June 2010
Self Improvement, Wisdom, Professionalism, Inspirational Stories, Positivity, Leadership, Management, Stress, Optimism and Peace, Productivity.


Pivot Table Tricks to Make You a Star

Posted on January 27th, 2010 in Featured , Learn Excel - 21 comments


Pivot  Table Tricks ExcelWe, data junkies, love pivot tables. We think pivot tables are solution for everything (except for may be global warming and that broken espresso machine down stairs).
Today, we are going to learn 5 awesome pivot table tricks that will make you a star.
Click on these links to jump to tips.
Drill down pivot tables | Change Summary from Total | Slice & Dice Pivots | Difference from last month | Calculated Fields in Pivots
(If you are not familiar with basic pivot tables, you should check out this excellent pivot tables tutorial)

1. Drill down on your Pivots with Double click

This is by far the simplest and most powerful pivot table trick I have learned. Whenever you want to see the values behind a pivot field just double click on it.
Lets say, the sales of Lawrence in Middle region  is $5,908 and you want to know which items contribute for this total, when you double click on the number $5,908 excel will show a list of all the records that add up to this number, neatly arranged in a new worksheet. Instant drill down.
See this magical trick in action.
Drill  Down Pivot Tables

2. Summarize Pivot Data by "Average" or some other formula

By default excel summarizes pivot data by "sum" or "count" depending on data type. But often you may want to change this to say "average", to answer questions like "what is the average sales per product". To do this, just right click on pivot table values (not on row or column headings) and select "summarize data by" and select "Average" option.
Summarize By Average Pivots
(In excel 2003, you have to do this from "field settings" menu option)

3. Slice & Dice your Pivot Tables with Grace

Re-arranging pivot table layouts is as easy as shuffling a pack of cards. Just drag and drop the fields from row areas to column areas (vice-a-versa) and you have the pivot table rearranged.
Here is a simple screencast explaining the secret
Slice And Dice Pivot Report

4. Show difference from last month (or year) without bending backwards

We all know that you can show monthly summaries using Pivots. But what if your boss wants you to also include "difference from previous month"  as well? Now, dont rush back to source data and add new columns. Here is the right trick to make you a star.
  • Just use field settings to tell excel how you want the data to be summarized.
  • Right click on any pivot table value, select "value field settings"
  • Now go to "Show value as tab" and Change "Normal" to "Difference from"
  • Select "Previous" from Base-item area. Leave Base field as-is.
Now, your pivot is updated to show difference from previous column.
Difference From Last Month Pivot Report
Bonus: There are quite a few value field settings you can mess with. Go play and discover something fun. :)

5. Add new dimensions to your Pivot Reports with Calculated Fields

Let us say you have both "sale" and "profit" values in your source data. Now, your boss wants to know "profit %" in the pivot report (defined as Profit/Sales). You need not add any extra columns in your source data, instead you can define custom calculated fields with ease and use them in pivot reports.
  • To do this, Go to pivot table options ribbon, select "formulas" > "calculated field"
  • Now define a new calculated field by giving it a name and some meaningful formula.
  • Make sure you adjust the cell formatting so that output of calculation can be displayed (for eg. change number to % format)
(In excel 2003, the formula option is available from Pivot menu in toolbar)
See this tip in action:
Calculated Fields Pivot Tables

What is your favorite pivot table trick?


JunaidTahir
http://mjunaidtahir.blogspot.com/
http://ae.linkedin.com/in/mjunaidtahir

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The Great Donkey Theorem
 

 


 

 

Equation 1 

Human = eat + sleep + work + enjoy 
Donkey = eat + sleep 

Therefore: 
Human = Donkey + Work + enjoy 

Therefore: 
Human-enjoy = Donkey + Work 

In other words, 
A Human that doesn't know how to enjoy = Donkey that works. 


++++++++++++ +++++++++ +++++++++ +++++++++ +++++++++ ++ ++ 

Equation 2 


Man = eat + sleep + earn money 
Donkey = eat + sleep 

Therefore: 
Man = Donkey + earn money 

Therefore: 
Man-earn money = Donkey 

In other words 
Man who doesn't earn money = Donkey 

++++++++++++ +++++++++ +++++++++ +++++++++ +++++++++ + 

Equation 3 


Woman= eat + sleep + spend 
Donkey = eat + sleep 

Therefore: 
Woman = Donkey + spend 
Woman - spend = Donkey 

In other words, 
Woman who doesn't spend = Donkey 

++++++++++++ +++++++++ +++++++++ +++++++++ +++++++++ + 


To Conclude: 
>From Equation 2 and Equation 3 

Man who doesn't earn money = Woman who doesn't spend 

So Man earns money not to let woman become a donkey! 
And a woman spends not to let the man become a donkey! 

