System

{{entity:Kids Remote Control Airplane}} ({{hex:DEEC1058}}), final review and acceptance assessment. The specification entered this session at “validated” status with 204 requirements, 3507 trace links, 7 diagrams, and 77 classified entities across 6 subsystems: {{entity:Airframe Subsystem}}, {{entity:Propulsion Subsystem}}, {{entity:Flight Control Electronics}}, {{entity:Radio Transmitter}}, {{entity:Power System}}, and {{entity:Ground Charging System}}. This is the 21st system to complete the full decomposition pipeline.

Coherence

The six subsystems partition the aircraft cleanly along functional boundaries. The {{entity:Propulsion Subsystem}} and {{entity:Flight Control Electronics}} are decomposed to component level (ESC MOSFET bridge, gate driver, microcontroller; receiver, FCE MCU, IMU, servos) — appropriate for their safety criticality. The {{entity:Ground Charging System}} and {{entity:Airframe Subsystem}} remain shallower, which is proportionate: the charger is external support equipment and the airframe is a single-material (EPP foam) structure. Seven architecture decisions ({{stk:ARC-REQ-001}} through {{stk:ARC-REQ-007}}) document explicit trade studies with rejected alternatives and accepted trade-offs — notably the ESC-integrated BEC single-point-of-failure acceptance mitigated by aerodynamic glide, and the ground charger mass trade against onboard charging.

flowchart TB
  n0["Kids Remote Control Airplane"]
  n1["Airframe Subsystem"]
  n2["Propulsion Subsystem"]
  n3["Flight Control Electronics"]
  n4["Radio Transmitter"]
  n5["Power System"]
  n6["Ground Charging System"]
  n7["USB Power Supply"]
  n8["Atmosphere"]
  n9["2.4 GHz ISM Band"]
  n10["Child Pilot"]
  n0 -->|contains| n1
  n0 -->|contains| n2
  n0 -->|contains| n3
  n0 -->|contains| n4
  n0 -->|contains| n5
  n0 -->|contains| n6
  n5 -->|7.4V power| n2
  n5 -->|5V BEC| n3
  n3 -->|PWM throttle| n2
  n4 -->|2.4GHz control frames| n3
  n3 -->|servo deflection| n1
  n8 -->|aerodynamic forces| n1
  n9 -->|shared spectrum| n4
  n7 -->|5V 2A| n6
  n6 -->|CC/CV charge| n5
  n10 -->|stick inputs| n4

Completeness

Every {{stk:STK-REQ-001}} through {{stk:STK-REQ-014}} traces to at least one SYS requirement. All 14 SYS requirements trace to SUB or IFC requirements. All 37 SUB and 26 IFC requirements now have VER entries — this session closed the final three gaps: {{sys:SYS-REQ-013}} (post-crash battery safety protocol), {{ifc:IFC-REQ-025}} (ESC MCU to gate driver signal integrity), and {{ifc:IFC-REQ-026}} (joystick to RF module frame timing). All five ConOps scenarios — Weekend Park Flight, Wind Gust Crash, Signal Loss Failsafe, Charging Fire Emergency, and Routine Maintenance — were validated as covered in the prior session, with gap closures for the wind gust and charging fire scenarios.

Acceptance Assessment

A procurement authority could contract from this specification: requirements are quantified with measurable acceptance criteria, architecture decisions document trade studies with cost/mass/safety justifications, and the sub-250g regulatory constraint is explicitly addressed. A test organisation could write a complete test programme from the 109 VER entries alone — each specifies bench setup, measurement method, pass/fail thresholds, and number of trials. The safety argument is coherent: hazard H-002 (LiPo thermal runaway, SIL 2) cascades through {{sys:SYS-REQ-005}} (balance charger cell monitoring), {{sys:SYS-REQ-013}} (post-crash protocol), {{sub:SUB-REQ-015}} and {{sub:SUB-REQ-016}} (charger IC thresholds), to corresponding VER entries. EN 71 toy safety compliance is addressed at stakeholder, system, and verification levels.

Per-Subsystem Summary

Subsystem	SUB Reqs	IFC Reqs	VER Entries	Diagram
Propulsion	6	4	15	Yes
Flight Control Electronics	5	7	14	Yes
Radio Transmitter	5	4	10	Yes
Power System	5	4	12	Yes
Ground Charging System	3	3	8	Yes
Airframe	4	1	5	Yes

Cross-Domain Insights

{{entity:Airbus A330}} ({{hex:DEEC1018}}, 97% Jaccard) and {{entity:Dassault Falcon 200}} ({{hex:D6FC1058}}, 94% Jaccard) share nearly identical trait profiles. The key differentiator is the {{trait:Biological/Biomimetic}} trait on the RC airplane — reflecting biomimetic wing aerodynamics — which the commercial aircraft share. The {{entity:Push-pull Train}} analog (97% Jaccard) is less instructive for aviation but confirms the powered-vehicle trait cluster is well-characterised.

Corrections

Three actions taken this session: (1) Reassigned homeless requirement REQ-SEKIDSREMOTECONTROLAIRPLANE-011 (transmitter battery life) to system-requirements as {{sys:SYS-REQ-014}}. (2) Created three VER entries closing the final verification gaps for {{sys:SYS-REQ-013}}, {{ifc:IFC-REQ-025}}, and {{ifc:IFC-REQ-026}}, with trace links. (3) Confirmed 0 tagged duplicates, 0 missing rationale, 0 missing verification fields.

Efficiency

The Kids Remote Control Airplane completed in approximately 16 sessions (486–501), including concept, scaffold, decomposition of all 6 subsystems plus ESC and Radio Transmitter component-level breakdown, QC, validation, and this final review. No sessions were wasted on rework loops.

Residual

69 semantic lint findings remain (2 high, 67 medium), all in the Ontological Mismatch category. The two high findings are classification artifacts: the {{trait:Biological/Biomimetic}} trait on the airplane (biomimetic wing design, not biological material) and the mechanical interface lacking {{trait:Physical Object}} (expected for interface concepts). The 67 medium findings flag missing manufacturing/material requirements for all Synthetic-classified components — appropriate for detailed design phase, not conceptual specification. These are accepted as-is.

Verdict

PASS. The specification is coherent, complete, proportionate, and testable. All ConOps scenarios are covered. The trace chain from stakeholder needs through to verification is unbroken. The safety argument for LiPo thermal runaway is sound. A procurement authority, test organisation, and safety authority could each use this specification as the basis for their respective activities. Baseline COMPLETE-2026-03-24 created. System marked complete.