Farnborough Air Show

Ex-military trainer fights air turbulence

 - November 16, 2006, 10:28 AM

Canada’s National Research Council, NRC Aerospace (Hall 4 Stand C17a), is gathering detailed wake turbulence data with a specially equipped aircraft. NRC’s CT-133, a former military trainer, has just completed instrument test flights. Researchers are focusing on en route wake turbulence behind commercial aircraft, which seem to be more dangerous than expected.

The CT-133’s new air data acquisition system, which collects 600 samples of air data and inertial data per second, flew six times in May for instrumentation development and calibration. In one subsequent flight, it flew behind three commercial aircraft–an Airbus A310, an A319 and a Boeing 767-300. “The data shows high-speed events which may be associated with flying through characteristic funnel vortices within the vortex cores,” Anthony Brown, NRC Aerospace research officer and test pilot, said.

The ongoing study is a follow-on of one that took place in 2004 on a Dassault Falcon 20. At that time, four flights were conducted to fly behind a cruising aircraft at altitudes of 24,000 to 39,000 feet. During those flights, the Falcon experienced aerodynamic g-loading and flight path upsets. Moreover, it underwent an engine flameout when it became entrained by the trailing vortices. These perturbations, which occurred at wake lengths of eight to 13 miles, were well within permissible separations. The Falcon was gathering data at 32 Hz instead of 600 Hz.

NRC research engineers want to clarify the risk. Eventually, they want to substantiate the need for wake vortex turbulence warning devices aboard aircraft.

Another team at NRC has been working on composite material part manufacturing, in a joint effort with Bell Helicopter Textron Canada. NRC Aerospace first developed expertise in manufacturing composite rib chords using resin transfer moulding (RTM). It also developed an adhesive process to bond the rib chords to Bell-manufactured wing skins. The RTM technology was subsequently transferred to Delastek, a company based in Grand-Mère, Québec. The effort paid off as Delastek has obtained a new contract with Bell to make another RTM part, NRC said.

In other news, NRC Aerospace announced that it is supplying test pilots to Diamond Aircraft. They fly the D-Jet very light jet in its development and certification program, from June to September.