On the eve of the 2013 Heli-Expo convention, the US Federal Aviation Administration (FAA) will ask manufacturers whether the basis for the airworthiness standards for part 27 and part 29 helicopters should be re-written.

The FAA will issue the request for comments on 22 February because it has received "some rotorcraft community interest" for increasing the 3,180kg (7,000lb) threshold that defines the part 27 and the more rigorous part 29 standards.

Bell Helicopter has been the most outspoken critic of the current policy after missing its weight target on the Bell 429 light twin. In August, the FAA rejected Bell's request for a 227kg exemption to the part 27 rule to allow the 429 to carry a full payload and all the required safety equipment.

Bell filed an appeal to the FAA's ruling in December, noting its exemption request was approved by more than a dozen airworthiness agencies, including the original 429 certification authority Transport Canada.

But other manfacturers, including AgustaWestland, have objected to Bell's request for a special exemption to existing part 27 standards, arguing that it designed its rival line-up to products assuming they would be required to meet the existing weight threshold.

The FAA, however, has long been considering a change to weight-based aircraft regulations. In recent years, the FAA has proposed changes to the Part 23 general aviation standards to abolish divisions by weight, arguing new technologies, such as fly-by-wire controls, make them irrelevant.

The weight standards for part 27 and part 29 helicopters have not been changed in 18 years.

"More recently we have recognized that the evolution of the part 27 and part 29 rules has not kept pace with technology and the capability of newer rotorcraft," the FAA says.

Source: Flight International