Introduction to the AN/APS-154 Advanced Airborne Sensor

Following the recent Red Sea “interception” of a P-8 and my thread on the system (the airframe is just the platform that gets the sensor where it needs to be) I thought it would be useful to describe what the “sensor” was clipped to the fuselage.

As always, views my own and facts can be corrected. @Raytheon_UK

1/25 The AN/APS-154 Advanced Airborne Sensor (AAS) is a state-of-the-art multifunction radar developed by Raytheon (now RTX Corporation) for the United States Navy’s P-8A Poseidon maritime patrol aircraft. Designed for intelligence, surveillance, reconnaissance, and targeting (ISR&T), the AAS represents a significant advancement in airborne radar technology. This thread attempts to follow its development from conceptualisation to operational deployment, elucidates its functionality, and examines its integration with the P-8A.
Furthermore, it explores opportunities for the United Kingdom and NATO allies—Canada, Norway, and Germany—to enhance their P-8 fleets, addressing capability gaps such as those left by the we retired Sentinel R1 and soon the Shadow R1, and concludes by highlighting its role as a force multiplier. Conceptual Origins of the AAS

2/25 The AAS was conceived in the late 2000s to counter evolving threats in littoral and maritime environments, where traditional radars struggled to detect low radar cross-section (RCS) targets, such as stealthy vessels, low-flying drones, or submerged submarines. Building on the classified AN/APS-149 Littoral Surveillance Radar System (LSRS), deployed on select P-3C Orion aircraft, the AAS aimed to enhance multi-function capabilities like moving target indication (MTI) and high-resolution mapping, adapting them for modern asymmetric warfare.

The Boeing P-8 Poseidon: An Essential Pillar of Contemporary Maritime Patrol and Anti-Submarine Warfare

1/25 In this quickly put together long thread, I shall attempt examine the Boeing P-8 Poseidon. The thread will attempt traverse its developmental trajectory from initial requirements to full operational service, with a particular emphasis on its integration and utilisation within the Royal Air Force (RAF).
Given the resurgence of underwater threats in the North Atlantic, the RAF’s (and others) recent and ongoing deployment of the P-8 underscores its strategic relevance. This thread is tailored for a predominantly British audience, highlighting RAF-specific applications, whilst attempting to remain relevant for other readers. It will follow my standard format and address the aircraft’s concept of operations, its synergies with complementary assets, the geopolitical significance of the Greenland-Iceland-United Kingdom (GIUK) Gap, specifically including recent multinational activities—and detailed analyses of its sensors, armaments, configurations, and comparisons to predecessors and contemporaries. It will explore the RAF’s infrastructure adaptations, procurement decisions, and the platform’s pivotal role in supporting the United Kingdom’s Continuous At Sea Deterrent (CASD).

As always, all views my own and facts can be challenged. This has been written (at pace) to give some context to the recent events other contributors (@TBrit90 @NavyLookout @pegge49 @auonsson)

For additional context I have worked on the RAF P-8 (not as an aviator) Nimrod MR2 and Nimrod MRA4 (the world’s best ASW long range fixed wing aircraft).

Apologies for grammar and any repetition.

The Boeing P-8 Poseidon demonstrates an uplift in maritime patrol capabilities, evolving from the United States Navy’s (USN) need to modernise its fleet in the face of evolving submarine technologies. For the RAF, the P-8 has restored a critical capability absent since the retirement of the Nimrod fleet, enabling robust surveillance over vast oceanic expanses. Its adoption by NATO allies, including the UK , reflects a collective commitment to countering asymmetric threats posed by advanced submarines from potential adversaries (specially Russian). In recent months, the RAF has markedly heightened its operational tempo with the P-8, deploying aircraft for extended missions in contested waters, thereby reinforcing the UK’s maritime security posture and contributing to alliance-wide deterrence efforts but also (in the RAf’s case) if nine aircraft was enough. Historical Origins and Initial Requirements

