TMB700 pilot had the ILS system completely unusable at hut.

Attributes
ACN	546411
Time
Date	200204
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : hut.airport
State Reference	KS
Altitude	msl single value : 2500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : hut.tower
Operator	general aviation : personal
Make Model Name	TBM 700
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer & glide slope : 13
Flight Phase	descent : approach
Route In Use	approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot oversight : pic
Qualification	pilot : multi engine pilot : commercial pilot : instrument
Experience	flight time last 90 days : 45 flight time total : 6300 flight time type : 300
ASRS Report	546411
Person 2
Affiliation	other
Function	observation : passenger
Events
Anomaly	inflight encounter : weather inflight encounter other other anomaly other
Independent Detector	other flight crewa other other : 2
Resolutory Action	none taken : detected after the fact none taken : anomaly accepted other
Consequence	other
Supplementary
Problem Areas	Passenger Human Performance Flight Crew Human Performance Aircraft Weather
Primary Problem	Aircraft

Narrative:

During ILS approach into hut, the localizer and GS bars oscillated and were completely unusable. Advised tower and they said no reported problems. After landing, found my passenger and I both had our cell phones on. Later, when we departed, we flew the approach again with cell phones off and had no problem. The avionics experts at my repair facility confirmed that cell phones can interfere with avionics. Guess the airlines are correct when they ask us to turn our phones off. Perhaps we, GA pilots, should add this to our checklists.

Original NASA ASRS Text

Title: TMB700 PLT HAD THE ILS SYS COMPLETELY UNUSABLE AT HUT.

Narrative: DURING ILS APCH INTO HUT, THE LOC AND GS BARS OSCILLATED AND WERE COMPLETELY UNUSABLE. ADVISED TWR AND THEY SAID NO RPTED PROBS. AFTER LNDG, FOUND MY PAX AND I BOTH HAD OUR CELL PHONES ON. LATER, WHEN WE DEPARTED, WE FLEW THE APCH AGAIN WITH CELL PHONES OFF AND HAD NO PROB. THE AVIONICS EXPERTS AT MY REPAIR FACILITY CONFIRMED THAT CELL PHONES CAN INTERFERE WITH AVIONICS. GUESS THE AIRLINES ARE CORRECT WHEN THEY ASK US TO TURN OUR PHONES OFF. PERHAPS WE, GA PLTS, SHOULD ADD THIS TO OUR CHKLISTS.

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.