Aeronautics Research 2002 - 2006 projects

Improving Aircraft Safety and Security
DRESS
Distributed and Redundant
Electro-mechanical nose
wheel Steering System
Background
An aeroplane is steered on the ground by
orienting the nose landing gear wheels.
On all commercial aeroplanes today,
these wheels are oriented by a hydraulically
actuated steering system. On automatic
landings, during the automatic
braking sequence, the steering system
is commanded by the fl ight control computers
in order to keep the aircraft on the
runway’s centre line. When reaching the
end of the runway, pilots have to regain
manual control of the aeroplane as there
is no automatic ground guidance on taxiways.
Even the automatic steering during the
automatic braking sequence is of limited
use since, due to the low safety level of
the current steering systems, airworthiness
regulations impose a minimum visibility
that would allow the pilots to be able
to safely regain manual control in case of
steering system malfunction and keep the
aeroplane on the runway by using manual
differential braking.
In lower visibility conditions, all landings,
ground manoeuvres and take-offs have to
be interrupted.
Continuous efforts are being made by the
aeroplane manufacturers and the air traffi
c management sector to fully automate
the approach, landing, ground manoeuvres
and take-off in order to increase the
air transport system effi ciency by being
able to operate the airports in true ‘all
weather’ conditions.
The weak link today is the current nose
landing gear steering system, which must
be improved in terms of safety so that it
is able to be integrated into the future
fully automated ground guidance system,
allowing the expected air transport effi -
ciency levels to be reached.
Objectives
The project objective is, therefore, to
gradually increase the reliability and
safety levels of the aeroplane ground
steering system.
Single-aisle aircraft
nose landing gear
195