2/25 The genesis of the P-8 Poseidon can be traced to the late 1980s, when the USN identified significant operational constraints in its ageing Lockheed P-3 Orion fleet. Issues such as airframe fatigue, escalating maintenance demands, and diminished range and endurance necessitated a successor capable of sustaining prolonged missions in increasingly contested maritime environments. This led to the initiation of the Multimission Maritime Aircraft (MMA) programme in 2000, which aimed to procure a platform excelling in ASW, anti-surface warfare (ASuW), and intelligence, surveillance, and reconnaissance (ISR), all whilst achieving substantial reductions in lifecycle costs through innovative design and manufacturing efficiencies.
Prospective designs included Lockheed Martin’s Orion 21, an evolutionary upgrade of the P-3; Boeing’s innovative proposal predicated on the commercial Boeing 737-800ERX airliner; and briefly, BAE Systems’ Nimrod MRA4, which withdrew from contention in 2002 due to the absence of a viable American industrial partner (sound familiar?)
Boeing’s selection on 14 May 2004, underpinned by a $3.89 billion system development and demonstration contract for at least 108 airframes, was predicated on the platform’s modularity, leveraging mature commercial technologies to expedite development and mitigate risks. This decision not only addressed the USN’s immediate needs but also laid the groundwork for international variants, including those adopted by the RAF to bridge a decade-long gap in long-range maritime patrol capabilities following the contentious cancellation of the Nimrod MRA4 in the 2010 Strategic Defence and Security Review.

Introduction to the UK’s Immigration Protest Crisis

Every now and again I like to focus on different parts of Defence and National Security. Views are my own, I’ve tried to stay apolitical.

1/25 The United Kingdom is grappling with a wave of protests centered on immigration, particularly the Home Office’s use of hotels to house asylum seekers. Demonstrations in Epping, Canary Wharf, and other regions have exposed deep community divisions, fueled by specific incidents and broader policy frustrations.

The recent announcement of “online monitoring units” to track social media has intensified concerns about free speech, further complicating an already volatile situation. This thread tries to examine the protests, their management, the role of agitators, and the risks of escalation if unaddressed. The Epping Protests – A Catalyst for Unrest

2/25 In July 2025, protests erupted outside the Bell Hotel in Epping, Essex, which has housed single male asylum seekers for years. The spark was the arrest of HGK , a 38-year-old Ethiopian asylum seeker, charged with sexual assault after allegedly attempting to kiss a 14-year-old girl. This incident inflamed local tensions, leading to demonstrations that escalated into violence, with significant implications for community cohesion and public safety.

The Ajax Ares Platform: A Comprehensive Analysis of British Army Modernisation, Peer Comparison, Procurement Challenges, and Strategic Missteps

This is a long read (a shorter version will also be published). Views as always my own and facts or statements can be challenged. Source references are available on request. All sources are open. (I have background in this subject, I drafted some of the questions for the Defence Select Committee during their inquiry into AJAX.

For more in-depth information on this, FRES and other land systems check out @thinkdefence and for Army strategic direction and organisation check out @nicholadrummond

Forward

1/20 The Ajax Ares platform, a key component of the British Army’s Ajax family of armoured fighting vehicles (AFVs), is designed to provide protected mobility and overwatch, replacing the ageing Combat Vehicle Reconnaissance (Tracked) (CVR(T)) Spartan. Developed under the Future Rapid Effect System (FRES) programme, the Ajax family has faced significant delays, technical issues, and controversies, collectively termed the “Ajax scandal.” This essay provides an in-depth examination of the Ajax programme’s original requirements, its historical context, and the technical specifications of the Ares variant, including its power plant, transmission, armour, C2 systems (with a focus on the delayed ZODIAC system’s role in intelligence dissemination), and limited weapon systems. It incorporates a recent statement by Defence Procurement Minister (Min DP) Maria Eagle, confirming Ares’ expanded role in infantry formations alongside Boxer, assessing its suitability, number of dismounts, and whether this reflects original requirements or poor strategic planning. The essay compares Ares with peer platforms—the Swedish CV90 and American M2 Bradley—to highlight its capabilities and shortcomings. It explores the MoD’s challenges, including noise and vibration issues, Parliamentary scrutiny, and the cancellation of the Warrior Capability Sustainment Programme (WCSP). It critiques the platform-for-platform approach, contrasts it with the Royal Navy’s Crowsnest programme, and evaluates the implications of emerging threats like First-Person View (FPV) Unmanned Aerial Vehicles (UAVs). Finally, it assesses the MoD’s damaged credibility and its impact on securing Treasury funding, arguing that systemic procurement failures threaten the British Army’s readiness. Table of Contents

