The Antonov An-70 is a Ukrainian transport aircraft - currently in development as of 2012 - intended to replace the aging fleets of An-12 series aircraft in the same role. The An-12 was first introduced in 1959 and saw production reach 1,248 units through a myriad of available variants with use of the type widespread among Soviet allied nations and states. The newer An-70 represents a larger, more powerful airframe with improved heavy-hauling capabilities and range allowing it to fulfill a breath of military- and civilian-minded roles as required. To date, two examples have been completed, the first prototype was lost to accident (along with its crew) while the second prototype was hastily developed from a static testbed. The An-70 is formally categorized as a medium-range transport which allows for intra-theater operations in the military sense.
Development of the An-70 was undertaken before the fall of the Soviet Empire (1991) with Russia and Ukraine taking an equal interest in the program and, thusly, funding was readily available for project growth. After the fall of the Soviet Union, the program suffered through the expected budget cuts and loss of the Russians as a prime supporting force. Nevertheless, progress was made to the point that the initial prototype undertook its first flight on December 16th, 1994. The fall of the Empire ushered in a new world and this included more interaction with the West. As such, the An-70 was deliberately completed with a modular configuration in which its digital suite could conform to NATO standards in the event that the aircraft would serve in foreign nations allied to the West. Over the next few months, the aircraft successfully completed required testing until, on February 10th, 1995, the prototype collided with an Antonov An-72 chase plane used in monitoring the in-flight testing. The An-70 was a complete loss.
Sold on the prospect of the An-70's capabilities, the accident forced the hand of Antonov to modify an existing An-70 static airframe to a fully-flyable prototype for continued development. Within two years, the follow-up prototype was made ready and recorded its own first flight on December 8th, 1996. It is this prototype that is currently being utilized to iron out the remaining test phases of the An-70 program. In January of 2001, the prototype was forced to complete a belly landing after a loss of power (two engines were shut down as well). The airframe was expectedly damaged in the ensuing landing and required months of repairs. Three important test flights were recorded as recently as September 2012 - showcasing the project's rather slow evolution (now spanning over two decades). The internals of the aircraft have been naturally modernized. While Russia does not maintain a direct stake in the program anymore, it is still interested in procuring the An-70 in number for its air force.
The outward design of the An-70 is typically Antonov. The fuselage is of a highly-contoured tubular shape with a short nose cone, forward-set flight deck and low ground clearance. The four engines are set in underwing nacelles (two to a wing) to which each wing is high-mounted along the fuselage sides for the required ground clearance of the engines and their respective propellers. Wings are naturally swept in a conventional fashion to promote maximum aerodynamic airflow. Access to the cargo hold is through a large access area at the rear of the aircraft (promoting a raised empennage base). The empennage is capped by a tall vertical tail fin with fuselage-mounted horizontal tailplanes. The undercarriage consists of a multi-wheeled main unit under amidships as well as a twin-wheeled nose landing gear leg under the flight deck. The typical base crew includes two pilots and a flight engineer as well as one or two other support personnel. There are several rectangular man-sized access doors along the sides of the fuselage.
The An-70 is outfitted with 4 x Progress D-27 series propfan engines of 13,900 horsepower each driving a pair of contra-rotating propellers. Propfan engines are relatively new developments in the world of aviation. The concept was solidified by Hamilton Standard in 1975 and patented in 1979. This advanced system of propulsion basically seeks to combine the performance capabilities of a modern turbofan engine with the economical benefits of a turboprop engine. The end result is an engine that proves not as thirsty as a turbofan with all of the inherent advantages of such a turbofan engine's thrust output. The An-70 benefits from this arrangement and can reach speeds of 485 miles per hour (cruise = 466mph) with a range of 5,000 miles and service ceiling nearing 40,000 feet.
Dimensionally, the An-70 sports a running length of 134 feet with a height of 54 feet and wingspan of 145 feet. She fields a weight of 146,000lbs when empty with a 320,000lb maximum take-off weight specification.
The deep wide body nature of the An-70 design allows it to conform to whatever cargo requirements an operator may need. This includes a cargo payloads of over 100,000lbs or seating for 300 combat troops and gear or up to 200 medical litters with support staff. Additionally, there is a proposed An-70 variant, the "An-112KC", which is intended as an inflight refueler - the cargo hold dedicated to large fuel stores and specialized equipment. The major difference between this variant and the base An-70 is a two-engine configuration (the two inboard engines are retained, the outboard pairing deleted). The outboard pairing is replaced by drag hose equipment as fuel is funneled through each wing, down the hoses and into the awaiting trailing aircraft's exposed fuel receptacle. At one point, the An-122KC was a long-shot contender for the United States Air Force's KC-X next generation inflight refueler program though the Antonov submission was expectedly rejected by the Americans. Another potential program (this by the Germans) pitted the French Airbus 400M (Atlas) against the An-70 in the late 1990s. However, the An-70 lost out on the potentially lucrative deal (largely due to European German politics) and the A400M was selected in its place.
As of this writing (2012), only Ukraine and Russia are the expected prime operators of the An-70 series. They have not reached operational service in the numbers required as of yet though Ukraine is expected to procure at least two early examples while the Russian Air Force is on record for 60 examples, these being delivered through 2020. The Russian Air Force version is slightly modified to suit strict operating requirements. This modernized form was flown as recently as September 27-30 to further testing.
Serial production will be handled by Aviant of Kiev, Ukraine.