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BG Archive
— Airlifter Comparisons — Stretched C-130J Hercules |
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C-130J – Bigger is Better or Magic Mushrooms?
In 2005, the British offered to lease C-130J Hercules
to Canada. Journalists derided the proposal saying that the RAF was offloading their short (and
there- fore undesirable) Hercules. In the Ottawa Citizen an unnamed source was quoted claiming that the “
last thing Canada needs is short aircraft ... Everyone is buying the long [C-130J] because it has
the range, payload and speed.” Alas, a mere fuselage stretch cannot endow a Hercules with magical
powers. So, what is the story?
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Short Stuff – Standard Fuselage C-130 Hercules
The standard model Hercules – whether an existing Canadian Forces CC-130E/CC-130H or the
new-build C-130J – has a 29.8m long fuselage, translating into a cargo hold floor
12.5m long (less the ramp) of which 12.19m is unimpeded. The empty weight for a C-130J is 34275 kg to which is added
20819 kg of fuel (25552 litres) plus an additional 8506 kg (10440 litres) of fuel in two external wing tanks.
Power is provided by 4 x 3424 kW AE 2100 turboprop engines which give the C-130Js an economical cruising
speed of 628 km/h.
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Stretch – Long Fuselage C-130 Hercules
The C-130J-30 is the latest ‘stretch’ model Hercules. Two extra fuselage sections are
inserted – adding 4.6m to standard length. The C-130-30 fuselage is 34.37m long. The cargo hold floor is
17.05m long (less ramp) of which 16.76m is unimpeded. The empty weight for the C-130J-30 rised to 35966 kg or
1691 kg more than the ‘short’ Hercules. The rest of the airframe remains the same. There no
increase in lift or engine power.
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“...Because I am so dwarfish and so low?” or a case of Cui Bono?
So, the ‘stretch’ C-130J-30 Hercules carries over a tonne and a half of extra airframe weight using
the same engine output as its ‘short’ stablemate. So much for “industry
source” claims of higher
speed and greater range. And payload ? A C-130J-30 can carry a heavier payload but only over a shorter
distance by trading fuel weight for cargo. More power makes C-130J-30s inherently superior to earlier
‘stretch’ Hercs, not to ‘short’ C-130Js.
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With the ’J model Hercules’ more powerful engines, a C-130J-30 will likely run out of internal
space before exceeding its payload weight limits. When hauling cargo from airport to airport, this is an
advantage. But there’s a downside. Stretch Hercs have a long rear overhang. If a pilot
‘rotates’ too quickly, the Hercules’ extended rear fuselage ‘ground scrapes’.
Usually this results in little more than a shower of sparks along a paved runway. However, the inability to rotate
as fully as a ‘short’ Herc does limit the ’-30s value in rough field operations. And
CF ’J-30s are being bought for tactical airlift. [1]
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[1] The Liberal Tactical Airlift program (which intended to procure 16 x C-130Js) morphed into the Harper
Conservative’s Airlift Capability Project-Tactical (which bought 17 x C-130J-30s just over two years later ).
There are several possible explanations for the insistance upon an all ‘stretch’ Hercules purchase.
The Air Force may have intended to use its handful of younger, ‘short’ CC-130Hs to perform all rough- field
tactical work (unfortunately, those aircraft are now racking up punishing flying hours in Afghanistan). Another
possibility is that Air Staff are just following the lead of the US Air Force which is standardizing on
C-130J-30s ( this would simplify US-based maintenance and maximize commonality but comes at a cost in rough field
performance. The final possible explanation for an all ‘stretch’ purchase does less credit to all involved.
In this scenario, Hercules replacement was delayed to clear the way for the purchase of the
‘strategic’ C-17. In turn, the C-130J-30 pushes the Hercules into the realm of the
semi-strategic, thereby creating a niche for a medium tactical role within FWSAR.
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