See these

Gateways provide links to websites about a particular subject area. They are a good way of finding quality information on the Internet, as they only link to sites if they have been evaluated according to a predefined set of quality criteria.
Here are some good examples for aerospace and defence:
AERADE is a collection of quality aerospace and defence resources available on the Internet. It is searchable and browseable by subject area and each resource is described to allow you to evaluate its potential before you visit it.
Intute: Science, Engineering & Technology is a guide to information on the Internet for education and research. The site features a catalogue of quality engineering resources.
Eldis Conflict and Security Resource Guide is a collection of selected key documents, resources and organisations that are available on the Internet. It is searchable and browseable and also contains a conflict blog.

The Internet offers great opportunities for interactive learning.
Let's look at some examples:
Advanced Topics in Aerodynamics an electronic book on aerodynamics, computational fluid dynamics, aeronautics, propulsion systems and related technology. Includes a reading list and a database.
Fundamentals of Aircraft Gas Turbine Engines an online course from the United States Army Aviation Logistics School at Fort Eustis, Virginia.
Tutorial Page of Aerospace Structures (TuPAS) each chapter ends with a 'test your knowledge!' section, with solutions. You need to enter an email address to access the tutorial
First Flight from the Open University. This site provides a simple introduction to key events in the history of flight and links to simple sites which explain the principles of flight.
Electronic Defence Writing provided by the Defence Academy of the UK, this is an interactive tutorial and guide on writing for the UK Ministry of Defence.
Defence for Researchers website provided by the UK Ministry of Defence aimed at researchers looking for UK defence policy and organisation information.
Most professional organisations now have their own website. You can expect to find plenty of information about the activities, publications and the services they offer. It is very unlikely that commercially sensitive information will be made available.
Here are some suggestions of sites you might like to visit:
Society of British Aerospace Companies (SBAC) includes aerospace industry surveys, marketing information and defence industrial strategy resources.
Federal Aviation Administration find US data on airports and traffic, statistics, licences and certificates, regulations and policy and safety.
Air Accidents Investigation Branch access the full text of formal reports, bulletins, progress reports and foreign reports.
European Aviation Safety Agency (EASA) develops common safety and environmental rules at the European level; the site provides a lot of full text regulatory information.
NASA a huge site documenting NASA's activities.
UK Ministry of Defence
Royal United Service Institute (RUSI) news, analysis and publications on defence and security issues. The majority of publications require a subscription.
RAND Corporation research and analysis in the areas of national security, international affairs, terrorism, science and technology. The full text of some of its reports are available free of charge.
Federation of American Scientists research information on strategic security including; the arms trade, biological and chemical weapons, intelligence, nuclear weapons, terrorism, weapon systems and defence policy.

The Internet has led to many types of document from patents and technical reports to journal articles and books being freely available in full text.
Here is a selection that you might find useful for your work or study:
Civil Aviation Authority publications can be searched or browsed; the majority can be viewed as PDF documents.
Boeing Current Market Outlook annually updated, this is Boeing's analysis of the 20 year market forecast for commercial aeroplanes.
AeroSafety World the full text of the Flight Safety Foundation's monthly journal.
esp@cenet searchable full text coverage of European patents, World patents, and those granted by 81 countries.
National Defense University Press free full text books, occasional papers, reports and the journal Joint Force Quarterly produced by the Institute for National Strategic Studies.
DSTAN UK Defence Standardization UK Ministry of Defence standards and standardisation policy.
Defence Analytical Services Agency for UK Defence Statistics the official website for UK defence statistics.
Project Gutenberg free full text electronic books. Contains books on the Art of War by strategists Jomini, Sun Tzu and Machiavelli. The Internet has allowed us to develop new ways of communicating and collaborating with like-minded people across the world.
Let's look at a few examples:
Wikis
A wiki is website that allows visitors to add, remove, edit and change content, often without the need for registration. Here is an example:
CFD-Wiki this wiki aims to create a free computational fluid dynamics reference and is being written by thousands of volunteer authors.
Blogs
A blog is a website usually but not always, maintained by an individual, which gives commentaries and opinions on a particular subject:
Counterterrorism Blog edited by a team of experts, this provides real time information about terrorism cases and policy developments.
ODI Blog from leading development experts at the Overseas Development Institute, ODI. ODI is a leading British think tank on humanitarian issues and international development.
Email discussion lists
Discussion lists use email to distribute information to many Internet users. You can generally visit their website to view messages sent to them, or you can receive messages via email if you subscribe:
Eng-Tips Forums: Aeronautic Engineers includes discussion lists about aircraft engineering, aerodynamic engineering and rotorcraft engineering.
The Internet has allowed us to develop new ways of communicating and collaborating with like-minded people across the world.
Let's look at a few examples:
Wikis
A wiki is website that allows visitors to add, remove, edit and change content, often without the need for registration. Here is an example:
CFD-Wiki this wiki aims to create a free computational fluid dynamics reference and is being written by thousands of volunteer authors.
Blogs
A blog is a website usually but not always, maintained by an individual, which gives commentaries and opinions on a particular subject:
Counterterrorism Blog edited by a team of experts, this provides real time information about terrorism cases and policy developments.
ODI Blog from leading development experts at the Overseas Development Institute, ODI. ODI is a leading British think tank on humanitarian issues and international development.
Email discussion lists
Discussion lists use email to distribute information to many Internet users. You can generally visit their website to view messages sent to them, or you can receive messages via email if you subscribe:
Eng-Tips Forums: Aeronautic Engineers includes discussion lists about aircraft engineering, aerodynamic engineering and rotorcraft engineering.