"Old" vs "New"

[CopilotDoug]

There are several airline/transport aircraft out there that have been re-engined and I was curious as to how much of a performance variation there is in max performance climb rates, normal climb, cruise, etc. Anyone with experience in both types of a model to compare performance?

Examples:
Original 727 v. the Super 727
Straight pipe DC8 v. CFM powered DC8
DC9-30 v. MD-90 or even the 717
JT3 707 v. CFM 707

 

[FreightNazi]

UPS Tay powered 727. Ready to level off in the climb? Turn the engine anti-ice on. Ready to start down? Turn on wing heat! Doesn't perform nearly as well as JT-8 powered 727-100 at higher altitudes.

 

[CrimsonEclipse]

There are several airline/transport aircraft out there that have been re-engined and I was curious as to how much of a performance variation there is in max performance climb rates, normal climb, cruise, etc. Anyone with experience in both types of a model to compare performance?

Examples:
Original 727 v. the Super 727
Straight pipe DC8 v. CFM powered DC8
DC9-30 v. MD-90 or even the 717
JT3 707 v. CFM 707

Most upgrades ('cept the tays) off a considerable increase in performance.
The -200's on the 1 and 3 pylons make the #2 unnecessary for power (but
needed for certification). Most CFM56 upgrades are derated but still offer
major hot and high upgrades. The B717 will damn near stand on its tail if
empty. The -200 upgrade on the 707's is also rather impressive.

More and more, companies are just replacing the entire airplane. Newer
aircraft not only cut down on fuel charges but maintenance is decreased,
in some cases, up to 80% (737-200 -vs-737-700).

The higher the potential utilization rate, the cost effective a new hull
will be.

CE

 

[CopilotDoug]

UPS Tay powered 727. Ready to level off in the climb? Turn the engine anti-ice on. Ready to start down? Turn on wing heat! Doesn't perform nearly as well as JT-8 powered 727-100 at higher altitudes.

No offense against the Tay, I didn't mention it because it was my understanding that UPS used these for fuel efficiency over the Standard JT8s.

Did the Tays offer any increase in maximum takeoff weight?

 

[CrimsonEclipse]

No offense against the Tay, I didn't mention it because it was my understanding that UPS used these for fuel efficiency over the Standard JT8s.

Did the Tays offer any increase in maximum takeoff weight?

No actually a decrease in MGTOW. They were more fuel efficient.
and low maintenance.

CE