wide-body airliner.
Boeing is already working on the Boeing 777X, which is meant to enter service in 2020 and will be the world's largest twin-engine jetliner.
The Boeing 777 has been a favorite with many airlines, including British Airways, Emirates and Air France.
First flight: 2002
With its E-Jet family, which includes the E170/175, seating 70 to 80 passengers, and the E190/195, that stretches to the 100 to 120-seat range, Brazilian manufacturer Embraer has grabbed a significant share of the regional jet market, in fierce competition with archrival Bombardier.
Robert W. Mann, a consultant and former airline planning executive, credits the E-Jet with bringing a "mainline look and feel" to the regional airline space at attractive unit costs.
A new generation of the family, the E-Jet E2 is being developed by Embraer and is expected to enter service in 2018.
With over 1,000 E-Jets delivered since 2004, it shouldn't be too difficult to fly on one of them.
First flight (An-148): 2004
First flight (An-158): 2010
Here's another product of the Antonov design bureau that may attract the interest of aviation enthusiasts because of its relative scarcity -- only around 40 have been built so far -- and its unconventional look, somehow reminiscent of the BAe 146.
Yet getting a ride on this regional jet isn't that complicated.
You just need to book a ticket with Rossiya or Angara Airlines of Russia, Cubana de Aviacion or Air Koryo.
First flight: 2005
This huge double-decker airliner has become an icon in its own right.
Despite its size, the A380 is a very quiet and amazingly maneuverable aircraft.
It's certified to carry over 800 passengers, although the typical configuration is for between 450 and 600 seats. The A380 is, thus, the aircraft of choice for high density long-haul routes.
Emirates is, by far, the largest operator of the type, but to see all routes flown by the A380 you can check out the Airbus website.
Sukhoi Superjet 100
First flight: 2008
The Superjet represents Russia's comeback to the civilian aircraft-making scene.
Manufactured in partnership with Alenia of Italy and several other foreign aerospace firms, the Superjet is a clean-sheet design that targets the growing regional jet market for aircraft with fewer than 110 seats.
There are quite a few ways to fly in the Superjet.
While most are operated by Russian airlines, Aeroflot being the largest, it's possible to fly the type in other regions, for example, with Interjet in Mexico, Sky Aviation in Indonesia and, soon, Cityjet in Western Europe.
First flight: 2009
The Boeing 787 Dreamliner represents a significant milestone in the history of aircraft manufacturing, being the first to make extensive use of composite materials.
By making the aircraft lighter, Boeing was able to offer airlines a long-haul aircraft efficient enough to connect many secondary markets directly and profitably, bypassing congested hubs.
You can see how many Dreamliners are up in the air at any one time and which airlines are flying them on Boeing's Dreamliner tracker.
Airbus A350 XWB
First flight: 2013
Launched in response to the initial success of the Boeing 787, the A350 is a wide-body long-haul airliner that seats between 280 and 400 passengers.
It therefore occupies the market space immediately below the larger A380 and is in direct competition with Boeing's Triple Seven and Dreamliner models.
Nearly 800 have been ordered so far and deliveries have been taking place since 2015.
It's already entered service with Qatar Airways, Vietnam Airlines, Finnair, TAM and Singapore Airlines, with many more airlines due to receive theirs soon.
First flight (CS100): 2013
First flight (CS300): 2015
This family of aircraft, which includes the CS100 and CS300 models, is Bombardier's attempt to break into the medium-sized airliner market (between 110 and 160 seats) and compete head-on with Boeing and Airbus.
You'll have to wait a few months to fly it commercially.
Entry into service is planned for July 2016, with Swiss Global Air Lines being the launch carrier and airBaltic following suit before the end of the year.