Narrative:

On sep/xa/99, I was the first officer on a flight from saltillo, mexico, to laredo, tx. The flight departed saltillo at approximately PM15Z. The flight went with relatively no problems while in the mexican airspace. However, while descending into laredo, when mexico's ATC gave us a frequency change to ZHU we began to have radio problems. The captain attempted to contact ZHU on the assigned frequency, but it appeared to have a stuck microphone. As the captain tried different methods to contact ZHU, I continued on our flight plan route, which was newla VOR (nld) direct to laredo VOR (lrd). While proceeding directly to laredo VOR, the radios began to work and the captain established radio contact with ZHU. To complicate matters, mexico's ATC did not pass on any flight information to ZHU with the handoff. So, ZHU told us to make an immediate left turn to a 300 degree heading and informed us that we were the ones with a stuck microphone. ZHU gathered our information on our flight plan from us and proceeded to give us vectors for a visual approach into laredo. We were vectored until established on approximately a 5 mi final when we were cleared for a visual approach to runway 17L at laredo. The radios worked fine once radio contact was established with ZHU up to the point when we were told to contact the tower. When the captain switched to the tower frequency, we could hear the same static noise that we thought earlier was a stuck microphone. We were unable to receive or transmit to laredo tower. I slowed the aircraft to final approach speed while the captain attempted to contact the tower. The captain tried the previous frequency, checked the circuit breakers, unplugged the mikes independently, checked the push-to-talk buttons and audio panels, etc, with no prevail. We were still unable to communicate with the tower. We had squawked 7600 on the transponder, and at this point were approaching short final. I told the captain that I thought we should do a go around since I could not see a steady green light gun signal from the tower. The captain stated no, that we were going to land now because it would be safer than going around. When we were in radio contact, we had been given TA's of other aircraft in the area. I am not sure if the captain saw a steady green light from the tower, but we went ahead and landed the aircraft on runway 17L. The captain taxied the aircraft off the runway and went to get his hand-held transceiver out of his flight bag. I could see that the tower was giving us a flashing green light to taxi. I informed the captain that I could see the light signal and moments later the captain had his hand-held and called the tower with it. The tower gave us taxi instructions to customs and asked us to call them on the telephone. As I waited for our paperwork at united states customs, the captain called the tower on the telephone. I do not know the details of the captain's conversation with the tower, but the captain told me afterwards that the person in the tower just wanted to know the nature of our problem. The captain also stated that the tower said they were giving us a steady green light to land and that the tower said they did not want us to do a go around.

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Original NASA ASRS Text

Title: A DA20 LANDS AT LAREDO ARPT WITHOUT OBTAINING OR NOTING A LNDG CLRNC WHEN THEIR RADIO IS UNABLE TO RECEIVE GND-TO-AIR.

