Final answer:
It is generally not advisable to leave the downline connected to the primacord reel during loading due to the risk of premature detonation and the priority of safety in blasting operations.
Step-by-step explanation:
Is it advisable to leave the downline connected to the primacord reel during the loading of the hole? This question pertains to blasting operations in mining and construction engineering. In general, it is not advisable to leave the downline connected to the primacord reel during loading because this could lead to premature detonation if there are any accidental ignitions, which could result in injury or fatality. Moreover, handling the materials with care is essential for safety. Thus, disconnecting the downline from the primacord reel can help prevent accidental firing and ensure a safer blasting operation.