For R21, what is the DF error angle if not otherwise stated?

For R21, what is the DF error angle if not otherwise stated?

• A. 2º
• B. 4º
• C. 6º
• D. 8º

Answer: (B)

In direction finding, the DF error angle is the range by which the indicated bearing can differ from the true bearing. When a problem doesn’t specify this tolerance, a standard default of 4 degrees is used. That means a bearing you read as 120° actually covers a possible true bearing from 116° to 124°. This default helps you consistently interpret bearings and plot fixes, especially when combining data from multiple DF readings. The other numbers aren’t used here because they don’t reflect the common default tolerance; 2° would be overly optimistic for practical DF work, while 6° or 8° would imply a larger uncertainty than the usual standard.

In direction finding, the DF error angle is the range by which the indicated bearing can differ from the true bearing. When a problem doesn’t specify this tolerance, a standard default of 4 degrees is used. That means a bearing you read as 120° actually covers a possible true bearing from 116° to 124°. This default helps you consistently interpret bearings and plot fixes, especially when combining data from multiple DF readings. The other numbers aren’t used here because they don’t reflect the common default tolerance; 2° would be overly optimistic for practical DF work, while 6° or 8° would imply a larger uncertainty than the usual standard.