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Background
— CH-124 Sea King Life Extension and Carson Blades |
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As Sea Kings retire from military service, they are being snapped up by civilian operators.
Upgrade options are beginning to proliferate for that civil market. A complete refurbishment can add up to 2000
flying hours and even fully digital ‘glass cockpit’ conversions are available.[2] Such intensive upgrades
are unlikely to appeal to either DND or the government – both of whom wish this MHP problem would just go
away. This has left discussions of potential upgrades focused on new composite rotor blades now
being fitted to fourteen Royal Navy Sea King HC.4s [3] for deployment to southern
Afghanistan.
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Ad hoc CF Sea King Afghan Medium Helicopters?
The composite blades fitted to those RN Sea Kings deliver impressive performance gains. If a straight-
forward rotor blade replacement can endow the Sea King with adequate hot-and-high performance, why not deploy
to Kandahar? The answer probably has more to do with the cost of shipping the helicopters into KAF and then
maintaining them there – as was the case with both CF-18s
and CH-146 Griffons. [4]
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And what of the composite blades allowing Sea Kings to operate in Afghanistan? Developed by Carson
Helicopters for their FireKing waterbombers, these blades are a bolt-in conversion. [5] The composite
replacement blades result in an immediate 10% improvement in performance, translating into 2000 lbs+ “of
increased maximum hover mass and a 49 knot increase of forward air speed at high altitude”. Seems like a
bargain but these blades are in hot demand and DND is not in the queue. That – and potential political embarass-
ment – work against Carson blades appearing on CH-124s.
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[1] Between 1998 and 2002, CF Sea Kings had their 1350 shp T58-GE-8F turboshafts upgraded
to T58-GE-100 standards. These 1500 shp powerplant are the most powerful available for Sea
Kings. ( US Navy SH-3H / UH-3H Sea
Kings were fitted with 1500 shp T58-GE-402s in 1991. In Italy, Agusta had planned a variant of their
licenced AS-61N powered by GE CT7-6s, as in the EH101, but this never happened).
[2] The glass cockpit conversion is being developed by Vector (formerly Acrohelipro) of Richmond BC together
with Carson Helicopters. Vector Aerospace (with SAGEM) had previously produced a ‘glass’
Integrated Cockpit Display System (ICDS) for the Bell 206 range.
[3] The British Sea King HC.4s are also fitted with new AgustaWestland composite tail rotors and Elbit Systems
D-NVGs. The latter is the same as the ANVIS/HUD system specified for Canada’s interim CH-47D Chinook order (also designated as AN/AVS-7 or AN/AVS-503).
[4] The Griffon may yet get its chance. The CH-146 utility helicopters are rumoured to be going to KAF
this summer for recce and escort.
[5] The replacement blades are actually produced by Ducommun AeroStructures (which is also contracted to
produce blades for Apache helicopters and others). Ducommun has produced over 150 S-61
composite rotor blades since 2004 and has follow-on contract for more.
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Photo Credits –
side views: Stephen Priestley/CASR, other imagess: DND, Ministry of
Defence (UK), QinetiQ, and Carson Helicopters.
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Further delays with the delivery of Sikorsky’s 
about life extensions for the CF Sea King fleet beyond their planned 2012 retire- ment date. This has fueled
much speculation over potential Sea King upgrades. In reality, there is not much scope for further
improvements – the CH-124 fleet
have already been fitted with new gearboxes and more powerful engines.[1] The Sea King can also mount a
modest defensive aid suite (although not all are since these suites are in short supply). A complete airframe
refurbish- ment is unlikely at this stage, so what is left?