Posted on Posted in Aerospace News, Defence Analysis

The INAS 312 “The Albatross” stationed at INS Rajali had distinction of operating the heaviest, fastest and highest flying turbo prop aircraft in the world, Tu 142 MKE. Before the legacy ASW platform could retire, the squadron was equipped with a next gen platform in the form of P8I Neptune.

The Indian Naval P8I Neptune (Indian variant of P8A Poseidon ASW platform designed by Boeing) is the next logical step in moving from a large turboprop Tu 142 MKE as a primary ASW platform. P8I, which is based on Boeing 737-800 ERX NG with elements from 900 series, albeit a civil airliner but a proven airframe, can withstand the new operational standards of high altitude surveillance. The sheer fact that P8I is a jet powered plane, powered by twin CFM 56-7 turbofans, and gives it an edge over existing systems as its its notice for launch and time to reach an area will be shorter than any existing turboprop.

The major structural changes in P8I from the civilian version include a weapon bay with bi-folding doors capable of carrying torpedoes, depth bombs etc., inclusion of underwing pylons, additional sensors and comms, three pneumatic release sonobuoy launchers in the aft sections of the airframe, countermeasures against AA systems, a MAD in tail (not included in American version of P8, P8A) and Electro Optic Sensing Head. The forward part of fuselage houses the nose radome and the air-refuelling receptacle. The nose section has a strengthened 737 landing gear and would also house the P8I’s radar.

The very nature of high altitude operational stance of the airframe makes it a potent system for Long Range Maritime Recon (LRMR) which was earlier covered by Tu 142 MKE. The MPA is also capable of undertaking Anti Sub Warfare ops and Anti Vessel Strike ops. The open architectural mission systems has allowed to Indian Navy to fit many indigenous required systems, thus allowing better data sharing and integration, and comm between other assets of Navy including surface vessels, naval bases and other aerial platforms. The MPA’s LRMR capability makes it an excellent defensive asset.

The system is very potent offensive maritime aerial asset due to primary focus on ASW and AVS capabilities. The plane follows a HI-LO-HI ASW movement profile near target area thus increasing operational range without in-flight refuelling, which although is also possible, to increase operational capability.

During ASW operations, the P8I is expected to conduct a multi-sensor prosecution led by its acoustic processing capability and supported by periscope detection functions of the radar, improved capabilities of its next-generation MAD system, and a highly accurate ESM system. For ASV operations, the P8I radar suite would serve as the primary search sensor, supported by its ISAR function, the ESM suite and Electro Optics for target identification and intelligence gathering. Neptune is equipped with High Altitude Anti-Submarine Warfare Capability (HAAWC) Air Launcher Accessory (ALA) that turns a Mark 54 All-Up-Round lightweight torpedo into a glide bomb, able to be deployed from up to 30,000 ft. The underwing pylons can also be equipped with AGM/RGM/UGM-84L Harpoon Block – II AShMs (21 were procured for P8I specifically)

The MPA is equipped with a BEL made IFF transponder (probably MK XI) and also BEL DataLink II. Data Link II enables communication in fleet ships, submarines, helicopters / aircraft and shore establishments. This system enables Indian Navy personnel to exchange messages as well as tactical data in a speedy, reliable and secure manner as claimed by BEL.

The Neptune is equipped with a forward looking modified version of AN/APY 10 multi-mission surface search radar, called APY 10 (I) with new features being added and export restrictions being applied on it. In Indian version

  • Precision Targeting capability has been removed
  • UHR ISAR (Inverse Synthetic Aperture Radar) capability has been removed
  • 1 and 3 foot SAR capability has been removed
  • Performance has been limited to meet 30 meter SAR geo-location accuracy
  • Interleaved Weather Capability has been added
  • Air-to-Air Target Detection / Tracking Capability has been added

The P-8I also has Telephonics APS-143C(V)3 OceanEye aft radar which has its own ISAR and IFF capability, complementing AN/APY 10 I which had its ISAR removed due to export constraints. It is optimized for target detection and sea clutter rejection in high sea states in all of these maritime applications. The radar’s rugged construction and its ability to detect small targets in high sea states makes it an excellent choice for mixed roles and demanding tasks.

AN/APS-143(v)3 OceanEye

The Indian P8I’s mission suite quite based on the lines of its Russian Counterpart in the Indian inventory, the IL 38 SD. The suite includes –

(a) The Maritime Patrol Radar (MPR)

(b) Sonic System

(c) Magnetic Anomaly Detector (MAD)

(d) Electronic Support Measures (ESM)

(e) Electro Optical Device/Forward Looking InfraRed

(f) Missile Approach Warning System (MAWS)

(g) Air Deployable Chaff and IR Flares

(h) Integrated Data Link

(i) Armament Package

The sensors on-board P8A were designed to be more accurate than existing systems to complement the removal of MAD, yet some sensors weren’t cleared for export like HC detector, forcing India to get MAD in its version of P8 to catch up.

Three P-8As with three P-8Is in background, easily identified by ARK on the fins

Let’s talk about MAD for a second. MAD is dry or a non-acoustic sensor which notices the disturbances in Earth’s Magnetic field, both natural and artificial. The artificial changes are brought by the passage of a large ferrous body such as ships, submarines, planes etc through the Earth’s magnetic field.

For ASW purposes, the ASW aircraft must almost be essentially overhead or very near the submarine’s position to detect the change or anomaly. The detection range is normally related to the distance between the aircraft sensor (“MAD head”) and the submarine. For this the detector must be in close proximity of the target, which is where Indian and American usage of the plane differentiates. Indian strategy is to fly the plane in HI-LO-HI movement profile near the target in order to better track the subs while Americans will be using a separate drone with MAD for the purpose, augmented by P8A flying at high altitudes. Even if subs use the Soviet tactic of hull being constructed from Titanium, the ferrous equipment on board can still cause distortions that can be picked up by the sensor. Neptune is equipped with CAE’s AN/ASQ 508A AIMS MAD. Not much is available about the specific product.

The plane is also important from an INTEL point of view, as Sensor systems on board also provide tactical situational awareness information for dissemination to fleet forces and Intelligence, Surveillance, and Reconnaissance (ISR) information for exploitation by the joint intelligence community.

The P-8 is designed to traffic on- and off-board data. “Wet” acoustic and “dry” ESM, EO, MAD and radar operators can be mixed to suit the mission. The operators, on 5-7 workstations, can change according to operations and the workstation can be configured on-the-fly. The advanced communication suite of the P8I meets the requirement of executing operations and information exchange simultaneously.

The plane is not just meant for the Navy, by that what I mean is with Indian Military looking at sort of joint structure to increase interoperability and maximum utilisation of assets, the P8I will integrated with the Indian Navy and IAF assets, including fighters, AWACS and ground station. This increases its area of influence and certainly increases the impact of a single station in the area. All three arms plan to undertake joint exercises to improve on this, with the latest exercise with P8I participation being Theatre level TROPEX 2017 which included assets from the Indian Air Force, Indian Army and the Indian Coast Guard exercise together.

The first aircraft arrived in India on the 15 May 2013 and as of date; all eight aircraft have been inducted into the Indian Navy and are fully integrated into its operations. All of them are based at INS Rajali and under the banner of INAS 312 A. 4 more platforms are on order and yet to come to the country.

Pic Credits – Boeing/Indian Navy



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