PA-24 Comanche
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 6; Flight Crew Total 896; Flight Crew Type 796
Situational Awareness; Workload
Aircraft Equipment Problem Critical; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Flight Crew Landed As Precaution; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Departure Airport
Aircraft; Human Factors
While performing initial flight test of new installation of flight instruments and avionics; I experienced failure of primary flight instruments upon departure. I noticed that rotation speed was below normal but insufficient runway distance to abort takeoff. Airspeed indicator and EFIS both failed on departure. As I tried to understand failure and transition to alternative instruments; I failed to turn to assigned vector and climb to assigned altitude during the crosswind departure. It should be noted that the avionics installation included a complete replacement of all instruments and a reconfiguration of the panel. Within approximately 2 minutes; I transitioned to whiskey compass for heading information and a combination of GPS and engine instruments to maintain flight control. During this time; ATC quizzed me on altitude and direction assignments at which time I indicated that I experienced instrument failure and was transitioning to whisky compass and climbing for terrain clearance.I departed the pattern and requested ATC clearance to circle east of the airport to get situation better under control. I returned to airport and requested permission to land noting that the airspeed indicator was inoperative and I was uncertain about the altimeter. I declined to declare an emergency. I completed pattern entry and landed without incident and thanked Tower for their assistance. The avionics installer later determined that there was a problem with the pitot-static system likely caused by contamination of the pitot tube and a leak in the static system even though it passed inspection. Root cause of the problem is that while I had conducted an extensive preflight inspection and the verified the pitot-static system check was not prepared to handle a complete failure on departure. I was slow to transition to alternate instruments (GPS and whiskey compass) but fortunately was able to recover within a few minutes.
PA-24 pilot lost his primary flight instruments shortly after takeoff because of a defective pitot-static system.