Lockheed LG-603 ATA Tank Carrier Aircraft

[overscan (PaulMM)]

1/100 Lockheed LG-603 ATA Tank Carrier Aircraft

Gallery

 

[overscan (PaulMM)]

1/100 Lockheed LG-603 ATA Tank Carrier Aircraft

Gallery

 

[Hank58]

Beautiful! Let me check what I can find, but interestingly the Lockheed C-X competitor was the model LG-610A, which lost out to the C-17. That puts the LG-603 design in the early 1980s.

 

[Pioneer]

Nice find Overscan!!

The wing arrangement, which appears to avoid cargo compartment, is very reminiscent of the Ilyushin IL-76 Candid design.

Regards
Pioneer

 

[Hank58]

Beautiful! Let me check what I can find, but interestingly the Lockheed C-X competitor was the model LG-610A, which lost out to the C-17. That puts the LG-603 design in the early 1980s.

Well, still looking. I know somewhere in old boxes in the basement I have something on the Lockheed ATA program. I'm almost certain this early to mid-1980s in-house IR&D project was the "Advanced Technology Airlifter" and under that topic many distinct design studies were executed. Most, as I vaguely recall, were centered on design optimization for efficient high-transonic cruise with significant computational fluid dynamics modeling (practical CFD tools just emerging at that time) and supercritical airfoil designs. I don't remember seeing this variant specifically for transporting tanks, but I do know the Army's main battle tanks (the M1 Abrams in particular, then at over 60 US tons) were too heavy for the C-130 and the C-141. Their requiring the outsized capability of the then C-5A fleet was a point on contention. The C-X requirements that spawned the C-17 definitely specified hauling M1 tanks, and the LG-603 has some superficial resemblance to the later LG-610A C-X proposal. I'll look a little more.

 

[Pioneer]

"I don't remember seeing this variant specifically for transporting tanks, but I do know the Army's main battle tanks (the M1 Abrams in particular, then at over 60 US tons) were too heavy for the C-130 and the C-141."

Good point, to which I concur Hank58. It would be interesting to see the Request for Proposal.
More importantly IMO, than the inability to carry the M1 MBT, was the C-130 or C-141 inability to carry the M2/3 Bradley, not just because of its weight, but it's dimensions. Something the YC-15 and YC-14 could at least do, if I remember correctly.

Regards
Pioneer

 

[overscan (PaulMM)]

This model, formerly owned by John Aldaz, is featured in American Secret Projects - US Airlifters since 1962. ATA program was indeed a C-X precursor from 1974.

 

[uk 75]

The USAF had used C5s to carry M60s from POMCUS storage sites in Europe to Israel to replace Israeli losses in the 1973 Yom Kippur war.
By the 1980s the need to reinforce Saudi Arabia in a crisis had led to the Rapid Deployment Force having tanks stored on forward positioned ships. With only the unfortunate M551 Sheridan available to the 82nd Airborne and the subsequent failure to find a replacement for the 9th Infantry Div test, the 24 Mech Div would have needed some tanks flown in. Hence the requirement?

 

[riggerrob]

Nice find Overscan!!

The wing arrangement, which appears to avoid cargo compartment, is very reminiscent of the Ilyushin IL-76 Candid design.

Regards
Pioneer

Convergence.

If you design two airplanes for the same mission, chances are they will develop similar external loft lines.
In this case, both designers decided to route the main wing over top of the fuselage pressure vessel. This maximizes height in the cargo compartment and simplifies pressure vessel construction. This disadvantage is that it requires a large fairing with complex curves.
Lockheed C-5 Galaxy got around the problem by adding a complete upper deck above the main cargo compartment. The crew and a few dozen passengers occupied the forward, upper compartment. If crew wanted to visit the upper aft passenger cabin, they needed to climb down to the main cargo deck, walk aft and up a second ladder. The main wing box/spar prevented direct access between the two upper decks.
We see similar under-fuselage fairings on the smaller business jet that route the wing completely under the pressure vessel. They use long "boats" with complex curves to smooth airflow around wing roots.

 

[Pioneer]

uk 75, unfortunately, it sounds like it might have been more efficient to have actually come up with a replacement for the M551 Sheridan than create a whole new class of transport aircraft. Poor old orphan M551 Sheridan, its always reminded me of that old rooten tooth, that didn't want to get pulled, because without it, it left a gap.....

Regards
Pioneer

 

[Hank58]

Just a couple of additional thoughts on airlifting armored vehicles. Vehicles way smaller that the M1 Abrams Main Battle Tank posed problems in the late 1970s and the 1980s. The height of the humble M2 Bradley Infantry Fighting Vehicle, all-up (turret installed), was outsized to the C-130 and the C-141, which both have essentially 10-foot wide, 9-foot tall cargo boxes (see the attached illustration with a C-130 and the fabled C-130WBS cross sections and the Bradley). That was one of the drivers for the 12-foot by 12-foot cargo box requirement of the AMST (and also what drove the box for the C-130WBS proposals). I also attach the somewhat snarky C-17 advertisement that notes one C-17 can carry the payload of two C-141B airlifters. This shows the merit of using a cargo box cross section on the C-17 that nearly matches the cross section of the C-5.

 

[riggerrob]

yes dear Pioneer,
Paratroopers have always struggled to buy vehicles capable of providing supporting fire for airborne infantry, but light enough to fly in existing transport airplanes. Locust, Harry Hopkins, Sheridan, Scorpion, Wiesel, etc. have all been valiant attempts, but none could carry enough armour to face main battle tanks. In the initial stages, they only need to out-gun light infantry, but American politicians fear that sending paratroopers with anything less than MBT will lose them votes ... er .... lose the battle ... lose American soldiers' lives.
It takes weeks or months to move enough MBTs - to the far side of the planet - to ensure victory in the first battle.
Reducing vehicle cross-section by removing equipment is problematical. Unbolting side armour is a minor inconvenience until it cathces up a few days later. Rolling onto a target without a turret is a no-go ... er ... stupid ... only suggested by logistics officers who have never fought on a hot DZ.

Sadly, only the USAF and Russian Air Force can afford transport airplanes large enough to carry MBTs.

Let's compare cargo compartment cross-sections.
C-130 108" high X 120" wide
C-5A 172" 228"
C-17 124 206
KC-90 120 132
A-400 157 262

Judging by the larger cargo compartment cross-sections, it appears that every new cargo plane tries to accommodate vehicles bigger than C-130 Hercules. While many air forces would like huge C-5s or Antonovs, they struggle to afford cargo planes that can carry a single MBT at a time.