What would be the cost of fitting two extra cameras for the crew to have a visual on the engines at any time ?
Cameras are an inflight version of a walk around.
Cost of the hardware is peanuts. Design, integration and certification is the pricey part. For it to be useful you have to be able to properly cover most of the airframe.
A bang followed by explosive decompression leaves a pilot wondering the size and location of the hole, so non cabin portions of the fuselage should be covered. Cameras on the wing looking back at the fuselage could achieve this.
Day/night capable cameras are a reliable means of quickly communicating to the crew the overall state of wing or tail.
Night capable cameras would give the crew confidence to stay in their seats rather than peering past windows with torches.
Cameras pointing at landing wheels also a good idea.
IR/visible spectrum cameras with views of the hold also useful to help confirm presence and scale of smoke.
High definition cameras plumbed to a 12-17 inch HD monitor offers a worthwhile improvement to situational awareness in an incident.
This adds up to +14 cameras
A touch screen with thumbnails to select active picture and a simple exposure control are basic controls. For $500 per camera the pictures can be in a loop record (continuous recording) to a solid state recorder.
Much new information can be gained after the event by study of images, in particular of events that cannot be tested on the ground.
No one is suggesting channel hopping the cctv images should be prioritised ahead of seat of the pants, intuitive flying when the worst happens.
Mickjoebill