Don't forget the limitations imposed by FS 2004 Multiplayer...

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As Ozzy mentioned. only using the default aeroplanes work, (and not always reliably even then!), or alternatively every flyer has to agree beforehand to use the same aeroplanes, either default, or downloaded...!!
The way that FSX Multiplayer works may be more suitable for this type of endeavour, in that all the flyers
different aeroplanes are always visible.... apparrently...

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Remember, for example, in FS 2004 if it is decided to organise a Microlight Fly-in, none of the craft will be visible in their true form because they are not part of the Default list of FS 2004 aircraft!
They will all appear as Cessna 172's...

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The idea is fine, but flawed by the limitations of FS 2004 Multiplayer..

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Cheers all...

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Paul...G-BPLF....

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Win 8.1 64-bit. DX11. Advent Tower. Intel i7-3770 3.9 GHz 8-core. 8 GB System RAM. AMD Radeon HD 7700 1GB RAM. DVD ROM. 2 Terra Byte SATA Hard Drive. Philips 17" LCD Monitor. Saitek Cyborg X Fly-5 Joystick. ...and a Briggs and Stratton Petrol Lawn Mower.