A Harrier Hovers Over the Brooklands Runway!
As several of our club are also members of the GTBA, we agreed to assist in holding a GTBA meeting at Brooklands a week after our club fly-in
Saturday 23rd June, in contrast the week before, was beautifully sunny. The promise of a good days flying (and spectating for the E&DMFC members who volunteered to assist) proved to be true!
The day started, for most, with a stroll down the line to see what had come along.
Wren Turbines LTD, ably represented by Mike Murphy and Simon had a range of goodies on show including their small MW54 turbine kit neatly displayed as shown below. The MW54 comes substantially complete. There are, I gather, a number of holes to drill and tap - the taps also supplied I think - and the engine then requires assembly. Alan Dobson in our club has bought one. When it has flown I'll pester him to write up his experiences on the web site as a number of others are interested in this practical sized engine. Wren also had the components for their new even smaller turbine - a miniature work of art as well as engineering!
A visit from Wren Turbines wouldn't be complete without some of their more exotic hardware. Today they brought along a small turboprop engine which, sadly, wasn't run and a turbine powered helicopter which, happily, did fly
Both the Helicopter and turboprop work on the principle of driving a second shaft and impeller from the gas turbines exhaust gasses. The output from this second shaft is then via a reduction gearbox.
Close Up of the Wren Turboprop |
The MW54 Kit |
The Wren Turbines Helicopter - Flown by Simon.
Close Up of the Hot Bit - note the size of the fuel tank!
A highlight of the day for me wasn't even gas turbine powered! Mike Koskela and a colleague brought along a ducted fan powered Harrier which is shown hovering at the top of this page. The ear defenders in the following pictures were not for show - It was stunningly noisy!
Their design is capable, apparently, of both hovering and forward flight, but does not really have the power to handle the high drag found when transitioning between the two.
Starting the Harrier
Just like the real thing, control in the hover was by attitude jets in the wings and tail using air bled off from the fan. The tail attitude jet mechanism can be seen on the photo at the bottom of the page.
Gyros on all three axes helped to make it controllable (in fact
it appeared to be rock steady in the hover!)
All in all, a very impressive piece of engineering.
Steadying the Harrier before Releasing it
In the Hover
Of course, the discussions inevitably turned to just what could be achieved if it was fitted with a gas turbine engine. The owners pointed out that this would be almost a complete re-engineering project:
One thing everyone was agreed upon was that someone would do it!
