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stephenph t1_j6i5w07 wrote

Reply to comment by redditlurker67 in eli5: Why do most airlines still use 2-pin audio jacks for the in-flight entertainment systems on their planes? by JJGLC92

And the electronics certification for Aircraft is slow and expensive. I think the dual jack was designed and approved before cell phones and media players were common (let alone allowed to be used)

Also, I would bet there was a level of "tech lock-in" ensuring the only source for the headsets were one or two companies.

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aspheric_cow t1_j6imjzt wrote

3.5mm earphone jacks have been standard for ages though - the original Sony Walkman (released in 1979) already had it. My understanding is that the airline industry deliberately chose a different connector so people won't steal the headphones. Then later, they switched to 3.5mm when headphones became dirt cheap and not worth stealing.

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Tinmania t1_j6jg4e9 wrote

The 3.5 mm earphone jack is far older than 1979. It was popularized by transistor radios in the 1950s. But it was mono not stereo. When they designed stereo airplane audio there wasn’t a 3.5 mm stereo standard yet. So they simply used two mono 3.5 mm earphone jacks for stereo headsets. Not much different than what they did with the air driven airplane headsets.

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stephenph t1_j6isy7p wrote

Yes the 3.5 jack has been a standard in personal electronics for years, and you are probably right about they reasons they designed the dual plug thing initially. but I think it was also, at least partially, what was submitted to the FAA and once it was approved it became the approved standard. Unlikely to change until they revisited entertainment systems. If there is no compelling (safety) reason they just don't redesign systems on passenger aircraft.

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fede142857 t1_j6krytl wrote

> If there is no compelling (safety) reason they just don't redesign systems on passenger aircraft.

True

I remember reading somewhere that the flight computers need to receive new navigation data every 4 weeks and the updates are still issued as floppy disks because it's not worth the cost of redesigning the system and getting it certified

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ark_mod t1_j6j0909 wrote

So your saying they haven't revisited entertainment systems since the 70s or 80s? Onboard wifi and on demand movies would disagree with you...

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Frogblaster77 t1_j6jc4uo wrote

Not on already certified and installed seats they're not. If it's a retrofit program with new seats being installed, then yeah the audio jacks would likely get upgraded to the latest design. But if it's already flying the only thing those seats are getting is a half-hearted wipe with a dirty rag.

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lostan t1_j6jffhs wrote

> deliberately chose a different connector so people won't steal the headphones.

this was alwaysmy guess.

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pbjking t1_j6jpnuy wrote

3.5 has been around so long cell phones don't have them anymore

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dryphtyr t1_j6jy4rj wrote

3.5mm was already pretty old when cell phones were the size of a suitcase

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devil_d0c t1_j6j291r wrote

Same reason there are still ashtrays in the bulkheads. A new type design without the ashtray is too expensive.

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LordGeni t1_j6j97u3 wrote

Iirc, They're still there by design. Just because people shouldn't smoke doesn't mean someone won't. So it's important there is a safe and obvious place for them to put it out.

I believe there was a plane delayed fairly recently because it was missing an ashtray and it was deemed a safety risk.

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tsme-esr t1_j6lp1di wrote

That's what the lavatory ashtrays are for

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