Jim Watt wrote:

:On Fri, 27 Feb 2004 16:44:24 -0000, "Sarah Hotdesking"
wrote:
:
:I received this today:-
:
:There are still people in this company who think we weigh aircraft to find
:out how much they weigh, not to calculate stresses. Of course we need to
:know how much the thing weighs. How are we ever going to know how many
:Thrust Pixies we need to get the thing off the ground if we don't know the
:weight? Or should that be "Lift Demons"? Pixies have largely fallen into
:disrepute - something about Bernoulli not being representative in unbounded
:conditions and cause and effect being transposed in the Newtonian model.
:
:In fact the use of Lift Demons on civil aircraft programmes is generally not
:that good an idea. The Demon binding contract tends to specify payment in
:blood or souls. This is readily achievable with aircraft of military
:function, but frowned upon in civilian circles as they may attempt to
:acquire payment outside of the terms of their binding contract. Lift Demons
:are not used on Elf bombers. We don't talk about Lift Pixies too often as it
:seems to upset the self-loading cargo.
:
:Pixies require payment in cakes, flowers or nice thoughts. These are readily
:sourced either from the in-flight catering, or provided cost-free by the
:passengers. Clearly this would not work well within an operational military
:environment. Air force cooking is not renowned for the "light and fluffy
:texture" that Thrust Pixies demand, the availability of flowers might be
:problematic in desert operations, and nice thoughts may also be hard to find
:during times of active operations.
:
:There is also a scalability issue. While one rampant Lift Demon would have
:few problems supporting a fighter aircraft (particularly if there is an
:immediate prospect of blood), it'll struggle to achieve level controlled
:flight of a 560tonne Airbus A380. Use of more than one Lift Demon on the
:same flight vehicle is contra-indicated (they squabble and eat each other).
:Communities of Thrust Pixies can be encouraged to work together on the same
:aircraft by the provision of advanced technologies such as Lemon fondant
:icing, variegated tulips or in-flight romantic comedies.
:
:Ryanair once requested Leprachauns be installed in place of Lift Pixies, but
:leprechauns have a mission statement which indicates their desire for
:monetary gain, and their willingness to search all over the world for it.
:This makes Lift Leprechauns expensive to keep (gold vs lemon fondant icing),
:and makes it difficult to establish a regular route network as the Lift
:Leprechauns don't like to continuously visit the same locations. By law,
:aircraft also have to have a full complement of In-Flight Gremlins, but
:these are generally not a problem unless you feed the Wingtip Vortex Faeries
:after midnight.
:
:Are Harriers equipped with sirens?

No. That sound is the diving alarm....