Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
A Jet Engine Question-What's This?  
User currently offlineMr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9
Posted (10 years 2 months 6 days ago) and read 6008 times:

Hi guys.

What are the small rectangular fairings with the square shaped holes in them, that are located on the bottom aft end of the engine cowlings on the 747-4 in this photo used for?

A wild guess on my part is that they are drain ports for oil that's leaked down onto the bottom of the engine cowling from the gearbox and bearing seals, etc.


View Large View Medium
Click here for bigger photo!

Photo © David Morrell - Avid Creations



After doing a good photo search of engine shots, I believe I've determined that the Pratt & Whitney PW 4056, General Electric GE CF6-80C, and Zeus Olympic engines all have this small fairing on their engine cowling. However, the Rolls Royce RB-211 does not. I guess the reason for this is simply based on a different engine design. What's the difference?

Here's some photos of engines that have this fairing .........

GE Engine.
View Large View Medium
Click here for bigger photo!

Photo © Mark Donoghue



Zeus Olympic Engine (you can just see it).
View Large View Medium
Click here for bigger photo!

Photo © Marian Musil



With the fairing (I don't know the engine types, but I'm sure they're either GE or PW engines).


View Large View Medium
Click here for bigger photo!

Photo © Anatol Kolendo
View Large View Medium
Click here for bigger photo!

Photo © Toby Willis



View Large View Medium
Click here for bigger photo!

Photo © Oliver Brunke



RB211 Engine (I believe) - without the fairing.


View Large View Medium
Click here for bigger photo!

Photo © Will Lanting



Without the fairing (I don't know the engine types for sure, but I believe 3 of the jets have RR RB211 engines).


View Large View Medium
Click here for bigger photo!

Photo © Glenn Stewart
View Large View Medium
Click here for bigger photo!

Photo © Greg Weir



View Large View Medium
Click here for bigger photo!

Photo © Darren Howie
View Large View Medium
Click here for bigger photo!

Photo © Jonathan Simmons




Does the JT9D-3A engine have this fairing? (I can't tell from the photo).


View Large View Medium
Click here for bigger photo!

Photo © Jack Hannen



Thanks,

Chris  Smile



"Just a minute while I re-invent myself"
11 replies: All unread, jump to last
 
User currently offlineAir2gxs From , joined Dec 1969, posts, RR:
Reply 1, posted (10 years 2 months 6 days ago) and read 5961 times:

Though I'm sure of this particular engine it is probably the drain masts & the access area for the thrust reverser cowl latches.

As a note, the grain mast or gang drain does not gather fluids that have dripped onto the cowl (that usually goes overboard if its any large quantity, otherwise it stays and stains the inside of the cowl until wiped up), the gang drain gathers fluid from the accessory pads and accessories via tubing and dumps it overboard without allowing it to gather and puddle in the cowling. Any fluid coming from the drain mast (except oil after servicing) requires some attention. Whether anything has to be done depends on quantity, origin and type.


User currently offlineBoeing767mech From United States of America, joined Dec 2000, 1030 posts, RR: 3
Reply 2, posted (10 years 2 months 5 days 22 hours ago) and read 5850 times:

Those fairings are for the Thrust reverser latches and also the Thrust Reverse guide rails for the translating cowl of the Thrust Reverser.

David



Never under-estimate the predictably of stupidty
User currently offlineMr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9
Reply 3, posted (10 years 2 months 5 days 22 hours ago) and read 5848 times:

Hello Air2gxs.

Thanks for your reply.

OK, so if I understand you correctly, the square hole in the fairing is infact for drainage, but, it's not for oil, hydraulic fluids, etc, that have leaked and caused a puddle on the bottom of the engine cowling, it's for fluid from the accessory pads and accessories which is dumped overboard via tubing and the square hole is where these fluids are dumped overboard.

Am I close to understanding?

Also, do you know how the RR RB211 engines allow leaking fluids to be dumped overboard. Do their engine cowlings have drain masts that are flush with the cowling? - therefore they're not visible from side views.


Chris  Smile



"Just a minute while I re-invent myself"
User currently offlineAir2gxs From , joined Dec 1969, posts, RR:
Reply 4, posted (10 years 2 months 5 days 21 hours ago) and read 5808 times:

A puddle in the cowling is not permitted, that's why this elaborate drain system exists. It also exists to help maintenance determine what is leaking and the rate. All engines, including APU's have a drain system.

The RR engines have drain ports that are flush with the cowl. The fairing itself houses part of the T/R system as Boeing767mech has stated.


User currently offlineMr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9
Reply 5, posted (10 years 2 months 5 days 20 hours ago) and read 5758 times:

Hi guys.

> Air2gxs, Thanks Again, you stated ........

"it is probably the drain masts and the access area for the thrust reverser cowl latches"

> Boeing767mech, Thanks for your reply. You stated ........

"Those fairings are for the Thrust reverser latches and also the Thrust Reverse guide rails for the translating cowl of the Thrust Reverser."

Thanks for your info guys. Here's two more questions about these Thrust Reverser (TR's) fairings .......

Is that square hole in the fairing large enough for a mechanic to fit his/her head & shoulders into in order to inspect/service the thrust reverser guide rails, etc? Also, do the holes in these fairings have anything to do with drain masts?

Regarding part of my original question about why some jet engines have these cowling fairings while others don't, well, I understand now that only jet engines with "Cascade" type TR's (with aft moving cowlings during deployment) have these fairings. This explains to me why the RR RB211 engines don't have these fairings ......... because they use "Target" type TR's.

