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Weer-radar

Het weer in Lybie wordt niet gekenmerkt door heftige onweersbuien. Natuurlijk komen ze wel voor, zelfs in de woestijn. Maar het is toch een uitzondering dat ze er zijn. De andere wwersverschijnselen zijn er ook; harde wind, vorst en zelfs ochtendmist. Veel van de Twin-Otters die in Lybie rondvlogen waen niet uitgerust om in ijscondities rond te vliegen. Ze hadden bijvoorbeeld geen deicing boots.

De witte vleugel voorrand verraden de afwezigheid van deicing boots - die gemaakt zijn van zwart rubber - op deze Twin-Otter.

A deicing boot is a device installed on aircraft surfaces to permit a mechanical deicing in flight. Such boots are generally installed on the leading edges of wings and control surfaces (e.g. horizontal and vertical stabilizer) as these areas are most likely to accumulate ice and any contamination could severely affect the aircraft's performance.

Design

A deicing boot consists of a thick rubber membrane that is installed over the surface. As atmospheric icing occurs and ice builds up, a pneumatic system inflates the boot with compressed air. This expansion in size cracks any ice that has accumulated, and this ice is then blown away by the airflow. The boots are then deflated to return the wing or surface to its optimal shape.

They are an older technology and have some drawbacks. Boots need to be replaced frequently (on the order of 2–3 years) and proper care for deicing boots is critical. Any holes in the boot will create air leaks that will decrease, if not eliminate, any effect that the boots may have. As such, boots must be carefully inspected before each flight and any holes or cuts must be patched.

Deicing boots have undoubtedly saved many lives and have permitted flight into known icing conditions, but they are unable to handle extremely severe icing. In these cases, ice can accumulate faster than the boots can shed it, or ice can accumulate on non-booted surfaces to the point where it disrupts airflow enough to cause a dangerous loss of lift or control.

Invention and use

Deicing boots were invented by the B.F. Goodrich Corporation in 1923 in Akron, Ohio. Goodrich in its quest to invent and develop icing boots, built one of the largest indoor facilities to replicate bad weather and icing on aircraft wings in Akron. [1]

Deicing boots are most commonly seen on medium-sized airliners and utility aircraft. Larger airliners and military jets tend to use heating systems that are installed underneath the wing's leading edge, keeping it constantly warm and preventing ice from forming.