So, We have: 
Man + Woman = Donkey + earn money + Donkey + Spend money 

Therefore from postulates 1 and 2, we can conclude 


Man + Woman = 2 Donkeys that live happily together!

 

 



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The 'Four LOOKS'

'LOOK' Back and get Experience..!

'LOOK' Forward and see Hope..!

'LOOK' Around and find Reality..!

'LOOK' Within and find confidence





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A Small but highly useful article by Paula Klee Parish

The below rules need to be remembered by all of us while writing emails....professional and personal!
 

There is a communication crisis occurring today. With the proliferation of text-speak and 140 character sentences, we have forgotten how to effectively communicate. For example, what happened to the professionally written email to a customer or even a colleague? For that matter, what happened to grammar and proper usage?

 
With the advent of hand held electronic devices and text messaging, we have somehow allowed ourselves to fall into the trap of "everything for the sake of speed and convenience." So what happens now? Do we shorten our speech so that we speak in abbreviated words and abbreviated sentences?
 
I thought this might be a good time to reaffirm some of the basic rules with the focus on writing and responding to E-Mails

To begin with a summary…Treat e-mails the same as a business letter. Include a short greeting [hi], even if the message has been going back and forth for several rounds. Remind employees that, while it is fine to use emotional icons in their personal e-mails, these are far too cute to be included in business e-mails.

 
I am starting with my own pet-peeve:
 
1. Read before sending and fix your mistakes.
 
Every time you send a message with errors in spelling, punctuation, or grammar you are letting people know that you do not care about the quality of your work or the reputation of your organization.
 
2. Ignore the mistakes of others.
 
It is petty to criticize mistakes such as incorrect spelling. It can cause an embarrassing situation and/or invite nasty reprisals. Fix the errors before replying or sending the e-mail on to others. Be kind.
 
3. Do not e-mail when angry or upset.
 
Take ten and breathe. Remember, perception is subjective. What you perceive may not be what the sender intended. Calm down before responding to a message that offends you.
 
What you send cannot be taken pack, so wait and then be polite. Avoid accusations and using abusive language. Words such as: please, sorry, and thank you project a positive and productive image.
 
4. Expect your message to go public.
 
Private e-mail is an oxymoron. It's like saying one is a little bit pregnant; it does not happen. Security administrators have access to it, and recipients might send it to others. Keep that in mind when you are writing. Pretend that every e-mail is a memo that might be posted on a bulletin board in the hall of your organization.
  
5. Send request in time.
 
When it is necessary to request help or support, or introduce a problem, do not wait until the last minute. Last minute messages frustrate and alienate people. E-mail can take minutes or hours to arrive, so plan ahead.
 
6. Respond immediately or make a note to respond soon.
 
Respond to e-mail as you should to phone messages. If you need time to think about your response or time to gather information, let the sender know that you will get back to them.

 

7. Be Brief.

 
E-mails have basically replaced memos and letters, but they are getting longer and longer. Use bullets where you can. Keep your message short and to the point. We receive many e-mails each day; we respond faster when messages are brief.
 
8. If the message must be long, start with requests and guide lines.
 
We tend to read the first few lines of a message thoroughly and browse through the rest. If you require a quick response, say so in the first few lines. If your message is long, start with a summary paragraph.
 
9. Write a good subject line.
 
Let the receiver know what to expect. A good subject line flags interest, and it makes it easier to find days later. The subject line is the true reason you are sending the e-mail.
 
10. Type like you would a letter.
 
E-mails can be difficult to read. Use short paragraphs and always put blank lines between paragraphs. Avoid all capital letters [SHOUT], emotional icons [  :) ], unique abbreviations [lol], and excessive punctuation [!!!!]. Yes, I am guilty here too.

 

      When should we not use e-mail?

