This is the second mishap involving a Taiwanese Army OH-58D Kiowa helicopter in the past two months. Credit: Handout.

A massive five-day military drill simulating a Chinese attack on Taiwan was marred by the death of two helicopter crewman, officials said.

The two crew members were killed in a helicopter crash Thursday as Taiwan’s military held drills across the island, Agence France-Presse reported.

Thursday’s climax of the five-day drill aimed to test how democratic Taiwan’s armed forces would repel an invasion from its giant neighbor, AFP reported.

Beijing regards Taiwan as part of its territory and has vowed to one day seize it — by force if necessary.

Thursday’s main simulation saw Taiwan fighter jets, warships and ground troops repelling an enemy attempt to land on a beach in the central city of Taichung in an operation involving some 8,000 service members, AFP reported.

The military said a Bell 0H-58D helicopter crashed as it returned to Hsinchu airbase from one of the exercises, killing the pilot and co-pilot.

Taipei has lived with the threat of invasion by China since the two sides split in 1949 after a civil war.

In recent decades it has found itself increasingly outnumbered and outgunned by China’s enormous People’s Liberation Army, AFP reported.

Beijing has piled military, economic and diplomatic pressure on Taiwan since President Tsai Ing-wen came to power in 2016 because she refuses to acknowledge its stance that the island is part of “one China.”

Tsai won a landslide re-election in January in what was seen as a strong rebuke to China’s strong-arm tactics against the island, AFP reported.

Following the tragic Kiowa helicopter crash, the Minister of National Defense Yen Teh-fa paid his respects to their families and praised the pilots as national heroes.

On Thursday evening, Yen visited Hsinchu Air Force Hospital to express his condolences. He stated that in order to reduce collateral damage, they sacrificed themselves in a final noble and righteous act, Taiwan News reported.

The pilot, Army Major Chien Jen-chuan, and the co-pilot, Captain Kao Chia-lung, both suffered serious injuries in the crash and were sent to the hospital.

The helicopter belonged to Taoyuan-based 601st Brigade of the Army Aviation and Special Forces Command, DefPost reported.

According to Major General Chang Tai-sung, commander of the Taoyuan-based 601st Brigade, the helicopter was trying to return to the airbase as it was showing low rotor speed while flying 400 feet above the ground two minutes after taking off from the base.

The general said that the crew members decided to return to the base to avoid causing civilian casualties as the chopper was flying above a residential area at the time of the warning, DefPost reported.

He added that the crash was probably due to the lack of rotor speed as the helicopter was attempting to perform an 180 degree left turn.

According to the military, both pilots were critically injured after the crash and were immediately sent to the nearby Hsin Chu Armed Forces Hospital where they succumbed to the injuries.

In response to the incident, the ROC Army has grounded all of its OH-58D helicopters pending safety checks. The Army has constituted a committee to investigate the cause of the accident, DefPost reported.

This is the second mishap involving a Taiwanese Army OH-58D helicopter in the past two months. In May, an ROC Army OH-58D helicopter sustained minor damage during a “hard landing” at a military base but the two pilots were uninjured.

The Bell OH-58D Kiowa Warrior is the latest model of the OH-58 Kiowa family of single-engine, single-rotor, military helicopters used for observation, utility, and direct fire support developed by American company Bell Helicopters (now Bell Textron).

In recent months Chinese warplanes have started buzzing Taiwan with unprecedented frequency, repeatedly breaching its air defence zone and prompting Taipei to scramble its own fighter jets, AFP reported.

The military mismatch has been compounded by Western governments being increasingly wary of selling Taiwan advanced weapon systems, fearful of incurring Beijing’s wrath.

That has pushed the island to develop its own hardware, including advanced missiles, boats and a new trainer jet.

Some of that hardware, including locally built surface-to-air and hypersonic missiles, was used during this week’s drills, AFP reported.

China’s increasingly muscular approach towards the island has also sparked renewed international co-operation with Taiwan.

Under US President Donald Trump, Washington has become far more willing to sell big-ticket items, including F-16 fighter jets and other hardware, AFP reported.

Earlier this week, Beijing vowed to impose sanctions on defense company Lockheed Martin in response to the US agreeing to upgrade Taiwan’s Patriot missile systems.