Martin P-3B/C `Iron Clad' variants
Country of origin: USA.
Role: Multisensor surveillance aircraft.
The `Iron Clad' (formerly known as 'Reef Point' (to mid-1997) and then
'Storm Jib' (mid-1997 to 1999) platform is a covert US Navy (USN)
intelligence gathering system that, as of Issue 7, has been identified as
being installed aboard a small number of Lockheed Martin P-3B or P-3C
maritime patrol airframes. So configured, such platforms are reported to
have been variously designated as P-3B(RP)/P-3C(RP) and/or (E)P-3B/(E)P-3C
aircraft. The 'Iron Clad' architecture is understood to incorporate
'sophisticated communications' systems (including satellite links)
together with a range of sensors that includes (or has included)
electronic/communications intelligence, acoustic analysis/recording,
chemical detecting and electro-optical (visible light and infra-red
domains)/optical surveillance systems. At an earlier stage in the
capability's history, a nuclear particulate `sniffer' is reported to have
been included in the suite, a capability that appears to have been removed
with the ending of the forty year 'Cold War' between the US and the former
Soviet Union. Specific sensors that have been associated with the `Iron
Clad' platform comprise the following:
- a `special'
DIrectional low-Frequency Analysis and Recording (DIFAR) -B sonobuoy
(see Known mission system specifications).
electro-optical Tactical Optical Surveillance System (TOSS - see Known
mission system specifications.
- the AN/ALQ-78
Electronic Support Measures (ESM) system (see Known mission system
Elsewhere, sources suggest that `Iron Clad' aircraft are fitted with
operator workstations along both sides of their main cabins and that,
in at least one case, an AN/AAR-47 missile approach warner (see Known
mission systems specifications) and a countermeasures dispensing
system have been installed. Further defensive aids provision appears
to have been added during 1999/2000, when two suspected 'Iron Clad'
platforms were logged with what appeared to be a pod-mounted radar
jammer on their outer port wing pylons. Again, a usually reliable US
source has suggested that the `Iron Clad' suite may include Battle
Group Passive Horizon Extension System (BGPHES) provision (see Known
mission system specifications).
Externally, the 'Iron Clad' configuration is little different from
that of the standard P-3 Orion maritime patrol aircraft, with what
differences there are centring on the former's use of optically flat
viewing ports for onboard imaging systems and non-standard arrays of
ventral and dorsal antennas. In terms of 'Iron Clad' airframe
modification and equipment installation, Lockheed Martin, Raytheon
Systems' Greenville, Texas facility and the USN's Naval Aviation DEPot
(NADEP) Jacksonville (located, as its name suggests, at Naval Air
Station (NAS) Jacksonville, Florida) are understood to have been
associated with the programme. In terms of platform performance, one
usually reliable source quotes a mid-1980s 'Iron Clad' aircraft as
having a maximum range of 7,408 km; an operational ceiling of 8,626 m
and a maximum endurance of 10 hours.
During 1969, USN Patrol Squadrons VP-4 and VP-26 are reported to have
established single aircraft temporary detachments to undertake covert
surveillance operations with 'Iron Clad'-like platforms. In this
context, it is worth noting that the then Martin Aircraft Company is
known to have modified two P-3A aircraft (BuNos 150520 and 150528) for
a USN `special project' during 1971. These platforms are reported to
have remained in service until 1975.
By the late 1970s, the previously described VP-4 and VP-26 temporary
surveillance detachments had been regularised into permanent
detachments with their own commanding officers.
During July 1982, the now permanent VP-4 and VP-26 surveillance
detachments were raised to squadron status and given the designations
Patrol Squadrons Special Projects Unit VPU-2 and VPU-1 respectively.
Of these, VPU-1 was based at NAS Brunswick, Maine while VPU-2 was
stationed at NAS Barbers Point, Hawaii. Both squadrons are understood
to have been equipped with 'Iron Clad'-type aircraft from the outset
and are most likely to have been initially involved in
`fingerprinting' the signatures of Sino-Soviet warships and, possibly,
submarines. As of this edition, the overall capability appears to be
utilised in much wider ways and it is worth noting that the mission
has been associated with the codenames `Church Plate' and `Church
Plate East'. As of the late 1990s, VPU missions were described by
usually reliable sources as including ship screening, search and
rescue/space vehicle recovery support and counter intelligence
operations. Here, the units were reported as using acoustic, visual
and EO (possibly including laser dazzlers) systems to prevent hostile
intelligence services gaining information on the USN's current and
evolving weapon system and electronic capabilities. Again, the two
VPUs were noted as possessing video production and editing and
intelligence dissemination skills and as deploying their aircraft for
an average of 220 days per year.
A small number of 'Iron Clad'-type platforms are known to have
participated in Operation 'Desert Storm', the January/February 1991
eviction by force of the Iraqi troops who had been occupying Kuwait
since the previous August. During the conflict, aircraft of the type
were noted at Masirah in Oman, Muharraq International Airport on
Bahrain and at Jeddah in Saudi Arabia from where, according to
sources, they flew stand-off overland surveillance, coastal
surveillance and coastal/island strike bomb damage assessment sorties.
