Jacking into aircraft intercoms at DVinfo.net

Nick Flowers · September 8th, 2008, 02:36 AM

Is there a standard plug for jacking into light aircraft and helicopter intercoms? USA and Europe? Civil and Army/ Air Force/ Navy? I've always used my own COS11 or Tram stuffed into some foam at the end of the headset's mic boom because it works well, but if there aren't too many varieties of jacks to cater for it might be worthwhile making some adaptor leads up.

Cheers,
Nick.

Allan Black · September 8th, 2008, 03:36 AM

I use the standard 1/4" phone plug, fits all the aircraft I've come across.

Shooting video is peripheral to the safety of the flight. You just have to watch you don't load the comms systems reducing the volume. I always get the captain/pilots approval prior and run a test with all cans plugged in. Older aircraft may be modified in that dept.

Sometimes the output socket you're given doesn't get used a lot and has corroded somewhat.

Spraying electronic circuit cleaner just before a flight certainly attracts the crews attention, that's the time to run your level tests.

Cheers.

Nick Flowers · September 8th, 2008, 03:51 AM

Excellent! Thanks Allan. Things have come on since I last investigated, years ago, when I found a nasty tip two rings and sleeve jack.

Nick

Gary Nattrass · September 8th, 2008, 03:57 AM

Nick I always thought that aircraft used this type of four pin plug for their comms?

http://www.aircraftspruce.com/catalo...s/11-00699.jpg

Nick Flowers · September 8th, 2008, 04:11 AM

Ah!! Now that is exactly the plug I found all those years ago. What's the betting that every country has its own standard? What goes into a Cessna socket in Australia won't go into a Jet Ranger in Montana, which won't suit a Harrier in Lincolnshire. Isn't life complicated?

Nick Flowers · September 8th, 2008, 04:16 AM

But perhaps this plug is exactly that which Allan had in mind? Phone jacks differ around the world too, of course!

Allan Black · September 8th, 2008, 04:31 AM

Nope Nick, mine is a std mono phone jack on a cable made up by the sparks at HARS. I don't need talkback and the other end has a 3.5mm minijack plug to go into small video recorders.

But most of the aircraft are older (read very old) maybe I'd short out a G4 Gulfstream :(

Jim Michael · September 8th, 2008, 06:02 AM

The plug in the photo looks like the type found in helicopters. Airplanes use a standard 1/4" headphone jack for the headphones and a smaller one for the mic. I don't recall the impedance.

Nick Flowers · September 8th, 2008, 09:10 AM

Good news, then. Just two leads to make up. Now for the major prize: on the 4 pole jack, which of the two connectors give the output of the talkback? I'm guessing tip and adjacent ring.

Nick Flowers · September 8th, 2008, 09:23 AM

Anyone following this thread will not be surprised to find that the story does not quite end here!

Aviation Headset Adaptors & Cables

This site shows that there are differences between US and UK NATO plugs and that converters exist!

I'm going back to stuffing a Tram into some foam on the headset mic boom!

Dean Sensui · September 8th, 2008, 12:57 PM

Jim has it correct. The one in the photo is a plug for a helicopter headset. Fixed wing aircraft generally use a combination of 1/4" phone for the headset and a smaller plug for the mic.

I got pretty decent intercom audio on a helicopter by sticking a Countryman lav into the earcups of a spare headset.

The headset was clamped around the mic, and the pilot's voice was clear enough. You can probably slip the mic into the headset if someone's wearing it, too.

Jim Michael · September 8th, 2008, 03:40 PM

Something else to consider - aircraft can be electrically noisy environments. I've been trying to chase down some noise in the Stinson and when I try to record it using a non-shielded microphone I'm getting quite a bit of static that makes the recordings unusable. Also, re the lav in the earcup trick, you may get inconsistent results with this if the headset is one of those noise attenuating headsets like the Bose. The way those work is they have a speaker that plays sound 180 degrees out of phase to what is heard in a little microphone in the earcup. The timing is critical so if your mic is in the wrong position you may get unacceptable results. Most of those headsets still work with the attenuation turned off, but they'll pick up more cabin noise. I think most of the online pilot shops sell the adapters to plug into the intercom, e.g. SkyGeek http://www.skygeek.com/jb-40.html

Paul R Johnson · September 8th, 2008, 04:45 PM

Don't forget that there is a DC voltage on one of the pins of the mic socket - so getting it round the wrong way and plugging into the mic rather than headset socket can be expensive!

Martin Pauly · September 9th, 2008, 10:55 AM

I used to fly as a hobby. I have the predecessor of this intercom:

Pilot USA

It's got an output for recording all audio, via a mini phone plug. Even if the aircraft has an intercom, this portable one can be used between one of the headsets and the built-in intercom, something I've done frequently when the aircraft's intercom had connections for fewer headsets than we had people on board.

I haven't tried it myself, but I'd bet money that a portable intercom such as this would be an easy way to record cockpit voices and air traffic controll messages.

- Martin

Nick Flowers · September 9th, 2008, 12:34 PM

This (above) seems to be the De Luxe answer, and if I knew that I was going on a series with lots of interviews and presenter stuff in a fixed wing aeroplane I reckon I'd buy one.

I'm not too sure if it makes economic sense for me to invest that much in something that - if past experience holds up - would be used no more than a couple of times a year. But the good thing about it is that with an adaptor you could use it in a helicopter as well. Good to know that it's out there if an aerial series materialises!

September 8th, 2008, 02:36 AM	#1
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	Jacking into aircraft intercoms Is there a standard plug for jacking into light aircraft and helicopter intercoms? USA and Europe? Civil and Army/ Air Force/ Navy? I've always used my own COS11 or Tram stuffed into some foam at the end of the headset's mic boom because it works well, but if there aren't too many varieties of jacks to cater for it might be worthwhile making some adaptor leads up. Cheers, Nick.

