A method for controlling a blade mounted on a vehicle, the method comprising the steps of: receiving at a first time a first computed roll angle estimate and a first computed pitch angle estimate, wherein the first computed roll angle estimate and the first computed pitch angle estimate are based at least in part on a first angular velocity measurement about a first axis, a second angular velocity measurement about a second axis, and a third angular velocity measurement about a third axis from a three-axis gyroscope mounted on the blade, wherein the first axis, the second axis, and the third axis are orthogonal; receiving at a second time a second computed roll angle estimate and a second computed pitch angle estimate, wherein the second computed roll angle estimate and the second computed pitch angle estimate are based at least in part on a fourth angular velocity measurement about the first axis, a fifth angular velocity measurement about the second axis, and a sixth angular velocity measurement about the third axis from the three-axis gyroscope mounted on the blade; the method characterized by receiving at a third time a blade slope angle measurement from a blade slope angle tilt sensor mounted on the blade; receiving at a fourth time a blade tip angle measurement from a blade tip angle tilt sensor mounted on the blade; determining whether a first time condition is satisfied, wherein the first time condition is represented by: the third time is greater than the first time and less than or equal to the second time; upon determining that the first time condition is satisfied: determining whether the received blade slope angle measurement is valid; determining whether a second time condition is satisfied, wherein the second time condition is represented by: the fourth time is greater than the first time and less than or equal to the second time; upon determining that the second time condition is satisfied: determining whether the received blade tip angle measurement is valid; and upon determining that the first time condition is satisfied, the received blade slope angle measurement is valid, the second time condition is satisfied, and the received blade tip angle measurement is valid: computing an estimate of the blade slope angle based at least in part on the received second computed roll angle estimate, the received second computed pitch angle estimate, the received blade slope angle measurement, and the received blade tip angle measurement. receiving at a first time a first computed roll angle estimate and a first computed pitch angle estimate, wherein the first computed roll angle estimate and the first computed pitch angle estimate are based at least in part on a first angular velocity measurement about a first axis, a second angular velocity measurement about a second axis, and a third angular velocity measurement about a third axis from a three-axis gyroscope mounted on the blade, wherein the first axis, the second axis, and the third axis are orthogonal; receiving at a second time a second computed roll angle estimate and a second computed pitch angle estimate, wherein the second computed roll angle estimate and the second computed pitch angle estimate are based at least in part on a fourth angular velocity measurement about the first axis, a fifth angular velocity measurement about the second axis, and a sixth angular velocity measurement about the third axis from the three-axis gyroscope mounted on the blade; the method characterized by receiving at a third time a blade slope angle measurement from a blade slope angle tilt sensor mounted on the blade; receiving at a fourth time a blade tip angle measurement from a blade tip angle tilt sensor mounted on the blade; determining whether a first time condition is satisfied, wherein the first time condition is represented by: the third time is greater than the first time and less than or equal to the second time; the third time is greater than the first time and less than or equal to the second time; upon determining that the first time condition is satisfied: determining whether the received blade slope angle measurement is valid; determining whether the received blade slope angle measurement is valid; determining whether a second time condition is satisfied, wherein the second time condition is represented by: the fourth time is greater than the first time and less than or equal to the second time; the fourth time is greater than the first time and less than or equal to the second time; upon determining that the second time condition is satisfied: determining whether the received blade tip angle measurement is valid; and determining whether the received blade tip angle measurement is valid; and upon determining that the first time condition is satisfied, the received blade slope angle measurement is valid, the second time condition is satisfied, and the received blade tip angle measurement is valid: computing an estimate of the blade slope angle based at least in part on the received second computed roll angle estimate, the received second computed pitch angle estimate, the received blade slope angle measurement, and the received blade tip angle measurement. computing an estimate of the blade slope angle based at least in part on the received second computed roll angle estimate, the received second computed pitch angle estimate, the received blade slope angle measurement, and the received blade tip angle measurement.