MD-80 Question

[FirstMate]

For Bafanguy and any other MD-80 gurus:
What is the difference in the models that have the square, flat edge tail cone and the ones with the rounded cone?
Thanks!
-FM

 

[five-alive]

I thought the "boat tail" was a retrofit. Anyway, I think its supposed to be lower drag than the cone tail, explaining why they chose it on the 777 over the cone tail.

 

[FirstMate]

Someone once told me you can differentiate between which a/c have glass technology and others that don't...we happened to be watching AA -80's pass by during the discussion, so I don't know if that holds true for all -80's...myth or fact anyone?

 

[flx757]

Not from the outside, as far as I know. Here at Alaska, unless you just happen to know which N numbers are the glass aircraft and which have round dials, you wouldn't know from the outside. It has nothing to do with the tailcone, that's for sure.

Early MD-80s ALL had the rounded tailcones. Later models then came with the "screwdriver" style, which then was available as a retrofit for earlier models. Today, any model MD-80...MD-82, -83, -87, -88 as well as MD-90s and B-717s have (or can have) the newer tailcone.

 

[bafanguy]

Small drag reduction as far as I know.....1/2% over all ( don't quote me ) ?? I'll do a literature search in the basement, but don't recall seeing/reading anything definitive on this. We called it the "screwdriver tip".

 

[habubuaza]

I believe it's just a drag reduction issue, and after a certain date that's how MD80 series aircraft were rolled out....

 

[bafanguy]

Basement Literature Seach...complete, Sir. Habub is correct. Here's a quote from PIP, first quarter '88, pg 9:

"The extended tailcone assembly is an integral part of the MD-80 Cruise Performance Inprovement Package. This fairing improves the airflow in the aircraft fuselage and increases aerodynamic efficiency. An equivalent of about 700 lb. weight reduction is realized by the approximate 0.4% cruise fuel burn improvement over the former tail...".

I had guessed 0.5% earlier ( insert picture [here] of me patting myself on the back ). Geritol washed down with a cheap Austrailian white wine...breakfast of champions.

Habub is also right about when the tails appeared. The first 8/9 DL MD-82's(steam gage ) came with the old tailcone. Starting with ship #910, they were delivered with the screwdriver...and the factory glass. Later, #901-909 were retrofitted ith the new tailcone and glass. I'm pretty sure about the numbers.

 

[CaSyndrm]

1% per year in fuel savings.

 

[FirstMate]

Awesome. Thanks for the info guys...

 

[XTW]

AKA- "Chisel Tail"