September 8th, 2008, 03:57 AM	#4
Gary Nattrass Trustee Join Date: Apr 2008 Location: Cornsay Durham UK Posts: 1,992	Nick I always thought that aircraft used this type of four pin plug for their comms? http://www.aircraftspruce.com/catalo...s/11-00699.jpg __________________ Over 15 minutes in Broadcast Film and TV production: http://www.imdb.com/name/nm1044352/

September 8th, 2008, 04:16 AM	#6
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	A second thought But perhaps this plug is exactly that which Allan had in mind? Phone jacks differ around the world too, of course! Last edited by Nick Flowers; September 8th, 2008 at 04:18 AM. Reason: grammar

September 8th, 2008, 09:23 AM	#10
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	The misery continues Anyone following this thread will not be surprised to find that the story does not quite end here! Aviation Headset Adaptors & Cables This site shows that there are differences between US and UK NATO plugs and that converters exist! I'm going back to stuffing a Tram into some foam on the headset mic boom!

September 8th, 2008, 12:57 PM	#11
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	Jim has it correct. The one in the photo is a plug for a helicopter headset. Fixed wing aircraft generally use a combination of 1/4" phone for the headset and a smaller plug for the mic. I got pretty decent intercom audio on a helicopter by sticking a Countryman lav into the earcups of a spare headset. The headset was clamped around the mic, and the pilot's voice was clear enough. You can probably slip the mic into the headset if someone's wearing it, too. __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

September 8th, 2008, 03:36 AM	#2
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,930	I use the standard 1/4" phone plug, fits all the aircraft I've come across. Shooting video is peripheral to the safety of the flight. You just have to watch you don't load the comms systems reducing the volume. I always get the captain/pilots approval prior and run a test with all cans plugged in. Older aircraft may be modified in that dept. Sometimes the output socket you're given doesn't get used a lot and has corroded somewhat. Spraying electronic circuit cleaner just before a flight certainly attracts the crews attention, that's the time to run your level tests. Cheers.

September 8th, 2008, 03:51 AM	#3
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	Excellent! Thanks Allan. Things have come on since I last investigated, years ago, when I found a nasty tip two rings and sleeve jack. Nick

September 8th, 2008, 04:11 AM	#5
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	Ah!! Now that is exactly the plug I found all those years ago. What's the betting that every country has its own standard? What goes into a Cessna socket in Australia won't go into a Jet Ranger in Montana, which won't suit a Harrier in Lincolnshire. Isn't life complicated?

September 8th, 2008, 04:31 AM	#7
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,930	Nope Nick, mine is a std mono phone jack on a cable made up by the sparks at HARS. I don't need talkback and the other end has a 3.5mm minijack plug to go into small video recorders. But most of the aircraft are older (read very old) maybe I'd short out a G4 Gulfstream :(

September 8th, 2008, 06:02 AM	#8
Jim Michael Major Player Join Date: Dec 2005 Posts: 895	The plug in the photo looks like the type found in helicopters. Airplanes use a standard 1/4" headphone jack for the headphones and a smaller one for the mic. I don't recall the impedance.

September 8th, 2008, 09:10 AM	#9
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	Good news, then. Just two leads to make up. Now for the major prize: on the 4 pole jack, which of the two connectors give the output of the talkback? I'm guessing tip and adjacent ring.

September 8th, 2008, 03:40 PM	#12
Jim Michael Major Player Join Date: Dec 2005 Posts: 895	Something else to consider - aircraft can be electrically noisy environments. I've been trying to chase down some noise in the Stinson and when I try to record it using a non-shielded microphone I'm getting quite a bit of static that makes the recordings unusable. Also, re the lav in the earcup trick, you may get inconsistent results with this if the headset is one of those noise attenuating headsets like the Bose. The way those work is they have a speaker that plays sound 180 degrees out of phase to what is heard in a little microphone in the earcup. The timing is critical so if your mic is in the wrong position you may get unacceptable results. Most of those headsets still work with the attenuation turned off, but they'll pick up more cabin noise. I think most of the online pilot shops sell the adapters to plug into the intercom, e.g. SkyGeek http://www.skygeek.com/jb-40.html Last edited by Jim Michael; September 8th, 2008 at 03:41 PM. Reason: embedded html removed

September 8th, 2008, 04:45 PM	#13
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,045	Don't forget that there is a DC voltage on one of the pins of the mic socket - so getting it round the wrong way and plugging into the mic rather than headset socket can be expensive!

September 9th, 2008, 10:55 AM	#14
Martin Pauly Major Player Join Date: Apr 2006 Location: Cedar Rapids, IA Posts: 563	I used to fly as a hobby. I have the predecessor of this intercom: Pilot USA It's got an output for recording all audio, via a mini phone plug. Even if the aircraft has an intercom, this portable one can be used between one of the headsets and the built-in intercom, something I've done frequently when the aircraft's intercom had connections for fewer headsets than we had people on board. I haven't tried it myself, but I'd bet money that a portable intercom such as this would be an easy way to record cockpit voices and air traffic controll messages. - Martin __________________ Martin Pauly

September 9th, 2008, 12:34 PM	#15
Nick Flowers Regular Crew Join Date: Jul 2008 Location: Chichester UK Posts: 167	This (above) seems to be the De Luxe answer, and if I knew that I was going on a series with lots of interviews and presenter stuff in a fixed wing aeroplane I reckon I'd buy one. I'm not too sure if it makes economic sense for me to invest that much in something that - if past experience holds up - would be used no more than a couple of times a year. But the good thing about it is that with an adaptor you could use it in a helicopter as well. Good to know that it's out there if an aerial series materialises!