Aircraft Hydraulic systems design flaw?

I have been watching again one of my favorite television series, aircrash investigation and been thinking that big airliners have clear design flaw.

What is a common with Japan Airlines 123, (,   United Airlines 232(sioux city crash) and one UPS plane that was show down with anti aircraft missile, but survived the crash landing.

All of these planes lost all the hydraulic systems. Usually these planes have three separate hydraulic systems, so they should be very reliable. The problem is that the same system goes through the whole plane. So if you get hit by missile to the wing tip, you loose all the three systems and it also takes out the tail control. So plane has only engine power to steer and to control altitude.

The flight 232 had engine explosion that destroyed all the three hydraulic systems. When I first heard about this, I started to think why they had all of those lines side by side? Maybe it would be a good idea to route one system in totally different path?

Later I watched the UPS flight from Irak, it got hit by anti aircraft handheld missile strike. Both engines survived, but wing tip was hit severely. They bleed out all the hydraulic fluids from all three systems, but were able to land the plane by using engine power to steer and control the plane and luckily all three crew members survived. This crash was 12 years after Sioux city crash. Nothing was done. They had developed Engine control software that could land this kind of plane that had lost hydraulic systems, but FAA concluded that it’s too rare event. So the system is not needed.

And in some point I understand FAA,  as if the UPS plane would have been hit to the engine, it would have not survived(if hydraulics and one engine would have been lost). What I don’t understand why the lost of wing tip looses the tail control? Even cars have brake systems, that if you loose one front brake, you are not going to bleed out the whole system, it’s just going to loose one front and one rear wheel, and other pair is going to stay working. Motorcycles have separate front and rear brakes. Polaris ATV’s have brakes that brake all the wheels from the handle, but you can still use separate rear brake that has separate reservoir for the rear brake.

My point is, that If you loose the wing tip, you cannot loose all the systems as all the systems should not go to the wing. One system should be reserved as tail backup only. And one for the wing backup, if the tail is lost.

Or just install valves to the wing mounting area, that can be shut down when the wing starts to bleed fluid. After all wing damage can occur easily in engine problem or in missile attach. As the missile seeks heat and engines are today mostly positioned to the wings.

Japan Airlines had collapse in the rear fuselage and part of the tail was lost and it took out all the control hydraulics. Again it should have lost only the tail, not the wing controls.

It’s too bad that so many lives were lost in these incidents. And the cause is design. A Triple proof system that cannot fail. But it still fails as they don’t take into account that there could be major damage to the plane and you cannot loose all the controls at the same time.

I have heard that some of the future planes don’t anymore use this kind of hydraulic, they could use electro hydraulic systems, that each flap and control surface has system that contains the pump, fluid and hydraulic piston and it’s controlled by electricity.  In this kind of system the lost of all the controls is almost impossible. It would take total electric blackout, and electrics are usually easier to backup compared to hydraulic systems.

So next time flying, watch the wing and think it holds three different blood systems and the planes is going to bleed to death if those lines are damaged. Three times backup, but side by side and all the fluid is lost in relatively small damage.



Lean Traffic

Lean Road? Lean traffic. Is it possible to use lean production methods for traffic? I think it is. After all even if we take couple of main principles from lean method and think how they work in traffic.

Lets start with the original seven muda are:(taken from wikipedia)

  • Transport (moving products that are not actually required to perform the processing)
  • Inventory (all components, work in progress and finished product not being processed)
  • Motion (people or equipment moving or walking more than is required to perform the processing)
  • Waiting (waiting for the next production step)
  • Overproduction (production ahead of demand)
  • Over Processing (resulting from poor tool or product design creating activity)
  • Defects (the effort involved in inspecting for and fixing defects)

1.Transport: This is what most of the traffic is, moving products or people that should not be moved in the first place:), I think movements like taking a DVD back to the rental store is pure waste as I have already watched it. Also picking it up is unnecessary as today it can be downloaded from the network services renting movies.

2.Inventory: Maybe having three cars, when you only use one? Or having a F40 ferrari for shopping. That is too much inventory. The less cars or ways of transports you have in inventory, the less cost there is. Every car needs a insurance and maintenance, so the cost builds up, it’s best to invest in one good car then to 5 poor cars.

