Narrative:

All three aircraft involved were flying in SFAR50-2 on the blue ? Route. I was the second airplane about 1/2 mi in trail of the first at one mi west of burnt canyon point. Since my aircraft was faster by about 10 KTS, I focused my attention outside my airplane to keep the first aircraft in sight while I passed. During the approximately 3 mins it took me to pass the first airplane was no more than 100' above my altitude. During this 3 mins I neglected my cockpit scan. As I was completing the pass we were informed (by radio) by an aircraft identing itself as the FAA that we were all (3) in violation of federal airspace and to return to the route as defined. I glanced at my altimeter and noticed I had inadvertently descended to 5100' MSL indicated. I immediately returned to 5500' and remained there for the rest of the flight. As for causes of the deviation, pilot distraction was probably the largest factor. By being preoccupied with passing safely, I neglected basic altitude control. I relied on the aircraft in front of me to show me a correct altitude. To prevent this in the future I have initiated the practice of not passing another aircraft unless there is sufficient horizontal distance that I do not have to be distraction by sep.

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Original NASA ASRS Text

Title: TWO ATX SMA ACFT FAILED TO STAY AT ASSIGNED ALT WHILE FLYING A GRAND CANYON TOUR.

Narrative: ALL THREE ACFT INVOLVED WERE FLYING IN SFAR50-2 ON THE BLUE ? RTE. I WAS THE SECOND AIRPLANE ABOUT 1/2 MI IN TRAIL OF THE FIRST AT ONE MI W OF BURNT CANYON POINT. SINCE MY ACFT WAS FASTER BY ABOUT 10 KTS, I FOCUSED MY ATTN OUTSIDE MY AIRPLANE TO KEEP THE FIRST ACFT IN SIGHT WHILE I PASSED. DURING THE APPROX 3 MINS IT TOOK ME TO PASS THE FIRST AIRPLANE WAS NO MORE THAN 100' ABOVE MY ALT. DURING THIS 3 MINS I NEGLECTED MY COCKPIT SCAN. AS I WAS COMPLETING THE PASS WE WERE INFORMED (BY RADIO) BY AN ACFT IDENTING ITSELF AS THE FAA THAT WE WERE ALL (3) IN VIOLATION OF FEDERAL AIRSPACE AND TO RETURN TO THE RTE AS DEFINED. I GLANCED AT MY ALTIMETER AND NOTICED I HAD INADVERTENTLY DSNDED TO 5100' MSL INDICATED. I IMMEDIATELY RETURNED TO 5500' AND REMAINED THERE FOR THE REST OF THE FLT. AS FOR CAUSES OF THE DEV, PLT DISTR WAS PROBABLY THE LARGEST FACTOR. BY BEING PREOCCUPIED WITH PASSING SAFELY, I NEGLECTED BASIC ALT CTL. I RELIED ON THE ACFT IN FRONT OF ME TO SHOW ME A CORRECT ALT. TO PREVENT THIS IN THE FUTURE I HAVE INITIATED THE PRACTICE OF NOT PASSING ANOTHER ACFT UNLESS THERE IS SUFFICIENT HORIZ DISTANCE THAT I DO NOT HAVE TO BE DISTR BY SEP.

Data retrieved from NASA's ASRS site as of July 2007 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.