Narrative:

I had decided to take off from an intersection departure which deviated from the original plan to taxi to the end of the runway for a run up and then takeoff. Because of the abrupt change in plans a proper takeoff briefing and configuration did not take place. However when lined up on the runway it was decided that the takeoff technique would utilize that of a short field (not because there was an actual reason to other than practice). As I lined up I set the flaps to 10 degrees; held the brakes; advanced the power to full; and released the brakes to begin the takeoff roll. The airspeed then became alive as I was holding the nose down until we reached a rotation speed of 55 kts. At this point I rotated and began a climb to maintain 59 kts. After clearing a 'simulated' 50 foot obstacle I had continued to maintain 59 kts; and set the flap lever to retract. This action resulted in a loss of lift during a critical phase of flight and with minimal room for correction (approximately 100 AGL). After I noticed a moderate loss of lift; and after hearing the stall warning horn with a speed of about 50 kts (vs is 47 kts); I recognized that I was very close to entering a power on stall. Having realized this I pitched the nose down to increase my airspeed and then reentered a cruise climb at 75 kts. I believe approximately 25 feet was lost during the correction. Factors leading to this was that of an improper takeoff briefing and checklists with a dedicated takeoff plan; and deviating from normal short field takeoff procedures. Instead of retracting the flaps at the time I did I should have first pitched for my cruise climb; have reached a safe stall retraction speed (65+ kts); and then counteract the loss of lift that comes from retracting the flaps. The reason for me retracting the flaps when I did was likely due to a lack of a briefing as previously stated; and inattention to my control inputs.

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Original NASA ASRS Text

Title: C172 pilot reported a loss of lift while practicing a short field takeoff.

Narrative: I had decided to take off from an intersection departure which deviated from the original plan to taxi to the end of the runway for a run up and then takeoff. Because of the abrupt change in plans a proper takeoff briefing and configuration did not take place. However when lined up on the runway it was decided that the takeoff technique would utilize that of a short field (not because there was an actual reason to other than practice). As I lined up I set the flaps to 10 degrees; held the brakes; advanced the power to full; and released the brakes to begin the takeoff roll. The airspeed then became alive as I was holding the nose down until we reached a rotation speed of 55 kts. At this point I rotated and began a climb to maintain 59 kts. After clearing a 'simulated' 50 foot obstacle I had continued to maintain 59 kts; and set the flap lever to retract. This action resulted in a loss of lift during a critical phase of flight and with minimal room for correction (approximately 100 AGL). After I noticed a moderate loss of lift; and after hearing the stall warning horn with a speed of about 50 kts (VS is 47 kts); I recognized that I was very close to entering a power on stall. Having realized this I pitched the nose down to increase my airspeed and then reentered a cruise climb at 75 kts. I believe approximately 25 feet was lost during the correction. Factors leading to this was that of an improper takeoff briefing and checklists with a dedicated takeoff plan; and deviating from normal short field takeoff procedures. Instead of retracting the flaps at the time I did I should have first pitched for my cruise climb; have reached a safe stall retraction speed (65+ kts); and then counteract the loss of lift that comes from retracting the flaps. The reason for me retracting the flaps when I did was likely due to a lack of a briefing as previously stated; and inattention to my control inputs.

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.