Why No MD80 Freighters?

[airvanman]

We had DC-9Fs in the past but not any MD80 srs aircraft built or converted - Why?

You can now get them for a song and loads are up for sale. Someone must be thinking of doing conversions?

[Boss Raptor]

very simple answer I am afraid - Boeing has done the full development and design in house on the MD80SF Freighter Conversion some years ago utilising the same door mount and structure as the DC9 and aimed at all MD80's but primarily the MD82 - however I am led to believe Boeing will not pursue the programme and/or offer/provide support to third parties who may wish to pursue a similar STC

I will not expand as to my own thoughts as to their reasons as it would not be correct to do so and I am sure commercial and rationalisation of fleet support comes into it

[CargoOne]

Aircraft of MD80 size should be paletized/containerized. MD80 is too narrow to load standart industry pallet (same story DC9). So it can be either bulk load or special size container, either option never attracted serious customers.

[Boss Raptor]

partly true but not actually quite eventually correct - the planned Boeing conversion loads conventional pallets but sideways in/on to address this problem - thereby keeping commonality

[Hunter58]

There are enough 737 classics around to convert....

[CargoOne]

Boss Raptor

You mean they were going to load pallets 88" wide? What was the planned total pallets number then?

Another problem common to rear-engine streched (or should we say overstreched?) aircraft like MD80 and F100 is weight&balance issues. I have seen proposed F100 freighter paperwork and w&b was a bit tricky and limiting.

[Boss Raptor]

standard narrow body pallet ala 707 and it appeared to work fine on loading/balance envelope - cant recall and the spec sheet for the MD80SF has been removed from Boeing.com since the suspension of the project, I probably still have the proposal in my UK office somewhere but am away for 2 weeks

[RevMan2]

If you load 125N pallets lengthwise, you'll get 30% (rounded down) than if loading normally.

737-300F = 8 Units, 5 if loaded lengthwise.
Never really a business case there, although I believe some were converted for use with 108N pallets.

[G&T ice n slice]

Hi.

I think you were looking for this thread?

herewith follows more than you want to know about the DC9-3x-series freighters:

We used to operate DC9-33-RC (“Rapid Change”) and handle another co’s DC9-3x-F (pure freighter)
this is all from memory, and it was a long time ago on a planet far, far way, so don’t shout at me if I’m rong

Various loading options (pallet positions) using 108x88N (274x224 cm) and/or 125 x 88 N (318x224 cm) pallets/containers
The 108x88N pallets were loaded with 108N cross-wise (width of aircraft) and the 88N in length of aircraft.
The 125x88N pallets were loaded with the 125N in length and 88N on width of aircraft.

Someone makes the comment that the 108x88N pallets aren’t industry standard. Ummm I hate to disagree but the 108X88N pallets were the industry standard from about 1943 (C54/DC4 onwards. military derived dimensions.)

The aircraft were fitted with a ball-mat in the doorway so the 125N pallets could be swung round before being pushed into place.

In fact the doorway opening was 136N so if the hi-lo was wide enough you could just slide pallets in ready positioned with the length of pallet. But generally most of the rest of the ground handling equipment was designed to fit inside the 9-foot road standard so the entry/exit points were along the short edge which meant that the 125N pallets would always be delivered in the wrong orientation. But I digress...

Load could be :
all 108x88N
or mix of 108x88N and 125x88N
or all 125x88N

various loading configurations as below
(a) 8 @ 108x88N
(b) 6 @ 108x88N PLUS 1 @ 125x88N
(c) 5 @ 108x88N PLUS 2 @ 125x88N
(d) 4 @ 108x88N PLUS 2 @ 125x88N
(e) 3 @ 108x88N PLUS 3 @ 125x88N
(f) 2 @ 108x88N PLUS 4 @ 125x88N
(g) 1 @ 108x88N PLUS 4 @ 125x88N
(h) 5 @ 125x88N (nil 108x88N)
[[DC9-33-F additional 2 x 88x54N pallets see comments below]]

The ‘standard’ versions used were :
(a) above which we referred to as ‘eight one-oh-eights’;
(c) above which we referred to as ‘five-and-two’;
(f) above which we referred to as ‘four-and-two’.
Thinking about this now there’s a rather obvious chance for confusion there....
(h) above which we referred to as ‘five one-two-fives’.

