In a dual ejection situation with ISS set to BOTH, what occurs first?

In a dual ejection situation where the ISS (Inter-seat Sequencing System) is set to BOTH, the mechanism is designed to prioritize the ejection sequence to enhance pilot safety. The rear seat ejecting first is a key feature of this system.

This configuration minimizes the risk of a collision between ejected seats in close proximity, allowing for a safer separation. The reason the rear seat can still eject even with a safety pin installed is that the ejection sequence is engineered to ensure that the rear seat has priority under these circumstances. The system can override some aspects of the safety mechanisms to ensure that the pilot's ejection is executed first, thereby preventing the risk of the front seat becoming a hazard during the ejection process.

This understanding reaffirms the importance of behind-the-scenes safety features during emergency ejection procedures, focusing on the rear seat’s role in maintaining a safe ejection path for both pilots.