Air carrier captain reported a flap setting issue during climbout and stated that a callout sounding...

Narrative:

It was a configuration 2 takeoff out of ZZZ and I was the PF. After passing 1;000 feet afe; I selected climb power and the first officer verified climb power. After accelerating through 'flap' speed I called for 'flaps 1;' the first officer selected flaps 1 and called 'flaps 1.' after the flaps were at 1 and as the airspeed was accelerating to '[clean]' speed; I engaged auto pilot 1 and stated 'autopilot 1.' while confirming autopilot 1 engagement on the FMA; I heard the first officer say 'flaps up' while disarming the spoilers. I immediately stated 'negative; negative!' and reset the flap lever back to flaps 1. After accelerating through '[clean]' speed the flaps were retracted.I feel that saying 'autopilot 1 or 2' can be confused with a flap configuration change. I have also noticed basic mistakes occurring with pilots returning from leave. It seems to happen a short time after their return to the line when comfort levels are starting to return.I feel that the PF should select autopilot on and use the callout 'autopilot is on.'

Original NASA ASRS Text

Title: Air carrier Captain reported a flap setting issue during climbout and stated that a callout sounding similar to the flap callout may have caused confusion.

Narrative: It was a configuration 2 takeoff out of ZZZ and I was the PF. After passing 1;000 feet AFE; I selected climb power and the FO verified climb power. After accelerating through 'Flap' speed I called for 'Flaps 1;' the FO selected flaps 1 and called 'Flaps 1.' After the flaps were at 1 and as the airspeed was accelerating to '[Clean]' speed; I engaged auto pilot 1 and stated 'Autopilot 1.' While confirming autopilot 1 engagement on the FMA; I heard the FO say 'flaps up' while disarming the spoilers. I immediately stated 'Negative; Negative!' and reset the flap lever back to Flaps 1. After accelerating through '[Clean]' speed the flaps were retracted.I feel that saying 'Autopilot 1 or 2' can be confused with a flap configuration change. I have also noticed basic mistakes occurring with pilots returning from leave. It seems to happen a short time after their return to the line when comfort levels are starting to return.I feel that the PF should select autopilot on and use the callout 'Autopilot IS on.'

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.

Attributes
ACN	1765465
Time
Date	202010
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Published Material / Policy

Air carrier captain reported a flap setting issue during climbout and stated that a callout sounding similar to the flap callout may have caused confusion.