Small aircraft on IFR flight plan is given wrong frequency by approach for contacting tower. Frequen...

Attributes
ACN	274142
Time
Date	199406
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : spg
State Reference	FL
Altitude	msl bound lower : 800 msl bound upper : 800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tpa tower : spg tracon : tys
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach landing other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 56 flight time total : 457 flight time type : 241
ASRS Report	274142
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	non adherence : far non adherence other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Inter Facility Coordination Failure Operational Deviation

Narrative:

When tampa approach handed me off to spg tower, I was 6 mi out. I heard 120.4 as the tower frequency, although that may have been what I heard because it is what I expected. I called tower twice on communication 1 waiting a bit between calls. Thinking that perhaps my radio had failed, I tuned communication 2 to 120.4 and called twice. Next, I felt that I must be on an incorrect frequency and checked the tower frequency on the approach plate. Since it was 120.4, I assumed I had had both communications fail or the tower was not in operation. At this point, I was directly over spg at pattern altitude and felt that I should be looking for other traffic so I called my position on 120.4 throughout my approach and landing. I looked for but saw no lights from tower. I did see 1 other aircraft in the pattern and followed it, wondering why they were not reporting position. When I taxied by the tower, they called me on 120.4 and told me they were now on 124.4. I feel that the 2 frequencys are very hard to distinguish. Had I not been in the pattern, I would have switched back to tampa approach to tell them I could not raise spg tower, but I wanted to keep my eyes outside the cockpit. Additionally, since I was on an IFR flight plan and communication failure was a possibility, I continued to land. I was surprised to learn that spg tower had no idea I was approaching, and apparently did not see me until after I landed. I would have thought tampa approach would have warned them. I feel that in frequency changes such as 120.4 to 124.4 everyone should be very careful to make sure the frequency is read back correctly. Additionally, I think that for any facility which changes frequency, they should monitor the old frequency until approach plates, AFD, and sectionals are updated to the new frequency. Spg tower did call me on 120.4 so monitoring the frequency would have been possible. I am aware of a similar situation at athens, GA, where a tower was recently installed. They do not monitor the old unicom frequency and I have heard planes in the pattern on unicom while the tower was trying to contact them.

Original NASA ASRS Text

Title: SMA ON IFR FLT PLAN IS GIVEN WRONG FREQ BY APCH FOR CONTACTING TWR. FREQ HAD BEEN CHANGED. ENTERED ATA WITHOUT CONTACT.

Narrative: WHEN TAMPA APCH HANDED ME OFF TO SPG TWR, I WAS 6 MI OUT. I HEARD 120.4 AS THE TWR FREQ, ALTHOUGH THAT MAY HAVE BEEN WHAT I HEARD BECAUSE IT IS WHAT I EXPECTED. I CALLED TWR TWICE ON COM 1 WAITING A BIT BTWN CALLS. THINKING THAT PERHAPS MY RADIO HAD FAILED, I TUNED COM 2 TO 120.4 AND CALLED TWICE. NEXT, I FELT THAT I MUST BE ON AN INCORRECT FREQ AND CHKED THE TWR FREQ ON THE APCH PLATE. SINCE IT WAS 120.4, I ASSUMED I HAD HAD BOTH COMS FAIL OR THE TWR WAS NOT IN OP. AT THIS POINT, I WAS DIRECTLY OVER SPG AT PATTERN ALT AND FELT THAT I SHOULD BE LOOKING FOR OTHER TFC SO I CALLED MY POS ON 120.4 THROUGHOUT MY APCH AND LNDG. I LOOKED FOR BUT SAW NO LIGHTS FROM TWR. I DID SEE 1 OTHER ACFT IN THE PATTERN AND FOLLOWED IT, WONDERING WHY THEY WERE NOT RPTING POS. WHEN I TAXIED BY THE TWR, THEY CALLED ME ON 120.4 AND TOLD ME THEY WERE NOW ON 124.4. I FEEL THAT THE 2 FREQS ARE VERY HARD TO DISTINGUISH. HAD I NOT BEEN IN THE PATTERN, I WOULD HAVE SWITCHED BACK TO TAMPA APCH TO TELL THEM I COULD NOT RAISE SPG TWR, BUT I WANTED TO KEEP MY EYES OUTSIDE THE COCKPIT. ADDITIONALLY, SINCE I WAS ON AN IFR FLT PLAN AND COM FAILURE WAS A POSSIBILITY, I CONTINUED TO LAND. I WAS SURPRISED TO LEARN THAT SPG TWR HAD NO IDEA I WAS APCHING, AND APPARENTLY DID NOT SEE ME UNTIL AFTER I LANDED. I WOULD HAVE THOUGHT TAMPA APCH WOULD HAVE WARNED THEM. I FEEL THAT IN FREQ CHANGES SUCH AS 120.4 TO 124.4 EVERYONE SHOULD BE VERY CAREFUL TO MAKE SURE THE FREQ IS READ BACK CORRECTLY. ADDITIONALLY, I THINK THAT FOR ANY FACILITY WHICH CHANGES FREQ, THEY SHOULD MONITOR THE OLD FREQ UNTIL APCH PLATES, AFD, AND SECTIONALS ARE UPDATED TO THE NEW FREQ. SPG TWR DID CALL ME ON 120.4 SO MONITORING THE FREQ WOULD HAVE BEEN POSSIBLE. I AM AWARE OF A SIMILAR SIT AT ATHENS, GA, WHERE A TWR WAS RECENTLY INSTALLED. THEY DO NOT MONITOR THE OLD UNICOM FREQ AND I HAVE HEARD PLANES IN THE PATTERN ON UNICOM WHILE THE TWR WAS TRYING TO CONTACT THEM.

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.

Small aircraft on IFR flight plan is given wrong frequency by approach for contacting tower. Frequency had been changed. Entered air traffic area without contact.