      Either make a phone call of visit in person to talk when:

  1. Emotions are high
  2. The message is delicate
  3. Too many misunderstanding are occurring

__._,

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Ever since China's first 3D newspaper was released, back in April, the public has been asking for more. And they're about to get it, as a limited number of the Hangzhou-based Daily Business editions are about to be issued, in 3D format.
British tabloid, The Sun, has announced it will be launching the first 3D newspaper, on June 5, a few days before the Soccer World Cup kicks off, in n attempt to raise awareness to the 3D broadcast of the sports event, by Sky News. Sorry guys, but you're almost two months late, in China, 3D newspapers are already yesterday's news.

 

 

 

 

 

 

 


 

 


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Determination and Patience

Determination is the strength that will enable you to pass the barrier of useless thoughts in order to create positive thoughts and to be successful in whatever you wish. It comes from within and its partner is patience. Patience teaches you not to push but rather to wait and appreciate the game of life instead, knowing that nothing remains the same, and everything will change at some point.


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Programmer to Team Leader:

"We can't do this proposed project. **CAN NOT**. It will involve a major
design change and no one in our team knows the design of this legacy system.
And above that, nobody in our company knows the language in which this
application has been written. So even if somebody wants to work on it, they
can't. If you ask my personal opinion, the company should never take these
type of projects."

 Team Leader to Project Manager :

"This project will involve a design change. Currently, we don't have any
staff that has experience in this type of work. Also, the language is
unfamiliar to us, so we will have to arrange for some training if we take
this project. In my personal opinion, we are not ready to take on a project
of this nature."

Project Manager to 1st Level Manager :

"This project involves a design change in the system and we don't have much
experience in that area. Also, not many people in our company are
appropriately trained for it. In my personal opinion, we might be able to do
the project but we would need more time than usual to complete it."

1st Level Manager to Senior Level Manager :

"This project involves design re-engineering. We have some people who have
worked in this area and others who know the implementation language. So they
can train other people. In my personal opinion we should take this project,
but with caution."

 Senior Level Manager to CEO :

"This project will demonstrate to the industry our capabilities in
remodeling the design of a complete legacy system. We have all the necessary
skills and people to execute this project successfully. Some people have
already given in house training in this area to other staff members. In my
personal opinion, we should not let this project slip by us under any
circumstances."

 CEO to Client :

"This is the type of project in which our company specializes. We have
executed many projects of the same nature for many large clients. Trust me
when I say that we are the most competent firm in the industry for doing
this kind of work. It is my personal opinion that we can execute this
project successfully and well within the given time frame.

Hatzz off to the creater ;)




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1-SpacePilot Pro 3D navigation mouse
3Dconnexions SpacePilot Pro 3D mouse was nearly is a dream mouse. This 3D mouse is designed to provide freedom in design work and for comfort in handling and 3D applications. The mouse design is also gelled perfect for advanced MCAD Navigation that's well supported by the intelligent function keys. The game-pad styled mice with soft-coated wrist rest, houses fully customizable five dual-function keys that access both primary and secondary functions. SpacePilot Pro adorns a color LCD to display function key assignments with direct access to MS Outlook mail, calendar and other task list, allowing the user to use the important applications and gain important information without many hassles. To be made available with compatible drivers for Windows XP, Vista, Linux and Solaris 8 and 10, the anti-Mac SpacePilot Pro would ship for $499.

The Orbita Mouse is the world's first wireless 3-axis mouse for a wide variety of chores, and a unique cylindrical design with a jog wheel for horizontal scrolling. With a resolution of 800DPI, the Orbita is a fully integrated intuitive and ergonomic control center. Using its ability to rotate from left to right to scroll, instead of the vertical up and down scrolling, the wireless cylindrical mouse is an incredible make, touting of 2.4GHz zero lag wireless communication. Given the quick and precise scrolling capability, with zoom and low cost jog, the mouse can help you scroll through documents more easily and in an improved manner. Integrated with a compass for 3D movement, it will control both 3 dimensional and general applications along with providing media editing facility. Embedded with Mac and PC compatibility, the Orbita comes tagged with a USB charging base.

3-Steampunk Paradox Mouse
Paradox Mouse is a piece of genus from Daniel Pon. Groomed in the magnificence of brass, bolts, gears, wood and vintage typewriter keys, there isn't really anything that lags in its contribution to supplement to the making of a mouse, intended to go along the modded keyboard and monitor. Shaped to mimic the a real mouse itself, Pon has carved the Paradox Mouse in LEDs with extra peripherals like a mouse skull, spine and shoulder blades, but all so efficiently embedded. Pon has a perfect custom mouse pad made to go with the insane mouse.

