Was re-reading the book "Kiwi Orions" by Paul Harrison recently, he touches on how the Mk82 depth bomb came about. On page 125:
During March (1995) Wing Commander C Inch and crew in NZ4203 carried out a series of bombing trials at the Kaipara Range. The weaponry being delivered was the Mk82 depth bomb, basically a standard Mk82 General Purpose bomb modified to act as a depth bomb and set to detonate at 50 ft below the surface. Monitoring the bomb runs was an Iroquois carrying photographers to record the bombs' release, trajectory and entry into the water.
The use of the Mk82 came about with the withdrawal of the Mk44 torpedo in 1993. This had left the Orions without an effective shallow water weapon to use against submarines.
To ensure the aircraft remained clear of the fragmentation on detonation, a minimum altitude of 500 ft and minimum speed of 300 kts was necessary. Thebomb forward throw was around 1800 ft, which provided a challenge for the pilots in selecting the release point.
The new bombs required an upgrade to the existing wing pylons to cater for the high-drag fin arrangement of the depth bomb.
Please excuse the following amateur analysis (hopefully some defence professionals or those in the know can shed more light on the topic etc).
In relation to the Mk44 torpedo,
this article (and others I've read) states that the Mk46 torpedo replaced the Mk44 (incidentally the RNZAF P-3K's still carry the Mk46, as well as the RNZN SH-2G's and the RNZN ANZAC Frigates).
But this
wiki article on the Mk44 states "
The Royal Australian Navy, however, continued to use it alongside its successor for a number of years, because the Mark 44 was thought to have superior performance in certain shallow-water conditions". Also it states "
The torpedo is, however, coming to the end of its usable life as the batteries have expired in many of the torpedoes. The New Zealand navy retired its Mark 44s in 1993 because it decided against renewing the batteries".
Incidentally I can find reference to the Mk44 on the
RAN website so am assuming they are still in service with the RAN, but there is no mention of them on the
RAAF (AP-3C) website so it appears that the AP-3C's carry now the Mk46 & AGM-84 Harpoon, and on the
US Navy (P-3C) website it states the weapons used are the AGM-84 Harpoon, AGM-84E SLAM, AGM-84H/K and AGM-65F Maverick missiles, Mk46/50/54 torps.
So I am wondering whether the RNZAF P-3K's are unique in carrying these Mk82 depth bombs, as "replacements" for the Mk44?
Fortunately there is a NZ LTDP project to replace the Mk46's so it will be interesting to see, whenever it eventuates, what the replacement will be, and whether it will be a single type or a couple of types to deal with different threat scenarios (and will that be the end of the Mk82 depth bomb)?
Now did I read last year the ADF's replacement MU90 torp has had issues with integration with the AP-3C but worked out fine with trials on RAN warships? (Sorry too lazy too dig back to confirm the facts as whether I've got that the right way round as it's now after midnight)! If so, presumably that will have bearings on the NZ LTDP Mk46 torp replacement project dragging out (although one would suppose sticking with what the USN P-3C's use would seem logical as the RNZAF P-3K is obviously US made with mainly if not exclusively US systems etc).
My understanding of the standoff capability mentioned in the LTDP was to enable the P-3K to fire the Maverick AGM like the Seasprite can (or did that not end up happening either?)
I also wonder just how much of the original mission systems are in the P-3K vs. COTS systems. From what I remember, NZ did due a system upgrade, but utilized a number of COTS systems which were modified. Not sure how well they could be adapted to enable use of weaponry.
-Cheers
A brief
Janes (non-subscriber) article here outlines the P-3K's upgrades over the years (and the book "Kiwi Orions" outlines the various upgrades over the years in more detail.
In summary the mission systems were upgraded 1981-1984 in Project Rigel 1 (but not so much the ASW, EW, stand off weapons, acoustics systems etc - that was to happen later in the 1980's as Project Rigel 2 which later was downgraded to replacing the acoustic detection and ESM systems, but then was ultimately canned due to Labour Govt defence reprioritisations and changing technology etc). Some COTS systems were fitted later in the interim, and after Project Kestral was instigated to replace the wings deal to corrosion etc, the Project Sirius was to be the next step to finally upgrade the obsolete ASW/mission systems, which again was canned by the next incoming Labour Govt in 1999. Although to their credit, that Labour Govt after some reviews (including the possibility of ditching the P-3's, something that only they would ever consider as an option, sheesh) did decide to upgrade the above surface detection/mission/radar systems, which is where we are at now at this point in time, supposedly the first upgraded aircraft is to return from L-3 in the US later this year (although the project is behind schedule). I haven't seen any public info detailing exactly what systems will be fitted apart from the general outline on the
MoD's LTDP website and the
RNZAF website, but again alas the ASW systems have not been upgraded. Let's hope the new Govt sees fit to complete the LTDP torp replacement project, the LTDP stand off weapon project and instigates a long overdue new ASW systems upgrade. Like in Australia, in the last few years, there has been occasional reports on NZ radio and in the newspapers on the growing submarine numbers in the Asia-Pacific region.
Defence analyst
Jim Rolfe comments on the current P-3K upgrade (the good and the bad)! Page 20/21:
New Zealand’s P‑3 Orion maritime patrol aircraft have been structurally upgraded and are now to have their mission management, communications, navigation and surveillance systems modernised to fit them for a role focused on surface rather than subsurface surveillance. Until that upgrade is complete, the Orions will be able to maintain DLOC for lower‑end military capabilities only. By the end of the project in 2010, the aircraft will be as capable as any in the world for its surface surveillance role, to the extent that there’s discussion of completing the refocusing to describe the force as an ‘Airborne Surveillance and Reconnaissance Force’ to reflect its potential roles. In the future, the aircraft could have command and control or airborne early warning duties, or it could have an enhanced attack capability—all depending on developments in technology and governmental will.
One thing the Orion won’t be able to do effectively, however, is to detect, track and attack submarines—its original role. The aircraft’s anti-submarine capability is obsolescent, if not obsolete. The government determined that the range of surface surveillance tasks available for a maritime patrol force, many of them non‑military tasks, meant that its priority for maritime patrol had to change, despite the increasing use of submarines by navies in the Asia–Pacific region.
By focusing on surface surveillance rather than subsurface capabilities, the RNZAF complements Australia’s maritime patrol capabilities. No doubt, at times in the future, therewill be a wish that the two countries between them had a greater subsurface capacity. Until then, they’ll be happy to have the increased surface surveillance provided by the patrol aircraft.