Test flights with extensive manoeuvres are planned for the evaluation of the
performance boundaries of the future European military transport aircraft A
400 M. A method of choice to terminate deep stalled flight conditions is to
integrate a rocket motor into the tail of the test airplane and to fire it to
level the airplane, thus mitigating the risk of a loss of the airplane. For
the test flights, one rocket motor with ignition and safety device and one spare
had to be delivered.
The key requirements for the DSRS are safety of operation, resistance against
lightning strikes, the thrust level and the time of operation. The most critical
issue was the extremely short time frame of 15 months allocated for development,
qualification and delivery. While BC assumed the the design authority for the
motor and the ignition and safety device, the interfaces were defined jointly
by BC and Airbus.
The tight time schedule imposed
- specific technical approaches (use of commercially and readily available
materials pre-products and parts)
- the use of well-known components (propellant with bonding system, igniter
and safety-and delay device)
- proven design concepts out of the centre of Bayern-Chemie´s widespanning
matrix of experience
- and careful project and technical management
With no time for a development loop, six motors were manufactured in one lot:
two for static firings, two for the qualification and two for delivery. BC´s
data base and modelling skills allowed the correct prediction of the mechanical
and thermal loads. A special challenge was to adapt a missile ignition safety
device design to the EMC philosophy of the aircraft industry. Intensive
The selected concept, together with skilled design capabilities and careful
risk management secured a straightforward successful development without major
design loops. At one point, BC´s shaker capacity was booked and the sister
company TDW supported the qualification testing with their shaker.
In the end, the DSRS was indeed ready for delivery within 15 months from the
signature of the contract. This is an excellent example for an extremely short
time to market. It was achieved because concept and design met the right combination
between unorthodox approaches and wide use of related experience. Tight requirements
were limited to the indispensable minimum, following the rules:
- performance parameters drive the schedule
- design to cost needs requirements to cost
The requirements on parameters of secondary importance were left as wide as
possible which allowed to use available components and to limit modifications
to a minimum.
