Narrative:

As pilot flying we departed on runway xxl; normal takeoff. As we reached acceleration altitude I reduced power to climb and stated 'climb.' as I said this the captain started his check in with departure. I waited for him to finish the call and stated 'climb' again. At this point I saw the hook coming up and safe speed was gone. I said something to the nature of we are below flap speed; lowering the nose and accelerating. The hook immediately started going back down; climb never stopped. We made our departure altitudes and continued climb.this all came together at once. The pm was making a call and I believe he mistook what I said. It was clearly a miscommunication. The captain had mentioned before we left the gate that he had not flown recently; this probably also played a role. We were in a light weight airliner and the climb and acceleration were quicker than we see with full aircraft.for myself I will delay the power call until there is a break in radio calls. Out of habit we pull the power and say climb.

Google
 

Original NASA ASRS Text

Title: Air carrier flight crew reported a miscommunication during initial climb in a lightly-loaded aircraft resulted in retracting the flaps prematurely.

Narrative: As pilot flying we departed on Runway XXL; normal takeoff. As we reached acceleration altitude I reduced power to climb and stated 'climb.' As I said this the Captain started his check in with departure. I waited for him to finish the call and stated 'climb' again. At this point I saw the hook coming up and safe speed was gone. I said something to the nature of we are below flap speed; lowering the nose and accelerating. The hook immediately started going back down; climb never stopped. We made our departure altitudes and continued climb.This all came together at once. The PM was making a call and I believe he mistook what I said. It was clearly a miscommunication. The Captain had mentioned before we left the gate that he had not flown recently; this probably also played a role. We were in a light weight airliner and the climb and acceleration were quicker than we see with full aircraft.For myself I will delay the power call until there is a break in radio calls. Out of habit we pull the power and say climb.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.