United4everDEN
Posts: 737
Joined: Fri Mar 12, 2004 12:36 pm

MD-80 Engine Question

Mon Nov 08, 2004 2:51 pm

Hello all,

Today I rode AA flight 1513 ORD-DEN, about my 6th flight on an MD-80. I was seated in row 28, in perfect view of the engine fan blades. We did the one engine taxi, and pulled onto the runway. I was really thinking, 'oh sh1t' as we spooled up to takeoff. It is pretty loud to begin with, so it was hard to hear it start up, but it obviously did.

So what good do the static fan blades have? Are these common on all MD-80s? All AA MD-80s?

Thanks,
Ryan
 
A10WARTHOG
Posts: 200
Joined: Mon Jul 12, 2004 7:32 am

RE: MD-80 Engine Question

Mon Nov 08, 2004 3:27 pm

The "static fan blade" are Inlet Guide Vanes that are used to straighten and guide the airflow into the first stage rotors. If I am not mistaken they are actually part of the case. The MD-80 have a turbojet engine (JT8D) on them. This engine is also on the 727 and 737-200 aircraft
 
BlueF9A320
Posts: 35
Joined: Fri Oct 01, 2004 3:32 pm

RE: MD-80 Engine Question

Mon Nov 08, 2004 3:37 pm

Actually the JT8D family of engines is actually a low bypass turbofan engine. The bypass ratio is close to 1:1, hence the relatively small size of the engine compared to modern day high bypass turbofan engine.

v/r

BlueF9A320
Audentes Fortuna Juvat...
 
A10WARTHOG
Posts: 200
Joined: Mon Jul 12, 2004 7:32 am

RE: MD-80 Engine Question

Mon Nov 08, 2004 3:47 pm

That right, my bad. I just read that in one of my books.
 
FBU 4EVER!
Posts: 980
Joined: Sat Jan 27, 2001 6:53 am

RE: MD-80 Engine Question

Mon Nov 08, 2004 5:51 pm

Actually,the MD-80 engines are JT8D-2xx series,whereas the early DC-9's,all 727's and 737-100/200 used the smaller JT8D-7/9/11/15 engines.These were also fanjets but the ratio was only some 0.43 if my memory serves me right.
"Luck and superstition wins all the time"!
 
miamiair
Posts: 4249
Joined: Thu Jul 15, 2004 9:42 pm

RE: MD-80 Engine Question

Mon Nov 08, 2004 6:54 pm

They are called stator vanes.
Molon Labe - Proud member of SMASH
 
AA717driver
Posts: 1502
Joined: Tue Feb 12, 2002 8:27 am

RE: MD-80 Engine Question

Tue Nov 09, 2004 2:16 am

There is a 5 minute warmup period that must be observed so the engine had to be started prior to taking the runway.

The -217's parts have a tendency to travel in directions other than that which they were intended if you don't observe the warmup and cool down limits...  Wow! TC
FL450, M.85
 
dl757md
Posts: 1482
Joined: Mon May 24, 2004 9:32 am

RE: MD-80 Engine Question

Tue Nov 09, 2004 3:13 am

They are called stator vanes.

Stator vanes are after each stage of compressor blades or the fan blades. They straigthen out the airflow that the preceding compressor section has swirled. Since they are behind the fan/compressor stages I think that what United4everDEN is referring to, are as A10warthog said, the IGVs, which are as he said, to straighten out the airflow entering the fan. Since they do not follow any fan/compressor section they are referred to as IGVs rather than stator vanes.

Dl757Md
757 Most beautiful airliner in the sky!
 
BR715-A1-30
Posts: 6525
Joined: Thu May 30, 2002 9:30 am

RE: MD-80 Engine Question

Tue Nov 09, 2004 12:38 pm

As a matter of fact, the ORIGINAL JT8D series engines (-1 thru -17) had not one, but TWO fans. One behind the other. If you look at a cutaway, you will see this feature.

JT8D-Basic
Puhdiddle
 
Lufthansa
Posts: 2303
Joined: Thu May 20, 1999 6:04 am

RE: MD-80 Engine Question

Tue Nov 09, 2004 12:58 pm

also the MD-80 JT8D-200 series engines have a much higher by-pass ratio than the original ones on the 727/737/DC-9 which is why they meet stage 3 (although only just!) still, i think its great. I love hearing an MD-80 take off, espectially in winter!

Thats what a real engine sounds like...not of this pussy wimpy CFM business.
Wings of a man!
ROAR!
 
timz
Posts: 6121
Joined: Fri Sep 17, 1999 7:43 am

RE: JT8D

Wed Nov 10, 2004 7:44 am

"...JT8D-7/9/11/15 engines.These were also fanjets but the ratio was only some 0.43 if my memory serves me right."

If my memory serves, their ratio was around 1:1. A Jane's from the 70s or 80s would tell.
 
User avatar
ATA L1011
Posts: 1276
Joined: Thu Mar 01, 2001 6:47 am

RE: MD-80 Engine Question

Wed Nov 10, 2004 8:25 am

I too love the sound of the MD80's Pratts but I love the way they sound during taxi and the transition sound from throttle up/down to taxi power.
Treat others as you expect to be treated!
 
September11
Posts: 3293
Joined: Fri May 21, 2004 12:49 am

RE: MD-80 Engine Question

Wed Nov 10, 2004 10:13 am

I like the feel of the roaring of a MD-80 engine! Take off and landing. Also power back, too.
Airliners.net of the Future
 
Silver1SWA
Crew
Posts: 4458
Joined: Wed Mar 10, 2004 6:11 pm

RE: MD-80 Engine Question

Wed Nov 10, 2004 10:29 am

I too love the sound of the MD80's Pratts but I love the way they sound during taxi and the transition sound from throttle up/down to taxi power.

Ahh, yesss...music to my ears! Now THAT'S what a jet engine is supposed to sound like. I love that whine!

As much as I like 737s, I dislike the "hissing" nature of their sound.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.