2/20

1. Introduction

2. Historical Context: The Road to Ajax 2.1 Early Requirements and Predecessor Programmes 2.2 The Future Rapid Effect System (FRES) Programme

3. The Ajax Family: Overview and Variants 3.1 Ajax: The Reconnaissance Variant 3.2 Ares: Protected Mobility and Overwatch 3.3 Other Variants: Athena, Argus, Apollo, and Atlas

4. The Ares Platform: Technical Specifications 4.1 Power Plant and Transmission System 4.2 Armour and Protection 4.3 Command and Control (C2) and the ZODIAC System’s Role in Intelligence Dissemination 4.4 Weapon Systems and Limitations

5. Maria Eagle’s Statement and Ares’ Expanded Role 5.1 Ares in Infantry Formations: Statement and Context 5.2 Suitability for the Infantry Role 5.3 Number of Dismounts and Replacement of CVR(T) Spartan 5.4 Original Requirement or Poor Strategic Planning?

6. Comparison with Peer Platforms: CV90 and M2 Bradley 6.1 CV90: Design and Capabilities 6.2 M2 Bradley: Design and Capabilities 6.3 Comparative Analysis: Ares, CV90, and M2 Bradley

7. The Ajax Scandal: Challenges and Controversies 7.1 Noise and Vibration Issues 7.2 Parliamentary Defence Committee Scrutiny 7.3 The Sheldon Review and Lessons Learned

8. The Platform-for-Platform Approach 8.1 Comparison with the Royal Navy’s Crowsnest Programme 8.2 Implications for Capability Development

9. The Warrior IFV: Background, Upgrades, and Cancellation 9.1 Warrior’s Role and Legacy 9.2 The Warrior Capability Sustainment Programme (WCSP) 9.3 The Recce Variant and Strategic Missteps

10. Emerging Threats: FPV UAVs and Ares’ Vulnerabilities 10.1 The Rise of FPV UAVs and Loitering Munitions 10.2 Ares’ Vulnerabilities and Required Upgrades

11. The MoD’s Procurement Challenges and Treasury Relations 11.1 Systemic Issues in UK Defence Procurement 11.2 Impact on MoD and Army Credibility 11.3 Financial Implications and Treasury Scepticism

12. Conclusion

Introduction to the CAPTOR Radar

1/25 The CAPTOR radar is the beating heart of the Eurofighter Typhoon’s sensor suite, enabling its air superiority and multi-role capabilities. Developed through a multinational effort, it has evolved from a Cold War-era concept to a cutting-edge system. This thread traces its journey from requirement to operational use, its technology, variants, and relevance today, with a focus on the UK’s investment in the ECRS Mk2. As always views are my own and posts can be corrected if errors are found. This is third in series of UK airborne radars (Blue Fox/Vixen, Fox Hunter and now CAPTOR). Larger radars will be covered soon (Search Water etc). Origins of the CAPTOR Radar

2/25 The CAPTOR, originally the ECR-90, was born in the 1980s under the Future European Fighter Aircraft (FEFA) programme, aimed at countering Soviet aircraft like the MiG-29. Led by the EuroRadar consortium (UK, Germany, Italy, Spain), it built on the Ferranti Blue Vixen radar from the Sea Harrier FA2, leveraging pulse Doppler technology for superior target detection in cluttered environments.