Here's some photos ........

Engines with Cascade type TR's with the fairings.


View Large View Medium
Click here for bigger photo!

Photo © Europix
View Large View Medium
Click here for bigger photo!

Photo © PixAir



View Large View Medium
Click here for bigger photo!

Photo © Tim Feise - APO Photos
View Large View Medium
Click here for bigger photo!

Photo © Christian Waser - Aviapix Zurich/Worldwide



Engines with Target type TR's and no fairings.


View Large View Medium
Click here for bigger photo!

Photo © Nicolas St-Germain
View Large View Medium
Click here for bigger photo!

Photo © Michael Fritz



This is neat stuff to learn about.  Big thumbs up

Chris  Smile




"Just a minute while I re-invent myself"
User currently offlineAloges From Germany, joined Jan 2006, 8730 posts, RR: 42
Reply 6, posted (10 years 2 months 5 days 16 hours ago) and read 5501 times:

That "Zeus Olympic Engine"... sweet!  Love They are GE CF6-50E2s.


Walk together, talk together all ye peoples of the earth. Then, and only then, shall ye have peace.
User currently offlineAir2gxs From , joined Dec 1969, posts, RR:
Reply 7, posted (10 years 2 months 5 days 4 hours ago) and read 5287 times:

The hole you see is the actual drain mast port. All the tubes run to this one area. It is not big enough to fit your head in. Usually, the fairing incorporates an access panel that is held closed by latches. When opened you gain access to the actual mast and the some of the T/R cowl latches. Undoing the latches allows you to open the T/R halves and gain access to the engine components under the cowl.

Note, not all engines are set up the same way. It all depends on the engine/airframe combination. An engine will always have some sort of drain mast, it varies as to where it discharges. If I remember correctly the drain mast on the tail engine of the MD11 discharges somewhere on the empennage (aft fuselage).

The fairing is just a convenient place to put the drains on some engines.

Look at the drain here:

View Large View Medium
Click here for bigger photo!

Photo © Anthony Cheng



The drain mast is an actual mast protruding into the airstream. (look at the #1 engine, #2 engine appears to have 3 objects: only 1 belongs to the engine, the other 2 are fuselage items).




User currently offlineVictor Hotel From Australia, joined Aug 2000, 305 posts, RR: 1
Reply 8, posted (10 years 2 months 5 days 3 hours ago) and read 5283 times:

Sorry, A bit off topic but looking at the two aft main gear bay doors and the forward left main gear door, looks almost like contact with air bubbles under it. Does anyone know what this is?


User currently offlineAir2gxs From , joined Dec 1969, posts, RR:
Reply 9, posted (10 years 2 months 5 days 2 hours ago) and read 5258 times:

Victor,

Not sure what you're looking at. The only thing that looks like a "bubble" is the lower beacon.


User currently offlineMr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9
Reply 10, posted (10 years 2 months 5 days ago) and read 5242 times:

Hi guys.

> Aloges, Thanks for explaining that the engine I thought was a Zeus Olympic engine (because of the photographer's comment), is actually a General Electric GE CF6-50E2 engine. You can even see the GE emblem on the side of the cowling. I understand now that it's the 747 that's named Zeus, not the engines!  Nuts I guess it's safe to say you like these sweet! engines.


View Large View Medium

Photo © Marcel Venema - Dutch Ops



> Air2gxs, Thank You, for your info and explanations. Now I understand that these fairing's main purpose is for the Thrust Reverser system and that on some engines they provide a convenient place to put the drains.

I can clearly see the drain masts on the engines of the A340. I guess the pipe that can be seen protruding out from the bottom of this GE CF6-50E2 engine is a drain mast.


View Large View Medium

Photo © Marian Musil



> Victor Hotel, I'm not sure about what you're looking at either, but, I suspect you might be looking at the curves of the #3 engine in the background directly behind the main landing gear.


Chris  Smile

[Edited 2004-09-19 16:57:00]


"Just a minute while I re-invent myself"
User currently offlineVictor Hotel From Australia, joined Aug 2000, 305 posts, RR: 1
Reply 11, posted (10 years 2 months 4 days 2 hours ago) and read 5100 times:

Sorry didn't explain very well. The skin on the actual gear bay doors looks rippled, if you enlarge the first picture. The rest of the aircraft skin looks smooth except the main gear doors.


Top Of Page
Forum Index

Reply To This Topic A Jet Engine Question-What's This?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Ideal Jet Engine Question? posted Wed Apr 12 2006 03:56:39 by Lehpron
Jet Engine Question. posted Tue Mar 16 2004 00:13:11 by Mr Spaceman
Please Help Identify This Jet Engine posted Fri Jul 14 2006 23:34:50 by EDDM
Engine Ingestion And Jet Blast Question posted Thu Jul 13 2006 19:14:48 by Phxplanes
Question About Jet Engine Sounds posted Sun Jun 20 2004 22:12:17 by Ngr
What Do These Jet Engine Tubes Do? posted Thu Sep 12 2002 21:00:22 by Mr Spaceman
Vents On Jet Engine Tailpipe Question? posted Thu Feb 7 2002 23:57:10 by Mr Spaceman
Question About This Picture. posted Sun Oct 15 2006 21:38:07 by Dl757md
JT8D Engine Question posted Fri Aug 11 2006 00:28:02 by FlyIAD1
What's This Noise On Landing In A 777 posted Mon Aug 7 2006 03:59:39 by UAL747

Sponsor Message:
Printer friendly format