A helicopter pilot reported having difficulty with his radios before entering the DC SFRA; so he landed in a field and called ATC on his cell. He continued toward the DC SFRA but became disoriented and landed again; failing to close his flight plan.

Narrative

I failed to close my flight plan as well as landing at a point other than my filed point of termination. I was en route in a [helicopter]. The weather was VMC and I was on a VFR flight plan. As I approached the Washington DC SFRA (Special Flight Rules Area); I attempted to contact Potomac Approach to gain entry into the SFRA. I was unable to reach them on my only VHF radio. Rather than penetrate the SFRA without proper clearance; I landed the aircraft adjacent to a quarry. I was able to contact Potomac via telephone and get assigned a discreet transponder code and radio frequency. I then took off and was able to get radio contact for my clearance into the SFRA. However; the distraction of my difficulty with the radio; the additional process of selecting an appropriate landing area; and my unfamiliarity with the VFR route; combined with the additional landing and difficulty with the radio; caused me to become disoriented as to course to destination. I was navigating by pilotage only and had no navigational aids on board the aircraft. I now was getting concerned about fuel quantity; so I landed in a field. As it turns out; I had landed prior to entering the SFRA. There I contacted a colleague to bring fuel so that I could complete the trip with the required fuel and reserve. While on the ground; I was contacted by ATC on my cell phone. They indicated that by my flight plan; I was overdue and they were trying to find me. I explained my situation and that there was no incident or accident damage to the aircraft. My original flight plan was then closed. I refueled and completed the trip with no further difficulty. Reviewing what happened; I realize that my initial inability to contact Potomac was my failure to properly tune the VHF radio. I will not make that error again. Additionally; I had not flown that route before and found that it was a factor in my visual reference. My inexperience in cross-country flying in that congested area led to my difficulty. My corrective action is to remain engaged in cross-country training and to review the lesser-used items that can be part of communications more often.