"Some birds aren't meant to be caged, their feathers are just too bright"- Morgan Freeman, Shawshank Redemption. This blog is from one such bird who couldn't be caged by organizations who mandate scripted software testing. Pradeep Soundararajan welcomes you to this blog and wishes you a good time here and even otherwise.

Friday, May 12, 2006

Where can you find the best testers of the world ?

Hi Reader,

This time it is going to be real serious post, no fun and no wild stuff but yet I am sure an inspiring and informative one.

The channel I watch to improve my testing skills are National Geographic and Discovery because it teaches a lot a testing through its Flight Crash Investigations. Whenever a flight crashes....

__ Where can you find the best testers of the world ? __

A Test Pilot is put to test !

Let me take an example of a flight crash which I felt interesting to talk about testing and then tell you why Flight Test Pilots are a cut above all of us doing so called Testing.

Aeroflot Russian International Airlines - Airbus A310-304 crashed on 23rd March 1994 which was heading from Moscow to Hongkong

You can read the story of crash here but let me explain to you after that how the investigation was/is done ( moreover , why you need to be a good tester if you want to be there investigating )

The Analysis -
  1. The Analysis starts with an organization like National Transportation Safety Board ( NTSB ) collecting each and every part of the plane debris and also listening and reading the data collected by the Flight Data Recorder ( Black Box ).
  2. Personnel from NTSB, in the above flight crash consulted a Test Pilot of Airbus to make a further analysis of why the Autopilot feature failed when a manual over-ride was forced on the so called most sophisticated On board computer auto pilot system.
  3. The Test Pilot and NTSB personnel listened to the audio conversations to find that the Pilot had taken his children to cockpit, let them to fly it for sometime while the auto pilot was still taking control of the plane, of course they were shocked but still why should it crash ?

What did that Test Pilot do ?

  1. He carefully noted down the Flight path, distance, speed, weather conditions, changes that the pilot did to the flight controls, auto pilot status, instrumentation details...
  2. He documented his observations and got it verified with NTSB personnel.
  3. He sat on an Airbus A310 simulator and did the same as the pilots from take off to 5 mins before the crash and also carefully did the same actions as the children on the plane's cockpit did.

What did he notice ?

  1. He noticed that when the child tried to over-ride the auto pilot system , the auto pilot failed and more importantly without an indication that it had failed.
  2. He also noticed that before the auto pilot cut off its control , there were some false trajectory projected on the pilot computer's display which further confused the pilot in the real time 2 mins before the crash actually happened.

What did this lead to ?

  1. This lead to some major design changes and an intensive Testing was taken up to ensure there are no more accidents since that crash killed all 75 on-board.
  2. This also lead the companies/certifying communities to release a plane only after testing it as completely as possible.
  3. This lead me to realize that the Test Pilots are the best Testers this world has.

What should you learn from this ? ( if at all you want to learn )

  1. Be it a flight crash or a system crash, investigate it properly.
  2. Take time from your manager if you want to dig out to find what exactly is the problem.
  3. Always try if there is a possibility of adding a data logger for the system you are working and be careful and ensure that atleast the Datalogger is tested properly. ( make it simple yet effective)
  4. Be sure what changes are needed after you notice a crash and wants to get it fixed.

Note : There was a comment in my previous post that "No customer would do wild things with the product when every company releases a user manual from Selva" , now Selva ... for the above incident , dont you think the wild test case would be "Giving the flight control to children and check what is happening in the simulator atleast" would be the most useful wild case ? Also when Taliban hit the Twin Towers with fast moving plane, didnt you see it as a good wild test case to test building strength ?

__ Where can you find the best testers of the world ? __

For the question "Where can you find the best testers of the world ?" the answer is ....Within you my dear readers...

... if you have a narrow vision, you cannot become a best tester whereas you can become one among the passenger who didn't survive. Ask yourself whether you want be inside a crashing plane our outside it , investigating the missing test case.

"Narrow minded mediocre testers, show you the broadest way to hell"


Pradeep Soundararajan



Anonymous said...


Selva said...

Hi Pradeep,

Hmm, never thought about the need for such wild test cases to save lives. Fully agreed.


Chaos And Order - "Satheesh" said...

Hey Pradeep,

This is one more good post from you.. !!!

Just a thought:
How nice it will be if God is a best tester and could predict the behaviour of people..?


Expressions said...

Good one again...where do u get such inspiration?:)

Joy Forever said...

That was a nice post... giving the controls to children would indeed be a good way to test the autopilot in a plane.
But I think hitting the buildings with aeroplanes (or simulating it) to test strength is not a very good idea. The occurrence of such incidents is so rare that the cost of testing will never justify the gain.
Also, point to be noted here, the towers did NOT fall as the result of the impact. they were strong enough to withstand it. However, the terrorrists had deliberately chosen (remember, Osama is a civil engineer) only long-distance flights.
that meant the planes were full of fuel. This fuel burnt for some time and melted the steel girdles in the building which then collapsed. However much testing you do, you can never protect a system against deliberate acts of destruction.

Anonymous said...

I was wondering whether people learn from such accidents and you are a HERO.