Indian Navy’s P-8I LRMP **–– God of the Seas
By Shashank Sinha
The Indian Navy (IN) has finally concluded a US$ 2-plus billion deal for eight Boeing P8I ‘Poseidon’ Long Range Maritime Patrol Aircraft (LRMP), in what is the biggest defence deal yet with the United States. The first aircraft is expected to arrive within 48 months of the contract being signed, with deliveries being completed by 2016.
The very first P-8A airframe is currently undergoing integration with onboard electronic surveillance, intelligence and attack systems, and is due to be delivered to the US Navy (USN) later this year to begin the test program which is expected to culminate with IOC 2012.
In many ways this is a revolutionary acquisition program for the IN, affecting a jump in its maritime surveillance capabilities in the region and better integrated joint operations with other players.
Origins
The Indian version called the P8I (for India) is a direct outcome of a two-year requirement study started in 1997 by the USN, for the replacement of its P-3C Orion fleet. Boeing and Lockheed Martin were shortlisted in 2002 for proposals, with the former presenting a 737-800 ERX based platform while the latter proposed an upgraded ‘Orion’.
Boeing went ahead to create a technology demonstrator based on the successful BBJ platform to test on board systems, leading to selection of P8 in July 2004. Five test airframes are expected to be produced by 2012 with full scale production to commence subsequent to IOC. By modifying an existing aircraft with a proven track record, Boeing was able to better focus its attention on behind-the-scenes engineering, and a streamlined production process involved in the project.
Figure1. P-8A Fact Sheet Retrieved 21 January 2009 from:
http://www.navair.navy.mil/mma/index.cfm?method=controller.about
Missions
The P8I will carry a heady mix of multi dimensional electronic sensors to carry out diverse missions:
Radar to detect surface shipping movements;
Magnetic Anomaly Detector (MAD) to detect submarine movements. The MAD is typically mounted on an extension from the tail of the aircraft in order to minimize the aircraft's magnetic field interference towards the MAD;
Sonobuoy dropped from the aircraft onto the sea to detect submarine movements, then transmit the data back to the aircraft;
ELINT sensors to monitor civilian and military telecommunications;
Infrared camera to monitor shipping movements.
Indian Navy is expected to retain the best of the US electronic suite, while also opting for quite a bit of mix and match by procuring some key sensors like Radar (Elta EL/M-2022(V)3) from Israel and Wescam MX-15 Electro-Optic/Infrared Sensor (EO/IR) from Canada.
In order to perform such varied missions, P8 would carry a crew 0f nine consisting of dual-pilot, five mission crew (plus relief pilot and in-flight technician). Each of the mission crew would be responsible of running the mission sensors through five integrated consoles.
Weapons
Like its predecessors the P-8 also sports an internal bomb bay to accommodate a mission specific mix of torpedoes, bombs and mines. The principle weapon is likely to be a derivative of Raytheon Mk54 torpedoes, modified for high altitude release, that will be more typical of a jet based MMA. A total of five Mk54 can be carried and should make an excellent addition to IN’s arsenal. Under wing hard points will provide for additional carriage of Harpoon missiles for ASW missions.
Operational Aspects
Prop or Jet?
The P-8 is not without its detractors though. Much of initial debate is focused on the suitability of a turbofan powered aircraft verses the conventional turboprop LRMP aircraft. Although, a jet powered aircraft would make a faster transit to the operating area than a turboprop, a jet is also inherently much less fuel efficient at low-level. It is the low-level performance of a 737, an area that an ASW aircraft spends considerable amount of time in that is giving many commentators cause for concern. This assumes special significance when using the Magnetic Anomaly Detector (MAD) to track a submarine (P-8I as opposed to P-8A will have one), the P-8 will need fly at around 200ft above sea level and make 2G, 60 degree tightly banked turns. With a fairly modest, highly swept super-critical wing optimized for high-level / high speed cruise, the handling and turning characteristics of a fully loaded 737-800 may not be optimum, and as some point out maybe downright dangerous.
To obtain a better understanding of the above scenario however, one has to appreciate how the typical Anti Submarine Warfare (ASW) operations are conducted today. There are basically three stages of ASW ops:
Detection
Tracking
Localization/attack.
Detection is done in any number of ways and can originate from different sensors. For the maritime patrol aircraft (MPA), it’s usually done at altitude using sonobuoys, either based upon intelligence or upon detection by some other asset. This is easy on the airframe because higher-level flight is usually smooth and aggressive high-G manoeuvres are rare. Passive tracking (using the target’s noise and not generating any yourself) of a located target is also relatively less demanding and again, at a higher altitude. Things get tough during the third stage that is localization for an attack. For this earlier platforms like the P-3 used active sonobuoys that “ping” to provide a distance and bearing to the target, which now knows you are there and begins high-speed evasive manoeuvring. The P-3 also used magnetic anomaly detection (MAD) to provide an “on top” mark from the sub’s steel hull. This is low-level, yanking and banking flight that puts the aircraft through a lot of relatively high-G as a result of steep turns and low-level turbulence, which really wears down both the airframe and crew. In fact, the USN is trying to extend the life of its remaining P-3s as much as possible by minimizing low-altitude flight. One step has been to create a kit that turns the P-3’s Mk 54 torpedo into a glide bomb that may be launched from altitude. The P-8A is being designed without MAD for USN, clearly reflecting an intention to minimize low-altitude flight, both for airframe ease and limiting a target’s chances of detecting a tracking airplane.