4-AirMouse
To lure the vulnerable consumers and other who're fed up with the orthodox styled mice and the trouble associated with them, a Canadian firm, Deanmark Ltd has introduced the AirMouse – that can be worn like a glove. Equipped with optical tracking laser, that last for a week on single charge, the mouse has been clinically tested to work by aligning itself with the user's hand and wrist ligaments to keep the hand in a neutral position, thus minimizing the excessive force required to function by the ordinary styled mice. Because, the AirMouse makes hand movement more easy and swift, it also enhances upon the user's mousing speed and accuracy.

Cyborg R.A.T. gaming mouse is created by the geniuses at Mad Catz. Uniform in design but realistically outrageous in general with all those buttons and knobs all around its body, the sleek and black mice would be made available for our gaming desires sometime this spring. In case the gamer in you is confused with how comfy these are, it'll be fitting to snatch words from the maker's mouth and give to you as "most comfortable gaming mice you'll ever use." The Mad Catz USB powered Cyborg R.A.T. gaming mouse offering 3200 dpi laser, to 5600 dpi laser fully adjustable, programmable technology would be available on four versions ranging from $50 to $130.


6-Optical Mouse with LEDs
This USB mouse with integrated LEDs and fan to cool your palm is the only mouse flaunting its own remote. The mouse offers standard 800pdi optical tracking, but to its novelty, with the remote to input messages of up to 12 characters it enjoys the basic diversity of sorts. If you are one of those busy souls who spend hours at the PC, the best feature of the mouse that you'll cherish would be the fans over the LEDs that'll keep blowing out air to keep your busy hand sweat-free, all for about $21 in Japan. 7-Ultra Slim Mouse Christened the MA-BTCARD, this ultra slim optical mouse is no burden to your mobility, it wouldn't occupy any space in your already cramped laptop bag. MA-BTCARD fits perfectly into the TypeII PC card slot in your notebook. The mouse is Bluetooth enabled, doing away with the wire ruckus, charging too isn't a snag – it can be charged in the PC slot itself and costs only $107.

8-Apple's Mighty Mouse
Apple's Mighty Mouse turns its back on the traditional scroll wheel and is equipped with a scroll area that gives the user control of the cursor movements merely by the change of the hand's posture. Minus buttons, the new mouse results in lesser hand strain for the user and has the added bonus of appearing translucent, sleek and stylish. The Mighty Mouse can provide audio feedback to the user concerning the rate at which the finger is moved over the active area. The area may also have haptic-like feedback features, which allow users to define the boundary of active surface area.

9-USB Wireless Finger Mouse
At the first look the wireless mouse that would fit onto the finger and had to be operated with the thumb brought apprehensions of straining the finger muscles, but the manufacturers of this wireless finger mouse assures us that this mouse is ergonomically designed. The USB Wireless Finger Mouse will reduce the desk space, anyway with laptops becoming thinner and touchscreen tablet PCs making their appearances the problem of space has already been solved. Nonetheless, a Wireless Finger Mouse could come handy with a continued usage time of 14 hours, 170 days of stand by time and capability of working from a 15meters distance. It has a built-in lithium-ion battery that takes 2 hours to be recharged. If you can support a 25g mouse on your finger that is heavier than any large ring on your finger then you can go for this mouse.

10-Mouser mouse
A unification of constructive technology and valuable construction, this computer mouse attracts the geek considering the multifaceted, comfortable and pleasant build we have in offer in this near original instrument. Designed by Andrey Chirkov, the mouser mouse is made in two materials with different qualities and texture. The pliable wood gives the mouse an artist retro look while the hard metallic frame used for the buttons gets it back to the modern manifestation. The buttons seems to be hanging in mid air, as the flowing form of the wood only helps the metal finish rest on the skillful body, while the original construction of the rolling wheel adds to the finishing details of the splendor


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Amazon.com
amazon

This logo doesn't seem to hide much at first sight, but it gives you a little insight in the philosophy behind the brand. First of all, the yellow swoosh looks like a smile: Amazon.com want to have the best customer satisfaction. The swoosh also connects the letters a and z, meaning that this store has everything from a to z.