Introduction to MoD Information Security

Further update - part 3

I’m not a lawyer but I do have some knowledge of information security.

1/25 The Ministry of Defence (MoD) operates in a high-stakes environment where safeguarding sensitive information is critical to national security and public trust. This thread explores the MoD’s information security processes, their alignment with UK laws and standards, and the fallout from the 2022 Afghan data breach, revealed after a superinjunction was lifted on 15 July 2025. Here is how the MoD manages data and where (I believe) it went wrong.

Views my own. The MoD’s Information Security Framework

2/25 The MoD’s information security is governed by the Government Security Classifications Policy (GSCP), which uses three tiers: OFFICIAL, SECRET, and TOP SECRET. Each tier has specific security controls to protect data based on its sensitivity and potential impact if compromised. This ensures proportionate safeguards for everything from routine admin to critical intelligence.

BLUF – A Two-Division Model for the British Army

1/25 The British Army should restructure into two divisions—one tracked, one wheeled—each with three brigades of three all-arms battle groups, to meet Strategic Defence Review (SDR) requirements. This suggestion aims to spark debate on sustaining NATO commitments in the High North and Baltics while enabling operations in the Middle East and Africa. The Heavy Division would sustain armoured battle groups, with brigades and divisions as resource providers, supported by modern equipment like Challenger 3 and Boxer. Cultural and structural challenges, including resistance to change and logistical constraints, must be addressed. A phased timeline from 2025 to 2032 aligns with equipment deliveries. Without significant reform, the Army risks irrelevance in a volatile strategic environment.

This thread has been put together following discussions with @thinkdefence and @MrSnaplegs last year (TD followed with a long read).

@nicholadrummond @509298 @BO3673 @PhilipIngMBE @BenWallace70 thoughts welcome on this Why Restructure the British Army?

2/25 The British Army faces evolving threats that demand a modern, agile force to remain relevant. The SDR, published in spring 2025, prioritises NATO deterrence and global deployability. A two-division model—one Heavy (tracked) for high-intensity conflict and one Expeditionary (wheeled) for rapid deployment—offers a solution. By focusing on all-arms battle groups, the Army can deploy flexible units while sustaining commitments. Reform is critical to avoid obsolescence amidst budget and personnel constraints.

CSG25 and Fleet Air Defence in CEPP

1/25 The UK’s Carrier Strike Group 2025 (CSG25), led by HMS Prince of Wales, embodies Carrier Enabled Power Projection (CEPP). This thread clarifies fleet air defence as a core CEPP KUR, countering doubts, and covers CSG25 assets, RN limitations, and challenges like no AAR or MADL. CEPP Overview

2/25 CEPP enables global power projection via CSG25, integrating naval, air, and land forces for combat, deterrence, and aid missions. Fleet air defence is a KUR, protecting the carrier to ensure CSG25’s effectiveness in contested Indo-Pacific regions, despite claims it is not central to CEPP.

Introduction to the NMH Programme

1/25 The UK’s New Medium Helicopter (NMH) programme, launched in 2021, aims to replace aging rotary-wing platforms but is mired in financial necessity and poor decisions by the MoD, DG Helicopters, and DE&S. The Puma HC2’s withdrawal has left a capability gap, with RAF Benson now without aircraft. Historical Context

2/25 Announced in the 2021 Defence Command Paper, NMH sought to replace four platforms: RAF Puma HC2, AAC Bell 212, RAF Bell 412 Griffin, and AAC AS365 Dauphin. Aging airframes and high maintenance costs drove the need, but financial constraints, not user needs, shaped the programme’s scope.

