Reporter wants the facility to adhere to the FAA's own tso to prevent radio interference.

Attributes
ACN	441750
Time
Date	199907
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : cos.tower
State Reference	CO
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : cos.tower
Operator	general aviation : personal
Make Model Name	PA-34-200 Seneca I
Operating Under FAR Part	Part 91
Flight Phase	climbout : takeoff
Flight Plan	VFR
Aircraft 2
Controlling Facilities	tower : cos.tower
Operator	general aviation : personal
Make Model Name	Baron 55/Cochise
Operating Under FAR Part	Part 91
Route In Use	arrival : vfr
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 10 controller time certified in position1 : 8 flight time total : 400
ASRS Report	441750
Person 2
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Supplementary
Problem Areas	ATC Human Performance ATC Facility Maintenance Human Performance
Primary Problem	Maintenance Human Performance
Situations
ATC Facility	communication equipment : cos.tower

Narrative:

A PA34 called tower (119.9) for takeoff clearance at the same time as a BE55 inbound called for landing clearance. The result was a loud squeal and missed communication. The FAA currently has a tso for devices designed to prevent simultaneous xmissions and radio modifications could be simply effected to eliminate or at least reduce the occurrence of blocked communication resulting from simultaneous xmissions.

Original NASA ASRS Text

Title: RPTR WANTS THE FACILITY TO ADHERE TO THE FAA'S OWN TSO TO PREVENT RADIO INTERFERENCE.

Narrative: A PA34 CALLED TWR (119.9) FOR TKOF CLRNC AT THE SAME TIME AS A BE55 INBOUND CALLED FOR LNDG CLRNC. THE RESULT WAS A LOUD SQUEAL AND MISSED COM. THE FAA CURRENTLY HAS A TSO FOR DEVICES DESIGNED TO PREVENT SIMULTANEOUS XMISSIONS AND RADIO MODIFICATIONS COULD BE SIMPLY EFFECTED TO ELIMINATE OR AT LEAST REDUCE THE OCCURRENCE OF BLOCKED COM RESULTING FROM SIMULTANEOUS XMISSIONS.

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.