Small aircraft experiences stuck microphone that culminates in communication radio failure while tra...

Attributes
ACN	127610
Time
Date	198910
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : iad
State Reference	VA
Altitude	msl bound lower : 3500 msl bound upper : 3500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 10 flight time total : 390 flight time type : 190
ASRS Report	127610
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew faa : investigated
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Departed west 66 for a direct flight to gai. Shortly after takeoff, radio and radar contact was established with dulles approach on 124.65 and encoding transponder was set as instructed. Shortly after receiving a traffic advisory from dulles, a mild burning smell was noted in the cockpit. The aircraft's voice-activated intercom 'failed' at the same time. Shortly thereafter it became apparent that a radio failure had occurred as well. Given the fact that dulles was aware of our intention to proceed to gai, I elected to proceed on course to gai while continuing to squawk the assigned code. The radio was not turned off since the burning smell had disappeared and I was using the working portion of radio, the VOR, to navigate. Upon landing at gai I went directly to the FBO desk in order to obtain a telephone number for dulles approach. FBO personnel informed me that dulles had already called. I telephoned the number I was given and spoke with a gentleman regarding the incident (I failed to get his name or title, though). After explaining my situation, I was informed that my radio transmitter had been stuck on for 'several' minutes. Dulles approach had been able to hear our cockpit intercom conversation during that time. We returned to 9w0 later that day (giving wide berth to the arsa) and removed the radio and push-to-talk (ptt) switch for examination and repair. It seems most likely that the ptt switch stuck in the transmit position. The radio then failed from overheating while continuously transmitting. The radio has been taken to a professional repair station. In hindsight, 2 alternate courses of action should have been considered. First, as soon as an electrical problem was suspected, the radio and other non-essential equipment should have been shut off. The transponder could be set to 7600, and a 180 degree turn out of the arsa initiated. The second alternative would have been to stay out of the arsa entirely and fly a longer indirect route to gai to the west.

Original NASA ASRS Text

Title: SMA EXPERIENCES STUCK MICROPHONE THAT CULMINATES IN COM RADIO FAILURE WHILE TRANSITING IAD ARSA.

Narrative: DEPARTED W 66 FOR A DIRECT FLT TO GAI. SHORTLY AFTER TKOF, RADIO AND RADAR CONTACT WAS ESTABLISHED WITH DULLES APCH ON 124.65 AND ENCODING XPONDER WAS SET AS INSTRUCTED. SHORTLY AFTER RECEIVING A TFC ADVISORY FROM DULLES, A MILD BURNING SMELL WAS NOTED IN THE COCKPIT. THE ACFT'S VOICE-ACTIVATED INTERCOM 'FAILED' AT THE SAME TIME. SHORTLY THEREAFTER IT BECAME APPARENT THAT A RADIO FAILURE HAD OCCURRED AS WELL. GIVEN THE FACT THAT DULLES WAS AWARE OF OUR INTENTION TO PROCEED TO GAI, I ELECTED TO PROCEED ON COURSE TO GAI WHILE CONTINUING TO SQUAWK THE ASSIGNED CODE. THE RADIO WAS NOT TURNED OFF SINCE THE BURNING SMELL HAD DISAPPEARED AND I WAS USING THE WORKING PORTION OF RADIO, THE VOR, TO NAVIGATE. UPON LNDG AT GAI I WENT DIRECTLY TO THE FBO DESK IN ORDER TO OBTAIN A TELEPHONE NUMBER FOR DULLES APCH. FBO PERSONNEL INFORMED ME THAT DULLES HAD ALREADY CALLED. I TELEPHONED THE NUMBER I WAS GIVEN AND SPOKE WITH A GENTLEMAN REGARDING THE INCIDENT (I FAILED TO GET HIS NAME OR TITLE, THOUGH). AFTER EXPLAINING MY SITUATION, I WAS INFORMED THAT MY RADIO XMITTER HAD BEEN STUCK ON FOR 'SEVERAL' MINUTES. DULLES APCH HAD BEEN ABLE TO HEAR OUR COCKPIT INTERCOM CONVERSATION DURING THAT TIME. WE RETURNED TO 9W0 LATER THAT DAY (GIVING WIDE BERTH TO THE ARSA) AND REMOVED THE RADIO AND PUSH-TO-TALK (PTT) SWITCH FOR EXAMINATION AND REPAIR. IT SEEMS MOST LIKELY THAT THE PTT SWITCH STUCK IN THE XMIT POSITION. THE RADIO THEN FAILED FROM OVERHEATING WHILE CONTINUOUSLY XMITTING. THE RADIO HAS BEEN TAKEN TO A PROFESSIONAL REPAIR STATION. IN HINDSIGHT, 2 ALTERNATE COURSES OF ACTION SHOULD HAVE BEEN CONSIDERED. FIRST, AS SOON AS AN ELECTRICAL PROBLEM WAS SUSPECTED, THE RADIO AND OTHER NON-ESSENTIAL EQUIPMENT SHOULD HAVE BEEN SHUT OFF. THE XPONDER COULD BE SET TO 7600, AND A 180 DEG TURN OUT OF THE ARSA INITIATED. THE SECOND ALTERNATIVE WOULD HAVE BEEN TO STAY OUT OF THE ARSA ENTIRELY AND FLY A LONGER INDIRECT ROUTE TO GAI TO THE W.

Data retrieved from NASA's ASRS site as of August 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 experiences stuck microphone that culminates in communication radio failure while transiting iad arsa.