1
Fatigue testing
RED BULL AIR RACE PLANE:
EDGE 540 V3
Constructed from a steel tube fuselage,
the Edge 540 has a composite wing
with an unconventional straight-edge,
empennage and fairings
Length: 6.1m
Wingspan: 7.44m
Empty weight: 531kg
Maximum g: ±12g
Climb rate: 3,700 ft/min
Total fuel capacity: 61.5 US gallons
Max full aerobatic airspeed: 265mph
“The aircraft are some of
the most throughly
inspected on the planet”
44 JUNE \\ AEROSPACETESTINGINTERNATIONAL.COM
time has again been put
on the airframe. This
usually lasts around five
hours. At this point the
aircraft is returned to Phase 2.
Jim Reed, Red Bull Air Race’s
technical director says, “The
aircraft’s design and structural
soundness are developed using
known material properties and
verified during the aircraft’s Phase 1
flight test program.
“The continued airworthiness of the
aircraft is verified during each condition
inspection at a minimum and any build
or design shortcomings are identified and
remedied in coordination with the
aircraft manufacturer.
“The aircraft are also inspected for
their airworthiness every time they are
assembled or disassembled. With many
events during a season, plus training
camps and performance flight testing, the
Red Bull Air Race raceplanes are some of
the most thoroughly and frequently
inspected aircraft on the planet.”
The tools and equipment used to test
and inspect the raceplane’s airframe for
stress and fatigue are broadly the same as
those used with commercial aircraft. But
Reed believes the manufacturer’s testing
regime, coupled with the continuous
build-up of flight history within the fleet,
is building a valuable knowledge base and
manufactured with the aim of providing superior
structural performance and reliability for the races.
Stuart Gilmore, Red Bull Air Race’s head of aviation and
sport says, “The Edge is constructed using a steel tube
frame and composite wing, empennage and fairings.
Whereas the MXS’s hull and wings are constructed from
carbon fiber for strength and durability.
“The aircraft are unrivaled in terms of structural
performance limits, +/- 12g for the Edge and +/- 14g for
the MXS. This enables the pilots to pull more g and lets
them turn tighter and faster than in any other form of
aviation or motorsport.”
All of the aircraft use the Textron-Lycoming IO-540
experimental engine, which is supplied bespoke to the
Red Bull Air Race. They use propellers supplied by
Hartzell. In the cockpit is an Electronic Flight
Information System customized to work in very high
dynamics and to provide the pilot with a
range of race-specific information.
“During races the aircraft are pushed to
their extremes in terms of structural
loading, maneuver limitations and engine
performance, and often in demanding
environmental limitations worldwide,”
says Gilmore.
TESTING AND CERTIFICATION
Certification and qualification for the Air
Race’s aircraft is different than with commercial aircraft
because they are in the experimental category.
After an aircraft is built it is inspected by an FAA
representative and flown for an FAA-prescribed period
of time, typically for between 25 and 40 hours during
“Phase 1” testing. This takes place within a previously
defined test area around the aircraft’s home base.
Any aircraft build anomalies or design shortcomings
are remedied during this period of flight test. During
Phase 1, the aircraft will perform all of the maneuvers it
may perform during its lifespan. After passing Phase 1,
the aircraft is free to operate per its operating limitations
during “Phase 2”. However, if a “Major Change” is carried
out on the aircraft during Phase 2, the aircraft is put
back into Phase 1 flight test until a prescribed period of
1 // Technician Adam Maccabe
(left) and tactician Werner Wolfrum
of of the Cashback World Racing
Team (Pete McLeod) before the first
Red Bull Air Race of the season in
Abu Dhabi, UAE.
EXPERIMENTAL AIRCRAFT
The leading place to find professionalism
in terms of both engineering innovation
and testing for sports aircraft is the Red
Bull Air Race. The competition, which has
run since 2003, is unfortunately ending
this year with Red Bull pulling its
involvement. It remains to be seen in
what form, if any, the race will continue.
Regardless the 2019 season is
continuing. Teams in the Red Bull Air
Race use either the Edge 540 or MXS
experimental aerobatic aircraft supplied
by Zivko and MX Aircraft respectively.
Both aircraft are designed and
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