some useful lsites

aircraftcompare.com

contentzone.eurocontrol.int/aircraftperformance

ourairports.com

airliners.net

airlines-inform.com

http://www.skybrary.aero/

http://planes.findthebest.com/

http://www.the-blueprints.com/

http://www.greatcirclemapper.net/

http://flightaware.com/

http://www.b737.org.uk/techspecsdetailed.htm

http://m-selig.ae.illinois.edu/ads/aircraft.html

http://www.airlineroutemaps.com/

Weather

1- http://www.holiday-weather.com/averages/

2- http://www.weatherbase.com/weather/

3- http://www.esrl.noaa.gov/psd/data/gridded/data.20thC_ReanV2.pressure.mm.html

4- http://iridl.ldeo.columbia.edu/maproom/Global/Atm_Circulation/Sea_Level_Pres.html?T=Oct%202013

airports

http://www.worldaerodata.com/