Two C206 pilots conducting training discovered that the nocal approach frequency was switched on the...

Attributes
ACN	1015459
Time
Date	201206
Local Time Of Day	0601-1200
Place
Locale Reference	TCY.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna Stationair/Turbo Stationair 6
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	VFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Component
Aircraft Component	Air/Ground Communication
Person 1
Function	Pilot Flying
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 55 Flight Crew Total 1340 Flight Crew Type 222
Events
Anomaly	Aircraft Equipment Problem Less Severe Conflict NMAC Deviation - Procedural Published Material / Policy
Miss Distance	Horizontal 0 Vertical 300

Narrative:

While maneuvering on a training flight operated under VFR with two pilots on board: pilot flying and pilot not flying. I was the pilot flying. The aircraft was receiving traffic advisories from norcal approach. Inadvertently; the radio was switched from the frequency we were supposed to be on to the previous frequency we had been on (both pilots were unaware that this switched occurred). A short time later; we saw an aircraft about 4 miles away and near our altitude. We kept the aircraft in sight and it passed about 300 ft above of our aircraft. Both pilots were confused that no traffic advisory was given by approach control. About 5 minutes later; we reported that we were ready to return to our departure airport and ATC informed us that we were on the incorrect frequency. We returned to the correct frequency and ATC informed us that they issued a traffic alert for that previously discussed aircraft. I am unsure how the frequency was switched; however; I believe one pilot accidentally hit the communication switch button (garmin G530) while adjusting the volume on the unit. More attention to detail can prevent this from occurring in the future. It is important to verify that the correct frequency is in the active window; especially after adjusting something on the G530. Also; having the com switch button redesigned by moving it to a safer location or set deeper into the unit for protection might aid to prevent inadvertently switching the coms.

Original NASA ASRS Text

Title: Two C206 pilots conducting training discovered that the NoCal Approach frequency was switched on their Garmin G530; but they did not discover the switch until after a near miss.

Narrative: While maneuvering on a training flight operated under VFR with two pilots on board: Pilot flying and pilot not flying. I was the pilot flying. The aircraft was receiving traffic advisories from NorCal Approach. Inadvertently; the radio was switched from the frequency we were supposed to be on to the previous frequency we had been on (both pilots were unaware that this switched occurred). A short time later; we saw an aircraft about 4 miles away and near our altitude. We kept the aircraft in sight and it passed about 300 FT above of our aircraft. Both pilots were confused that no traffic advisory was given by Approach Control. About 5 minutes later; we reported that we were ready to return to our departure airport and ATC informed us that we were on the incorrect frequency. We returned to the correct frequency and ATC informed us that they issued a traffic alert for that previously discussed aircraft. I am unsure how the frequency was switched; however; I believe one pilot accidentally hit the COM switch button (Garmin G530) while adjusting the volume on the unit. More attention to detail can prevent this from occurring in the future. It is important to verify that the correct frequency is in the active window; especially after adjusting something on the G530. Also; having the com switch button redesigned by moving it to a safer location or set deeper into the unit for protection might aid to prevent inadvertently switching the COMs.

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.

Two C206 pilots conducting training discovered that the nocal approach frequency was switched on their garmin G530; but they did not discover the switch until after a near miss.