In the wake of the Maui wildfire disaster and as a statewide drought continues unabated, the threat of wildfires is top of mind for many in Hawaii.

In particular, Oahu’s own wildfire worries occurred earlier this month in the mountains east of Mililani Mauka.

Starting on Oct. 30 and lasting for more than a week until Nov. 7, the Honolulu Fire Department did battle with a wildland blaze that started as a small reported brush fire.

That wildfire, which initially scorched 300 acres but eventually blackened almost 1,700 acres of largely rugged, steep ridge lines, was deemed inaccessible to firefighters on the ground.

To battle this blaze, HFD’s aviation program of three helicopters — all built in late 20th century and nearing the end of their useful serv­ice lives — were brought to bear, days before the wildfire was squelched by a spate of heavy rainfall.

But according to HFD Battalion Chief Robert Thurston, who leads the department’s aviation wing, it was the assistance from the U.S. Army, Hawaii Air National Guard and state Division of Forestry and Wildlife, among others, who bombarded the blaze from above with successive airborne water drops, that kept the Mililani Mauka fire contained.

During a meeting Wednesday of the City Council’s Committee on Public Safety, Thurston told the panel that the Army’s contribution of larger helicopters was vital to fighting the Mililani Mauka fire.

“They provided Chinooks along with Black Hawk helicopters,” he said.

He noted that the Chinook’s water-carrying capacity is 2,000 gallons, while the Black Hawk can carry 660 gallons of water per flight.

By contrast, HFD’s three MD 520 helicopters can carry only 100 gallons in their respective water buckets per trip.

Overall, Thurston said statewide resources are limited when it comes to firefighting aircraft.

“The state of Hawaii does not have a stand-alone aviation program at present; they contract that service out,” he said, adding the contractors are usually sightseeing helicopter tour companies. “It was contracted to, I believe, a combination of Windward and Paradise helicopters.”

He added “their helicopters are similar models to ours, which carry 100 gallons in their water buckets.”

“So you can see the limitations of our buckets versus our Army partners and National Guard partners,” he said.

But the main issue with the Fire Department’s MD 520 helicopters is that they’re aging.

“Most of our helicopters were manufactured in the 1990s,” Thurston said of single-engine aircraft that have a range of 242 miles and a roughly two-hour flight time. “They’ve been refurbished, but they are coming to the end of their service life.”

He noted that “it’s very costly, and it takes the aircraft out of service for a long duration for that refurbishment.”

“We feel the taxpayers’ dollars are better used in investing in modern technology, and modern aircraft with a broader scope of capabilities,” he added.

To that end, Thurston said the Fire Department was trying to acquire a new twin-engine helicopter, which HFD hopes to receive by October.

“So our current fleet is limited to a 100 gallons per bucket,” he said. “The new aircraft that we’ll be taking … will have (a) 280-gallon capacity, so triple our current capacity with that.”

Moreover, he said HFD’s current single-engine helicopters have only a few backup systems — for example, if the engine goes out, there is no other to take its place.

“With a twin-engine you have redundant fuel systems, you have redundant filtering systems, you have redundancy as far as the engine itself,” Thurston said, adding if an engine fails on a twin-engine helicopter, it can fly on its remaining engine.

But HFD’s aviation program has other limitations.

“We cannot fly when winds are greater than 30 knots and the gust spread is more than 15 knots,” Thurston said. “The aircraft are Visual Flight Rules all of the time; we cannot fly by instruments.”

And HFD helicopters are typically grounded during nighttime hours, he added.

“We’ll fly at night for rescues, where we have a life-safety issue or incident,” he said, but noted firefighting at night is considered too dangerous. “Water bucket drops are not permitted. … The risk is just too high, and the reward is too low.”

Thurston noted, however, that a twin-engine helicopter could change that policy. “That subject might be revisited in the future,” he added.

Thurston also said HFD’s six pilots are also limited in terms of their own on-duty flight times — for safety reasons, each pilot cannot fly beyond an eight-hour shift.

Meanwhile, the Council had questions for the Fire Department.

Council member Andria Tupola had concerns over the length of time it took for HFD to fight the Mililani Mauka fire and how fighting similar wildfires in the future might affect the city budget.

“Those kinds of things we have to take into consideration,” Tupola said. “That is, the fire was two weeks, and it cost $2 million plus in-kind from the Army. … What does that equal, what do we foresee for the next, upcoming year and do we have enough resources?”

In response, Assistant Fire Chief Joseph Kostiha said the department would review the Mililani Mauka incident to come up with a “quantitative amount” with regard to the cost to fight this wildfire.

“But I just want to say that without the help of the partner agencies … the fire, in my estimation, would have lasted well over a month,” Kostiha told the panel. “Without those heavy aircraft supporting or operating … in any portion that was endangering life and property or coming near it, the fire would have exponentially cost a lot more money and man-hours.”

Council member Val Okimoto asked why HFD used helicopters rather than ground crews to battle the Mililani Mauka fire.

“The main reason was the topography, and the lack of fire escape routes or safe zones for our personnel to retreat to if we were to put them on the ground,” Thurston said. “So the bulk of the firefighting was done from the air.”

“And if it had been something that came closer to the homes, it would have been a different plan?” Okimoto asked.

“Yes, absolutely,” Thurston replied. “We would have deployed hand crews with hose lines.”

There were no reported injuries and no structures were destroyed due to the Mililani Mauka fire. The cause of the fire reportedly remains under investigation.