Pilot acting as safety pilot on instrument approach finds confusion between published CTAF frequency...

Attributes
ACN	149849
Time
Date	199006
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : tus
State Reference	AZ
Altitude	agl bound lower : 0 agl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : tus
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach
Flight Plan	None
Person 1
Affiliation	Other
Function	other personnel other
Qualification	pilot : instrument pilot : private
Experience	flight time total : 900
ASRS Report	149849
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Chart Or Publication
Air Traffic Incident	other
Situations
Publication	Unspecified

Narrative:

I was acting as a safety pilot on an IFR training flight on june, 1990 from phx to tucson (ryan). Flight conditions were night VFR. I was using my approach plates (they were up to date, last revision received the previous week). The PIC was using nos approach plates (again up to date). It appears that my approach plates show a different 'CTAF' frequency than both the nos approach plates and the sectional chart (as per aim). Is 125.8 the new CTAF, or is this a misprint on my chart?. If the chart is wrong, then the company needs to be informed. If however, this is the ryan CTAF, then perhaps a NOTAM needs to be printed for all the pilots using the nos charts (and for that matter anyone using the sectional chart). There was only one other aircraft in the pattern at the time, and he was using 125.8, so we used the same frequency for safety. I have enclosed copies of all the charts for you, along with our duat readout. Callback conversation with reporter revealed the following information. Reporter states confusion occurred because each pilot was tuning a different frequency for the CTAF due to information on two different charts. When they heard the helicopter calling on tower frequency they felt safest procedure was to remain on same frequency.

Original NASA ASRS Text

Title: PLT ACTING AS SAFETY PLT ON INSTRUMENT APCH FINDS CONFUSION BETWEEN PUBLISHED CTAF FREQS LISTED ON NOS CHART AND COMMERCIAL CHART.

Narrative: I WAS ACTING AS A SAFETY PLT ON AN IFR TRNING FLT ON JUNE, 1990 FROM PHX TO TUCSON (RYAN). FLT CONDITIONS WERE NIGHT VFR. I WAS USING MY APCH PLATES (THEY WERE UP TO DATE, LAST REVISION RECEIVED THE PREVIOUS WK). THE PIC WAS USING NOS APCH PLATES (AGAIN UP TO DATE). IT APPEARS THAT MY APCH PLATES SHOW A DIFFERENT 'CTAF' FREQ THAN BOTH THE NOS APCH PLATES AND THE SECTIONAL CHART (AS PER AIM). IS 125.8 THE NEW CTAF, OR IS THIS A MISPRINT ON MY CHART?. IF THE CHART IS WRONG, THEN THE COMPANY NEEDS TO BE INFORMED. IF HOWEVER, THIS IS THE RYAN CTAF, THEN PERHAPS A NOTAM NEEDS TO BE PRINTED FOR ALL THE PLTS USING THE NOS CHARTS (AND FOR THAT MATTER ANYONE USING THE SECTIONAL CHART). THERE WAS ONLY ONE OTHER ACFT IN THE PATTERN AT THE TIME, AND HE WAS USING 125.8, SO WE USED THE SAME FREQ FOR SAFETY. I HAVE ENCLOSED COPIES OF ALL THE CHARTS FOR YOU, ALONG WITH OUR DUAT READOUT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. RPTR STATES CONFUSION OCCURRED BECAUSE EACH PLT WAS TUNING A DIFFERENT FREQ FOR THE CTAF DUE TO INFO ON TWO DIFFERENT CHARTS. WHEN THEY HEARD THE HELI CALLING ON TWR FREQ THEY FELT SAFEST PROC WAS TO REMAIN ON SAME FREQ.

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.

Pilot acting as safety pilot on instrument approach finds confusion between published CTAF frequencys listed on nos chart and commercial chart.