SA Flyer - May 2009 - Glen Dell – Upgrades his plane to Win - Guy Leitch

For the 2009 Red Bull Air Racing series, there are only six races, so it’s vital to do well from the first race.

Throughout 2008 Glen had been planning his performance upgrade. His first step was to order a new Lycoming engine from Ly-Con in the USA. To extract the maximum aerodynamic improvements for his Edge 540 he enlisted the aid of Brazil’s Professor Paulo Iscold.

By the time Professor Iscold arrived in South Africa early in January he had already designed most of the components. The list of aerodynamic refinements is long but, according to all calculations, a significant performance improvement will be realized. The upgrades include: new wing tips, a lowered canopy and turtle deck, a new cowling, new wheel spats and wheel leg and root fairings.

Glen’s team consists of Leon Joubert (Team Technician), Justus Venter (Team Coordinator), Chris Hattingh (Production Manager – Global Composite Solutions), and Arthur Smith (Composite Specialist), Professor Paulo Iscold (Aerodynamics Designer – Federal University of Minas Gerais – Brazil).

ENGINE AND PROPELLER
A key to success this year is the new engine and prop combination. The Engine is a brand new blueprinted Lycoming AEIO-540 built by Ly-Con. The new engine is significantly more powerful and weighs several pounds less than the stock specification. Although the documented output is 327 + HP, the actual output is much higher – and will probably stay a secret!

The new propeller for this engine is a composite Hartzell 3-blade specifically designed for the Red Bull Air Race. Most race pilots fly with this exact model.

THE WINGTIPS
This is another key upgrade. The idea behind the wingtips is to reduce drag and increase G capability. Less drag makes higher speeds and faster acceleration possible. The new wingtips also allow increased roll acceleration. All the required flutter analysis and load test were successfully completed.

THE COWLING
The new cowling reduces overall frontal area. The cooling inlets and outlets are optimized for cooling drag reduction. Unfortunately the first race is in Abu Dhabi where temperatures are about 20 degrees Celsius higher than in South Africa. This poses special challenges which put the oil temperature at risk and a shortage of testing time may delay its installation. Cylinder head and exhaust gas temperatures are however perfect.

CANOPY AND TURTLE DECK
The new canopy design was supplied courtesy of last year’s World Champion, Hannes Arch. The height of the canopy was reduced and so the turtle deck had to be cut down as well. This means that the turtle deck now has a smooth rounded curve which makes the aircraft more visually appealing. The new lines are emphasized by the bold new paint scheme.

THE WHEEL SPATS AND WHEEL LEG FAIRINGS
There is much more to wheel spat design than meets the eye. The new wheel spats have a natural laminar flow design of 60% (i.e. the maximum thickness of the airfoil profile is at 60%) and the attachment of these spats to the wheels are critical. As a result the spats have been optimized for straight and level flight at an angle of incidence of 2 degrees. The new gear leg fairings match the profiles of the fuselage and the wheel spats and once again help with the overall reduction in drag.

WING ROOT FAIRINGS
These have been designed, manufactured and fitted Arthur smith and replace the old heavy rubber strips. With a smooth rounded wing root, overall drag is reduced.

A HOLISTIC APPROACH
The aircraft rebuild project was all about targeted weight and drag reduction with no quality comprise. The total drag reduction is considerable and will play a major part at this year’s races.

No stone was left unturned to decrease the weight of the aircraft. The Red Bull Air Race Part E requirements limits weight to 540kg and every gram more than that is a performance penalty. A light aircraft with a strong engine is essential to success.

When asked what the most important factors are to success, Glen reckons the balance between man and machine is, “40% aircraft, 40% pilot and 20% luck!”