Loading positions [‘RC’ version] were referred to a “A” through “H” - with the “A” pallet being the most forward position in the aircraft, “H” in the tail.

Our standard versions: Pallet configurations
(a) above : loaded A-B-C-D-E-F-G-H [all 108N pallets flush together]
(c) above : loaded A-B-C-D-E + F-H [A to E 108N and F-H 125N with “+” representing a 14 inch (36cm) gap between position E and position F
(f) above : loaded A-B ++ D-E-F-H [A &B 108N and D-H 125N with “++” representing a 28 inch (72cm) gap between position B and position D
(h) above : loaded +++ B-D-E-F-H [all 125N flush together with “+++” representing a 79N gap between the crashnet and the first pallet.
This 5x125N version could be a b***r to trim occasionally, as the ‘B’ position had to be a ‘crushable’ load {being in effect the ‘A’ pallet} which generally meant that it was comparatively lightweight so the c-of-g would always end up a bit back.


The only difference as far as I can remember between the ‘RC’ and the ‘F’ was that the RC had hat-racks in place (but stowed of the way) and also had the rear toilet and the forward galley in place, whilst the ‘F’ didn’t have these obstructions.

However the actual locking positions for pallets were the same for both the ‘RC’ and the ‘F’, but the ‘F’ would usually be loaded with a ‘half-pallet’ in both front & rear positions. the half-pallet was 54x88N. these pallets would be loaded with the 54N in the length of the aircraft and the 88N in the width - at the rear this was to fit inside the pressure bulkhead and at the front to fit in the forward curvature of the aircraft and to allow access to the forward door

The biggest difference between the ‘RC’ and ‘F’ versions was that the pallet/container contours were slightly more favourable on the ‘F’ version (no hatracks in the way) You could load a standard 125x88N ‘square’ lowerdeck pallet at 64N high on the ‘F’ whereas for the ‘RC’ you had to chop a triangle out along both of the long sides of the pallet to clear the hatrack. From memory this contour started at 56N above pallet and was 6 inches in at the 64n height. volume loss was fairly minimal, but sometimes it did mean that a transfer ‘lower deck’ pallet would end up with 1 odd box unloadable with its companions ((or loaded on top with a big label saying “RELOAD ME PLEASE”)).

The odd gaps I refer to (see above under “Our standard versions: Pallet configurations”) were HUGELY useful ((note NOT the 5x125N version where there were no protusions allowed as could penetrate the crashnet))

in the 5x108 plus 2x125N versions the 14N gap could be used to accommodate the cut-out of a standard LDC (baggage container) this meant that you could load two LDCs back-to back on a single 125N pallet (one cutout into gap between ‘F’ and ‘E’ and one cutout into a gap left on the ‘H’ pallet). Similar trick with the 2x108N plus 4x125N version.

Nevermind all those overlength bits, which would fit into the gaps and not mean losing space on another pallet.

In fact ‘overlength’ pieces were not a problem with the DC9 RC/F, since loading them onto a 125N pallet running lengthwise in the aircraft meant that you could overhang aft, forward or fore-aft. With a bit of care, squared graph-paper, a sharp pencil & a good ruler you could plan awkward long pieces very easily.

As regards other loading items, the aircraft was easy to trim in almost any configuration: basically lightest to heaviest pallet fore to aft and there you were done! (except of course now and again when zone-limits would get in the way).

Maximum weights of pallets (other than the “A” pallet which had to be crushable) - again from memory - were 3675Kg for a 108N pallet and 4255Kg for a 125N pallet, except a 125N pallet in ‘F’ position could be 6350Kg ((zone limit for F-H was 8500Kg, so then max in ‘H’ was 2150)). The ‘F’ position was virtually over the wing carry-through box. I have a vague feeling that a 125N pallet in the ‘E’ position could also be a much higher weight.

