Takeoff without clearance from london.

Attributes
ACN	479960
Time
Date	200007
Day	Tue
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : egll.airport
State Reference	FO
Altitude	agl single value : 0
Environment
Light	Dawn
Aircraft 1
Controlling Facilities	tower : egll.tower
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : position and hold ground : takeoff roll
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	479960
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	479757
Events
Anomaly	non adherence : clearance other anomaly other
Independent Detector	other controllerb
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

I was first officer on a flight lhr-ord. We were on the runway holding when tower issued what all 3 pilots heard as a takeoff clearance. Captain read back cleared for takeoff XXX. Tower immediately came back with revised departure heading/frequency. After airborne, tower said we did not have takeoff clearance. Supplemental information from can 479757: 4 pilots on headsets heard tower give us takeoff and heading change we all thought.

Original NASA ASRS Text

Title: TKOF WITHOUT CLRNC FROM LONDON.

Narrative: I WAS FO ON A FLT LHR-ORD. WE WERE ON THE RWY HOLDING WHEN TWR ISSUED WHAT ALL 3 PLTS HEARD AS A TKOF CLRNC. CAPT READ BACK CLRED FOR TKOF XXX. TWR IMMEDIATELY CAME BACK WITH REVISED DEP HDG/FREQ. AFTER AIRBORNE, TWR SAID WE DID NOT HAVE TKOF CLRNC. SUPPLEMENTAL INFO FROM CAN 479757: 4 PLTS ON HEADSETS HEARD TWR GIVE US TKOF AND HDG CHANGE WE ALL THOUGHT.

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.