Narrative:

I was taxiing in my 172 skyhawk to the departure end of the active runway 28 [at trk]. There was clearly glider activity on the adjacent runway; as I had seen them taking off all morning and was paying attention to where they were headed. I was using an ipad with foreflight as my primary navigation; supplemented with on-board GPS; and then chart pilotage. On taxi I noticed that my radio was very static-filled and scratchy. I was having a hard time hearing anything. My passenger noticed this as well; and asked me to turn down the radio (I declined). I thought that the problem with the radio was somebody else on the same frequency with a stuck mike or some other problem with the local CTAF frequency. I was in a hurry to takeoff; as the airport was already busy and I was concerned about density altitude; as it was forecast to be extremely hot. Trk is at about 6K MSL so it's high; and it was going to be hot. I was anxious and wanted to get out of there. I fueled up and taxied to the departure end of 28; and I crossed the intersecting runway where the gliders were operating without even stopping. I got a radio call from the tow plane on the runway as I crossed where he asked if I saw him. I responded with two clicks; as I was already past the center-line of runway 1-19. The pilot of the glider made a radio call stating 'I think he has his radio turned down.' I responded with 'I hear you; but transmissions are barely audible and broken.' I don't believe that the tow plane was moving yet; but they were about to begin takeoff roll. I realized what had happened at this point; and felt like this could have been a very close call. Nothing happened besides me scaring the glider and tow pilots; and then scaring myself; but there are a few factors here that contributed to this: 1.) I wasn't aware of the runway configurations; and I either ignored the signage or it wasn't very clear. I didn't know that I was crossing a runway (active or otherwise.) I was in a hurry; and stressed; but I still don't feel like the signage and markings were very clear. 2.) using foreflight on an ipad and a new dual GPS unit; I had a new scosche dual cigarette lighter charger that I purchased from [an aviation supply retail store] to power both the ipad and the GPS unit. I had used this on the way down with no issues. But; once airborne; I noticed that the radio noise was not going away. I began to be concerned that I was having dual radio failure; as this was happening on both of my radios. I was concerned about having total communication loss. I made a call to tower and they read me loud and clear; but I was still having a very difficult time hearing anything. As I was troubleshooting this I unplugged the cigarette lighter charger. The noise ceased; and everything was ok. The charger was emitting frequencies that were reading my radio unlistenable. This was the number 1 problem in this entire situation; combined with poor situational awareness on my part; and being rushed. I was really surprised by this for two reasons: 1.) I had used this charger on the flight to trk two days prior with no poor results. This was one of the reasons it took me a while to even test it. 2.) this charger was expensive and purchased because I thought it was shielded to prevent this kind of problem. I had heard of this problem happening with other cheap auto chargers; so I spent the 30 dollars on the better; aviation-specific charger. This was the closest call I have ever had. It was scary and stupid; and I accept responsibility for the close call. I learned something here. That said; something needs to be done to help insure that these kinds of chargers don't interfere with radios and other in-flight instruments. This could have been much worse. As the ipad and other electronics move into the cockpit we need to make sure that they help; and don't do harm. This is the future for sure (and I love foreflight on the ipad; it's the best thing to happen in GA in a decadeor more) but let's make sure that we can make this move forward safely.

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Original NASA ASRS Text

Title: C172 pilot reported communication difficulty that led to a runway incursion that he later traced to interference from a power splitter.

Narrative: I was taxiing in my 172 Skyhawk to the departure end of the active Runway 28 [at TRK]. There was clearly glider activity on the adjacent runway; as I had seen them taking off all morning and was paying attention to where they were headed. I was using an iPad with Foreflight as my primary navigation; supplemented with on-board GPS; and then chart pilotage. On taxi I noticed that my radio was very static-filled and scratchy. I was having a hard time hearing anything. My passenger noticed this as well; and asked me to turn down the radio (I declined). I thought that the problem with the radio was somebody else on the same frequency with a stuck mike or some other problem with the local CTAF frequency. I was in a hurry to takeoff; as the airport was already busy and I was concerned about density altitude; as it was forecast to be extremely hot. TRK is at about 6K MSL so it's high; and it was going to be hot. I was anxious and wanted to get out of there. I fueled up and taxied to the departure end of 28; and I crossed the intersecting runway where the gliders were operating without even stopping. I got a radio call from the tow plane on the runway as I crossed where he asked if I saw him. I responded with two clicks; as I was already past the center-line of Runway 1-19. The pilot of the glider made a radio call stating 'I think he has his radio turned down.' I responded with 'I hear you; but transmissions are barely audible and broken.' I don't believe that the tow plane was moving yet; but they were about to begin takeoff roll. I realized what had happened at this point; and felt like this could have been a very close call. Nothing happened besides me scaring the glider and tow pilots; and then scaring myself; but there are a few factors here that contributed to this: 1.) I wasn't aware of the runway configurations; and I either ignored the signage or it wasn't very clear. I didn't know that I was crossing a runway (active or otherwise.) I was in a hurry; and stressed; but I still don't feel like the signage and markings were very clear. 2.) Using Foreflight on an iPad and a new Dual GPS unit; I had a new Scosche dual cigarette lighter charger that I purchased from [an aviation supply retail store] to power both the iPad and the GPS unit. I had used this on the way down with no issues. But; once airborne; I noticed that the radio noise was not going away. I began to be concerned that I was having dual radio failure; as this was happening on both of my radios. I was concerned about having total communication loss. I made a call to Tower and they read me loud and clear; but I was still having a very difficult time hearing anything. As I was troubleshooting this I unplugged the cigarette lighter charger. The noise ceased; and everything was OK. The charger was emitting frequencies that were reading my radio unlistenable. This was the number 1 problem in this entire situation; combined with poor situational awareness on my part; and being rushed. I was really surprised by this for two reasons: 1.) I had used this charger on the flight to TRK two days prior with no poor results. This was one of the reasons it took me a while to even test it. 2.) This charger was expensive and purchased because I thought it was shielded to prevent this kind of problem. I had heard of this problem happening with other cheap auto chargers; so I spent the 30 dollars on the better; aviation-specific charger. This was the closest call I have ever had. It was scary and stupid; and I accept responsibility for the close call. I learned something here. That said; something needs to be done to help insure that these kinds of chargers don't interfere with radios and other in-flight instruments. This could have been much worse. As the iPad and other electronics move into the cockpit we need to make sure that they help; and don't do harm. This is the future for sure (and I love Foreflight on the iPad; it's the best thing to happen in GA in a decadeor more) but let's make sure that we can make this move forward safely.

Data retrieved from NASA's ASRS site as of July 2013 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.