3. Moving:  moving is fun, like motorcycling. Sometimes people that are very green and environmentally aware are saying that using the bus is way to safe the world, but actually most of the bus traffic is totally useless. Trips to some big store far away or another country.  Also a bus driving a given route empty without passengers is a waste that doesn’t happen with individual cars. Cars only move when they are used. A bus moves even without passengers.

To be more lean in some choices in your life could make it much more lean and also more profitable. When selecting where to live, the closer you are to the work place, the less unnecessary movement you have to do. Also the position of your summer place if you have one, could be a huge difference in traffic over 30 years.

Unnecessary walking cannot be that bad, as people need to stay healthy. But walking from store to the car with heavy bag can be a pain full experience.

4.Waiting: It seems to be real problem in traffic, You are waiting for traffic lights to change, waiting for the traffic to clear out. Waiting for a bus or train. To eliminate waiting traffic needs good roads that can handle problem situations and heavy traffic. They need to have automatic traffic lights that react to coming cars or more roundabouts, so when there is no other traffic, you don’t need to wait.

5.Overproduction: How traffic is over producted? Maybe by just moving too much stuff unnecessary.

6.Overprocessing: Overprocessing the traffic could be thinked as traffic lights where they are not needed. Or traffic cameras where there is no point to follow the speeds. Sometimes people still have GPS devices to warn about the traffic cameras, so to have those devices and still have cameras is just one big overprocessing and waste at the same time.

7.Defects: This could be car problems, quality issues with a given car, or handling traffic insidents. Problems with the road surface,  falling trees, the whole infrastructure can  cause major defects in traffic.

Waste: waste could be counted as waste products generated by traffic, exhaust gas, wastewater from car wash sites and so on, or other kinds of waste. Like Bus driving around empty. It’s total waste. Parked car wastes some parking space. When road salt corrodes the car and it looses value, that is waste.

When reading about Lean manufacturing you start to think about it every time you need to wait. And you think is it necessary that you have to wait in traffic light, and what causes that wait. How much better it would be if you didn’t have to wait. When filling up your car you think how much fuel it uses and start to think that it’s a waste and how much better it could be if it would consume less fuel.

Every thing that doesn’t add value to the customer has to be eliminated, and the customer in traffic is you. If something doesn’t add value to you, it could be better if it would be avoided. Many times it feels that the customer is actually the goverment and road users are actually just a milking cow that can be easily milked for easy money to fill up the budget deficit. And in democratic countries you are the one voting for these people.


Lean Manufacturing

I’m a lean manufacturing fan. And, if you are tired of waiting, you could be too.  The main idea of lean manufacturing comes from toyota, but it’s also made from common sense. By eliminating Waiting,  unnecessary movements and everything that doesn’t make the product better, you are also making product in the best way possible.

I’ve noticed so many times that Waiting is a main part of job, In SW line you are waiting for new SW, new corrections, you are waiting for your laptop to respond, installation times. Time differencies between sites, the waiting is a major part of it.

Waste is not so clear in SW area as you are always making lot of SW packages, that never go to customer. But I don’t consider those as a waste.  I consider that waste is unnecessary mails. Unnecessary reporting, reports that are old before they are  born. Anything that doesn’t provide value to the customer.

In some way, waste is also packages that don’t contain enough new implementation. They are too safe, It’s easy to make a working package without taking any corrections, but that is not what SW testing is trying to do. It has to take lot of corrections and find faults. In that view the expectations are contradictory. In one way everyone wants the package to work, but everyone also needs new implementation. And problems need to be found. Without failure problems cannot be found.  So in some way you need to welcome the failure and realize that it’s part of the job and it’s valuable.

What is not valuable is waiting for your laptop to work. That is just a pure waste that does nothing, it only elevates your blood pressure. There is no reason to keep 100thousand earning sw engineer that has poor laptop and it causes him to get frustrated and to work at 80%. After all, all of his work is done through this laptop/computer.

Everytime you get mails, thing what value they hold. Everytime you wait for something, think is this waiting necessary. What causes this wait?

In lean manufacturing you should not wait, you should pull new stuff in when you have the capability to do so.

You should eliminate movement, waiting, overprocessing, waste and every activity that doesn’t provide real value for the customer.