Andrew Doyle/MUNICH
DaimlerChrysler Aerospace (Dasa) has revealed details of its technical evaluation of the Antonov An-70 medium transport, which is being studied as an alternative to the Airbus Military Company's A400M (formerly Future Large Aircraft) by Germany, France, Italy and Spain.
The manufacturer concluded it would be technically possible to "westernise" the Ukrainian aircraft to meet the seven-country European Staff Requirement (ESR) for a common tactical airlifter, the assistant managing director of Dasa's MiG fighter upgrade subsidiary MAPS, Claus Frey, told the Munich branch of the Royal Aeronautical Society on 11 February.
Frey and his team were charged by the German Government with evaluating the planned production-standard An-70 against the technical requirements of the ESR.The aircraft meets the ESR in terms of payload/range and airfield performance with its existing ZMKB Progress D-27 propfan engines, says Frey, although a full-authority digital engine control and engine monitoring system would have to be introduced. Work to extend the hot-section life of the D-27 would also be required.
"The biggest change for a westernised version of the An-70 is the need for an absolutely new avionics system and cockpit," says Frey. The cockpit stations for the flight engineer, navigator and radio operator would have to be replaced by a single "tactical operator" position.
Although the two An-70 prototypes (the first of which was lost in an accident) have flown more than 100 test flights, Dasa's assessment of the type's stability and control performance was based on just 25-30 of the test flights carried out to date, says Frey. He admits that the amount of information available was limited, but points out that the flight test data confirms the results of extensive wind tunnel testing.
The procedures used to develop the aircraft's digital flight control system are "comparable to western programmes", says Frey. While a significant part of the An-70's flight envelope has yet to be explored, the risk of any required modifications to the aircraft's configuration is considered "minor".
So far 102 flights of an anticipated 1,800hr flight test programme for Russian certification have been carried out, but Dasa estimates a 3,000hr test programme would be required to achieve western approval. This would include 2,000hr for basic certification, followed by work on areas such as low-level flying and parachute drops.
"The harmonisation of certification procedures is necessary, but the An-70 would be certifiable against Joint Aviation Requirements (JAR)-25," Frey says.
Among other issues identified by Dasa, the "flotation" capability of the undercarriage on soft surfaces falls short of the ESR, and Dasa suggests lengthening the axles of each wheel-pair to solve this problem. An in-flight refuelling capability and a floor-integrated cargo handling system are also required to meet the ESR.
A series of bids to meet various European airlifter requirements have recently been submitted by Airbus, Antonov, Boeing and Lockheed Martin.
Source: Flight International
