Bob Kuykendall
May 23rd 07, 06:04 PM
Earlier, "Brian Glick" > wrote:
>
> The foam gets water logged...
Quite, quite unlikely.
The foam used in sandwich core composite construction is closed-cell
foam that does not admit water beyond the first layer of cells. And
even that layer is sealed by the sandwich skin so that very little if
any core foam is exposed.
History suggests that the majority of such water landings in composite
ships resulted in floating gliders.
As to why the ASW27 Brian cites sank, I consider it somewhat of an
anomaly. It might be that the later composite ships with more carbon
and thinner core foam are not buoyant; especially if they are
ballasted or if the ballast valves are left open on landing, if they
are heavily equipped (i.e. motorgliders or turbos), or if the pilot
leaves the parachute in the cockpit before going ashore.
Thanks, Bob K.
http://www.hpaircraft.com
>
> The foam gets water logged...
Quite, quite unlikely.
The foam used in sandwich core composite construction is closed-cell
foam that does not admit water beyond the first layer of cells. And
even that layer is sealed by the sandwich skin so that very little if
any core foam is exposed.
History suggests that the majority of such water landings in composite
ships resulted in floating gliders.
As to why the ASW27 Brian cites sank, I consider it somewhat of an
anomaly. It might be that the later composite ships with more carbon
and thinner core foam are not buoyant; especially if they are
ballasted or if the ballast valves are left open on landing, if they
are heavily equipped (i.e. motorgliders or turbos), or if the pilot
leaves the parachute in the cockpit before going ashore.
Thanks, Bob K.
http://www.hpaircraft.com