Fedex

fedex
This is probably one of the best known logos with a hidden meaning. If you look closely, you'll see an arrow that's formed by the letters E and x. This arrow symbolizes speed and precision, two major selling points of this company.
Continental

continental
Continental is a manufacturer of tyres. You could actually see this in their logo, because the first two letters create a 3-dimensional tyre.
Toblerone
toblerone
Toblerone is a chocolate-company from Bern, Switzerland. Bern is sometimes called 'The City Of Bears'. They have incorporated this idea in the Toblerone logo, because if you look closely, you'll see the silhouette of a bear.
Baskin Robins

baskin-robbins
The old logo of Baskin Robbins had the number 31 with an arc above it. The new logo took this idea to the next level. The pink parts of the BR still form the number 31, a reference to the 31 flavours.
Sony Vaio

vaio
Sony Vaio is a well known brand of laptops. But did you know that the name Vaio logo also had a hidden meaning? Well, the first two letters represent the basic analogue signal. The last two letters look like a 1 and 0, representing the digital signal.
Carrefour

carrefour
Carrefour is one of the biggest European retailers, and it's also French for "crossroads". The logo symbolizes this word via two opposite arrows. They also added the first letter of the name, because if you look closely you'll see the letter C in the negative space between the two arrows.
Unilever
unilever
Unilever is one of the biggest producers of food, beverages, cleaning agents and personal care products. They produce a huge amount of different products and they wanted to reflect this in their logo. Each part of the logo has a meaning. For example: the heart represents love, care and health - feeling good, a bird is a symbol of freedom. Relief from daily chores – getting more out of life.
Formula 1
formula1
At first, this logo might not make much sense. But if you look closely, you'll see the number 1 in the negative space between the F and the red stripes. I also love how this logo communicates a feeling of speed.
Sun Microsystems
sunmicrosystems
The Sun logo is one of the most famous ambigrams in the world. You can read the brand name in every direction; both horizontally and vertically. This logo was designed by professor Vaughan Pratt of the Stanford University.
NBC

nbc
The NBC (National Broadcasting Company) is one of the biggest American television networks. I think most of you have already seen the peacock in this logo. The peacock has 6 different tail feathers, referring to the six divisions at the time that this logo was created. The peacock's head is flipped to the right to suggest it was looking forward, not back.
 

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Airliner Black Boxes

 


 
untitled 2.bmp
 The "black box" is a generic term for two recording devices carried aboard commercial airliners. The Flight Data Recorder (FDR) records a variety of parameters related to the operation and flight characteristics of the plane. The Cockpit Voice Recorder (CVR) records the voices of the flight crew, engine noise, and any other sounds in the cockpit. All large commercial airliners and certain varieties of smaller commercial, corporate, and private aircraft are required by law to carry one or both of these boxes, which generally cost between $10,000 and $15,000 apiece. The data these devices provide is often invaluable to experts investigating the events leading up to an accident. The recovery of the boxes is one of the highest priorities in any mishap investigation, second only to locating survivors or recovering the remains of victims. FDR information is also often used to study other aviation safety issues, engine performance, and to identify potential maintenance issues.
 



cockpit-voice-recorder.jpg

Example of a Cockpit Voice Recorder (CVR)



Despite the nickname "black box," the FDR and CVR are actually painted a bright high-visibility orange with white reflecting strips to make them easier to spot at a crash scene. The meaning of the term black box itself is somewhat unclear. Some suggest it refers to the black charring that occurs in a post-crash fire while others believe the color black is a reference to the deaths often associated with an accident investigation. The design of modern black boxes is regulated by a group called the International Civil Aviation Organization (ICAO). The ICAO determines what information the black boxes must record, over what length of time it is saved, and how survivable the boxes must be. The ICAO delegates much of this responsibility to the European Organisation for Civil Aviation Equipment (EUROCAE) that maintains a document called the Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems.
Black boxes first began to appear in the 1950s and became mandatory during the 1960s. These early devices used magnetic tape for data storage, much like that used in a tape recorder. As the tape is pulled over an electromagnetic head, sound or numerical data is recorded on the medium. Analog black boxes using magnetic tape are still present aboard many planes, but these recording devices are no longer manufactured. Newer recorders instead use solid-state memory boards, called a Crash Survivable Memory Unit (CSMU), that record data in a digital format. Instead of the moving parts present in older recorders, solid-state devices use stacked arrays of memory chips similar to a USB memory stick. The lack of moving parts eases maintenance while reducing the chance of a critical component breaking in a crash. Solid-state recorders can also save considerably more data than older magnetic tape devices and are more resistant to shock, vibration, and moisture.



