"impractical plan" is a correct and usable phrase in written English.
It refers to a plan or idea that is not feasible or realistic. You can use it when discussing plans that are not practical or achievable. Example: Despite its good intentions, the company's proposed expansion into a new market was deemed an impractical plan due to the high costs and competition from established businesses.
Hugo Chávez, Venezuela's president, has championed an impractical plan to pump his country's natural gas across the Amazon rainforest to Buenos Aires.
Billionaire Donald Trump has called for mass deportations, which some of his rivals criticize as an impractical plan that would hand Democrats a talking point as they seek to appeal to Latino voters.
"I believe we need to give people the good grace to pop into a local corner shop for ten minutes to buy a newspaper or a loaf of bread without risking a £70 fine," he said recently.This impractical plan echoes a widespread but mistaken belief that parking rules can work even if they are lackadaisically applied.
Already, impractical plans to force the long-term unemployed to pay more of their own rent have been ditched, and in a curious coda to yesterday's speech he signalled that the bill covered "lots of difficult issues and many things that we will have to examine all over again".
On Monday, he went to Texas to denounce Trump's heartless and impractical immigration plan.
In October Mr Obama scrapped an impractical insurance plan to pay for nursing homes and other long-term care.
But I never truly realized how impractical the plan for 2012 was until I spent last Friday at the Regional Plan Association's annual meeting, devoted to Manhattan's far West Side.
In fact, PAC cannot take into account the real state of the production environment, and it may produce unrealistic or impractical production plan.
The club house has an impractical floor plan, and contains gyms for martial art and changing rooms for the pitch.
Dayton O. Hyde, 88, is speaking in an early scene of "Running Wild," Suzanne Mitchell's quietly grand documentary about him and about his impractical, long-ago plan to create a sanctuary for wild mustangs.
The initial reactions from public officials were cool, and some said the steep pitch of the Tappan Zee, compared, for example, with the flat Walkway Over the Hudson, could make a park plan impractical.