Narrative: ON SEP/XA/99, I WAS THE FO ON A FLT FROM SALTILLO, MEXICO, TO LAREDO, TX. THE FLT DEPARTED SALTILLO AT APPROX PM15Z. THE FLT WENT WITH RELATIVELY NO PROBS WHILE IN THE MEXICAN AIRSPACE. HOWEVER, WHILE DSNDING INTO LAREDO, WHEN MEXICO'S ATC GAVE US A FREQ CHANGE TO ZHU WE BEGAN TO HAVE RADIO PROBS. THE CAPT ATTEMPTED TO CONTACT ZHU ON THE ASSIGNED FREQ, BUT IT APPEARED TO HAVE A STUCK MIKE. AS THE CAPT TRIED DIFFERENT METHODS TO CONTACT ZHU, I CONTINUED ON OUR FLT PLAN RTE, WHICH WAS NEWLA VOR (NLD) DIRECT TO LAREDO VOR (LRD). WHILE PROCEEDING DIRECTLY TO LAREDO VOR, THE RADIOS BEGAN TO WORK AND THE CAPT ESTABLISHED RADIO CONTACT WITH ZHU. TO COMPLICATE MATTERS, MEXICO'S ATC DID NOT PASS ON ANY FLT INFO TO ZHU WITH THE HDOF. SO, ZHU TOLD US TO MAKE AN IMMEDIATE L TURN TO A 300 DEG HDG AND INFORMED US THAT WE WERE THE ONES WITH A STUCK MIKE. ZHU GATHERED OUR INFO ON OUR FLT PLAN FROM US AND PROCEEDED TO GIVE US VECTORS FOR A VISUAL APCH INTO LAREDO. WE WERE VECTORED UNTIL ESTABLISHED ON APPROX A 5 MI FINAL WHEN WE WERE CLRED FOR A VISUAL APCH TO RWY 17L AT LAREDO. THE RADIOS WORKED FINE ONCE RADIO CONTACT WAS ESTABLISHED WITH ZHU UP TO THE POINT WHEN WE WERE TOLD TO CONTACT THE TWR. WHEN THE CAPT SWITCHED TO THE TWR FREQ, WE COULD HEAR THE SAME STATIC NOISE THAT WE THOUGHT EARLIER WAS A STUCK MIKE. WE WERE UNABLE TO RECEIVE OR XMIT TO LAREDO TWR. I SLOWED THE ACFT TO FINAL APCH SPD WHILE THE CAPT ATTEMPTED TO CONTACT THE TWR. THE CAPT TRIED THE PREVIOUS FREQ, CHKED THE CIRCUIT BREAKERS, UNPLUGGED THE MIKES INDEPENDENTLY, CHKED THE PUSH-TO-TALK BUTTONS AND AUDIO PANELS, ETC, WITH NO PREVAIL. WE WERE STILL UNABLE TO COMMUNICATE WITH THE TWR. WE HAD SQUAWKED 7600 ON THE XPONDER, AND AT THIS POINT WERE APCHING SHORT FINAL. I TOLD THE CAPT THAT I THOUGHT WE SHOULD DO A GAR SINCE I COULD NOT SEE A STEADY GREEN LIGHT GUN SIGNAL FROM THE TWR. THE CAPT STATED NO, THAT WE WERE GOING TO LAND NOW BECAUSE IT WOULD BE SAFER THAN GOING AROUND. WHEN WE WERE IN RADIO CONTACT, WE HAD BEEN GIVEN TA'S OF OTHER ACFT IN THE AREA. I AM NOT SURE IF THE CAPT SAW A STEADY GREEN LIGHT FROM THE TWR, BUT WE WENT AHEAD AND LANDED THE ACFT ON RWY 17L. THE CAPT TAXIED THE ACFT OFF THE RWY AND WENT TO GET HIS HAND-HELD TRANSCEIVER OUT OF HIS FLT BAG. I COULD SEE THAT THE TWR WAS GIVING US A FLASHING GREEN LIGHT TO TAXI. I INFORMED THE CAPT THAT I COULD SEE THE LIGHT SIGNAL AND MOMENTS LATER THE CAPT HAD HIS HAND-HELD AND CALLED THE TWR WITH IT. THE TWR GAVE US TAXI INSTRUCTIONS TO CUSTOMS AND ASKED US TO CALL THEM ON THE TELEPHONE. AS I WAITED FOR OUR PAPERWORK AT UNITED STATES CUSTOMS, THE CAPT CALLED THE TWR ON THE TELEPHONE. I DO NOT KNOW THE DETAILS OF THE CAPT'S CONVERSATION WITH THE TWR, BUT THE CAPT TOLD ME AFTERWARDS THAT THE PERSON IN THE TWR JUST WANTED TO KNOW THE NATURE OF OUR PROB. THE CAPT ALSO STATED THAT THE TWR SAID THEY WERE GIVING US A STEADY GREEN LIGHT TO LAND AND THAT THE TWR SAID THEY DID NOT WANT US TO DO A GAR.

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.