Duganair Technologies (DTI) has received US Federal Aviation Administration approval for a version of its Quiet Wing System Stage 3 modification that allows the use of 40° flap settings on the Boeing 727.
DTI says the clearance allows operators to regain the 727's original short field performance capabilities that are normally lost with other hushkitted or re-engined Stage 3 versions which use flap 30° or 25° settings for approach.
Until now, flap 40 has been locked out because it generates the greatest amount of airframe noise and requires higher engine thrust.
The DTI solution uses the 5kt (9km/h) stall speed advantage of the kit's winglets to make up for the increased drag of the flaps.
Source: Flight International
