Narrative:

Flight planned to depart dca IFR to mmu. It was my copilot's let to fly. Upon our passenger arrival we were informed of an en route stop at ttn to drop off a passenger. Having no time to amend the flight plan through FSS I elected to attempt the destination change in-flight directly with ATC. Thinking to myself, with this routing our change in destination may not be too difficult to effect. Departure from dca went without a hitch. Baltimore approach handed us off to philadelphia where I first informed our controller of our destination change and asked if he could amend our flight plan. He replied 'maintain 5000' and report ATIS at jtn. ATIS was current, 2500 scattered, 8000 overcast 7 mi visibility, ILS runway 6 inner circle to land runway 24. The WX had been better than expected. A handoff to the next controller followed shortly. We were given vectors for conflicting traffic then cleared direct to ard VOR. At 3 mi I asked the controller for further clearance at which time he told us to maintain 5000 and contact new york approach. It was apparent at that point that our destination change was never passed along from the previous controller. I quickly informed him of our request to land at ttn at which time he gave us a clearance to turn right to 180 degree and maintain 5000'. The WX conditions at the airport and vicinity were better than anticipated. Both my copilot and I could see the airport ahead of us and believed that we could proceed to and land at the airport VFR. I informed the controller of our desire to cancel IFR and proceed VFR, no reply. My copilot misunderstanding some communication he heard as the controller's acknowledgement of our cancellation began a descent to set up for a VFR approach to the airport. I was preoccupied outside looking for 2 other aircraft making their apches to ttn. Turning my attention back inside I realized we had descended 700'.

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Original NASA ASRS Text

Title: FLT CREW OF IFR HELICOPTER DEVIATES FROM ASSIGNED ALT.

Narrative: FLT PLANNED TO DEPART DCA IFR TO MMU. IT WAS MY COPLT'S LET TO FLY. UPON OUR PAX ARRIVAL WE WERE INFORMED OF AN ENRTE STOP AT TTN TO DROP OFF A PAX. HAVING NO TIME TO AMEND THE FLT PLAN THROUGH FSS I ELECTED TO ATTEMPT THE DEST CHANGE INFLT DIRECTLY WITH ATC. THINKING TO MYSELF, WITH THIS ROUTING OUR CHANGE IN DEST MAY NOT BE TOO DIFFICULT TO EFFECT. DEP FROM DCA WENT WITHOUT A HITCH. BALTIMORE APCH HANDED US OFF TO PHILADELPHIA WHERE I FIRST INFORMED OUR CTLR OF OUR DEST CHANGE AND ASKED IF HE COULD AMEND OUR FLT PLAN. HE REPLIED 'MAINTAIN 5000' AND REPORT ATIS AT JTN. ATIS WAS CURRENT, 2500 SCATTERED, 8000 OVCST 7 MI VISIBILITY, ILS RWY 6 INNER CIRCLE TO LAND RWY 24. THE WX HAD BEEN BETTER THAN EXPECTED. A HANDOFF TO THE NEXT CTLR FOLLOWED SHORTLY. WE WERE GIVEN VECTORS FOR CONFLICTING TFC THEN CLRED DIRECT TO ARD VOR. AT 3 MI I ASKED THE CTLR FOR FURTHER CLRNC AT WHICH TIME HE TOLD US TO MAINTAIN 5000 AND CONTACT NEW YORK APCH. IT WAS APPARENT AT THAT POINT THAT OUR DEST CHANGE WAS NEVER PASSED ALONG FROM THE PREVIOUS CTLR. I QUICKLY INFORMED HIM OF OUR REQUEST TO LAND AT TTN AT WHICH TIME HE GAVE US A CLRNC TO TURN RIGHT TO 180 DEG AND MAINTAIN 5000'. THE WX CONDITIONS AT THE ARPT AND VICINITY WERE BETTER THAN ANTICIPATED. BOTH MY COPLT AND I COULD SEE THE ARPT AHEAD OF US AND BELIEVED THAT WE COULD PROCEED TO AND LAND AT THE ARPT VFR. I INFORMED THE CTLR OF OUR DESIRE TO CANCEL IFR AND PROCEED VFR, NO REPLY. MY COPLT MISUNDERSTANDING SOME COM HE HEARD AS THE CTLR'S ACKNOWLEDGEMENT OF OUR CANCELLATION BEGAN A DSCNT TO SET UP FOR A VFR APCH TO THE ARPT. I WAS PREOCCUPIED OUTSIDE LOOKING FOR 2 OTHER ACFT MAKING THEIR APCHES TO TTN. TURNING MY ATTN BACK INSIDE I REALIZED WE HAD DESCENDED 700'.

Data retrieved from NASA's ASRS site as of August 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.