Accepts Some Airbus Recommendations, But Not All
Following certification of the A380 with European and US
regulatory agencies, the International Civil Aviation Organization
(ICAO) has released it's final rules regarding safe separation
times and distances to account for the superjumbo's wake
vortex.
Airbus A380 product marketing manager Corrin Higgs told
Engineering News, "We have been doing a lot of testing ourselves
– unprecedented testing with other makes of aircraft,
including the Boeing 747 and 777, as well as other Airbus types,
including the A318 – to check the wake effects of the A380;
we couldn't detect any such effect."
Higgs says Airbus worked with several agencies and independent
experts in developing recommendations for the ICAO to work
from.
"The ICAO accepted some of these recommendations, but not all,"
he said.
ANN reported in September the
result of Airbus testing and recommendations to the ICAO. A
steering group made up of Airbus engineers, ICAO officials and
other experts concluded the A380 is not much different than a
747 in cruise. For aircraft behind the A380 while on approach, the
group recommended six miles for aircraft designated as "heavy," and
eight miles for aircraft designated as "medium" or "light." Airbus
expressed hope that operational experience and further testing
might allow even closer distances
According to Engineering News, the ICAO accepted the steering
group's recommendation for flight during cruise abolishing all
vertical and horizontal distance restrictions other than standard
radar separation; the A380 is to be treated as a 747 for that
phase. It also accepted the group's recommendations for
mimimum following distances during approach, which has some Airbus
officials scratching their heads.
Higgs says, "...a medium A320 has to follow an A380 at a greater
difference than a light Cessna 172 has to follow a 747 – this
is hardly logical; it shows the conservatism of the ICAO’s
approach."
Also of concern for Airbus is the decision to keep the A380's
following distance behind a heavy at four miles. The manufacturer
had hoped the ICAO would follow the steering group's recommendation
and reduce that number to 2.5 miles based on its exhaustive
testing.
This decision dashed Airbus hopes to quell concerns the A380
would foul up traffic flows at high-density airports. Any increase
in following distances or times has a domino effect on all
following traffic. Airbus had hoped a decrease in following
distances for the A380 would mitigate the longer distances other
aircraft must use to follow it.