fdr-egyptair990.jpg

Magnetic tape from within the FDR of EgyptAir 990 that crashed in 1999



Whatever the medium used to record the data, the purpose of the black boxes is to collect information from various sensors aboard an aircraft. The Cockpit Voice Recorder, for example, saves sounds from microphones located on the flight deck. An area microphone is typically placed in the overhead instrument panel between the pilots, and an additional microphone is located in the headset of each member of the flight crew. These microphones pick up conversations between the flight crew, engine noises, audible warning alarms, landing gear sounds, clicks from moving switches, and any other noises like pops or thuds that might occur in the cockpit. The CVR also records communications with Air Traffic Control, automated radio weather briefings, and conversations between the pilots and ground or cabin crew. These sounds often allow investigators to determine the time of key events and system failures.
Analog magnetic tape recorders are required to store four audio channels for at least 30 minutes while digital solid-state devices are required to record for two hours. Both types use continuous recording such that older information is written over as new data is collected beyond the maximum time limit.



fdr-plots.jpg

Sample data recovered from a Flight Data Recorder



The Flight Data Recorder collects data from a number of sensors to monitor information like accelerations, airspeed, altitude, heading, attitudes, cockpit control positions, thermometers, engine gauges, fuel flow, control surface positions, autopilot status, switch positions, and a variety of other parameters. Most parameters are recorded a few times per second but some FDRs can record bursts of data at higher frequencies when inputs are changing rapidly.
The data measured by the different sensors is collected by the Flight Data Acquisition Unit (FDAU). This device is typically located in an equipment bay at the front of the aircraft beneath the flight deck. The FDAU assembles the desired information in the proper format and passes it on to the FDR at the rear of the plane for recording. The Federal Aviation Administration (FAA) required the FDR to record between 11 and 29 parameters, depending on aircraft size, up to 2002 but now requires saving a minimum of 88 sets of data. Analog FDRs can save a maximum of around 100 variables while digital recorders are often capable of collecting over 1,000 parameters over the course of 25 hours.



recorder-locations.jpg

Diagram of data flow to aircraft black boxes



Power for the black boxes is provided by electrical generators connected to the engines. The generators on most large airliners produce a standard output of 115 volt, 400 hertz AC power while some smaller planes instead generate 28 volt DC power. Black boxes are typically designed to use only AC or DC power but not either one. Recorders built for compatibility with the AC power supplies on larger planes cannot be used on small DC-powered aircraft. In the event of engine failure, larger aircraft are also equipped with emergency backup power sources like the auxiliary power generator and ram air turbine to continue operating the black boxes. In addition, the ICAO is considering making a battery mandatory on solid-state recorders to provide an independent power supply in the event of a complete power failure aboard the plane.
A common misconception states that the black boxes are "indestructible." No manmade device is indestructible, and no material has ever been developed that cannot be destroyed under severe enough conditions. The black boxes are instead designed to be highly survivable in a crash. In many of the worst aviation accidents, the only devices to survive in working order are the Crash Survivable Memory Units (CSMUs) in the black boxes. The remainder of the recorders, including the external case and other internal components, are often heavily damaged.



black-box-interior.jpg

Interior cut-away of a black box design



The CSMU, however, is contained within a very compact cylindrical or rectangular box designed to safeguard the data within against extreme conditions. The box is composed of three layers to provide different types of protection to the recording medium. The outermost shell is a case made of hardened steel or titanium designed to survive intense impact and pressure damage. The second layer is an insulation box while the third is a thermal block to protect against severe fire and heat. Together, these three layered cases allow the FDR and CVR to survive in all but the most extreme crash conditions.
Current regulations require the black boxes to survive an impact of 3,400 g's for up to 6.5 milliseconds. This rapid deceleration is equivalent to slowing from a speed of 310 miles per hour (500 km/h) to a complete stop in a distance of just 18 inches (45 cm). This requirement is tested by firing the CSMU from an air cannon to demonstrate the device can withstand an impact force at least 3,400 times its own weight. The black boxes must also survive a penetration test during which a steel pin dropped from a height of 10 ft (3 m) impacts the CSMU at its most vulnerable point with a force of 500 pounds (2,225 N). In addition, a static crush test is conducted to demonstrate that all sides of the CSMU can withstand a pressure of 5,000 pounds per square inch (350 kg/cm�) for five minutes. The fire resistance of the CSMU is further tested by exposing it to a temperature of 2,000�F (1,100�C) for up to an hour. The device is also required to survive after lying in smoldering wreckage for ten hours at a temperature of 500�F (260�C).



