IT'S SURE to set the chalk flying, but one Virginia legislator has made a shockingly direct and sensible proposal to improve what goes on in the classrooms. There is nothing expensive or complicated about the legislation introduced in Richmond by Del. George W. Grayson of Williamsburg, either, but he'll need all the help he can get from parents and others who want the best teaching their tax dollars can buy.

Mr. Grayson's proposal would improve the competence of teachers by making some reasonable changes in requirements for teacher certifications. It calls for a probationary period of up to three years before anyone is granted a professional teaching certificate. There would be various ways to earn a certificate: with a baccalaureate degree and either completion of a teacher-training program or completion of an equivalent program plus successful teacher experience, or with certification by a superintendent that the applicant has the qualitites to be an effective teacher. Mr. Grayson's proposal also would continue emphasis on a nationally recognized professional competency examination, tests of basic writing skills and some sense of the legislature on all pending proposals for requirements of professional education courses before publishing any more changes in the rules.

So where's the rub? Many teachers in the local systems, including top-flight classroom performers who support these proposals, are less than eager to testify in favor of legislation that their professional organizations and less-than-professional colleagues oppose; they would just as soon not rock the boat. Similarly, many politicians in Richmond will look twice before annoying teacher organizations.

But Mr. Grayson's efforts deserve loud cheers from anybody who believes, as he does, that "for years we have made excuses about the uneven quality of public education in Virginia. We have relentlessly blamed television, segregation, desegregation, drugs, rising divorce rates, permissiveness, inadequate funding and other factors. . . . The teacher is the most important element in education and any successful reform must begin by improving the competence of individuals who teach, or aspire to teach, our youngsters." With enough evidence of public support, perhaps this fundamental lesson won't be lost on the lawmakers as it has been so many times before.