Mdt has frequency assignment with poor, scratchy, broken communication. Reported by several aircraft...

Attributes
ACN	219277
Time
Date	199208
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bpt
State Reference	TX
Altitude	msl bound lower : 8800 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : n90
Operator	common carrier : air carrier
Make Model Name	Medium Transport
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure other departure sid : sid
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 140 flight time total : 6000 flight time type : 800
ASRS Report	219277
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : anomaly accepted other
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 300
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other

Narrative:

Operating as a scheduled carrier from jfk to bos, executing the kennedy 6 departure to bpt. Communication had been switched several mins prior from jfk departure on 135.9 to 133.1. Reception on 133.1 was scratchy and broken as reported by other aircraft as well. While passing 8800 ft on the bpt 228/19, crew observed a potential conflicting target on TCASII and visually located the traffic. Within approximately 10 seconds, the crew received an RA command, but since traffic was in visual contact, did not deviate from climb clearance. Shortly after a 'monitor vertical speed' command had been given by the TCASII, the voice of the ATC controller was heard calling out the traffic which had just passed. The controller's transmission was weak but readable. Within 5 mins, now level at 9000 ft on the bpt 228/3 and still communicating with ATC on 133.1, the crew visually located the traffic. The crew received another RA command but did not deviate from assigned altitude because the traffic was in visual contact. The departure controller was hindered in his normal duties of separating traffic by a limited ability to communication with the pilots involved. Partial radio failure appears to be the primary cause of a potentially dangerous situation. Proper operation and use of TCASII assisted aircrews in overcoming the communication limitations of the controller. VMC WX allowed all aircraft to see and avoid while under ATC control.

Original NASA ASRS Text

Title: MDT HAS FREQ ASSIGNMENT WITH POOR, SCRATCHY, BROKEN COM. RPTED BY SEVERAL ACFT. CTLR TA RECEIVED AFTER TFC PASSED. TCASII HAD INDICATED PROX AND CREW HAD VISUAL CONTACT. HAS SECOND EXPERIENCE WITH SAME SCENARIO.

Narrative: OPERATING AS A SCHEDULED CARRIER FROM JFK TO BOS, EXECUTING THE KENNEDY 6 DEP TO BPT. COM HAD BEEN SWITCHED SEVERAL MINS PRIOR FROM JFK DEP ON 135.9 TO 133.1. RECEPTION ON 133.1 WAS SCRATCHY AND BROKEN AS RPTED BY OTHER ACFT AS WELL. WHILE PASSING 8800 FT ON THE BPT 228/19, CREW OBSERVED A POTENTIAL CONFLICTING TARGET ON TCASII AND VISUALLY LOCATED THE TFC. WITHIN APPROX 10 SECONDS, THE CREW RECEIVED AN RA COMMAND, BUT SINCE TFC WAS IN VISUAL CONTACT, DID NOT DEVIATE FROM CLB CLRNC. SHORTLY AFTER A 'MONITOR VERT SPD' COMMAND HAD BEEN GIVEN BY THE TCASII, THE VOICE OF THE ATC CTLR WAS HEARD CALLING OUT THE TFC WHICH HAD JUST PASSED. THE CTLR'S XMISSION WAS WEAK BUT READABLE. WITHIN 5 MINS, NOW LEVEL AT 9000 FT ON THE BPT 228/3 AND STILL COMMUNICATING WITH ATC ON 133.1, THE CREW VISUALLY LOCATED THE TFC. THE CREW RECEIVED ANOTHER RA COMMAND BUT DID NOT DEVIATE FROM ASSIGNED ALT BECAUSE THE TFC WAS IN VISUAL CONTACT. THE DEP CTLR WAS HINDERED IN HIS NORMAL DUTIES OF SEPARATING TFC BY A LIMITED ABILITY TO COM WITH THE PLTS INVOLVED. PARTIAL RADIO FAILURE APPEARS TO BE THE PRIMARY CAUSE OF A POTENTIALLY DANGEROUS SITUATION. PROPER OP AND USE OF TCASII ASSISTED AIRCREWS IN OVERCOMING THE COM LIMITATIONS OF THE CTLR. VMC WX ALLOWED ALL ACFT TO SEE AND AVOID WHILE UNDER ATC CTL.

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.

Mdt has frequency assignment with poor, scratchy, broken communication. Reported by several aircraft. Controller TA received after traffic passed. TCASII had indicated proximity and crew had visual contact. Has second experience with same scenario.