PA-28 pilot reported a near midair collision event during a two plane formation flight as second air...

Narrative:

I was the second aircraft in a formation flight ferrying an aircraft under an ads-B waiver in the sfra under the class B airspace. It was my first formation flight and I was focused on the lead aircraft in front of me and to my left. The lead aircraft was communicating with ATC while I utilized my single functioning radio to talk to that aircraft. It was getting late in the day and we were under pressure to get the aircraft back to the FBO before dark since these were newly acquired aircraft that haven't flown in several years. The helicopter approached the formation from the right at the same altitude. Focusing on the lead aircraft; I did not observe the helicopter until close proximity. I immediately initiated a diving right turn to avoid a collision with the helicopter losing approximately 200 ft. The helicopter took no evasive action and flew right between me and the lead aircraft in the formation. I immediately climbed back to 1500 ft. And rejoined the formation. I radioed the lead aircraft and informed him of the situation and asked if he received any alert from ATC since we were under flight following. He replied 'negative'. It is in my opinion the helicopter nor the lead aircraft ever saw each other and the helicopter intended to pass safely behind the lead aircraft but failed to observe my aircraft. Neither the lead aircraft or myself had ads-B in capability and would not have been able to detect the helicopter by any other means except visually. I believe that better visual scanning and possibly less reliance on being able to see other aircraft in ads-B airspace could have prevented this situation.

Original NASA ASRS Text

Title: PA-28 pilot reported a NMAC event during a two plane formation flight as second aircraft with an unidentified helicopter that flew between the two aircraft.

Narrative: I was the second aircraft in a formation flight ferrying an aircraft under an ADS-B waiver in the SFRA under the Class B airspace. It was my first formation flight and I was focused on the lead aircraft in front of me and to my left. The lead aircraft was communicating with ATC while I utilized my single functioning radio to talk to that aircraft. It was getting late in the day and we were under pressure to get the aircraft back to the FBO before dark since these were newly acquired aircraft that haven't flown in several years. The helicopter approached the formation from the right at the same altitude. Focusing on the lead aircraft; I did not observe the helicopter until close proximity. I immediately initiated a diving right turn to avoid a collision with the helicopter losing approximately 200 ft. The helicopter took no evasive action and flew right between me and the lead aircraft in the formation. I immediately climbed back to 1500 ft. and rejoined the formation. I radioed the lead aircraft and informed him of the situation and asked if he received any alert from ATC since we were under flight following. He replied 'negative'. It is in my opinion the helicopter nor the lead aircraft ever saw each other and the helicopter intended to pass safely behind the lead aircraft but failed to observe my aircraft. Neither the lead aircraft or myself had ADS-B in capability and would not have been able to detect the helicopter by any other means except visually. I believe that better visual scanning and possibly less reliance on being able to see other aircraft in ADS-B airspace could have prevented this situation.

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	1738811
Time
Date	202003
Local Time Of Day	0601-1200
Place
Locale Reference	PCT.TRACON
State Reference	VA
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	VFR
Aircraft 2
Make Model Name	Helicopter
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	VFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 179 Flight Crew Total 535 Flight Crew Type 520
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 1000

PA-28 pilot reported a near midair collision event during a two plane formation flight as second aircraft with an unidentified helicopter that flew between the two aircraft.