Tuesday, April 13, 2010











Aviation fuel




Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures, amongst other properties.
Most aviation fuels available for aircraft are kinds of petroleum spirit used in engines with spark plugs i.e. piston engines and Wankel rotaries or fuel for jet turbine engines which is also used in diesel aircraft engines. Alcohol, alcohol mixtures and other alternative fuels may be used experimentally but are not generally available.
Avgas is sold in much lower volumes, but to many more individual aircraft, whereas Jet fuel is sold in high volumes to large aircraft operated typically by airlines, military and large corporate aircraft.




The Convention on International Civil Aviation, which came into effect in 1947, exempted air fuels from tax. Australia and the USA oppose a worldwide levy on aviation fuel, but a number of other countries have expressed interest




























Avgas
Main article: Avgas
Avgas is a high-octane fuel used for aircraft and racing cars. The term Avgas is a portmanteau for aviation gasoline, as distinguished from mogas (motor gasoline), which is the everyday petroleum spirit used in cars. Avgas is typically used in aircraft that use reciprocating or wankel engines.



Jet fuel
Main article: Jet fuel
Jet fuel is a clear to straw colored fuel, based on either an unleaded paraffin oil (Jet A-1), or a naphtha-kerosene blend (Jet B). It is similar to diesel fuel, and can be used in either compression ignition engines or turbine engines.




In use
"Single-point" redirects here. For other uses, see Single point (disambiguation).

Aviation fuel storage tanks
Aviation fuel is often dispensed from a tanker or bowser which is driven up to parked aeroplanes and helicopters. Some airports have pumps similar to filling stations that aircraft must taxi up to. Some airports also have permanent piping to parking areas for large aircraft.
Regardless of the method, aviation fuel is transferred to an aircraft via one of two methods: overwing and underwing. Overwing fuelling is used on smaller planes, helicopters, and all piston-engine aircraft. Overwing fuelling is similar to car fuelling — one or more fuel ports are opened and fuel is pumped in with a conventional pump. Underwing fuelling, also called single-point, is used on larger aircraft and for jet fuel exclusively. For single-point fuelling, a high-pressure hose is attached and fuel is pumped in at 40 PSI and a max of 45 PSI. Anything higher needs to be stopped for it can cause damage to the wings. Since there is only one attachment point, fuel distribution between tanks is either automated or it is controlled from a control panel at the fuelling point or in the cockpit. As well, a dead man's switch is used to control fuel flow.
Because of the danger of confusing the fuel types, a number of precautions are taken to distinguish between AvGas and Jet Fuel beyond clearly marking all containers, vehicles, and piping. AvGas is treated with either a red, green, or blue dye, and is dispensed from nozzles with a diameter of 40 millimetres (49 millimetres in the USA). The aperture on fuel tanks of piston-engined aircraft cannot be greater than 60 millimetres in diameter. Jet Fuel is clear to straw in colour, and is dispensed from a special nozzle called a "J spout" that has a rectangular opening larger than 60 millimetres in diameter so as not to fit into AvGas ports. However, some jet and turbine aircraft, such as some models of the Astar helicopter, have a fuelling port too small for the J spout and thus require a smaller nozzle to be installed in order to be refuelled efficiently.


Energy content
The net energy content for aviation fuels depends on their composition. Some typical values are:[1]
BP Avgas 80, 44.65 MJ/kg, density at 15 C is 690 kg/m3
Kerosene type BP Jet A-1, 43.15 MJ/kg, density at 15 C is 804 kg/m3
Kerosene type BP Jet TS-1, (for lower temperatures) 43.2 MJ/kg, density at 15 C is 787 kg/m3
[edit] Chemical composition
Aviation fuels consist of blends of over a thousand chemicals, primarily Hydrocarbons (paraffins, olefins, naphthenes, and aromatics) as well as additives such as antioxidants and metal deactivators, and impurities. Principal components include n-octane and isooctane. Like other fuels, blends of Aviation fuel used in piston engined aircraft are often described by their Octane rating.
[edit] Safety precautions

