edwardlcy Posted November 6, 2012 Share Posted November 6, 2012 Good day guys, was wondering if there is a simple DIY design for a test set to pinpoint the location of a location of a bleed air leak at nacelle or dry bay area, please do share thanks! Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted November 7, 2012 Share Posted November 7, 2012 ...a simple DIY design for a test set to pinpoint the location of a bleed air leak at nacelle or dry bay area... NO But it's ("test set") already built into the aircraft, bleed air pressure gauge (gage). If you have a leak your bleed air leak check will be BAD pressure drops faster than allowed. 30psi to 15psi in no less than 8.5 sec's or 16sec's (or 20 sec's) depending on model and local requirements. Close one engine bleed air valve recheack leak rate... if it is still BAD (too fast) leave the first valve closed and close the next engine and repeat until you get a "Good leak check" takes longer than 8.5 sec's or 16sec's (or 20 sec's) depending on model and local requirements. If you get a good leak check "After" closing an engine your leak is in that nacelle. If all engines are closed, divide your wing or close one (Lt or Rt) wing isolation valve and recheck; still bad? Aircraft with divider valve your leak is on the left side start checking for the leak. Aircraft with wing isolation valves... close remaining wing isolation valve... BAD check your leak is in the center section Good your leak is on the last wing to be isolated... Quote Link to comment Share on other sites More sharing options...
edwardlcy Posted November 7, 2012 Author Share Posted November 7, 2012 Thanks for the advice, but I'm looking for a simple gadget of sorts to pinpoint the location of a bleed air leak such as an event when nacelle overheat light illuminate during reverse thrust, there usually is a leak in one of the gaskets, but where? Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted November 7, 2012 Share Posted November 7, 2012 Do you have nacelle overheat detectors in your drybay? (around the engine bleed air valve) We call this the horse collar area the engine to wing contured panel... Do your bleed air check with only the engine in question. If the leak check is good the leak is in the ducts from your diffuser to your engine bleed air check valve. After that the only way to find the leak is to use your eyes...check clamps and the "ribbed" "accordian" areas of each duct the movement of the engine makes these areas crack. Quote Link to comment Share on other sites More sharing options...
Ronc Posted November 7, 2012 Share Posted November 7, 2012 edwardlcy, You could consider a "man on the stand run" if your regulations allow. I had the honor of troubleshooting the exact same problem you identified, Nacelle overheat in reverse. I found the leak at the tenth stage where the bleed air collector mounts to the compressor case at the 3 oclock position. Changed the gasket and never had the problem with that engine again! Ron Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted November 15, 2012 Share Posted November 15, 2012 if you have dye penetrant crack detection kit available, spray suspect area with developer and do a short run - also works great for oil and fuel leaks Quote Link to comment Share on other sites More sharing options...
edwardlcy Posted November 15, 2012 Author Share Posted November 15, 2012 edwardlcy, You could consider a "man on the stand run" if your regulations allow. I had the honor of troubleshooting the exact same problem you identified, Nacelle overheat in reverse. I found the leak at the tenth stage where the bleed air collector mounts to the compressor case at the 3 oclock position. Changed the gasket and never had the problem with that engine again! Ron yup we do "man on the stand run" too sometimes, but visual for bleed air leak is hard to spot, i'm looking for an easier solution by means of a DIY portable flexi-rod type of infrared or temperature sensor test kit that will light up or sound an alarm to pinpoint location where there is a bleed air leak. if you have dye penetrant crack detection kit available, spray suspect area with developer and do a short run - also works great for oil and fuel leaks dye penetrant can only be used on rigid pipelines to check for cracks right? can it be applied where connecting pipelines and worn gaskets are? Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted November 15, 2012 Share Posted November 15, 2012 dye penetrant can only be used on rigid pipelines to check for cracks right? can it be applied where connecting pipelines and worn gaskets are? doesn't matter. if there is an air leak it will be blown off, same with fluid leaks, it will stain. i just use the developer powder spray in the suspect area Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted November 16, 2012 Share Posted November 16, 2012 An infared camera should work... http://www.testequipmentdepot.com/flir/popups/jet-engine.htm Quote Link to comment Share on other sites More sharing options...
Herc 308 Posted November 22, 2012 Share Posted November 22, 2012 A thermo gun that the fire fighters use works good also. Quote Link to comment Share on other sites More sharing options...
JKendrick Posted August 2, 2013 Share Posted August 2, 2013 Good day guys, was wondering if there is a simple DIY design for a test set to pinpoint the location of a location of a bleed air leak at nacelle or dry bay area, please do share thanks! Flir has come out with very reasonable Heat Guns. They have a Flir Rep "Dan" I worked with in the past. The guns can be bought with a GPC Card and show very accurate temp. changes. It gives you like a 6th sense of visual sight where you can see things like never before. The digital laser guns are worthless for troubleshooting. They can give you the temp. of a target the size of a sheet of plywood. The visual screen will allow you to find instantly where the problem is. I think that every support section should have a Flir gun on hand. From a hot spot in wiring to brake checks these guns have potential. The industrial maintenance industry has used them for years. Joe Quote Link to comment Share on other sites More sharing options...
red07ss Posted August 21, 2013 Share Posted August 21, 2013 I've always used an infared gun, but do the run at night so the plane is good and cold which allowes you to spot the leak quicker. Another tool I like to use for fuselage pressure leaks (kind of off topic but kind of relates to air leaks) is simply baby powder puffed into the air from inside the plane. Quote Link to comment Share on other sites More sharing options...
tusker Posted September 12, 2013 Share Posted September 12, 2013 there is one for sure.....I come back to you with the proper name of the stuff Quote Link to comment Share on other sites More sharing options...
nosepicker Posted September 18, 2013 Share Posted September 18, 2013 (edited) I use a ruler with toilet paper taped to the end of it. Works good and it's cheap....budget crisis and all. Edited September 18, 2013 by nosepicker Add stuff Quote Link to comment Share on other sites More sharing options...
P3_Super_Bee Posted September 18, 2013 Share Posted September 18, 2013 I use a ruler with toilet paper taped to the end of it. Works good and it's cheap....budget crisis and all. We used an inspection mirror or mechanical fingers with paper taped to the end. would also slice the paper so it had like brush bristles... Costs nothing. You always have paper, tape and the tool box... Though maybe the thermo imaging camera would allow checking without doing the "Man On The Stand" turn... Quote Link to comment Share on other sites More sharing options...
JTECH Posted September 19, 2013 Share Posted September 19, 2013 we use the tp for any pressurization leaks from inside the aircraft, and man on the stand is old school but seems to work well. I knew some guys from LM that used the thermal imaging device with little success. I can recall a long time ago trimming a Pratt N Whitney on a Boeing 707 standing beside and fighting the fan blow by, that was exciting stuff. Quote Link to comment Share on other sites More sharing options...
tusker Posted October 11, 2013 Share Posted October 11, 2013 some guys use LPI developper........ Quote Link to comment Share on other sites More sharing options...
red07ss Posted November 27, 2013 Share Posted November 27, 2013 I find lots of elusive bleed air leaks using the FLIR gun (Infa-Red). If the squadron dosent have one I'd try borrowing one from the base fire department Quote Link to comment Share on other sites More sharing options...
tusker Posted November 28, 2013 Share Posted November 28, 2013 well,,,,doesn't cost much to try the developper......or else I rest my case Quote Link to comment Share on other sites More sharing options...
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