The UK’s F-35A and F-35B Procurement: Strategic Shifts and Challenges

1/25 The UK’s recent decision to purchase 12 F-35A jets alongside its F-35B fleet marks a significant shift in defence policy. This thread explores the rationale, sacrifices, and challenges, focusing on the nuclear role, NATO, and impacts on Carrier Enabled Power Projection (CEPP).
It follows my F-35B post from yesterday - talk about “timing” 😎 Rationale for F-35B

2/25 The F-35B was chosen in the 1998 SDR for its STOVL capability, essential for HMS Queen Elizabeth and Prince of Wales. This prioritised CEPP to project power globally, especially in the Indo-Pacific and reflected the expeditionary outlook of the UK at that time. F-35B was a fudge as it was neither the RAF or RN’s choice of F-35 (politics and industrial lobbying).

UK’s F-35B Ambitions (updated)

1/25 The UK’s adoption of the F-35B Lightning II aims to deliver cutting-edge, fifth-generation capabilities for the RAF and RN. However, integrating this platform faces challenges in weapon systems, logistics, operational concepts, and sovereignty, raising questions about value for money and strategic fit. Weapon System Integration Issues

2/25 Integrating UK-specific weapons like Meteor and SPEAR 3 is delayed to the 2030s due to F-35 Block 4 upgrade and other issues. The F-35B’s current fit, limited to Paveway IV and AAMs, restricts its versatility, especially for SEAD/DEAD missions critical in modern conflicts like Israel-Iran.

Introduction to UK GBAD Status

1/25 The UK’s ground-based air defence (GBAD) relies on the Sky Sabre system, operated by 16 Regt RA. However, limited deployability and 2005/6 cuts have weakened the UK’s ability to protect bases like RAF Akrotiri from Iran’s long-range missiles, exposing strategic vulnerabilities in a tense global environment. Sky Sabre System Overview

2/25 Sky Sabre, introduced in 2021, integrates CAMM missiles, Giraffe AMB radar, and MIC4AD command systems. It can engage aircraft, drones, and munitions up to 25km, with 360° radar coverage to 120km. Operated by 16 Regt RA, it’s a medium-range solution but limited by asset scarcity.

The RAF King Air Shadow Programme – A Deep Dive into Its Origins, Systems, Role, Challenges, and Future

1/25 Origins of the Shadow R1

The RAF’s Shadow R1 programme, based on the Beechcraft King Air 350CER, began as an Urgent Operational Requirement (UOR) in the 2000s to meet intelligence needs in Afghanistan. The conflict demanded real-time ISR to support ground forces, driving the need for a flexible, manned platform. 2/25 Why the King Air 350CER?

The King Air 350CER was chosen for its proven reliability, cost-effectiveness, and adaptability. Its twin-turboprop design, powered by Pratt & Whitney PT6A-47A engines, offered up to 7 hours of endurance, ideal for regional surveillance from austere airfields.

Introduction to Artisan and NS110/200 Comparison

Follow Up Part 1 on my T31 Thread

1/25: The Artisan Radar (BAE Systems) and Thales NS110/200 radars are key to Royal Navy’s T26 and T31 frigates. This thread compares their hardware, software, strengths, weaknesses, C2 integration, and RN challenges in supporting dual radar systems from different suppliers in complex maritime environments.
Technical Overview: Shared Capabilities

2/25: Both Artisan and NS110/200 operate in S-band, balancing range and resolution for air and surface surveillance. They detect aircraft, missiles, UAVs, and ships in cluttered littoral zones, using digital beam-forming for robust tracking in high-threat scenarios.

The Prevail Partners Littoral Strike Ship: A Transformative Approach to Supporting the Future Commando Force

1/25 The Prevail Partners Littoral Strike Ship (LSS) offers a bold vision for the UK’s Future Commando Force (FCF). Designed to support agile, tech-driven Royal Marine operations, it rethinks naval platforms for modern littoral warfare. 2/25 The FCF, part of the 2021 Integrated Review, shifts Royal Marines to small, agile units for special ops in contested littorals. It counters A2AD threats and supports rapid, low-footprint missions. The LSS is built to enable this vision with flexibility and forward presence.

