Final answer:
During a normal automatic ground start sequence, typically two igniters fire in a jet engine.
Step-by-step explanation:
In many jet engines, the igniters are used during the initial start of the engine and then turned off once the engine is running. During a normal automatic ground start sequence, typically two igniters fire.
The igniters are responsible for igniting the fuel-air mixture in the combustion chamber. They produce a spark to initiate the combustion process.
However, it's important to note that the number of igniters firing during a ground start sequence can vary depending on the specific engine design and manufacturer. Some engines may have more or fewer igniters.