DD-Foam - energy-absorbing, viscoelastic seat foam for gliders. It combines high seating comfort with the ability to absorb short-term impact loads.

Due to its energy-absorbing properties, DD-Foam is THE protection for the spine during hard landings and crashes. Energy-absorbing foams are used, for example, as seat cushions in ejection seats.

The memory effect also significantly increases seating comfort. The foam ensures even pressure distribution and pressure reduction, adapts to the body, and allows for long flights without a feeling of pressure. It is used in the medical field when it comes to gentle positioning of the body.

Foams of this type have been known in gliding for decades and are offered under various product and trade names depending on the manufacturer and supplier, such as Dynafoam, ImpactFoam, Protect Foam, ...

• Material: viscoelastic PU
• Structure: open-cell
• Density: firm 5 lb/ft³ ≈ 80.1 kg/m³
• Memory effect: yes
• Energy-absorbing: yes

When seated in the half-reclining position that most modern gliders have the 13mm DD-Foam already reduces forces on the spine dramatically, for an upright seating position 25mm thickness is recommended. The absorption of short-time peak forces is of highest importance.

After a study was presented the RAF made it compulsory for all their gliding groups to use DD-Foam in their gliders.

New results from long years of using the 23mm cushins on the ASK-13 of Lasham gliding centre:
1) The cushions are not only helpful in case of a crash, flight instructors confirm to clearly suffer from less problems with back pain.
2) Follow-up tests in Farnborough of more than 5 rough years being used in instruction flights (some cushions for more than 1000 takeoffs) showed, that those cushions (most of them used carelessly and exposed to sun or rain) hadn't changed measureably.

The use of DD-Foam cushions in EVERY aircraft, even when they are thin, makes sense in every case and when someone is to small he should ONLY use DD-Foam cushions (or if applicable an absolutely stiff underlay below DD-Foam) to sit on.

More information:

• Article in Gliding Safety [more]
• Article by Tony Segal [more]
• OSTIV report [more]
• Article in Free-Flight [more]

We supply DD-Foam in raw cut, usually a few millimeters larger than specified, making it ideal for custom fitting to your needs.