One nice thing about the ‘RC’ was that the rear airstairs were there. so very long, light objects (yacht masts, pole-vaulters’ poles etc) could be carried up the airstairs and tied-down against the cabin wall in the space next to the 125x88N pallets ((gap between wall & pallet was 10 inches by ‘very long’ I think we got up to 21 feet long before we chickened out and stopped trying longer pieces. This was because we couldn’t calculate what the theoretical maximum was, and at 21 feet long at 04:00 on a stormy December’s night we had a wet, cold and just slightly annoyed head loadie bang into the office and say (censored).

The max payload of the “RC” was 14,000 (and something) Kgs. We averaged around 12,000Kg per departure. Monday & Sunday nights averaged about 9,000 but the other 7 ops were pretty solid (a.k.a. overbooked). I would guess we had about average density cargo overall (i.e. about 150K/M3), so generally we weren’t voluming out before we weighted out.

As regards unloading/loading the Aircraft.
If loaded with 108N pallets in the forward positions unloading would generally follow a sequence:
(1) the crashnet was released and the ‘A’ position paller moved slightly forward & relocked. (now clear of forward door edge)
(2) the ‘B’ pallet was then unloaded and the next pallet aft moved forward.
(3) before this pallet was unloaded the pallet behind it was also moved forward. Only once that had been done was another pallet unloaded.
This would be continued until no pallets were aft of the c-of-g whereupon the pallets would al be offloaded, with the ‘A’ position pallet removed last.
Loading was reverse, with the ‘A’ pallet going in first & positioned temporarily forward (clear of the door), then moving in each pallet in order aft-to-forward position. Again as far as possible no pallets were moved into final postion until the next forward pallet was onboard in the doorway.
Last action was to position the ‘A’ pallet in place and connect the crashnet. I was always told by the W&B guys that you couldn’t actually stand the DC9 on it’s tail, but aftera an embarassing incident with a DC6F & a large generator loaded through the rear door....

Overall I liked the DC9 RC & F. My experience with B737 was that there were a HUGE number of things you couldn’t do, the contour was much more of an issue (for connecting lowerdeck pallets) and just generally wasn’t as freight-friendly. But I only came across the 737 on occasional sub-charters so who knows?

As to why no MD80-series freighters? I would guess the same reason as no DC9-40/50 series freighters. The extra length probably means that the wing-carrythough box and the fuselage itself is already at close to safe structural limits to accommodate a relatively low-density load, i.e. passengers compared to freight and that trying to strengthen to take a freight door (heavy)and a freight floor (heavy) would just not be worthwhile. Additionally I cannot imagine that such a conversion would be particularly easy to trim. Finally with fuel costs the way they are and with ‘thirsty’ JT8s I cann’t imagine that the economics of a conversion would work.

Congratulations you’ve reached the end of my ramblings !

Cheers
p.s. sorry - I didn't fly the things, I was just the chap who organised something to go on board & pay for the fuel, which occupation, according to a tempoprarily excess-to-requiremnts-at-the-time F.O. who was assigned to help us out in the freight world, was actually nearly as much fun as doing the flying. But then again maybe he was just being nice...

[Dutch74]

Whoa......................

[Buster Hyman]

Well done G&T, you've just killed a potential 12 page thread with that post!

;);):ok:

[G&T ice n slice]

Glad you liked it..

Just don't get me started on the DC8-5x-F (actually tthey were all 'RC-ish') OR the DC8-5x-Combi Abadan-Rangoon-HKG and ABD-RGN-SIN.

G

[Buster Hyman]

One of the very first aircraft that I stood next to as it taxied to the stand was an ANZ DC8F and it wasn't a re-engined one either...my teeth still rattle just thinking about it!:uhoh:

[airvanman]

G&T :D Good un.

;) Why no Fokker 100 Freighters?

Cheers!
Airvanman