RAF Poseidon - Not too long to wait?
Reports suggest that the first of nine P-8A Poseidon being built for the RAF (ZP801, line number 6560) has been spotted on the flight line at Renton, waiting it's first flight. Seasoned Boeing-watchers have estimated that the aircraft should fly in mid to late October.
Previous Boeing commercial derivative aircraft destined for military use like the Boeing 737 AEW&C were built as normal commercial airframes, and were then delivered green to a completion centre where the necessary modifications (including structural cut outs and apertures for antennas, etc.) would be made.
The P-8A is built differently. For the Poseidon, Boeing has introduced in-line production, process, meaning that all aircraft modifications unique to the P-8 are made in sequence during fabrication and assembly. All of the necessary structural changes are incorporated as the airframe is being built, in other words, rather than afterwards. This removes the time and cost of building an aircraft, tearing it down, and then rebuilding it.
And though the P-8A looks very similar to the Boeing 737-800 upon which it is based, there are a host of major structural differences. Quite apart from the weapons bay installed in the aft lower fuselage and the hardpoints for weapons pylons under the wing, and the cut-outs for two large observation windows, the P-8A is built using a significantly thicker guage of aluminium skin. The Poseidons fuselage and wings incorporate additional stringers, frames and fasteners, while the normal apertures for passenger windows are missing.
This all means extra work for the fuselage and wing production lines at Spirit AeroSystems in Wichita, Kansas and Renton respectively, where components for the P-8A are built using the same assembly jigs as those destined for commercial 737 airliners.
To allow it to produce P-8 and 737 fuselages on the same line (despite the significant differences) Spirit has created a down-stage sub-assembly position where the weapons bay and auxiliary fuel tank will be integrated before they are installed on the line. Completed fuselages are shipped from Wichita to the final assembly line at Renton by rail.
Although P-8A final assembly could have been performed on one of the two existing moving 737 assembly lines at Renton, Boeing decided to create a third, ITAR-compliant line for the Poseidon. This meets the Pentagon's security requirements and allows for slightly stretched flow times (which are necessitated by the P-8As extra wiring harnesses and cargo-bay auxiliary fuel tanks, for example), but could still be used to assemble commercial 737s if Boeing needed extra capacity.
Boeing says that by implementing established best practices and common, commercial production-system tools, it has been able to reduce flow time and cost while ensuring quality.
Following final assembly and painting, each P-8A leaves Renton and Boeing Commercial Airplanes and makes the short flight to Seattles Boeing Field for mission system installation by Boeing Defense, Space & Security.
After arrival at Boeing Field, each P-8A is moved across East Marginal Way South to the old Thompson building (where the first few 737 airliners were built, back in the early 1960s). The move is made by night, to minimize disruption to the traffic!
Because the Thompson building isnt quite wide enough to accommodate a Poseidon, the aircrafts raked wingtips are removed and then reattached when it emerges from systems installation, before final testing and customer delivery.
Those with an eye for such things may notice that the RAFs P-8As have been assigned appropriate but slightly out-of-sequence registrations ZP801 to ZP809.
The UK announced its intention to order nine P-8 aircraft In November 2015, as part of the 2015 Strategic Defence and Security Review. The US State Department approved a proposed Foreign Military Sale to the UK for up to nine P-8 aircraft and associated support, at an estimated cost of $3.2 billion in March 2016, and the UK Government committed to the purchase in July 2016.
The British aircraft will be manufactured as part of three larger production lots, and the first two British P-8s are expected to arrive at RAF Lossiemouth in Scotland (where £400m is being invested in new support infrastructure for the aircraft) in 2019. The next three aircraft will be delivered in 2020 and the final four will follow in 2021. This schedule is reportedly dependent on the pace of construction of infrastructure and may slip by between six months and a year.
On Thursday, 13 July 2017 Sir Michael Fallon, the Defence Secretary, revealed that the nine new P-8A Poseidon Maritime Patrol Aircraft will be operated by No.s 120 and 201 Squadrons from RAF Lossiemouth in Moray. No.120 Squadron will form under Wing Commander James Hanson from April 2018, with No.201 Squadron following in 2021.
There are a number of questions about the UKs P-8A procurement, but the RAF and MoD have proved remarkably unwilling to answer many of these. Comparisons between the P-8A and the ill-starred Nimrod MRA.Mk 4 are discouraged, and there is an absolute refusal to talk about the essentially uncompleted nature of the selection of the Poseidon, and about any alternatives to the P-8A that may have been considered. Nor does there seem to be much appetite to talk about the P-8As performance, nor about the troubled Multistatic Active Coherent system upon which the P-8As ASW capabilities are to be based, while detailed discussion about the practicality of conducting ASW from high level seem to be similarly frowned upon.
Aerospace Analysis and Insight will return to these issues soon, however!