However, this certainly doesn’t mean that the P-8 is wholly unsuitable for low altitude operations and designed to completely avoid it. Boeing tried to allay similar reservations on part of the USN, during the technology demonstrator trial in December 2003, when a 737 BBJ2, simulating a P-8, did a tour of major US Naval Air Stations. The strenuous set of demonstrations included tactical manoeuvres at an altitude of 200ft, and simulated single engine manoeuvres.
In actual scenarios, MPA don't normally fly down to 200ft, only descending to low levels once a target has been identified. For normal ops, current tactics call for flight at a cruise altitude, with a series of quick dives to drop sonobuoys and torpedoes. It would not be safe to fly at 200ft for the whole flight anyway, no matter whether it's a P-3 or a P-8. Apart from the stress on man and machine, a loss of power at low level would also mean a catastrophic loss of altitude. As mentioned earlier, the ASW aircraft will increasingly shed the need to fly low, as glide torpedoes come on line. Some respite in this department will also come from UAVs working in conjunction, which will take over the majority of level flying.
To what extent the above solutions remain relevant to Indian Navy is however still open to interpretation. The Indian P-8I will surely need to undertake some amount of low level flying to operate the MAD gear. Although it is not something beyond the capability of the P-8, in a tactical scenario, it is bound have an impact on the endurance requirements. Again, this is not something limited to a jet platform, and the P-8I too will benefit as more UAVs enter the IN operations. It must also be mentioned here, that MAD sensors are not optimal and certainly never primary sensors for submarine detection being prone to clutter from undersea ore deposits etc.
Twin Jet: How Safe?
The second most significant issue for the P-8 is the question regarding safety regime of a twin jet configuration. As operators make transition from earlier quad turboprop platforms like P-3, Tu-114 and Il-38, they have voiced apprehensions about a twin jet platform’s inherent lack of redundancy. The issue might seem redundant today in the age of safe twin jet air transports, but it was serious enough for at least one potential operator, namely the Japanese, who sight this factor as one of the reasons to go for their indigenous Kawasaki P-1 MPA powered by four turbofans.
However, apart from some inherent danger of an engine failure at low level, the risk factor should be the same as for any twin jet commercial liner. An engine failure seems less and less probable in the age of modern aero engines, and the P8 scores here, being based on a proven design/power plant combination. Even in the case of such eventuality, loss of an engine doesn’t necessarily results in an immediate crash. Based on known cases of similar failures during landing takeoff stage, the aircraft begins to bank, providing the crew some time to react and compensate. In the event of a similar failure in cruise regime, it doesn’t automatically translate into loss of 50% of power. Since the aircraft does not cruise at 100% engine power to begin with, and upon losing one engine, thrust is increased on the other engine to compensate. This is more likely to result in a fall in power from 70% down to around 55% (the other engine can be pushed harder in emergencies), and the primary effect will be on cruising speed, rather than flyability.
Range and Reach
Thanks to highly fuel efficient modern engine technology, the P-8 in spite of carrying much less internal fuel, compares favourably in range and endurance, to some of the older prop based platforms it will succeed:
P-8 ‘Poseidon’
P-3 ‘Orion’
IL-38 ‘May’
Speed
490 knots (564 mph)
Speed
330 knots (379.8 mph)
Speed
347 knots (399 mph)
Range
1200+ nautical miles radius
(1,381 miles) with 4hours on station
Range
845 nautical miles radius (973.1
miles) with 3 hours on station
Range
1188 nautical miles radius (1367 miles) Total endurance 12 hours
Fuel
10,000 pounds
Fuel
60,000 pounds
Fuel
48,000 pounds approx.
Gross Weight
187,700 pounds
Gross Weight
139,760 pounds
Gross Weight
39,700
*Figures for P-8 after
http://www.navair.navy.mil/mma/index.cfm?method=controller.about
*Figures for P-3 after
http://www.fas.org/man/dod-101/sys/ac/p-3.html
*Figures for IL-38 after
http://www.military-today.com/aircraft/ilyushin_il38_may.htm
As evident from above table, although the P-8 is 25 percent heavier than P-3C and Il-38, the P-8 carried about one-sixth the fuel capacity, has two less and more efficient engines, which provide greater operational missions range and quicker on station time due to greater speeds.
Conclusions
The P-8I deal is in many ways a revolutionary deal for the Indian Navy, and it should dramatically improve its surveillance and ASW capabilities. It is also a representation of the new found confidence in Indo-US security relationship. It must stand out as the single most high technology defence hardware transfer to India as compared to previous deals of weapon locating radars, surface ship and transport aircrafts. Performance-wise, the Boeing P-8 is the most capable successor to any legacy LRMP platform like the P-3 Orion it is designed to replace, or in the Indian case the venerable Tu-142 Bear.
It's based off a very successful airliner, with over 5,400 built and around 7,000 ordered, giving us an assured supply of spares and technical support. Despite the high unit cost and perhaps some yet to be ascertained high life cycle costs, apart from issues with end user agreements, India is picking up a system which ran into more than $3.89 billion in development costs. In fact we should expect further airframes to join the fleet in midterm future as Indian Navy expands its operations and a force of 8 aircrafts may turn out to be too stretched out to meet operational requirements. Although IN has traditionally fielded very small LRMP fleets comprising of around a dozen platforms (Japan for instance plans to induct as many as 78 P-1 aircraft), faced with an increasing PLAN SSN threat in mid to long-term, it may opt for an expanded force structure of such platforms.