ELT (Emergency Locator Transmitter)

[Min Chun 0]

G'day Mwingers here

I'm quite curious abour ELT (Emergency Locator Transmitter) ..

What's that and it will be activated once a plane crash happen? For what purpose?

Thanks

[Gavin Andrew David 6]

On aircraft alone or what

 

I know Breitling watch also got that feature

 

Frequency 121.500 mhz

 

Look up " Emergency Position-Indicating Radio Beacons "

[Min Chun 0]

On aircraft alone or what

 

I know Breitling watch also got that feature

 

Frequency 121.500 mhz

 

Look up " Emergency Position-Indicating Radio Beacons "

 

Just know the frequency, other then that I am really blur with it.

Mind to explain more about it Gavin either on a/c alone or wat?

Edited September 2, 2006 by Min Chun

[Ricky Tiong 0]

Funny you asked this question Min Chun. I am currently doing a project on designing a 'smarter' ELT.

 

Basically when an ELT activates, it will send out a distress signal which a satellite will detect and in turn the search and rescue will be notified. The newer 406MHz system uses Doppler Effect to approximate the location of the signal.

 

The satellite system is also known as Cospas-Sarsat (www.cospas-sarsat.org).

[PC Yuen 0]

ELT - a device that transmits emergency frequency for SAR ( search & rescue) team. How it works? Upon impact (crash) it will automatically transmit. Thats why its very important to armed ELT before flight. And of course check the battery supply. Normally it can last 30days upon activation. Hope this helps.

[simon T 0]

the ELT will be activated once it senses a high deceleration rate..provided the ELT panel on the Aft overhead panel in the flight deck is 'ARMED'..

[Nick R. 0]

remember seeing one of those on the Alaskan crab fishing boats in Discovery's 'Deadliest Catch' series

[Tze Shan 0]

ELT - a device that transmits emergency frequency for SAR ( search & rescue) team. How it works? Upon impact (crash) it will automatically transmit. Thats why its very important to armed ELT before flight. And of course check the battery supply. Normally it can last 30days upon activation. Hope this helps.

yuen, got what you meant hehe...

[Min Chun 0]

the ELT will be activated once it senses a high deceleration rate..provided the ELT panel on the Aft overhead panel in the flight deck is 'ARMED'..

 

high deceleration rate?

meaning the difference between the thrust during the cruise and engine which stop turning[no thrust] after crash?

Hopefully can get what I mean by using poor english ya

 

Other than that i think i can roughly know bout ELT from you guys' explaination.Thanks a lot mate

[Jerry Ang 0]

high deceleration rate?

meaning the difference between the thrust during the cruise and engine which stop turning[no thrust] after crash?

 

It activates exactly the same as your car air bag. Try ram your car at 100kph to a solid concrete beam (high deceleration rate), your air bag "activates". Same here. Try flying at 400 knots & ram into the forest of Amazon (high deceleration rate), your ELT "activates".

[Min Chun 0]

Yeap, get what you guys mean

Thanks alot.

Btw, how does it work actually? It will send a msg automatically to a centre for search&rescue?

[Andrew Lim 1]

I have another question related to this:

 

Are all airliners equipped with ELT? If so, why does it seem that on some plane crashes, the SAR team simply takes ages to locate the crash site?

 

And if the ELT activation is dependent upon the rate of deceleration, does that mean it won't activate if a plane were to stall, hit the ground at a low speed, and then start to pusing here and there before stopping?

 

[zealich 0]

I think ELT only equip in big airline. so it will take ages to locate those small plane..as for the speed I think if low deceleration rate will need maual activation...

[Pieter C. 5]

I think ELT only equip in big airline.

 

No way !!!

 

The trainer I used, a Cessna 152, was also equipped with it

 

(my instructor even checked it once after I made a 'hard' landing, if it had gone off )

[Alan B. 5]

Beside the ELT that is built into the aircraft, there are also mobile ELT in the cabin that will be activated by the cabin crew. The number depends on the aircraft i.e. B737 there are 2. The assigned crew will activate it by extending the antenna and immerse the lower part in water. At sea just tie to life raft or life jacket. On land fill the plastic bag that it is wrapped-in with water or urine. It will transmit on 121.5Mhz and 243Mhz (if am correct). It should last for 48 hours.

 

Sorry for the nick.... I have informed to have it changed. It should be Alan B next time!

[Min Chun 0]

On land fill the plastic bag that it is wrapped-in with water or urine.

Alan,pardon my ignorance.. do you mind explaining more about this?

thanks ya for the info

Btw, you are with any airlines?

[Tony 1]

Min Chun,

 

Mobile ELTs activate upon contact with water. Special type of battery, I guess.

[Alan B. 5]

Yes the transmitter battery is water activated. There is a maker on the bottom of the transmitter that is the indicator of the water level. If no water is available, liquid like urine can also be used. The transmitter is wrapped in a plastic bag that can be used to contain the liquid............Yes I was with MH for 8 years.

[Min Chun 0]

Thanks a million guys.

Roughly got the idea how does it work.

[Min Chun 0]

 

ELT on small aircraft? Now you know

 

 

 

[Guest Levent]

While working at Denim Air Operations I got a call from the Dutch Coast Guard. They had received a call from their French colleagues, because they had picked up an ELT signal from one of our aircraft.

 

Let me tell you, your hart sinks a bit when you get a call like that.

 

A check of the flight schedules revealed that the aircraft, a Dash 8, was on the ground in Barcelona. Apparently maintenance crew had somehow managed to break off the ELT arming lever and the thing went off. The French had picked up the signal, and as it was a PH-registered aircraft they notified the Dutch coast guard.

[M N Fairizuan 0]

There are three types (to my knowledge) of transmitters (or ELT) carried on board MAS a/c.

- RESCU (Radio Emergency Search Communication Unit) 99 on board B737 - 48 hours

- RESCU 406 - on board B734/A330 series - 50 hours

- ADT AF (Automatic Fixed) /AP (Automatic Portable) - onboard A330 series

 

RESCU 99/406 - transmitter provides a homing signal for a range of 200 to 250 nautical miles by transmitting distress signal on 121.5 MHz for civil distress frequency, 243 MHz for military frequency and 406.025 MHz for satellite network (COSPAS-SARSAT, as someone mentioned earlier on for RESCU 406 & ADT 406 model). SARSAT = Search and Rescue Satellite Added Tracking.

 

Operation (Crashland).

- Break water solubale tape holding the antenna

- Remove platic bag and fill it with water and salt (if provided) otherwise fill it with urine

- Insert lower part of tthe transmitter into da bag and ensure the liquid enters the vent holes to activates the batt.

- place in upright position and secure on clear, open ground to ensure max. transmission.

- shake or replace the liquid at intervals time to maintain full power output

 

Operation (Ditching).

- Unroll free end of the cord

- Tie cord/lanyard to slide/raft/lifevest

- place transmitter in the water and let it drift

 

ADT 406 AF - fixed at the aft ceiling of the a/c and automatically activated once on impact with G-Force strong enough to trigger ELT. Manually, lift the flip guard, pull and slide the toggle swith to the ON position. Once activated, ADT enters into waiting mode for 30 secs before actual transmission. On activation, intermittent beeps and red light flashes for 30 secs. Actual transmission, steady beebs and red light illumination (unlike RESCU units, no indicators)

 

ADT 406 AP (same as ADT 406 AF) except this unit is a vital equip to be taken aout after impact and portable.