ATA 26

[DesEngineer4]

Hello,

I am working on smoke deduction routing for an Aircraft Interior. Could anyone please help in understanding about Sniffer Ports like,
i) I have an input saying to use 4 sniffer ports but are there any parameters to select no of sniffer ports required per sqft?
ii) We have an input which talks about what distance we need to maintain between two sniffer ports, likewise, are there parameters/guidelines to consider before locating a sniffer port?
iii) I'm referring some old projects to select a suitable Hose/Sceets and to a select a standard support. What should we consider before selecting a Hose/Sceet? AND Is there any catalogue parts for standard supports?

Please help us with your Inputs. Thank you for your time and support!




Thanks & Regards

 

[Sparweb]

FAA AC 25-9 is the simple answer to your question. Which is not so simple.

The big picture is: You have a large volume of cargo space, and a fire can start in any part of it, and may burn at any rate from smolder to inferno. Now prove that you can detect the fire within 60 seconds.

I don't know of a way to do that analytically. Sure you can calculate stuff, but number aren't proof until they're backed up with real-world data. Usually it's done by conservatively estimating the distribution of sensors, comparison with other similar aircraft, and then a series of tests. The AC can help you with all of those. The AC is intended to be used in conjunction with test plans acceptable to the local aviation airworthiness authorities in your country, and a design of cargo interior that contains and isolates smoke.

All of the above, for numerous reasons, may forbid, or may allow, you to use SCEET ducting. IMO I don't think that's what you want to use, but I've never gone all the way through that version of smoke detection before. I've seen aircraft with the "sniffer tube" system and it was all done with aluminum tubing. Don't infer that it's a requirement based on what I just said; I'm just reporting what I've seen.

 

[rb1957]

1) talk to the guy who's making the finding !
2) make sure you've done 1)
3) then talk to vendors

where are you ? NA, Europe, other ?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[DesEngineer4]

Hi I'm from CA

Maybe I didn't put my question properly.

1- How can we determine which location is needed for smoke detection and where the detector should be installed.
2- How do we choose which kind of smoke detector to install in a corridor, bedroom, cabin, or restroom? Does it depend on how big the area is? (Meanwhile referring to a few projects that I've seen that use ambient smoke detectors in cabinets and closets and draw-true smoke detectors in bedrooms and restrooms.)
3- How do we determine how many sniffer ports to utilize and where to deploy them.


Thanks & Regards

 

[Sparweb]

Hi
The answers you are literally asking for don't exist in a form that isn't proprietary. They did the work to determine what parameters work safely. That's the effort you're expected to do too.

You need to be advised on methods of aerospace design acceptable to regulatory agencies such as EASA or FAA. You will get that from accessing the AC I linked above, and by reading numerous other FAA AC's that are related to it. If you are asking the question you are asking, and unwilling to do the research necessary to develop the design yourself, then you absolutely need an expert who has done this before.

This is sarcasm but it is intended to clarify the correct design philosophy, by parody of the wrong philosophy: Diligent design works a lot better than asking random strangers on the internet to make all of the decisions for you.

FYI, we frown on sharing proprietary data, mostly because engineers like me create that proprietary data and we are paid our salaries when its value is respected.

 

[DesEngineer4]

That was too deep. But I got your answers. Thank You Sparweb!

Thanks & Regards