The Evolution of Amphibious Warfare and the Role of the Commando Insertion Craft in the Future Commando Force

1/25 Amphibious warfare has shaped military strategy for centuries, enabling power projection from sea to shore. The Royal Marines, Britain’s elite amphibious force, rely on specialised landing craft to execute such missions, a practice rooted in historical operations like the D-Day landings of 1944. 2/25 World War II’s Normandy invasion showcased the Landing Craft, Vehicle, Personnel (LCVP), or “Higgins Boat,” with its flat-bottomed design and bow ramp for rapid troop deployment. This simple, effective concept became the standard for amphibious assaults, persisting through decades of conflict.

The MBDA SPEAR 3 Missile Programme – Delays, Integration Challenges, and Strategic Shortfalls

1/25 The MBDA SPEAR 3 missile, intended to equip the UK’s F-35B with stand-off precision strike capability, is now delayed to the early 2030s. This thread examines the programme’s issues, its impact on Carrier Enabled Power Projection, and why the F-35B (currently) falls short of its strategic objectives. Original Requirement:

2/25 SPEAR 3 (Selective Precision Effects At Range Capability 3) is a network-enabled, air-to-surface missile designed to engage mobile and relocatable targets at ranges exceeding 60 miles, critical for Suppression of Enemy Air Defences (SEAD) and deep strikes.

The Type 42 Batch 1 Destroyer – Conception, Design, and Early Service

1/25 This series of threads will explore the evolution of the Type 42 Destroyer, the design, the batches, the Falklands and the Gulf. It is open to comment, criticism, dits and photos. @IntercityFC and others, please feel free to add. I also point people to the great podcast ShipWrekt and these episodes: podcasts.apple.com/gb/podcast/shi…

podcasts.apple.com/gb/podcast/shi… 2/25 The Type 42 Batch 1 destroyer, or Sheffield-class, was a cornerstone of the Royal Navy’s 1970s fleet, balancing ambition with austerity. Conceived to replace the costly Type 82, it delivered area air defense via the Sea Dart missile system. This thread explores its design, constraints, and early roles.

For those that know me I’m all about balance so..

The Parachute Regiment: Origins, Evolution, and the Enduring P-Company Tests

1/25 We will examine the Parachute Regiment’s training, its historical inception, and the rationale for the Pre-Parachute Selection (P-Company) tests. We trace the regiment’s evolution since 1945 and the standards that define its elite airborne status. 2/25 Formed in 1940 during the Second World War, the Parachute Regiment was established following Winston Churchill’s directive for airborne forces. Inspired by German paratrooper successes, the regiment was tasked with rapid, high-impact operations.

The Royal Marines: Origins, Evolution, and the Enduring Commando Tests (maintaining the standard)

1/25 This thread examines the Royal Marines’ training, its historical inception, and the rationale for the Commando Tests. It traces their evolution since 1945, the conferment of Commando status, and the unchanging standards that define their status. 2/25 Established in 1664 as the Duke of York’s Maritime Regiment of Foot, the Royal Marines served aboard naval vessels, maintaining discipline and engaging in combat. By the 18th and 19th centuries, their amphibious role expanded to include land campaigns.

The County-Class Destroyer – The Royal Navy’s First Digital Warship

1/25 The County-class destroyer, launched in the 1960s, was a groundbreaking step for the Royal Navy, blending missile technology and automation. This thread explores its design, innovations, and legacy, from conception to its role in conflicts and eventual decline. Opinions my own, facts can be questioned. 2/25 Origins and Concept

Conceived in the 1950s amid Cold War tensions, the County class was designed to shield aircraft carriers from Soviet bombers like the Tu-95 “Bear.” It marked a shift from gun-based to missile-based warfare, aiming to counter high-altitude nuclear threats with guided weapons.