I NDUSTRI Pesawat Nusantara Terbang (IPTN) has abandoned plans to use its second N250 regional prototype as an airworthiness-certification vehicle in a bid to avoid any further postponement of the aircraft's maiden flight.

The Indonesian manufacturer had intended using prototype PA2 to begin certification, but has concluded that it could not conform with changes being enforced by the US Federal Aviation Administration without entailing further delays. The aircraft's first flight has already been pushed back by seven months. It is now officially re-scheduled for 12 December.

IPTN had earlier been told by the FAA that there were insufficient component and material documents to accept the PA2 as a certification aircraft. It has demanded that Indonesia's Directorate General of Air Communications instruct IPTN to bring its vendor record system in line with international standards (Flight International, 9-15 October).

Industry sources say that the problem affected considerably more than the earlier reported 200 line items installed on the PA2. To ensure total conformity with FAA stipulations would have required re-assembly of many of the aircraft's components and systems and would have further delayed its first flight.

The PA2 is the first production-size 64- to 68-seat N250-100 to be built, and IPTN still hopes to use the aircraft to gain limited certification credit from the FAA. The aircraft will be the first N250 to be fitted with uprated Allison 2,980kW (4,000shp) AE2100C turboprops. Officials suggest that it could be used for system troubleshooting.

IPTN's flight-test certification programme had originally called for the PA2 to be used to validate the N250-100's controllability and manoeuvrability, trim, stability, stall characteristics, powerplant, hydraulic and electrical power performance, fly-by-wire flight-control and automatic flight-control system, and extreme hot and cold climate performance.

The bulk of certification work will now fall on the PA3 and PA4, which are due to join the flight- test programme in the second and third quarters of 1997. With IPTN required to complete more 1,200h of certification flight testing, the addition of a fifth N250-100 prototype is being considered.

Source: Flight International