Gas turbine engine with one piece acoustic treatment

1. A gas turbine engine comprising:

a fan rotor having fan blades received within an outer nacelle, and said outer nacelle having an inner surface, said outer nacelle secured to an inner portion through a mount flange at a first axial location;

an acoustic treatment extending inwardly said outer nacelle and across said first axial location of the mount flange and further inwardly toward said fan blades;

wherein said acoustic treatment is continuous for 360° about a center axis of the fan rotor, said acoustic treatment is provided with an anti-icing feature;

wherein a distance is defined from a plane defined by leading edges of said fan blades to an axial location of a forwardmost part of said outer nacelle, and an outer diameter of said fan blades being defined, and a ratio of said distance to said outer diameter is between 0.2 and 0.5;

wherein said acoustic treatment includes a honeycomb material; and

wherein said anti-icing feature includes the delivery of air to said nacelle.

2. The gas turbine engine as set forth in claim 1 , wherein said forwardmost part of said nacelle extends outwardly for varying extents across a circumference of said nacelle, and said ratio of said distance to the outer diameter for all locations of said nacelle being between about 0.2 and 0.45.

3. The gas turbine engine as set forth in claim 1 , wherein said ratio is greater than about 0.25.

4. The gas turbine engine as set forth in claim 3 , wherein said ratio is greater than 0.30.

5. The gas turbine engine as set forth in claim 1 , wherein said ratio is less than 0.40.

6. The gas turbine engine as set forth in claim 1 , wherein a fan drive turbine driving said fan rotor through a gear reduction.

7. The gas turbine engine as set forth in claim 1 , wherein said mount flange is an A-flange.