Old(er) aircraft question..

[PENKO]

Say my DC8 needs a new engine, where do I get it from? Are those old inefficient engines still in production? Are the scrapheaps my only option? How long have those old engines been produced?

Similar question for 'younger' old aircraft like the DC10, L1011. Are those engines still being made? What about other parts, like brakes. Who still manufactures those old obsolete designs to original secification? Must get quite expensive..


Maybe a daft question, but it's been bugging me for a long time

[411A]

As these older aircraft are scrapped, they are dismantled of various parts, and these parts are retained by certain companies for the re-sale to operators that need them.
A large business, make no mistake.

[Dan Winterland]

'Your' DC8 may have RR Conways which are still being re-manufactured to keep the RAF's fleet of VC10s going.

And I bet it's expensive!

[dixi188]

Engines are overhauled, with many parts replaced with new items.

Manufacturers are required to provide product support for many years after aircraft go out of production. Typically 25 years although this may be longer if there are still customers for their services.

A lot of aircraft are "Parted out" (Scrapped) and the useable components may be overhauled or repaired and sold on for further use. This is where accurate aircraft records are important so that the hours flown and flight cycles of parts is known.

A former employer bought several Lockheed Electras and Airbus A300s to strip for spares to support the operational fleet.

Hope this helps.

[PENKO]

Of course, I have no DC8!
So these old engines are still being manufactured by RR. Interesting.

411, I recently read an article about these scrapping companies, big business indeed. But how about stuff like engines, brakes...are there really enough of those lying around in 'the desert'? Or are GE and P&W still manufacturing those old engines for the DC10's and 747-200's flying around?


edit:dixi, just read your post about overhauling the engines, thanks!

[Storminnorm]

I don't think that the Conway fitted to the early DC 8 bears
an awful lot of resemblance to the more modern version
fitted to more recent aircraft.
They'd need an awful lot of work to convert them one way
or another.

[clunckdriver]

Penko, In many cases I have found the product suport for older aircraft to be superior to that provided for some of the new stuff! The MU2 comes to mind along with the 400 series Cessna twins as being examples of this , on the flip side we are stuck with very poor suport for some of the new corporate jets. If one looks through Trade A Plane one can find all sorts of companies who part out and suport these older aircraft, on top of this there are those who obtain the rights to produce parts for the older fleet.

[Lancelot37]

How does the use of newer and more modern lubrication oils affect the reliability of these engines? A lot of development has taken place since they were designed.

[clunckdriver]

Lancelot 37, In the case of turbine engines Its hard to say weather the new oils are behind the large extensions in TBO, however in the case of complex piston engines its plain to see {ie GITSO Conts} At O'Haul the lack of wear and carbon deposits are obvious even to the naked eye, thats the good news, the bad news is that a lack of sound operating methods by pilots with little or no knowledge of piston engines often undoes the good done by the new oils.

[lomapaseo]

Dixi188

Manufacturers are required to provide product support for many years after aircraft go out of production. Typically 25 years although this may be longer if there are still customers for their services.

I believe that the manufacturer can surrender his manufacturing and/or repair certificate at any time and thus his responsibility for upholding airworthiness (product support) in the eyes of the regulations.

The incentive to keep the original cerificate by the manufactuer is the profit from spare parts sales and repair programs. As design and testing is discontinued from the manufacturing cycle then the attractiveness of after market sales of used but not abused parts take hold.

[barit1]

FedEx and others are still operating 1970-vintage DC-10-10s (albeit converted to MD10 freighters), and GE is glad to keep supporting their CF6-6 engines at a fair profit. Likewise the LM2500 for industrial & marine apps, and the TF39 engines on USAF C-5's, although the latter aircraft are finally being upgraded to CF6-80C engines.

So P&W JT3D fans on a DC-8 are a very close cousin to TF33 engines in the B-52H, and the USAF expects to keep them flying another few decades. It is said that the mother of the last B-52 pilot has not yet been born.

[error_401]

I would go digging for STC's (supplemental type certifications) where somebody may have put newer engines on the old contraption already.

E.G. As far as I know Jet Aviation used to fly a DC8 or 707 with new engines. Needs verification.

Many old piston engined aircraft have been modified for turboprops DC3 (not sure) and the nice tri motor conversion of the vintage Dornier.

I know the problem is inherent on the C4xx series of light twins. The centurion looked as an option but then ...

Finally all a question of money. The manufacturers sure are happy to supply as long as it pays for them to have the old parts.

[barit1]

Re-engining

Probably the first commercially successful re-engining program was the Convair 580 (Allison 501 in place of R-2800s). 20 years later it was the DC-8-70 series (CFM56 vs JT3Ds)). In both cases over 100 ships were reworked.

