|Quoting FlagshipAZ (Reply 1):|
Probably the difference in engine thrust would be the deciding factor.
This might indeed be true but I'm pretty sure the original type certificate data sheet for the -11 (for example) authorizes JT
-1 through -7B just as it does for the -14/-15.
I flew several thousand hours in DC-9-15 exclusively and flew with the whole range of engines mounted with no perceptible differences noted. It has been a long time but I think I recall that our basic configuration was -7A or -7B. We were a pretty dirtbag outfit (how's that for honesty) and probably bought our engines by the ton. I think I recall a lot of intermix flying with a dash seven on one side and a dash five purchased out of a boneyard in Outer Umbrellastan on the other. Further it seems that any intermix we had to operate both at the lower thrust rating. I'm pretty sure I also flew with a -9 operated at -7 thrust for a while but no kidding, it really has been a while.
I know for certain that we occasionally ran JT
-1 for a time and once took one of them to the overhaul shop and got a phone call back from them the first day it was on their floor. It seems that we had a Pratt & Whitney prototype or something (call it a dash 0.5) because the compressor case was not split into two longitudinal halves that could be unbolted for disassembly. They had to remove the bullet and that assembly, slide the first compressor stage off the shaft, unbolt the stators behind it, slide the second stage off and so on. No one in that shop had ever seen such a thing.
But through it all the aircraft remained a -15, according to its stamped-in-metal dataplate.
Ran across this among my stuff:
DC-9-10 Popular nomenclature for Series 10
DC-9-11 (Series 10), initial production, JT8D-1 then also JT8D-1A/-1B/-5/-7/-7A/-7B/-9/-11/-17, MGTOW 77,700lb (later to 85,700lb); all converted to -14
DC-9-12 (Series 10), JT8D-5, later -1/-7, MGTOW 79,500lb, later 85,700lb; all converted to -14
DC-9-13 (Series 10), JT8D-5, later -1/-7, MGTOW 85,700lb; none built
DC-9-14 (Series 10), JT8D-5, later -1/-7, MGTOW 87,500lb, later 90,700lb
DC-9-14 (F) (Series 10), freighter conversion of -14 with SCD
DC-9-15 (Series 10), JT8D-1, later -7, MGTOW 90,700
DC-9-15 (F) (Series 10), freighter conversion of -15 with SCD
DC-9-15F (Series 10), freighter with SCD; JT8D-7, MGTOW 90,700lb
DC-9-15F (MC) (Series 10), Minimum Change (DAC
), -15F with folding seats
DC-9-15F (RC) (Series 10), Rapid Change (DAC
), -15F with seats on pallets
Or maybe it just comes down to whether the panel was...
Proper gray or Tijuana Turquoise.
Happiness is not seeing another trite Ste. Maarten photo all week long.