Rutan: “We had an unstable rudder”

by | Jul 28, 2009 | Seradata News | 0 comments

tail zoom.jpg
credit Flight/Alan Radecki / caption: see the notch in the bottom of the rudder

In the photo above the new modification to the WhiteKnight Two prototype Eve’s rudder, a notch cut into the bottom of it, can be seen and above it, glinting in the sun, are the vortex generators previously added. The photo was taken on Monday 27 July during the mothership’s take-off at about 07:37 local time at Mojave air and spaceport as it began its journey to Oshkosh

Scaled Composites founder and chief engineer Burt Rutan told Hyperbola about the latest change to the rudder during a brief chat the aircraft designer had with media after WK2 landed at Wittman regional airport in Oshkosh on Monday 27 July

Rutan explained that originally the only “aerodynamic balance weight,” as he puts it was “on the top” of the rudder and what the company discovered during the first flight, back in December 2008, was that due to that “we had an unstable rudder, it was wandering…it was not an optimum first flight because of that.”

He described the rudder issue as a situation where when the bottom rudder is “shielded” by the landing gear wake its stablising effects are “taken away”. So they decided to add a weight to the bottom of the rudder to increase its stabilising effect – its ability to cope with the wake vortices of the gear essentially

Rutan’s engineers’ solution then was to add that weight to the bottom to ensure that the gear wake did not, in his words, “change the [rudder’s] hinge moments,” and ensure that the rudder forces were good

He finished by saying that that was the “major aerodynamic change we made”

This explanation doesn’t entirely explain the notch, the most recent change, which actually removes some of the mass of the bottom of the rudder, which Rutan says had to be increased, but it does confirm much of what Hyperbola and Flightglobal has written about

Due to technical problems we can’t provide the video of this discussion but hope to in the near future

About Seradata

Seradata produce the renowned SpaceTrak Launch & Satellite Database. Trusted by 100 of the world’s leading Space organisations, SpaceTrak is a fully queryable database used for market analysis, failure/risk assessment, spectrum analysis and space situational awareness (SSA).

For more information go to www.seradata.com/spacetrak

Related Articles

NORAD to track Santa again

As part of the Christmas celebrations, NORAD (North American Aerospace Defence Command) is attempting to track Father Christmas (Santa Claus) Read more

Musk plans a stock offering for SpaceX after successful IPOs in his other firms

Elon Musk, the billionaire Internet, clean energy and rocket entrepreneur who made his initial fortunes in the internet business, most Read more

US military once planned to explode atom bomb on Moon

There has been much tabloid interest in what is a re-release of the revelation originally made by the protect's leader Read more

Opinion: ESA has chosen badly with respect to its launch vehicle development

ESA really had three choices with respect to its launch vehicle development: it could built the Ariane 5 ME which Read more

Musk goes for methane-burning reusable rockets as step to colonise Mars

While speaking at the Royal Aeronautical Society in London in November, the billionaire former Paypal Internet executive, Tesla electric car Read more

No space predictions (or space errors) in Skyfall as James Bond serves his country well (Updated)

While the latest James Bond adventure Skyfall (Director: Sam Mendes) does use a lot of 'Big Brother' surveillance technology to Read more

History: UK gave up impressive space programme including plans to launch UK astronauts “just to get into Europe”

There will be sadness in those "space cadets" in the United Kingdom of all ages as we note that new Read more

Opinion: The madness of imprisoning earthquake scientists may halt satellite seismic forecasting research

To world scientific dismay, on 22 October, seven scientists working at the Italian National Commission for the Forecast and Prevention Read more

Categories

Archives