During the early part of 1992, sources suggest that a programme was
initiated to replace four existing VPU aircraft with four new
platforms modified from P-3C airframes BuNos 159504, 160285, 160288
and 160292. Work on the effort is supposed to have been undertaken by
NADEP Jacksonville, with three aircraft being delivered during US
Fiscal Year (FY) 93 and one in FY94. As of this issue, aircraft BuNos
160285 and 160288 cannot be confirmed as being (or as ever having
been) anything other than `line' P-3Cs, while aircraft BuNos 159504
and 160292 are known to have been in service with VPU-2 during the
third quarter of 1998.
As part of the US government's post-`Cold War' base closure review,
1993 saw the decision made to close NAS Barbers Point, Hawaii during
July 1999 and transfer its tenant units to the US Marine Corps base at
Kaneohe Bay, Hawaii. Elsewhere in the programme, the period 1993/1994
is reported to have seen 'Iron Clad' platforms providing intelligence
and surveillance support for humanitarian relief operations in Rwanda
and Operations 'Restore Hope' (1993 peacekeeping operations in
Somalia) and 'Uphold Democracy' (the 1994 US invasion of Haiti).
During US FY97, the now defunct (see following) US Defense
Airborne Reconnaissance Office (DARO) assumed responsibility for the
'Iron Clad' programme. After studying the capability, DARO determined
that there was a national need to maintain the 'Iron Clad' fleet for
the `foreseeable future'. Accordingly, it was recommended that 'Iron
Clad' mission suites should be installed in two low-time P-3Cs (as
replacement for the two existing P-3B 'Iron Clad' platforms (see
following) whose fatigue lives were scheduled to run out during 2001)
and that a mission system rationalisation programme should be
initiated. Here, key objectives were to be:
of onboard subsystems in order to maximise capability, reduce operator
workloads and simplify logistical support
- the integration
of new mission and communications equipment including `Have Quick'
secure radios, a satellite communications system and DARO's 8 to 12
GHz/12 to 18 GHz band Common High-Bandwidth DataLink (CHBDL).
As originally proposed, the new mission and communications equipment
segment of the effort was scheduled to take place during US FYs98 and
99. At the same time, the cost of modifying the two low-time P-3Cs to
'Iron Clad' standard was estimated at then year US$26.6 million. As
part of its FY 98 funding deliberations, the US Senate's Defense
Appropriations Committee is reported to have recommended adding US$7
million to the 'Iron Clad' funding request as a down payment on the
described P-3C conversion programme. As of Issue 7 (and aside from the
noted P-3C effort which still appeared to be live during late
1998/early 1999), it was unclear as to whether or not DARO's 'Iron
Clad' standardisation recommendations had been followed through
following its closure on 1 June 1998. Thereafter, oversight of DARO's
various programmes was transferred to a reorganised Command, Control,
Communications and Intelligence (C3I) Office within the US Department
of Defense (DoD). Returning to the specific 'Iron Clad' programme,
VPU-1 was redesignated as Special Projects Patrol Squadron One on 8
April 1998, with VPU-2 becoming Special Projects Patrol Squadron Two
six days later on 14 April 1998.
During the period March to July 1999, VPU-2 is understood to have
relocated from NAS Barbers Point, Hawaii to Marine Corps Air Facility
Kaneohe Bay, Hawaii in response to the former's closure. As of
November 1999, usually reliable sources were suggesting that the USN
wanted to set the establishment of each VPU at three 'Iron Clad'
configured P-3C aircraft plus a single P-3 training/transport
platform. Early in the following year, the same sources were noting
that the US Congress had approved an increase in spending on a
hyperspectral analysis system for the service's EP-3E (see separate
entry) and 'Iron Clad' intelligence collection aircraft. The related
Adaptive Spectral Reconnaissance Programme (ASRP) was described as
making use of a hyperspectral sensor to detect anomalies in the
electromagnetic spectrum and to cue high-resolution, narrow field of
view IR or optical sensors against targets identified as generating
the anomalies. At the time of the report, the ASRP concept was
understood to have undergone 'limited' testing.
US Navy Atlantic Fleet
Patrol and Reconnaissance Wing Five
Base: NAS Brunswick, Maine.
Formation date: 1 July 1982.
Remarks: As of the third quarter of 1998, VPU-1 was reported as
being equipped with P-3B aircraft BuNos 153450 and 154577 and P-3C
aircraft BuNos 159506 and 161122.
US Navy Pacific Fleet
Patrol and Reconnaissance Force Pacific
Base: MCAF Kaneohe Bay, Hawaii.
Formation date: 16 July 1982.
Remarks: As of the third quarter of 1998, VPU-2 was reported as
being equipped with P-3C aircraft BuNos 159504, 160292 and 160293.
Known mission system specifications
Type: Passive EO missile warning system.
