Avic's various units stress time and again that one of their biggest challenges is achieving airworthiness certification, including from the CAAC. The basic problem, says Yin Shijun, CAAC deputy director general for airworthiness, is that its engineers do not have enough opportunities to accumulate airworthiness knowledge—though judging from the many projects proposed by Avic companies, that may not be a problem for long.
In conjunction with the June certification of the AC311, Avicopter announced orders for 62 of the single-engine, 2.2-ton aircraft from state enterprises, some linked with the manufacturer. The order figure is remarkably large for the nascent local market, but it is unclear whether the contracts are binding, since “orders” announced by Chinese manufacturers sometimes do not represent binding contracts, especially when the customer is a state firm.
Avicopter sees the AC311 as crucial for its goal of developing a lineup of helicopters in the 1-13-ton range. “According to a domestic and international research and analysis, light helicopters in the 2-ton class account for more than 40% of the civil market and the prospects for their employment are vast,” the company says.
The AC311 can carry six people and has a 900-kg (2,000-lb.) maximum load capacity, 620-km (385-mi.) range, 4-hr. endurance and 242-kph (150-mph.) maximum cruise speed. “The tips of the main rotor blades are elliptical, improving aerodynamic efficiency and reducing aerodynamic noise,” the manufacturer says.
The rotorcraft is similar to and follows the configuration of the Eurocopter AS350 Squirrel, an unauthorized copy of which Avicopter builds as the AC301. The Chinese company says it has independently developed the AC311 using three-dimensional digital techniques and that it has been designed in accordance with international airworthiness standards. Industry officials say Eurocopter did not help. Honeywell has supplied its LTS101-700D-2 engine for the program, but Turbomeca signed an agreement with Avic unit China South Aviation Industry last year to cooperate on the Arriel 2B1A for the AC311.
Despite the unexpectedly late certification, development of the helicopter appears to have been quick and was presumably aided by familiarity with the Squirrel. Preliminary design was completed in 2009 and detail design and engineering development in March 2010. First flight occurred the following November. In 2011, the company said it would be certified by the end of that year, while a third new helicopter, the 1-ton AC310, would be approved by May 2012. The AC310 has yet to achieve certification, though.
Another key challenge for Avicopter is to develop dynamic components that need overhauling only after long intervals. Even in China, buyers cite the need for frequent overhauls of Avicopter aircraft as a reason for buying more expensive imported helicopters. Avicopter says the AC311's dynamic components are designed to be long-lasting, but it gives no figures.
The type is also important because it will provide work for Avicopter's new base at Tianjin. The company, owned jointly by the Tianjin city government and Avic, also encompasses long-established Chinese helicopter plants such as Harbin Aircraft and Changhe Aircraft, in Jingdezehn. The AC311 was originally a project of Changhe.
The plant remains the builder of the AC313, developed from the military Z-8, itself a license-built version of the French Super Frelon. The rotorcraft has already been redesigned once to conform to updated certification standards—the CAAC refused the manufacturer's application to certify the Z-8 for civil use in 2004, the agency's Yin tells International Aviation, the Chinese partner of Aviation Week. The CAAC determined then that an aircraft certified to military standards in China in the 1970s was not a candidate for civil use now. That appears to have sent the design authority, the China Helicopter Research and Development Institute, back to the drawing board to develop the considerably revised AC313.
The aircraft has new main and tail rotors, Pratt & Whitney Canada PT6B-67A turboshafts and a fuselage using composite material. Like other Chinese aircraft, it has high-altitude operations as a key objective, so that it can fly from bases on the Tibet-Qinghai plateau. The CAAC has certified it to operate from fields as high as 4,500 meters (14,800 ft.).