locator-beacon.jpg

Underwater Locator Beacon on a black box



Other requirements specify survivability limits when immersed in liquids. The CSMU must endure the water pressure found at an ocean depth of 20,000 ft (6,100 m), and a deep-sea submersion test is conducted for 24 hours. Another saltwater submersion test lasting 30 days demonstrates both the survivability of the CSMU and the function of an Underwater Locator Beacon (ULB), or "pinger," that emits an ultrasonic signal once a second when immersed in water. These signals can be transmitted as deep 14,000 ft (4,270 m) and are detectable by sonar to help locate the recorders. A final series of tests includes submerging the CSMU in various fluids like jet fuel and fire extinguishing chemicals to verify the device can withstand the corrosive effects of such liquids.
Upon completion of the testing, the black boxes are disassembled and the CSMU boards are extracted. The boards are then reassembled in a new case and attached to a readout system to verify that the pre-recorded data written to the device can still be read and processed.
Another factor important to the survivability of the black boxes is their installation in the tail of the aircraft. The exact location often varies depending on the plane, but the FDR and CVR are usually placed near the galley, in the aft cargo hold, or in the tail cone. The recorders are stored in the tail since this is usually the last part of the aircraft to impact in an accident. The entire front portion of the plane acts like a crush zone that helps to decelerate the tail more slowly. This effect reduces the shock experienced by the recorders and helps to cushion the devices to improve their chances of surviving the crash.



fdr-united93.jpg

Flight Data Recorder recovered from United Airlines 93 in 2001



Once the black boxes have been located following an accident, they are typically taken into custody by an aviation safety agency for analysis. In the United States, responsibility for investigating most air accidents belongs to the National Transportation Safety Board (NTSB). Many countries lacking the capability to analyze black boxes also send their recorders to the computer labs of the NTSB or some of the better-equipped investigative organizations in Western nations. Care must be taken in recovering and transporting the recorders so that no further damage is done to the devices that might prevent important data from being extracted.
Upon receipt of the recorders, the NTSB uses a series of computer and audio equipment to process and analyze any information that can be recovered. The data is translated into formats readily usable by investigators and is usually critical in identifying the probable cause(s) of the accident. This process may take many weeks or months depending on the condition of the black boxes and the level of processing required to make sense of the data. Outside experts are also often consulted to help analyze and interpret the data.



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Animation image created using FDR data from American Airlines 587 that crashed in 2001



Flight Data Recorder information is typically presented in the form of graphs or animations used to understand instrument readings, flight characteristics, and the performance of the aircraft during its final moments. Cockpit Voice Recorder information is usually more sensitive and laws strictly regulate how it is handled. A committee including representatives of the NTSB, FAA, the airline, the manufacturers of the aircraft and engines, and the pilots union is responsible for preparing a transcript of the CVR's contents. This transcript is painstakingly created using air traffic control logs and sound spectrum analysis software to provide exact timing. Although the transcript can be released to the public, only select and pertinent portions of the actual audio recording are made public due to privacy concerns.
Flight recorder design has improved considerably since the devices were first introduced in the 1950s. However, no recording device is perfect. Black boxes are sometimes never found or too badly damaged to recover some or all of the data from a crash. To reduce the likelihood of damage or loss, some more recent designs are self-ejecting and use the energy of impact to separate themselves from the aircraft. Loss of electrical power is also a common event in aviation accicents, such as Swissair Flight 111 when the black boxes were inoperative for the last six minutes of flight due to aircraft power failure. Several safety organizations have recommended providing the recorders with a backup battery to operate the devices for up to ten minutes if power is interrupted.



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Cockpit Voice Recorder recovered from United Airlines 93 in 2001



Another recommendation is to add a second independent set of recorders on a separate electrical bus to insure redundancy in the event of a system failure. The additional recorders would be located as close to the cockpit as possible while the existing black boxes remain in the tail to reduce the likelihood of a single failure incapacitating both sets. Accident investigators have also argued for the installation of a third black box to record cockpit video. Though pilots have so far resisted the move because of privacy issues, video data would be useful to better understand pilot actions in the moments leading up to an accident.
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