Products required meet strict quality guidelines

The Eurofighter Typhoon is designed and produced using innovative engineering methods to ensure reliable, high combat performance. The very latest technology, manufacturing techniques and materials are used in its production, hence the specification of IGS products.

BAE Systems – a transatlantic defense and aerospace company responsible for the manufacture of the Eurofighter Typhoon – has been sourcing products from Industrial Gas Springs (IGS) for a twin-engine multi-role canard-delta wing strike fighter aircraft since production commenced in 2001.

The Eurofighter Typhoon is designed and produced using innovative engineering methods to ensure reliable, high combat performance. The very latest technology, manufacturing techniques and materials are used in its production, hence the specification of IGS products.

IGS struts are utilized in various locations on the Eurofighter Typhoon aircraft including windscreen, ladder, ladder door, avionic bay door (twin seat only), MDP door and AC external power access door units.

“BAE Systems selected Industrial Gas Springs over competitors as they had a good track record in other applications, although at the time they had no experience in the military aerospace sector,” comments Aidan Lowe, senior systems engineer, Typhoon General Systems. “Our technical team found the company demonstrated a supportive ‘can do’ attitude regarding specific requirements and offered excellent bespoke designs. Another vital aspect was their ability to rapidly prototype new design iterations allowing the team to refine the design solution in a short timescale.”

Quality requirements
Strict guidelines had to be met in specifying materials and equipment for the manufacture of Typhoon and an off the shelf product would not have been good enough.

Strict guidelines had to be met in specifying materials and equipment for the manufacture of Typhoon and an off the shelf product would not have been good enough.

For example, these relatively simple gas struts had to be designed to meet the vigorous requirements of the Typhoon environmental handbook that included the ability to withstand extreme conditions as defined in MIL-STD-810D. The IGS units were manufactured from high-grade materials and tested to the same levels as fully operational flight standard equipment.

“Further differentiators for us when selecting the gas springs were the nil maintenance, effective performance and lightweight properties of the struts. The ability to operate effectively over the entire ground operating temperature range -31°C to +90°C was also vital,” says Lowe. 

“Competitive products required recharging after a period of time and due to low unit cost of the gas struts, there was no requirement to instigate an expensive and complicated maintenance policy/ infrastructure to support them – instead IGS struts could be removed on failure and replaced. However, I am not aware of this being necessary across the in-service fleet in all the time we have been using them.”
 
The ladder unit is used to control the rate of descent of the ladder under its own weight. This application is part of the aircraft’s integral system, allowing the pilot to enter and exit the aircraft without the use of external steps, which would have to withstand extreme environmental conditions. 
 
Applications
The ladder door unit primarily controls the rate of the door opening to prevent damage.

In addition, it maintains the door in an open position (via a sprung-loaded locking shroud). While this was intended for a specific application, once demonstrated, the basic gas strut design was adopted in other areas of the aircraft.

Gas springs assist the raising of the windscreen to reduce risk of injury to operators due to its weight. The IGS implementation allowed this maintenance assist ‘strut’ to be installed on the aircraft with a very low mass penalty.

Once opened, the windscreen can be held in the open position using ground equipment struts, making it more accessible and safer for maintenance personnel.

The AC external power access door unit is a lightweight and simple gas strut that holds the door in the open position and prevents damage that can be caused by the wind catching it.

Gas struts are also used to assist in the opening of the twin seat avionic bay doors and maintain them in the open position for maintenance purposes.
 
The MDP door unit is used to automatically open the access door on release of the catch. It also features internal position notches that allow the door to be opened and set to various angles – allowing it to act as an effective shade against dazzle from sunlight.
 
“Eurofighter Typhoon is now the aircraft of choice for six nations' air forces – Germany, Italy, Spain, United Kingdom, Austria and the Kingdom of Saudi Arabia,” comments James Godbold, field sales manager, Industrial Gas Springs. “We are delighted to be supporting the production of such an exceptional aircraft and believe that our bespoke gas springs have contributed to the safety and high performance of the Typhoon.”