Flight crew of two small aircraft in formation reported flying below minimum safe altitude.

Attributes
ACN	1750269
Time
Date	202007
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	RV-4
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	None
Flight Plan	None
Aircraft 2
Make Model Name	Amateur/Home Built/Experimental
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	None
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Flight Instructor Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 80 Flight Crew Total 2100 Flight Crew Type 100
Person 2
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 30 Flight Crew Total 2500 Flight Crew Type 190
Events
Anomaly	Conflict Ground Conflict Less Severe Deviation - Procedural FAR Deviation - Procedural Published Material / Policy

Narrative:

I was engaged in formation training with aircraft Y over a rural area. We completed our join up training and lead aircraft Y started a descent over a small reservoir. In the descent; I began to overtake him due to my aircraft's clean aerodynamics and was forced to break away. As I attempted to rejoin aircraft Y over the reservoir I was in trail and struggling to catch up with him. It was then that I realized we were possibly below 500 ft. AGL and since I was unsure of the [elevation] of the lake; I pulled up quickly to maintain legal distance from boats and people on the water. In all my focus on the lead aircraft Y; I lost situational awareness and for some reason he accidentally descended below 500 ft. In the future I will be less fixated on the lead aircraft. He possibly did not realize there were people on the open water and by the time he did it was too late to climb away from them; or just didn't realize how low he was due to outside fixation.

Original NASA ASRS Text

Title: Flight crew of two small aircraft in formation reported flying below minimum safe altitude.

Narrative: I was engaged in formation training with Aircraft Y over a rural area. We completed our join up training and lead Aircraft Y started a descent over a small reservoir. In the descent; I began to overtake him due to my aircraft's clean aerodynamics and was forced to break away. As I attempted to rejoin Aircraft Y over the reservoir I was in trail and struggling to catch up with him. It was then that I realized we were possibly below 500 ft. AGL and since I was unsure of the [elevation] of the lake; I pulled up quickly to maintain legal distance from boats and people on the water. In all my focus on the lead Aircraft Y; I lost situational awareness and for some reason he accidentally descended below 500 ft. In the future I will be less fixated on the lead aircraft. He possibly did not realize there were people on the open water and by the time he did it was too late to climb away from them; or just didn't realize how low he was due to outside fixation.

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.