smartt1982 From United Kingdom, joined Nov 2007, 212 posts, RR: 0 Posted (3 months 1 week 6 days 9 hours ago) and read 2586 times:
Anytime I see some of the older jets take off e.g. older MD 80 series etc. I notice a fiar amount of what I would describe as a very smokey oily exhaust trail.
Now I realise that the aircraft and engines are probably not the newest but is this just the way the engines are, even with the necessary and required maintenance these older engines will allows produce more a s smokey oily exhaust trail?
Polot From United States of America, joined Jul 2011, 1499 posts, RR: 0 Reply 1, posted (3 months 1 week 6 days 8 hours ago) and read 2567 times:
Quoting smartt1982 (Thread starter): Now I realise that the aircraft and engines are probably not the newest but is this just the way the engines are, even with the necessary and required maintenance these older engines will allows produce more a s smokey oily exhaust trail?
Yes- because the smokey trails stem from design, not maintenance. They just don't burn as cleanly as newer engine designs, and no amount of maintenance can fix that.
srbmod From United States of America, joined Mar 2001, 16888 posts, RR: 51 Reply 3, posted (3 months 1 week 6 days 6 hours ago) and read 2488 times:
Quoting Polot (Reply 1): Yes- because the smokey trails stem from design, not maintenance. They just don't burn as cleanly as newer engine designs, and no amount of maintenance can fix that.
Early jet engines at times required water injection in order to product the needed thrust for takeoff. As technology improved, the need for water injection was lessened as engines were able to produce the necessary thrust without having to use water injection.
The MD-80s are really the last of the "smoky" airliners as the engine tech has improved even further. The engines on the MD-80 are updated versions of the same engine they used on the DC-9 as well as the 727 and the 737-100 and 737-200.
fuelfool From United States of America, joined Feb 2011, 133 posts, RR: 0 Reply 5, posted (3 months 1 week 6 days 2 hours ago) and read 2393 times:
Between the nasty exhaust of the huffer and the engines on the DC8, I used to feel like I could feel cancer cells forming in my body every time we fired one up.
I love the smell of jet fuel in the morning...Smells like victory!
jetstar From United States of America, joined May 2003, 1524 posts, RR: 10 Reply 6, posted (3 months 1 week 4 days 3 hours ago) and read 1882 times:
The black smoke you see coming from the exhaust of jet engines in carbon. One of the effects of these carbon particles was erosion of the turbine blades. The jet engine manufacturers redesigned the combustion chambers to burn up the carbon internally instead of it coming out of the exhaust and this basically eliminated exhaust blade erosion.
Many years ago when I was working on the turboprop Grumman Gulfstream 1, the RR Dart engines would build up a clump of carbon within the combustion chamber and when it grew large enough, it would let go and come out the exhaust pipe, you would see these on takeoff as a puff of black smoke. I believe the term RR used was clingers and it was causing erosion problems on the turbine blades, RR redesigned the combustion chamber and it solved the problem.
When I was flying the JetStar and ATC called out traffic and if the visibility was clear enough you could spot the airplane by the black smoke, especially if they were climbing out on takeoff.
It was in the late 1970’s or so when due to FAA, I believe under pressure from the EPA the engine manufacturers redesigned the combustion chambers and they had to be installed whenever the engine was overhauled.
KELPkid From United States of America, joined Nov 2005, 5932 posts, RR: 4 Reply 9, posted (3 months 1 week 2 days 17 hours ago) and read 1481 times:
Under certain conditions, the IAE V2500 gives off a little bit of smoke trail, guess it is the Pratt & Whitney heritage of the combustor showing through
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
LH707330 From United States of America, joined Jun 2012, 181 posts, RR: 0 Reply 10, posted (3 months 1 week 1 day 18 hours ago) and read 1169 times:
Quoting KELPkid (Reply 9): Under certain conditions, the IAE V2500 gives off a little bit of smoke trail, guess it is the Pratt & Whitney heritage of the combustor showing through
Often that's due to dirt in the combustor, I've seen CFM56s and other new engines do this as well.
Sponsor Message: 
From United Kingdom, joined Nov 2007, 212 posts, 
From United States of America, joined Jul 2011, 1499 posts, 
From India, joined Jan 2001, 31201 posts, 
From Japan, joined Aug 2003, 7637 posts, 
Sponsor Message: 
Printer friendly format
