This week’s block is called Aircraft, according to Barbara Brackman’s Block Base.
Cutting Instructions:
Light Fabric- cut 1 square @ 3 7/8 inches. Cut this square in half on the diagonal.
cut 5 squares @ 2 3/8 inches. Cut 3 of these in half on the diagonal.
Dark Fabric- cut 2 squares @ 3 7/8 inches. Cut these squares in half on the diagonal
cut 2 squares @ 2 3/8 inches
You will have a leftover 3 7/8 inch light triangle.
Take the 2 light 2 3/8 inch squares and draw a line across the square on the diagonal. Place these right sides together with the 2 3/8 inch dark squares and sew a scant 1/4 inch on either side of the drawn line. Cut in half on the drawn line and press towards the dark side of the triangle square. You will have one of these triangle squares extra.
Arrange these triangle squares with the light 2 3/8 inch triangles as shown in the photo below. Make three of these units.
Take these three units and one light 3 7/8 inch triangle and match them up with the four dark 3 7/8 inch triangles as shown in the picture below and sew together into the finished triangle square units. 
Lay those units out as shown in the photo below and sew together to finish the sampler square.
Go here to find the finishing instructions, keeping in mind that this square has the dark triangles on the outside.