Narrative:

We had been cleared for takeoff on runway 24R at lax. An air carrier Y large transport was on the adjacent runway, 24L, and had also apparently been cleared for takeoff because although he was not moving, we could clearly hear his engines at a high power setting. Our clearance to take off was acknowledged, 'fly 250 degree heading and maintain 2000'.' the takeoff was normal, and we proceeded as instructed. While leveling off at 2000', we heard a loud engine noise in the cockpit. Approximately 3 seconds later we looked out of our right front window and saw air carrier Y climbing out from below our aircraft at about our own altitude. The noise we had heard was from the engines of his aircraft. Tower then asked us if we had air carrier Y in sight. We told them we did. Air carrier Y was now on our right side and began turning back toward us. We took evasive action and descended to about 1600'. We switched to departure who asked if we were told to keep air carrier Y in sight. We had not been and, in fact, we told him we were the first aircraft to begin our takeoff roll. We informed departure that air carrier Y had almost hit us. We also told departure that it was at our own discretion that we took evasive action. When we arrived at our destination (ccr), the captain called lax and talked to ATC. They told him we were not at fault, that they had played the tapes back 3 times so far. The captain was told to call them back the next day. The main cause of this near miss was lax tower failing to instruct one of the 2 aircraft to keep visibility sep with the other. However, if air carrier Y had maintained a 250 degree heading, as we did, they would not have crossed our flight path (they must have been 10-20 degrees from their assigned heading). The lax tower and air carrier Y both made mistakes, and we almost paid for it.

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Original NASA ASRS Text

Title: CLOSE PROX ACR-MLG ACR-LGT BOTH ON DEP CLIMB FROM PARALLEL RWYS AT LAX.

Narrative: WE HAD BEEN CLRED FOR TKOF ON RWY 24R AT LAX. AN ACR Y LGT WAS ON THE ADJACENT RWY, 24L, AND HAD ALSO APPARENTLY BEEN CLRED FOR TKOF BECAUSE ALTHOUGH HE WAS NOT MOVING, WE COULD CLEARLY HEAR HIS ENGS AT A HIGH PWR SETTING. OUR CLRNC TO TAKE OFF WAS ACKNOWLEDGED, 'FLY 250 DEG HDG AND MAINTAIN 2000'.' THE TKOF WAS NORMAL, AND WE PROCEEDED AS INSTRUCTED. WHILE LEVELING OFF AT 2000', WE HEARD A LOUD ENG NOISE IN THE COCKPIT. APPROX 3 SECS LATER WE LOOKED OUT OF OUR RIGHT FRONT WINDOW AND SAW ACR Y CLBING OUT FROM BELOW OUR ACFT AT ABOUT OUR OWN ALT. THE NOISE WE HAD HEARD WAS FROM THE ENGS OF HIS ACFT. TWR THEN ASKED US IF WE HAD ACR Y IN SIGHT. WE TOLD THEM WE DID. ACR Y WAS NOW ON OUR RIGHT SIDE AND BEGAN TURNING BACK TOWARD US. WE TOOK EVASIVE ACTION AND DSNDED TO ABOUT 1600'. WE SWITCHED TO DEP WHO ASKED IF WE WERE TOLD TO KEEP ACR Y IN SIGHT. WE HAD NOT BEEN AND, IN FACT, WE TOLD HIM WE WERE THE FIRST ACFT TO BEGIN OUR TKOF ROLL. WE INFORMED DEP THAT ACR Y HAD ALMOST HIT US. WE ALSO TOLD DEP THAT IT WAS AT OUR OWN DISCRETION THAT WE TOOK EVASIVE ACTION. WHEN WE ARRIVED AT OUR DEST (CCR), THE CAPT CALLED LAX AND TALKED TO ATC. THEY TOLD HIM WE WERE NOT AT FAULT, THAT THEY HAD PLAYED THE TAPES BACK 3 TIMES SO FAR. THE CAPT WAS TOLD TO CALL THEM BACK THE NEXT DAY. THE MAIN CAUSE OF THIS NEAR MISS WAS LAX TWR FAILING TO INSTRUCT ONE OF THE 2 ACFT TO KEEP VIS SEP WITH THE OTHER. HOWEVER, IF ACR Y HAD MAINTAINED A 250 DEG HDG, AS WE DID, THEY WOULD NOT HAVE CROSSED OUR FLT PATH (THEY MUST HAVE BEEN 10-20 DEGS FROM THEIR ASSIGNED HDG). THE LAX TWR AND ACR Y BOTH MADE MISTAKES, AND WE ALMOST PAID FOR IT.

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.