Transponder question

reply to post by soulwaxer


SwissAir 111 had smoke in the cockpit/cabin before they had a fire warning. The fire in the IFE system eventually killed everyone on board when the plane slammed into the ocean.

Sometimes by the time you have an actual fire it's far too late.

Zaphod58
Simple answer, fire. Fire on a plane is ridiculously dangerous. There are cases when something has shorted and cutting the power, either through the off switch or circuit breaker stops the fire danger.

So is there a provision to turn off the black boxes? If not, how do they get around the fire danger?

What about putting more powerful transmitters in the black boxes, or some other option?

Seems like we should have the technology available today to avoid losing commercial airplanes, but as mentioned before, cost could be one reason it's not implemented. The cost of losing planes isn't cheap though even if they aren't used in subsequent terrorist attacks, but if they are the cost could be even higher.

reply to post by Arbitrageur


All equipment on an aircraft has a circuit breaker in the cockpit that the crew has access to.

Are there transponder systems available that are completely passive, not requiring a power source, that can be picked up on detectors either locally or via satellite? Maybe a low yield radioisotope shielded from passengers and ground crews?

Zaphod58
reply to post by soulwaxer

 

SwissAir 111 had smoke in the cockpit/cabin before they had a fire warning. The fire in the IFE system eventually killed everyone on board when the plane slammed into the ocean.

Sometimes by the time you have an actual fire it's far too late.

You will probably find a lot of these "electrical" fires where on planes that have Kapton wiring, the very wiring insulation that is banned in military airframes due to cracking and breaking of the insulation.

Kapton wiring is nasty stuff.

reply to post by shappy


You know it's bad when the military bans it from use. I'll be glad when the last of that crap is gone. Whoever certified it for aircraft needs to be shot (yes that's being facetious).

Zaphod58
reply to post by shappy

 

You know it's bad when the military bans it from use. I'll be glad when the last of that crap is gone. Whoever certified it for aircraft needs to be shot (yes that's being facetious).

Wiring should stop arcing and electrical fires but Kaptop just keeps on burning , Badly.

Even new planes today use it.

www.newschannel5.com...

reply to post by Sammamishman


The other half and I were talking about a transponder that activates if the primary shuts off in flight. Encase it in a box with a battery power supply independent of the AC.

reply to post by shappy


Your link went to the basic page not a story.

I THOUGHT Kapton had been banned after the MD-11. It looks like Airbus used it until about 2005, and Boeing stopped in the 767 quite awhile ago.

The simple answer is "pilots are trusted." Transponders need to be turned off for many reasons. Basically everything that takes power on an aircraft can cause interference, short-circuts, or otherwise mess up the safety of flight and needs to be switchable. You don't want a sparky transponder setting the plane on fire when you can just turn it off. If all airplanes had transponders and they couldn't be turned off all planes on the ground would be showing as well. There would be no clear spots on an airplane map. Besides, if a bad person was able to take an airplane he would probably have enough knowledge to disable it no matter how it is built. Then it would only be causing problems for the pilots. I don't see a problem with transponders the way they are now.

JHumm
Why is the transponder able to be turned off by the pilot ?
Would it not make since to have it so it cannot be turned off or tampered with in any way ?

there are other uses for the transponder signal other than for ATC. TCAS uses the broadcast information to determine if two planes are on a collision path, but if you had your transponder ON when you are on the tarmac you would be setting off false readings on TCAS.

there are three positions off, standby and alt. you have it in alt once you take the active runway that way everyone around you knows you're more than just taxing on the ground.

besides the off position there is also a circuit breaker that can be pulled which you would use if smoke suddenly started coming out of it. so you do need a way to remove power from it.