A British Airways Airbus A321 being refuelled.
Any fuelling operation can be very dangerous, and aviation fuelling has a number of unique characteristics which must be accommodated. As an aircraft flies through the air, it can accumulate a charge of static electricity. If this is not dissipated before fuelling, an electric arc can occur which may ignite fuel vapours. To prevent this, aircraft are electrically bonded to the fuelling apparatus before fuelling begins, and are not disconnected until fuelling is complete. Some regions require that the aircraft and/or fuel truck be grounded as well.[citation needed]
Aviation fuel can cause severe environmental damage, and all fuelling vehicles must carry equipment to control fuel spills. In addition, fire extinguishers must be present at any fuelling operation, and airport firefighting forces are specially trained and equipped to handle aviation fuel fires and spills. Aviation fuel must be checked daily and before every flight for contaminants such as water or dirt.
Many airlines now require that safety belts be left unfastened should passengers be aboard when refuelling happens.[citation needed]'
Dyes for the fuel are required in some countries:

Friday, January 1, 2010

Boeing - Commercial Airplaines


Commercial Airplanes

Boeing Commercial Airplanes, a business unit of The Boeing Company, is committed to being the leader in commercial aviation by offering airplanes and services that deliver superior design, efficiency and value to customers around the world. There are more than 12,100 Boeing commercial jetliners in service, flying passengers and freight more efficiently than competing models in the market.

Boeing traces its history to aviation pioneer William Boeing who, in 1916, built the company's first airplane, a seaplane for two with a range of 320 nautical miles (515 km). Since then, Boeing has defined the modern jetliner and introduced the twin-aisle cabin, the glass cockpit and countless other innovations.

Today, Boeing Commercial Airplanes offers a family of technologically advanced airplanes, including one that can seat more than 500 and another that boasts the longest range in the world, at more than 9,300 nautical miles (14,966 km).
Meanwhile, Boeing Commercial Airplanes and its global network of suppliers are hard at work building the airplane of tomorrow, a next-generation jet that will set the standard for fuel-efficiency and passenger comfort.
Boeing Commercial Airplanes employs about 65,400 people under the leadership of President and CEO James (Jim) F. Albaugh. The business unit brought in revenues exceeding $28 billion in 2008.
With headquarters in Renton, Wash., Boeing Commercial Airplanes has operations in more than a dozen cities and countries. The business unit comprises five airplane programs, VIP-derivative airplanes, extensive fabrication and assembly facilities, and a global customer support organization.

Saturday, October 3, 2009

windows 7



An Introduction to Windows 7


On October 22nd Microsoft will release the latest version of its flagship Windows operating system; Windows 7. After taking a hit from the much maligned Windows Vista, Microsoft went back to the drawing board and is hoping to win back consumer confidence with its latest release. In this month's Tech Brief we'll give you a preview of Windows 7 and review its new features, explore what versions will be released, and discuss when or if it makes sense for your business to make the switch.


New Features in Windows 7

Whether you’re currently an XP or Vista user, the new features in Windows 7 will be apparent from the start. Here are just of few of the multitude of features present in Windows 7:

Enhanced Desktop – some of the most noticeable changes in Windows 7 take place right on the desk
Snap: In previous versions of Windows when you wanted to compare two windows side-by-side you had to manually resize them. With Snap all you have to do is drag a window to the edge of the screen and it will automatically be resized to fit half the screen.
Improved Show Desktop: Gone is the “show desktop” shortcut in the quick launch section of the task bar. With Windows 7 all you need to do is move your mouse to the lower right of the screen and all the windows will automatically become transparent, allowing you to quickly access any files or applications on the desktop.
Isolating a Window: Have a cluttered desktop and want to minimize all your windows except one? Just grab the top of the active window, shake it, and all the other windows will minimize to the taskbar. Shake it again and they’ll reappear.
Sticky Notes: There’s no need to clutter up the outside of your monitor with sticky-notes any longer. Windows 7 has a built in application which will place virtual sticky notes on your desktop.

