The US military is still working on how to keep the president's new helicopter from burning the White House lawn

A test aircraft left scorch marks on the White House lawn a few years ago, and the military is still trying to figure out how to fix that.

• The US military is still trying to solve a problem with the new presidential helicopter.
• The helicopter expected to serve as the new Marine One sometimes scorches the lawn when it lands.
• Possible solutions to the problem are expected by June at the earliest.
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The US military and a leading defense contractor are still searching for a solution that will keep the new helicopter expected to eventually serve as Marine One from burning the White House lawn, Bloomberg News reported Friday.

The military is in the process of replacing the aging executive transport fleet of 11 Sikorsky VH-3D and eight VH-60N helicopters, which are designated with the call sign "Marine One" when the president is aboard, with roughly two dozen VH-92A helicopters.

The new helicopters are expected to achieve initial operational capability as early as July. The White House Military Office will then make decisions about when the helicopters will enter service as presidential transport aircraft.

Although initial operational capability may only be a few months away, the military and defense firm Lockheed Martin are apparently still trying to resolve the lawn-scorching issue.

During a test flight in September 2018, the aircraft left scorch marks on the White House's South Lawn, Bloomberg News previously reported. The scarring was not seen in every test.

Last year, the Government Accountability Office reported that the military had not effectively demonstrated "that it can meet the requirement to land on the White House South Lawn without causing damage."

The government watchdog explained that "heat from the auxiliary power unit and/or engine exhaust continue to damage the lawn under certain conditions."

The Department of Defense operational testing office said in January that "the damage was found to be primarily due to engine exhaust, auxiliary power unit exhaust, and discharge of aircraft fluids onto the grass."

Megan Wasel, a Naval Air Systems Command spokesperson, recently told Bloomberg that "under hot day environmental conditions, a risk remains of damaging a grass surface from heat from the engines with rotors turning."

Lockheed Martin spokesperson Melissa Chadwick told the outlet that "we are making progress in addressing VH-92A landing zone mission requirements.

Wasel said that the Navy and Lockheed Martin are currently working on "concepts to reduce rotors-turning exhaust damage."

She said "potential solutions" to the landing problem are expected as early as June. There has already been some success with an "exhaust deflector," as well as certain adjusted operational techniques and procedures.

The aircraft is going through operational testing at the moment, and evaluators are looking at "the full range of activities necessary to perform the presidential transport mission," Pentagon spokesperson Jessica Maxwell told Bloomberg.

She further explained that those involved in the ongoing operational testing will "note if the aircraft does any damage to the landing zones while performing operationally representative mission profiles."