Description: The Lockheed Martin/Alliant AN/AAR-47 is a
lightweight, EO missile warning system that comprises multiple Optical
Sensor Converter (OSC) units, a Computer Processor (CP) and a
control/indicator unit. Of these, the OSC units (usually four in
number) are mounted on the exterior of the aircraft in such a way as
to provide 360º coverage in azimuth. Functionally, the OSC units
detect the IR component of the exhaust plume of an approaching missile
and hands off the received data to the CP for processing. The CP
generates a threat warning for the aircraft's crew and automatically
initiates an appropriate countermeasures response. Multidirectional
threats are prioritised for response sequencing and the CP also
incorporates a built-in test function. The control/indicator shows
threat bearing and priority and is used by the pilot to set up
appropriate aircraft manoeuvres. As applied to the 'Iron Clad'
aircraft, the AAR-47 OSCs are located on either side of the platform's
nose and rear fuselage, presumably looking forward and abeam and aft
Altitude: up to 15,240 m
Weight: 20.5 kg (complete system with four OSC units)
Type: Airborne radar Electronic Support (ES) system.
Description: Functionally, the Lockheed Martin AN/ALQ-78 ES
system automatically detects and characterises radar signals,
establishes their bearings and hands off parametric data to the host
aircraft's central computer for processing and display formatting. As
applied to the standard P-3 maritime patrol aircraft, the equipment
incorporates a high-speed rotating antenna/scanning superheterodyne
receiver signal acquisition package and is described as normally
operating in an omnidirectional search mode. Part of the system is
housed in a pod that is carried on the Orion's port or starboard wing
root stores pylon.
Battle Group Passive Horizon Extension System (BGPHES) payload
Type: Intelligence data dissemination system.
Description: The USN's BGPHES architecture consists of
shipborne terminals and airborne payloads and is designed to provide a
battle group commander with a controllable, over-the-horizon sensing
capability that functions without revealing his position to an enemy
through the use of active systems such as radar. In the ES-3A
carrierborne signals intelligence aircraft (see separate entry), the
BGPHES airborne payload takes the form of the demountable RS-6BN
transceiver package that is described as having `some' commonality
with the RS-6B system fitted to US Air Force Lockheed Martin U-2S
high-altitude reconnaissance aircraft (see separate entry). RS-6BN is
noted as incorporating multiple R56BN transceivers and is supported by
the 8 to 12 GHz/2 to 18 GHz band, 10.7 Mbytes/s data rate CHBDL.
Functionally, the RS-6BN payload appears to be capable of both
acquiring and transmitting data and is understood to be remotely
controllable from any BGPHES surface terminal within its line of
DIrectional low-Frequency Analysis and Recording (DIFAR)
Type: Sonobuoy acoustic detection technique.
Description: The DIFAR acoustic detection technique makes use
of a sonobuoy capable of generating two beam patterns that are at
right angles to each other. Both patterns are measured and are
transmitted to a monitoring aircraft together with an omnisense
component to resolve the 180º ambiguity inherent within the two
beams. Associated signal processing includes comparison of the two
beam signals, usually using an arctan function to determine angle.
Using this technique, Direction-Finding (DF) accuracy is described as
being within 10 to 15º of true target location. If a higher order of
DF accuracy is required, cardioid processing can be used whereby the
two beam signals are added to or subtracted from the omnicomponent to
form four cardioid (heart-shaped) beams, each of which points in a
direction with a null opposite.
Tactical Optical Surveillance System (TOSS)
Type: Electro-optic surveillance system.
Description: Thought to have been first installed aboard 'Iron
Clad'-type aircraft during the 1980s, the TOSS surveillance system was
developed by the then USN Naval Air Development Center at Warminster,
Pennsylvania. As applied to 'Iron Clad', the equipment is installed in
what, in the standard maritime patrol P-3, is the Tactical Co-ordinator's
station. As such, an optically flat viewing window for the system
replaces the standard aircraft's forward, starboard side, observation
aircraft BuNo 153450 is thought to have served in the 'Iron
Clad'-type collection role with both USN Patrol Squadron VP-26
(in whose colours it is shown here) and VPU-1. Identified
external indications of its 'Iron Clad'-type role include the
blister fairing under the aircraft's nose radome and flat
plate fairings just aft of the cockpit glazing (1997)
is thought to be a P-3C 'Iron Clad' aircraft showing the
type's fore and aft AAR-47 MAW sensor heads, the optically
flat viewing window for the TOSS system and its dorsal and
ventral antenna arrays. The view also shows the anonymous
paint finish most recently adapted to conceal the platform's
true role. Previously, 'Iron Clad'-type aircraft have
frequently been painted in false markings to hide their true
identities (Lindsay Peacock) (1998)
during April 2000, suspected 'Iron Clad' aircraft '227'
displays the type's then current anonymous paint scheme and
the supposed radar jamming pod described in the main text on
its outboard port wing pylon (Lindsay Peacock) (2001)
PR-32: its systems and its damage
PR-32: its systems and its damage (Source: PA News)
1. Nose cone and AN/APS-134(V) maritime surveillance radar antenna
lost during collision
2. Circular radome believed to contain the OE-319 surveillance
3. The EP-3E's dorsal and ventral fairings are thought to contain
the OE-320 direction-finding antenna group
4. Outside port engine's propeller blades damaged during collision
5. Wingtip antenna housing for the AN/ALR-76 radar band electronic