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Background
— Aurora Alternatives — Lockheed Orion Options |
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Although AIMP (Aurora Incremental Moderniz- ation Project) was phenomenonly expensive, the cancellation of
ASLEP (the Aurora Service-Life Extension Project ) precipitated the search for a CP-140
replacement. An obvious possibility was installing Aurora systems (to AIMP block III) in Orion
airframes. Such rebuild programs [1] have relied upon stored ex-USN P-3s (above) but stocks have been well picked
over.
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There are a host of refurbished Orion projects – ranging from straightforward rebuilds like that
adopted for Norwegian P-3s [2] to complete redesigns incorporating features of the failed P-7A
(Lockheed’s much revised Orion entered in the late ’80s US Navy LRAACA program). A major feature
of the stillborn P-7A was an extended wing centre section resulting in greater wingspan. Some Orion
updates incorporate this stretched P-7 wing (eg: the Orion II, below), others adopt the P-7A engines (the
never-built GE38/T407) and 5-bladed propellers – eg: the Orion II again, and as optional
engines on the Orion 2000 (above, left) and the Orion 21 (above, right).
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The major P-3 Orion redesigns proposed by various aerospace firms are as follows:
• P-3H/Orion II – standard P-3 fuselage with extended P-7A wings [3] and engines.
• Orion 2000 – P-3 with P-7A engines and mission equipment (offered to RAF). [4]
• Orion 21 – Orion 2000 development (new-build or rebuilt P-3C ) various engines.
• Valkyrie – Loral/E-Systems proposal to rebuild ex-USN P-3s (offered to RAF).[4]
• P-3 Procyon – a Raytheon program based on second-hand P-3 airframes. Engine
options varied: RR AE2100s, P&WC PW150 or T56 (as Procyon Quick Reaction).
Most of these projects date back to 2000. Many will no longer be actively offered.
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So Canada faces two hurdles if it were to choose the Orion rebuild route. Many of the proposals were based on
potential production runs of at least 50 aircraft. Even if all 18 Aurora were to be replaced (and
that’s a big if ) the order would not be big enough to warrant production. The second concern is over what
the CF would be gaining by such an order. Ideally, the P-3 airframes selected for refurbishing would have fewer
hours on them than the CP-140s but, as mentioned, few such airframes remain. Were a few low-hour P-3s to
emerge, rebuilding them would be expensive and the finished product little better than the Aurora.
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For the Record: Engine and Propeller Options for Orion Upgrades
For completeness, we’ll review the various powerplant options for the major Orion rebuild
proposals. Most rely on the existing P-3C (and Aurora) powerplant combination: Hamilton
Standard 54H60-77 propellers (left) driven by Rolls-Royce (formerly Allison) T56-A-14 turboprops (right). The
combo was a natural – 54H60 and T56 series also power early-model Hercules, familar to maintenance
crews, and parts are in stock. But the 1950s technology offers no performance advantage over existing the
Aurora.
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An option mentioned specifically for the Procyon ( but equally applicable to other Orion updates) is
the Pratt & Whitney PW150A. The PW150A is primarily a commercial engine although it was proposed for the ‘C-130M’ Hercules modernization. [6] The propeller
matched with the PW150A was from Smiths Aerospace/Dowty’s 6-bladed R400 series (a similar combo is used on
Bombardier’s Q400 airliner). While the 6-bladed prop is related to those used on the C-130J which Canada hopes to buy, the P&WC engine is unlikely to
see CF service resulting in minimal parts commonality or training advantage. In any case, all such
considerations are probably moot. The CF likely won’t be offered an Orion update and, if they were, the
odds of such an offer being accepted is remote.
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[1] We have listed only a sampling of proposed Orion updates and rebuilds. These offerings should be thought
of as packages. Most of the remanufacturing options already exist separately. Lockheed Martin leads
in such activities, naturally, but many other firms participate.
[2] Lockheed Martin received a US $95M contract for a service life extension project for six Luftforsvaret
P-3Cs involving new wings, tails, and other components. Interestingly, these RNorAF Orions are based at
Andøya at 69°N, the same latitude as Igloolik, NU or Murmansk.
[3] The P-7A wing centre section was to be of greater span than the original P-3 structure. This would allow
three centre section weapons pylons per side (the P-3C has two per side). Overall span would increase to 32.5m (from
30.35m) with an area of 133.6m2 (up from 120.8m2).
[4] The Replacement Maritime Patrol Aircraft project was intended to find a successor to the RAF’s aging fleet
of MR2 Nimrods. Several Orion options were proposed (along with the Dassault
Atlantique 3) but BAE’s rebuilt Nimrod 2000 was chosen as the MRA4
Nimrod.
[5] The US Navy E-2C Hawkeye is powered rather like a Hercules – Allison (RR) T56A-427 engines
drive Hamilton Standard 54460-1 four- bladed propellers. The new propeller is Hamilton Sundstrand’s NP2000, an
8-bladed military derivative of the commercial, six-bladed 568F. The NP2000 was designed as a replacement
propeller for E-2s, C-130s, and P-3s while being compatible with PW150 and AE2100 engines.
[6] In 2006, Snow Aviation proposed rebuilt Hercules to the CF with PW150As driving NP2000 8-bladed
props as an option. The Shaanxi Y-8F600 (a modernized Y-8/An-12 copy) is the only military design using these
engines – PW150Bs driving 6-bladed Dowty R-408 props.
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More modern engine and propeller options mentioned include a revived GE38/T407 P-7A engine with 5-bladed
propeller. Since the core for this engine currently exists only as the CFE738 commercial turbofan (below), this
is
likely unrealistic. Another, more realistic proposal, is using the Royce-Royce AE2100 as used in the
modernized C-130J Hercules – repeating past Hercules / Orion engine commonality although
not propellers. While the C-130J uses 6-bladed Dowty props, the P-3 Procyon proposal
used 8-bladed Hamilton Sundstrand units as adopted for USN E-2C Hawkeyes. [5]