Takeoff made without clearance at quito, ecuador. Radio problems were a factor.

Attributes
ACN	493620
Time
Date	200011
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sequ.airport
State Reference	FO
Altitude	agl single value : 0 msl single value : 9223
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : takeoff ground : position and hold ground : taxi ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 20 flight time total : 4000 flight time type : 400
ASRS Report	493620
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 150 flight time total : 17000 flight time type : 2500
ASRS Report	493619
Events
Anomaly	non adherence : clearance other anomaly other
Independent Detector	other controllerb
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	ATC Human Performance Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Pushed back aircraft for engine start and taxi. We were in quito, ecuador. We called ground for taxi and clearance. We were unable to contact ground on radio #1. We also tried radio #2 with same results. We finally contacted ground on #2 radio, but was still garbled. We were given taxi into position and hold which we did. After 30 seconds, we were given takeoff clearance. I acknowledged cleared for takeoff and we took off. The captain did not hear the cleared for takeoff clearance. I told him I did and acknowledged it. After takeoff, tower said we did not have takeoff clearance. I believe the radios had a problem which led to this problem. I heard the takeoff clearance and acknowledged it. Maybe my transmitter was not working. This aircraft has a history of radio problems. Supplemental information from acn 493619: we were unable to determine if it was a stuck microphone or the tower had a radio problem. I did not hear the controller say cleared for takeoff. I said 'I didn't hear that are we cleared for takeoff?' the first officer said 'yes.' I assumed with the radio problems we had on taxi I had my volume down too low. My concern was that someone may have had a hand-held radio transmitting at the end of the runway and jamming the frequencys.

Original NASA ASRS Text

Title: TKOF MADE WITHOUT CLRNC AT QUITO, ECUADOR. RADIO PROBS WERE A FACTOR.

Narrative: PUSHED BACK ACFT FOR ENG START AND TAXI. WE WERE IN QUITO, ECUADOR. WE CALLED GND FOR TAXI AND CLRNC. WE WERE UNABLE TO CONTACT GND ON RADIO #1. WE ALSO TRIED RADIO #2 WITH SAME RESULTS. WE FINALLY CONTACTED GND ON #2 RADIO, BUT WAS STILL GARBLED. WE WERE GIVEN TAXI INTO POS AND HOLD WHICH WE DID. AFTER 30 SECONDS, WE WERE GIVEN TKOF CLRNC. I ACKNOWLEDGED CLRED FOR TKOF AND WE TOOK OFF. THE CAPT DID NOT HEAR THE CLRED FOR TKOF CLRNC. I TOLD HIM I DID AND ACKNOWLEDGED IT. AFTER TKOF, TWR SAID WE DID NOT HAVE TKOF CLRNC. I BELIEVE THE RADIOS HAD A PROB WHICH LED TO THIS PROB. I HEARD THE TKOF CLRNC AND ACKNOWLEDGED IT. MAYBE MY XMITTER WAS NOT WORKING. THIS ACFT HAS A HISTORY OF RADIO PROBS. SUPPLEMENTAL INFO FROM ACN 493619: WE WERE UNABLE TO DETERMINE IF IT WAS A STUCK MIKE OR THE TWR HAD A RADIO PROB. I DID NOT HEAR THE CTLR SAY CLRED FOR TKOF. I SAID 'I DIDN'T HEAR THAT ARE WE CLRED FOR TKOF?' THE FO SAID 'YES.' I ASSUMED WITH THE RADIO PROBS WE HAD ON TAXI I HAD MY VOLUME DOWN TOO LOW. MY CONCERN WAS THAT SOMEONE MAY HAVE HAD A HAND-HELD RADIO XMITTING AT THE END OF THE RWY AND JAMMING THE FREQS.

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.