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PAT-8812-SIG-LATARCHETYPE: Silent Signal Degradation

Telemetry Polling Lag & Stale State Latching

Sub-Type: Asynchronous Sensor Update Freeze

VEC:AUTH:0.65COUP:0.35LAT:0.91OVR:0.25
Authority Gradient
0.65
Feedback Coupling
0.35
Telemetry Latency
0.91
Override Suppression
0.25
Structural Pattern Audit Brief
Critical Multi-Node (Level 4)PAT-8812-SIG-LAT

Sensor acquisition thread drops update cycles but UI displays last-known good values with no freshness indicator, deceiving decision nodes into assuming steady state.

Failure Invariant Breach
Physical_Sensor -> Driver_Buffer -> Display_Node (Stale Value Latch)
Absent Safety Recovery Mechanism
Heartbeat timestamp verification and automatic stale-data greying

Fundamental Invariant Rules

INV-01:Telemetry displays must invalidate state representations when timestamp delta exceeds 3x nominal polling interval.

Engineered Resilience & Mitigation Strategies

MIT-01:Cryptographic monotonic timestamping on all sensor telemetry packets
MIT-02:Visual fail-open warning indicators when telemetry freshness decays

Canonical Incident Manifestations (4)

FAA-AD-2018-23-51Aerospace & Avionics

FAA Emergency Airworthiness Directive: AOA Resolver Stale State Freezes

Physical sensor state frozen due to hardware anomaly. Telemetry_Channel continued latching last-known good values to Decision_Node without state invalidation timestamp.

NIST-CVE-2021-32944Industrial Control Systems & SCADA

CISA Advisory ICSA-21-084: SCADA Modbus PLC Stale Register Latching

Network buffer congestion desynchronized PLC internal registers from physical sensors. Status telemetry reported healthy communication while physical Constraint_Boundary was breached.

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BEA-AAR-2009-0601Commercial Aviation

Air France Flight 447: Pitot Tube High-Altitude Icing & Dual Side-Stick Cancellation

Transient physical Telemetry_Channel blockage triggered automation disconnect. Decision_Node executed continuous contradictory control inputs, which remained unobserved by supervisory node due to decoupled side-stick physical telemetry.

NASA-OIG-2024-0824Human Spaceflight & Propulsion

Boeing Starliner CFT-1: Helium Flange Leaks & Reaction Control Thruster Thermal Deselection

Thermal saturation degraded physical valve seal Buffer_Reserves. Flight control software automated health checks detected performance delta and permanently deselected thruster Decision_Nodes, trapping spacecraft in degraded operational state.

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