From the FAA Part 61 FAQ's:
QUESTION: I have a situation where a flight school is allowing two pilots (PP #1 and PP #2), who are both private pilots and both hold airplane single-engine land ratings, to go out together for PIC training. Both pilots are enrolled in the school’s Commercial Pilot - Airplane Single Land course. No instrument flight training (i.e., otherwise no use of a view limiting device, hood, etc.) is occurring. The training is purely to practice takeoffs, landings, performance maneuvers, etc. The aircraft being used is a Cessna 172. The school assigns PP #1 to serve as the pilot in command (i.e., § 1.1) for the flight. During the flight, PP #2 is the sole manipulator of the controls and then they switch seats and PP #1 becomes the sole manipulator of the controls. At the conclusion of the flight, the breakdown of the flight was the total flight time flown was 3.0 hours. The flight occurred during daytime visual conditions. PP #2 was the sole manipulator of the controls for 2.0 hours. PP #1 was the sole manipulator of controls for only 1.0 hours. But PP #1 served as the PIC for the entire flight. How does each pilot log the time?
ANSWER: Ref. § 61.51(e)(1)(i); PP #1 logs 1.0 PIC flight time, 1 hour of airplane single-engine land time, and 1 hour of total flight time. PP #2 logs 2.0 PIC flight time, 2.0 hours of airplane single-engine land time, and 2.0 hours of total flight time.
The rule that addresses logging of time is § 61.51. Section 1.1 merely addresses the legal basis for serving as pilot in command, but not logging the time.
QUESTION: Similar situation and again the situation is two pilots (PP #1 and PP #2), who are both private pilots and both hold airplane single-engine land ratings, go out together for PIC training. Both pilots are enrolled in this school’s Commercial Pilot - Airplane Single Land course. No instrument flight training (i.e., otherwise no use of a view limiting device, hood, etc.) is occurring. The training is purely to practice takeoffs, landings, performance maneuvers, etc. The aircraft being used is a Cessna 172. The school assigns PP #1 to serve as the pilot in command (i.e., § 1.1) for the entire flight. During the entire flight, PP #2 is the sole manipulator of the controls. At the conclusion of the flight, the breakdown of the flight was the total flight time flown was 3.0 hours. The flight occurred during daytime visual conditions. PP #2 was the sole manipulator of the controls for the entire flight. PP #1 served as the PIC for the entire flight and never once touched the controls.
How does each pilot log the time?
ANSWER: Ref. § 61.51(e)(1)(i) and § 61.51(a)(1) and (2); PP #2 logs 3.0 of PIC flight time, 3.0 hours of airplane single-engine land time, and 3 hour of total flight time.
PP #1 cannot log any of the time for the purpose of recording the time to document training and aeronautical experience used to meet the requirements for a certificate, rating, or flight review of this part. Nor can PP #1 log any of the time for the purpose of recording the time for the aeronautical experience required for meeting the recent flight experience requirements of this part.. Otherwise, PP #1 cannot use any of the time for meeting the requirements of § 61.51(a)(1) and (2).
Notice how I very specifically qualified my answer as it relates to PP #1. In effect, I said PP #1 cannot log any of the time for meeting the requirements set forth in § 61.51(a)(1) and (2). And § 61.51(a)(1) and (2) states:
(a) Training time and aeronautical experience. Each person must document and record the following time in a manner acceptable to the Administrator:
(1) Training and aeronautical experience used to meet the requirements for a certificate, rating, or flight review of this part.
(2) The aeronautical experience required for meeting the recent flight experience requirements of this part.
{Q&A-353}