One project TWA was considering in the mid-70s was to refit their CV880s, removing the straight-jet CJ805-3s with JT8D fans. Never happened, although some detailed engineering was underway.

LH at one time proposed reworking their 737-200 fleet a la 737-300 w/ CFM56s, but it was a bridge too far. Likewise Spantax wanted to "upgrade" their CV990's, replacing 4 CJ805-23 fans with 2 CF6's. (I wonder how long the MLG extensions would have to be?)

Similarly Delta and All Nippon threatened to refit their L-1011s with CF6-80A engines, and if they could have gotten TWA on board, it might have happened. DL and NH both had CF6-powered 767s coming on board 1982-83, so there was a commonality factor to consider.

[Biggles78]

Penko, Google aircraft boneyard and check out the links. Google Earth is also a good place to see exactly what has been stored for .........

[glhcarl]

Similarly Delta and All Nippon threatened to refit their L-1011s with CF6-80A engines, and if they could have gotten TWA on board, it might have happened. DL and NH both had CF6-powered 767s coming on board 1982-83, so there was a commonality factor to consider.

I would like to know how DL and NH would have accomplished installing CF6's on the L-1011 when Lockheed (the manfacture of the L-1011 by the way) studied the use of CF-6's and found that the engineering requirements were too much to overcome? The CF-6 is longer and lighter than the RB-211 installation would have required new wing pylons, a new S-Duct, a complete redesign of the aft body so the engine mounts could be relocated and the longer engine faired in to the fuselage. In addition to the above use of the CF-6 would redesign of the electrical, hydraulic, fuel and pneumatics systems match up with the CF-6. All that and a complete flight test program to prove the new design airworthy?

Finally, by 1883 the RB-211 was proving its self to be very reliable. It was about that time when DL set a record of having a RB-211 on-wing for 15,000 hours.

[barit1]

The CF6-80 family, developed about 1980 (doh!), is roughly 24" shorter than earlier versions.

Delta had experience with the DC-8-70 re-engining and in fact accomplished conversion of a dozen of their own aircraft (under license from Cammacorp, the STC holder), and proceeded to convert several dozen other DC-8's for worldwide customers. I don't think they saw a TriStar conversion as an overwhelming challenge.

[barit1]

In 1986 I spent some time at the Royal Jordanian main shop in Amman. Rolls had a crew of 8-10 UK technicians (I carpooled with them) there attempting to expedite RB shop visits to keep their L-1011 fleet healthy. Their average RB life on-wing was a few hundred cycles. True, it was a trying environment, but nonetheless a highly labor-intensive program.

[glhcarl]

Delta had experience with the DC-8-70 re-engining and in fact accomplished conversion of a dozen of their own aircraft (under license from Cammacorp, the STC holder), and proceeded to convert several dozen other DC-8's for worldwide customers.

Delta did not do the engineering for the DC-8 re-engining they installed kits they bought from Cammacorp.

I don't think they saw a TriStar conversion as an overwhelming challenge.

All I can say is you have no idea what your talking about!

If the re-engining could have been accomplished it would have been. It was investigated by Lockheed more than once and each time it was determined to be technically and econmically unfeasible.

Do you actually think that Delta could accomplish the engineering required for an L-1011 re-engining program when Lockheed couldn't. I worked with Delta engineering for years, they were not equipped and did not have substantiating data that would have been required for such an undertaking.

Their average RB life on-wing was a few hundred cycles.

I wonder why they never reported that to Lockheed? I think that it they were having so many engines problems we would have heard about it in the L-1011 support center?

How much L-1011 experance do you actually have? I have read other posts you made where you made outragious statements about the TriStar? As for me I was there when s/n 1001 was placed in the wing mate jig. I was in L-1011 product support for over over twenty (20) years and have over thirty (30) years on the program.

[barit1]

glhcarl:

I wonder why they never reported that to Lockheed? I think that it (sic) they were having so many engines problems we would have heard about it in the L-1011 support center?

I cannot answer that question, because as you imply, I never worked on the TriStar directly. My impression is that it's clearly an outstanding airplane even today.

But my experience at RJ, the numbers quoted, the conversations I had with R-R and RJ people, are just as I related.

And I suspect All Nippon was interested in having IHI or Kawasaki take on the pylon/mount/systems design for a CF6-80A conversion in collaboration with DL and NH. Maybe it was all a game of "chicken", or maybe it was genuine. But the talk was real.

[captjns]

Say my DC8 needs a new engine, where do I get it from? Are those old inefficient engines still in production? Are the scrapheaps my
only option? How long have those old engines been produced?

Contact any heavy Mx shop. They can lead you in the right direction.