ABOARD THE USS GEORGE H. W. BUSH, Persian Gulf — Recent investigations into a series of U.S. airstrikes that allegedly killed scores or hundreds of civilians near Mosul, Iraq, have raised troubling questions about the way the fight against the Islamic State is being prosecuted.

But a less-known story about a planned strike aborted with only seconds to spare is proof for Capt. James McCall that his aviators are doing what they ought. McCall, the commanding officer of Carrier Air Wing 8, attached to the Bush, told Military.com the nerve-wracking call took place in mid-April.

F/A-18 Super Hornets attached to the wing’s Strike Fighter Squadron 87 were operating near Mosul, where a coalition ground campaign to flush ISIS militants out of the urban stronghold rages on. The carrier, which has been deployed since January and currently patrols the waters of the Persian Gulf, launches between 12 and 20 such missions daily, over Syria as well as Iraq.

“They were issued their clearance to drop. They had about 20 seconds before they were going to release ordnance, and that ordnance would have impacted the target within, say, 45 seconds of the drop,” McCall said. “In those moments beforehand, one of the aircrew thought he saw someone leave a building, and he couldn’t possibly identify that person as a soldier or a civilian. So he issued an abort on the radio.”

The mission called off, the pilots watched as, over the next 10 minutes, hundreds of civilians poured out of buildings adjacent to the one the man had come out of. While not all the people coming into view would have been reached by the collateral effects of the planned strike, the aviators estimated, many of them would have been.

Despite the harrowing nature of the close call, McCall is encouraged by the outcome of the incident.

“That to me is a great story that tells me that we’ve given them enough training — granted, not always necessarily experience — but we’ve prepared them adequately for them to make those hard decisions,” he said. “And when a guy comes back and says, ‘I potentially aborted the bomb affecting civilians,’ then I think, ‘Hey, our guys understand the implications of their actions.’ ”

While the four Super Hornet strike fighter squadrons within the wing did not participate in the Mosul strikes currently under investigation, McCall said, the reports have prompted the units to re-examine elements of training on avoiding civilian casualties, already a rigorous part of their drilling and workups.

“I think our culture is such that any time an adverse event happens … I think it is by our nature to take that and see if we can draw any lessons out of that, that we can apply to the near term as well as the long term to ensure that those things don’t happen again,” he said. “Even though our air wing was not involved in some of the accusations that came out, we take a look at it, and we certainly go, ‘Hey, is there any threat we can pull out of this that affects the way we do business, that can make us safer and more effective in the long run.’ ”

While the squadrons have been conducting airstrikes on Islamic State targets since February in support of this deployment, McCall said training to prevent collateral damage was underway long before the carrier passed through the Strait of Hormuz and entered the Gulf. While the carrier was in transit from its homeport of Norfolk, Virginia, to the waters of the 5th Fleet, pilots were gaming out complex airstrike scenarios requiring sharp judgment calls and meeting with attorneys to discuss rules of engagement and decision-making.

“We invest a lot of time in an average pilot’s progression, getting ready for a deployment, and close-air support,” McCall said. “Actually physically dropping the bomb is probably the easiest part of that. It’s this judgment piece that is the difficult piece. And it requires them to practice that. It requires us to put them in scenarios that are difficult and sometimes gray in the training environment.”

There have been other instances, McCall said, when his pilots have called off strikes because they lacked complete certainty of the collateral impact of the planned action. While he acknowledged that even the best training can’t inoculate against tragic human error, he said the careful training and preparation give him the confidence that the wing’s fighter squadrons will represent the coalition well.

“One of the unique things I believe about aviation is we send these kids out, a thousand miles away from leadership, and we tell them, ‘OK, now you make decisions that have strategic impact to our country and our coalition,’ ” he said.

“So I have to be able to trust those guys to make really difficult decisions in really challenging scenarios. Does it mean it’s perfect? No, because there are humans in the loop,” McCall said. “But I also think that’s one of the great things. We have real human beings in the loop and we’re making decisions, and I think we do spend a lot of time making sure our folks get that right.”