Boeing 737-800 MMA
The Lockheed P-3 Orion has been operated by the US Navy for nearly 40 years as their primary maritime patrol, ASW, anti-surface warfare aircraft and in the EP-3 version for reconnaissance and intelligence gathering. Unfortunately when the Soviet Union disintegrated, the US Congress decided to acquire a ‘peace dividend’ for domestic programmes by using funds planned for the P-3/EP-3 replacement and, as a consequence, the US Navy began retiring P-3s and re-assigning their crews. However, in an increasingly dangerous world the remaining P-3s and EP-3s have been in demand all over the world in the fight against international terrorism. So as consequence of another miss-guided political decision, and the US Navy finds itself having difficulty operating a rapidly aging fleet with a limited number of experienced crews.
However, the various P-3s and EP-3s are fast approaching the end of their fatigue life and to replace these valuable aircraft the US Navy is planning to acquire 110 versions of a new aircraft that can provide maritime and land patrol, anti-submarine warfare, reconnaissance and intelligence gathering – known as the Multimission Maritime Aircraft (MMA). The two contenders for this $4 billion programme are Boeing, with a modified version of their 737-800 Boeing Business Jet (BBJ), and Lockheed Martin, with an upgraded new build P-3 called the Orion 21.
Originally planned to enter service in 2015, the requirement for the MMA has now apparently moved forward to 2010, a demanding timescale, however, even this reduced timescale will still require the aging P-3 / EP-3 to undergo structural repairs to enable the aircraft to operate safely. Given the many demands on the current defence budget, together with the development work still outstanding, it must remain doubtful if this timescale can be achieved.
To meet the many requirements of the MMA, Boeing is offering a developed variant of the latest version of the highly successful 737-800 Boeing Business Jet (BBJ) as their MMA platform. This new version of the Boeing Next-Generation 737-800 will operate at an increased gross weight, enabling it to carry the various specialised military systems, sensors, weapons and stores deployment capability. The aircraft will have a larger payload capability than the P-3, a faster transit speed to the patrol area and a similar fuel economy at low level. Despite the capacity of the fuselage, the 737-MMA will only carry a crew of 8, consisting of 2 pilots and 6 mission crew.
However, many observers have questioned whether it would be safe operating a twin-engined jet at low-level out over the ocean many miles from an airfield. Although using a jet powered aircraft for the MMA roles would enable a faster transit speed to the operating area than a turboprop, a jet would also be much less fuel efficient at low-level. It is the low-level performance of a 737, in an area that any MMA aircraft would have to spend a considerable amount of time, that is giving many observers cause for concern. The only other jet MPA aircraft, the Nimrod, has a fairly large, modestly swept wing that provides plenty of lift and turning performance in the critical low-speed / low-level scenario necessary for the ASW role. Typically, when using the Magnetic Anomaly Detector (MAD) to track a submarine, the 737-800 MMA 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 optimised for high-level / high speed cruise, the handling and turning characteristics of a fully loaded 737-800 MMA at low speed / low-level will be ‘interesting’. The 737 MMA has an internal weapons bay just aft of the wing, as well as six hardpoints on the wings that can carry stores, however, carrying anything under the wingwill add significantly to the aircraft's aerodynamic drag and increase fuel consumption.
The US Navy has also recently asked both companies to include options for a tanker varient of the MMA. Although the MMA will be fitted with a fuel probe and have the ability to dispense fuel as well, this change will almost certainly increase the unit cost of each aircraft above the original $55M price cap. However, this new aircraft should finally address the US Navy's lack of a navy specific AAR asset to support their fleet of offensive aircraft - during Operation Iraqi Freedom this task was frequently undertaken by RAF Tri-Star and VC-10 aircraft. However, the advantages of a 737 MMA, rather than an Orion 21, in the AAR role when refuelling jets are obvious and this new requirement could tip the advantage in Boeings favour.
There is no doubt that the widely-used Lockheed P-3 will have to be replaced, in some cases sooner rather than later and there are many compelling arguments in support of a jet, rather than a turboprop powered aircraft. However, it remains to be seen whether Boeing will successfully convince many sceptical observers that attempting to adapt the successful 737-800 is the best solution. Nevertheless, on 14 Jun 04 it was announced that Boeing had been awarded a $3.89 billion contract to build up to 109 of their 737 MMA aircraft for the US Navy.