The Mecham Recall Committee plans to obtain papers today to start its petition drive Friday against Arizona Gov. Evan Mecham. Mecham, 63, a Republican, has drawn fire for abolishing the state holiday honoring Dr. Martin Luther King Jr., for defending the use of the word pickaninnies in a 40-year-old book and for controversial appointments. The committee will have 120 days to collect signatures of 216,746 registered voters. If the drive is successful, which political observers doubt, a recall election probably would be held next spring. Mecham says the recall movement "lacks substance."