The Reddit query about aircraft camera systems—prompted by a viewer of accident-analysis channels like Mentor Pilot—touches on a topic that generates recurring discussion among enthusiasts but is well understood within the industry: cameras exist on many transport-category aircraft today, but their absence from certain critical functions reflects deliberate design tradeoffs rather than oversight. Modern widebodies, including the Airbus A380 and A350 and Boeing 787, are equipped with external tail-mounted and belly-mounted cameras primarily for ground maneuvering, gate docking, and gear-down confirmation, displayed on cockpit or cabin monitors. Some aircraft also carry cargo-compartment smoke detectors tied to annunciator panels rather than visual feeds. What the poster is really asking about—dedicated engine-bay cameras or cargo-hold video to visually confirm fire location—remains largely absent from certification requirements, and that gap is rooted in both technical limitations and certification philosophy rather than cost alone.
The engine-misidentification scenario the poster references is a well-documented human-factors problem, most infamously in the 1989 Kegworth 737 accident, where crew shut down the healthy engine after misreading vibration and smell cues. Contemporary aircraft have since evolved: engine indication and crew alerting systems (EICAS/ECAM), N1/N2/EGT parameter displays, and automated engine-fire detection loops (using pneumatic or resistive sensing wire that responds to heat and pinpoints the affected engine) exist precisely to eliminate the ambiguity a camera might otherwise be expected to resolve. Regulators and manufacturers have generally favored redundant sensor-based detection—which works reliably in smoke, darkness, and structural damage scenarios where a camera lens could be obscured, melted, or lose power—over optical systems that introduce additional failure points, wiring runs through fire zones, weight, and certification burden under DO-160 environmental qualification and FAA/EASA fire-detection standards (14 CFR 25.1203). A blocked or destroyed camera in the exact area experiencing a fire is not a hypothetical risk; sensor loops are physically routed to remain functional under conditions that would blind a lens.
For working pilots, the practical takeaway is that checklist discipline, cross-checking multiple independent parameters (fire bell, EICAS message, engine instruments, and often a confirmatory "fire handle" light) exists specifically because single-source data, visual or otherwise, is considered insufficient for irreversible actions like engine shutdown or fire-bottle discharge. Training emphasizes verifying which engine before touching a firewall shutoff, precisely because Kegworth-type errors stem from procedural and cognitive shortcuts, not sensor deficiency. Cargo compartment smoke detection likewise triggers procedural checklists (diversion, Halon discharge) rather than requiring visual confirmation, since the priority is suppression and landing, not investigation, once smoke is detected.
Broader industry trends do point toward expanded use of cameras, but for different purposes than fire diagnosis: enhanced ground-maneuvering vision systems, cabin surveillance for security post-9/11 (locked cockpit door monitoring is now mandatory on many transport aircraft), and increasingly, exterior ice/contamination inspection cameras on some business jets. Some manufacturers have also explored tail-cam systems for pilots to visually inspect wings during icing conditions. However, extending camera systems into engine nacelles or cargo bays for fire diagnosis has not gained regulatory traction, largely because existing detection-loop technology already satisfies certification requirements more reliably than an optical system could in a fire's actual thermal and visibility environment. Pilots and operators should expect continued incremental adoption of cameras for situational awareness and ground operations, but not as a replacement for the redundant, environmentally hardened sensor architecture that fire and smoke detection systems currently rely upon.