HomeGroup – One of the most popular features of Windows 7 is its new HomeGroup feature. With HomeGroup, Windows links computers in a home so they can share photos, music, videos, documents, and printers. Although you can currently do this in Vista in XP, HomeGroup makes it far easier by automatically configuring sharing. With homegroup you can build a digital library from the media across different machines. No longer will you have to try to figure out where your vacation pictures are, just search across HomeGroup and access them from any machine.

Improved Search– Windows 7 introduces smarter searching by instantly showing results as you type, grouping results in categories, and highlighting search terms within snippets of documents to make them easier to scan. In addition to searching networked PCs on HomeGroup, Windows 7 search will also check external hard drives and attached USB storage.

Extended BitLocker Encryption– Vista introduced the BitLocker encryption tool which protected your data if you computer was ever stolen. Windows 7 takes this a step further and now covers removable drives such as external hard drives and USB flash drives by protecting them with a passphrase, smart card, or recovery key.

Improved Built-In Applications – Some of most commonly used built-in applications are getting makeovers in Windows 7. Paint has been updated with a new ribbon-enhanced user interface as well as new brush styles, shapes, and editing options. Wordpad also gets a ribbon and new editing options, in essence making it a stripped-down version of Word 2007. The always popular Calculator gets some new options as well including “lifestyle templates” that help you calculate things such as gas mileage, hourly wages, and mortgage payments.

Faster Boot-Up Time – Despite enhanced applications, increased security, and a slick new desktop, one of the features of Windows 7 that will impress users the most is the faster boot-up time. Tests have shown that well-powered machines can boot Windows 7 in about 15 seconds, with average-powered machines clocking in around 30 seconds.


Editions

Although six versions of Windows 7 will be released, only four will be available for purchase in the United States (the other two will be released to developing markets). These editions are:

Windows 7 Home Premium- The Home Premium is geared towards the average user with the Aero Glass user interface, advanced window navigation, touch screen support, improved media format support, enhancements to Windows Media Center, and the ability to create home networks.

Windows 7 Professional- Geared towards power users and small business professionals, the Professional edition of Windows 7 includes all the features of the Home Premium edition but also provides more security and networking features like the Encrypting File System, advanced network backup, joining managed networks with Domain Join, and support for location-aware printing.

Windows 7 Enterprise - Targeted at the enterprise market segment and only available to organizations which have a Software Assurance Contract with Microsoft, the Enterprise edition will contain all the features of the Professional Edition as well as BitLocker Drive Encryption, support for Multilingual User Interfaces, BranchCatch, and Direct Access.

Windows 7 Home Ultimate - Windows Home Ultimate will include all the same features as the Enterprise edition but will be sold commercially to home users.

Interestingly, the features of each edition of Windows 7 will be stored on your machine when you install it, but you'll only have access to those of the edition you have a license for. If you wish to upgrade to a different edition you can use the Windows Anytime Upgrade to purchase a new license and unlock the additional features.


When Should You Upgrade?

As is the case with any new operating system, unless you absolutely need some of the features offered in Windows 7 there is no need to upgrade to it immediately upon its release. Although it has gone through a thorough and well documented testing process, there still could be undiscovered problems which could cause issues if you implement it across your entire network.

To be on the safe side, it's good to wait at least 6-12 months following its release before you install a new operating system. By that time the initial feedback from the early adopters is in and the first wave of patches and updates typically start to get rolled out.


Final Thoughts...

So far the early reviews of Windows 7 have generally been positive and it looks like Microsoft might have their first widely success operating system since Windows XP was released in 2001. One thing is for certain though, with millions of aging XP systems still out there that will need to be replaced, Windows 7 won’t be going anywhere anytime soon.