Guest

AC-767-engine Question

Thu Feb 13, 2003 8:50 am

I was spending some time at the Boeing Website lately and having gotten through the aircraft orders/deliveries-list I was amazed about Air Canada and the diversity in the powerplants of their B767-fleet .Their -200/200ER are listed as having JT-9D-engines while the -300ER´s are powered by the more advanced PW4000´s.Along comes the CF6-80-powered B767-300ER that was added to the fleet when Canadian Airlines was merged into AC and we end up having a fancy mish-mash of powerplants within a single aircraft-type fleet and I´m trying to figure out the maintenance nightmare they eventually have to deal with.......!Now that´s not the point of my question however,I´m just not sure about what exactly is the difference between the JT-9D and the PW4000 on the 767.I know they are powerplants of "different generation" but I didn´t know that there are 767´s with JT9D´s up there (thought all PW´s on 767´s were automatically PW4000).Is JT-9D still an option on the seven-sixes today and how many of them have been built?


View Large View Medium
Click here for bigger photo!

Photo © Legolas Flix



View Large View Medium
Click here for bigger photo!

Photo © Javier F. Bobadilla



View Large View Medium
Click here for bigger photo!

Photo © Florian Kondziela



Marco
 
gigneil
Posts: 14133
Joined: Fri Nov 08, 2002 10:25 am

RE: AC-767-engine Question

Thu Feb 13, 2003 4:56 pm

The JT9D went out of production in October of 1990, if I'm not mistaken.

Many of UA's 762s are JT9D powered as well, as are QF's.

I wish I could tell you the difference. I can't. The PW4000 is a much more advanced engine.

N
 
boeingnut
Posts: 390
Joined: Tue Oct 30, 2001 5:46 am

RE: AC-767-engine Question

Thu Feb 13, 2003 10:21 pm

According to "http://www.pratt-whitney.com">Pratt & Whitney's web site, there were over 2700 JT9Ds built.

I forgot where I read it (I am sorry about that, I think it was in one of the books about the development of the 777), but I think that the PW4000 has something like 30% less parts than the JT9D, mainly due to welding together of many parts, making it a much easier engine to take apart.

Compare the stats of both engines (again, taken from PW website):

JT9D
Engine Characteristics
Fan tip diameter:
93.4 inches
Length,flange to flange:
132.7 inches
Takeoff thrust:
48,000 -56,000 pounds
Flat rated temperature:
86 degrees F
Bypass ratio:
4.8-to-1
Overall pressure ratio:
26.7
Fan pressure ratio:
1.67

PW4000 - 94" fan version
Engine Characteristics
Fan tip diameter:
94 inches
Length,flange to flange:
132.7 inches
Takeoff thrust:
52000 - 62000 pounds
Flat rated temperature:
86 or 92 degrees F
Bypass ratio:
4.8-to-1 to 5-to-1
Overall pressure ratio:
27.5 -32.3
Fan pressure ratio:
1.65-1.80

And here is some more info (fairly general, though) showing the evolution of technology from the JT9D up to the current generation of PW engines (PW2000, PW4000, etc.) (Again, from pratt-whitney.com)

Flying Feats

Full-Authority Digital Electronic Control (FADEC)

The industry's most experienced and reliable engine control system was introduced into commercial aviation in 1984 on the PW2000 engine. Compared to earlier hydro-mechanical systems, the microprocessor-based FADEC significantly reduces pilot workload with "set and forget" thrust management and improves fuel economy. Engines with modern FADEC units have increased capabilities for on-condition monitoring, fault diagnostics and troubleshooting.

Thermal Barrier Coatings

These advanced coatings are used to help protect hot section components, such as combustor liners and turbine airfoils, from the engine's intense temperature environment. Uniformly sprayed at approximately 0.002-inch thick, the coating enables parts to withstand much higher operating temperatures and achieve longer part lives to reduce maintenance costs.

Single-Crystal Materials

These super-alloys eliminate a metal's grain boundaries – a source of mechanical failure with conventional metals. This produces a much stronger material with greater temperature capability that is ideal for components of the engine's combustor and turbine sections. Advanced single crystal alloys are used in all of Pratt & Whitney's modern military and large commercial engines.

TALON Combustion Technology

This is the next generation of low-emissions combustor technology. It is especially designed to lower oxides of nitrogen. TALON retains the Floatwall's segmented liner construction for easy maintainability and the use of airblast fuel nozzles for excellent fuel atomization and shorter residence times.


I hope this helped some. If you need some more info, I can try and talk to some of my contacts in PW to get some real in depth information.
Excuse me, but what does God need with a starship?
 
boeingnut
Posts: 390
Joined: Tue Oct 30, 2001 5:46 am

RE: AC-767-engine Question

Thu Feb 13, 2003 11:51 pm

http://www.pratt-whitney.com

This automatic linking "feature" messed up my link.
Excuse me, but what does God need with a starship?

Who is online

Users browsing this forum: No registered users and 14 guests