Odd engine settings....YouTube vids

FR85

Been looking af some of these, and the way engines respond during the take off roll seems bizarre.

EGT on 3 on this vid at 4.03 approx, EPR, FF and N1 seem normal, why the drop in EGT? Again, all over the place at 5.33
http://www.youtube.com/watch?v=F7qcRhAs6GM

And again here, Fuel Flow and N1 is all over the place!! No. 2 just before the camera pans up seems to be loving the gas!!!
http://www.youtube.com/watch?v=2KreKVGomZQ

Now I assume this is in limits and the F/E is keeping an eye out but is this down to individual engine temperments or are there mix matched engines on the aircraft, ie different models or the RR RB211/ P&W JT9D?

Also, I remember reading that no two 747 classic cockpits are the same due to different orders by airlines, note the auto pilot command switches!!

smurfjed

Excellent video thanks for sharing

I'm guessing that its a Pratt engine as its N1 limited, with the Rolls you can intermix the engines, a D4X and D4 intermix meant that all engines had to be operated as a D4. Intermixing between a D4 and C2 would result in 2 different thrust settings, however, you would have different EPR settings or in this case N1.

This video appears to be made up from a number of different videos, if you look at the Thrust Limit computer, its based on CLB thrust of 101.6 and shows engine 50E2, and then at 5.33 you have N1 settings of 106/107. I don't think that i can ever remember seeing all 4 engines with equal settings, remember that these are old engines.

This is a nicely retrofitted Classic, FMS, glass displays etc. Due to the age of the aircraft, there are many different cockpit configurations including a couple that are total glass. We have 4 of them left in operation and each one has a different cockpit layout

Final point about the video, its a pity that they didnt allow it continue in real time for the landing.

smurfjed

FR85

This video appears to be made up from a number of different videos, if you look at the Thrust Limit computer, its based on CLB thrust of 101.6 and shows engine 50E2, and then at 5.33 you have N1 settings of 106/107. I don't think that i can ever remember seeing all 4 engines with equal settings, remember that these are old engines.

The vids are most probably edited and patched together by some idiot in an office!!

Would different thrust settings increase fuel burn due to a constant yaw on the aircraft over long sectors? The fuel burn does look consistant on the Martin Air vid, it's just the EGT that gets me!!
I under stand that the engines are old but I would have imagined that all engines should provide a stable/equal amout of thrust, most of all during take off!!

Is your company still flying the Classic?? I'd hate to see their fuel bill!! I don't know what it is but I've been studying both the 742 and 722 systems, check lists and operations for the last couple of months......complete waste of a mans time as seen as I'll never get with in a sniff of one!!!

smurfjed

Is your company still flying the Classic??

Still operating the SP, 200,300,400 and 8F, with a couple of derelict 100's sitting around.

should provide a stable/equal amout of thrust, most of all during take off!!

Nope, jumpseated a lot in these aircraft, kinda disconcerting to see the FE pull back a throttle during the takeoff roll to keep it within temperature limits. We operated from a place in Asia, 10,000 ft runway with no obstacles, so it was always a limited takeoff weight, the aircraft used to scrape out over the runway end lights. Extremely exhilarating takeoff. Look at pictures of PIA operating out of Manchester and you will see what i mean.

smurfjed

FR85

smurfjed wrote: »

Still operating the SP, 200,300,400 and 8F, with a couple of derelict 100's sitting around.

Nope, jumpseated a lot in these aircraft, kinda disconcerting to see the FE pull back a throttle during the takeoff roll to keep it within temperature limits. We operated from a place in Asia, 10,000 ft runway with no obstacles, so it was always a limited takeoff weight, the aircraft used to scrape out over the runway end lights. Extremely exhilarating takeoff. Look at pictures of PIA operating out of Manchester and you will see what i mean.

smurfjed

Would love a tour at some point of a Classic!!! Thanks for all your info!!!

pclancy

FR85 wrote: »

I under stand that the engines are old but I would have imagined that all engines should provide a stable/equal amout of thrust, most of all during take off!!

No way. A first officer regaled me recently with a story of a certain 737-300 in Air Nz's fleet that always needed a good bit of left rudder to keep on the centerline. With both throttles at the same setting no.1 was producing a good bit less then no.2 but wasnt a big enough issue to warrant an engine change before its next major service

There's a lot of things that can be slightly wrong with an aircraft yet still be perfectly safe to fly.

FR85

pclancy wrote: »

No way. A first officer regaled me recently with a story of a certain 737-300 in Air Nz's fleet that always needed a good bit of left rudder to keep on the centerline. With both throttles at the same setting no.1 was producing a good bit less then no.2 but wasnt a big enough issue to warrant an engine change before its next major service

There's a lot of things that can be slightly wrong with an aircraft yet still be perfectly safe to fly.

I've studied this as mentioned and can remember the Britiish Airtours 732 in Manchester, they knew of reported problems in the left engine as reported but I just looked at the vids and thought it out of the norm to continue TO!!!

Thanks for all info, love learning!!!