Aircraft begins takeoff roll from bwi, md, without takeoff clearance from tower.

Attributes
ACN	378997
Time
Date	199708
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bwi
State Reference	MD
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Jetstream 32
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 4000 flight time type : 40
ASRS Report	378997
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : ground less severe non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : rejected takeoff other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

As first officer on a jetstream 32, I have responsibility for all radio and PA calls until airborne. As our taxi speed slowed, as we approached the departure end of the runway at bwi, tower announced for our flight number to taxi into position and hold. We had just completed the taxi checklist and had not yet contacted tower. I read back the position and hold clearance and told the captain that I'd 'be in back' meaning I'd be on the PA and not monitoring tower frequency. I gave the 'seat belt -- tray table' PA and then told the captain, 'I was back,' meaning I was monitoring tower frequency again. He had already taxied into position and said 'run the box, let's go,' meaning for me to complete the pre-takeoff checklist and that we were to depart now. I assumed that he heard and responded to a takeoff clearance while I was talking on the PA. He then recapitulated target torque and that he was 'PF.' we had accelerated through 50 KIAS when tower said 'air carrier XXXX hold your position, hold your position.' the captain immediately aborted the takeoff, I looked up and saw another aircraft departing the intersecting runway approximately 3000 ft in front of us. I responded to tower saying only our flight number. As we decelerated the captain told tower that we'd been clearing the runway at the next intersection. We taxied back and (with clearance) took off. The captain maintains that we were cleared for takeoff not cleared into position and hold. I responded to the position and hold clearance and never heard cleared for takeoff. It is not uncommon for one pilot to be talking on the PA while the other is talking on tower frequency. This assures that the frequency is always monitored and I cannot think of a better division of tasks which would be safer than this one. If I had verified that tower cleared us for takeoff, then the captain may have responded with some other answer aside from 'yes.' this quick query may have prevented our near miss.

Original NASA ASRS Text

Title: ACFT BEGINS TKOF ROLL FROM BWI, MD, WITHOUT TKOF CLRNC FROM TWR.

Narrative: AS FO ON A JETSTREAM 32, I HAVE RESPONSIBILITY FOR ALL RADIO AND PA CALLS UNTIL AIRBORNE. AS OUR TAXI SPD SLOWED, AS WE APCHED THE DEP END OF THE RWY AT BWI, TWR ANNOUNCED FOR OUR FLT NUMBER TO TAXI INTO POS AND HOLD. WE HAD JUST COMPLETED THE TAXI CHKLIST AND HAD NOT YET CONTACTED TWR. I READ BACK THE POS AND HOLD CLRNC AND TOLD THE CAPT THAT I'D 'BE IN BACK' MEANING I'D BE ON THE PA AND NOT MONITORING TWR FREQ. I GAVE THE 'SEAT BELT -- TRAY TABLE' PA AND THEN TOLD THE CAPT, 'I WAS BACK,' MEANING I WAS MONITORING TWR FREQ AGAIN. HE HAD ALREADY TAXIED INTO POS AND SAID 'RUN THE BOX, LET'S GO,' MEANING FOR ME TO COMPLETE THE PRE-TKOF CHKLIST AND THAT WE WERE TO DEPART NOW. I ASSUMED THAT HE HEARD AND RESPONDED TO A TKOF CLRNC WHILE I WAS TALKING ON THE PA. HE THEN RECAPITULATED TARGET TORQUE AND THAT HE WAS 'PF.' WE HAD ACCELERATED THROUGH 50 KIAS WHEN TWR SAID 'ACR XXXX HOLD YOUR POS, HOLD YOUR POS.' THE CAPT IMMEDIATELY ABORTED THE TKOF, I LOOKED UP AND SAW ANOTHER ACFT DEPARTING THE INTERSECTING RWY APPROX 3000 FT IN FRONT OF US. I RESPONDED TO TWR SAYING ONLY OUR FLT NUMBER. AS WE DECELERATED THE CAPT TOLD TWR THAT WE'D BEEN CLRING THE RWY AT THE NEXT INTXN. WE TAXIED BACK AND (WITH CLRNC) TOOK OFF. THE CAPT MAINTAINS THAT WE WERE CLRED FOR TKOF NOT CLRED INTO POS AND HOLD. I RESPONDED TO THE POS AND HOLD CLRNC AND NEVER HEARD CLRED FOR TKOF. IT IS NOT UNCOMMON FOR ONE PLT TO BE TALKING ON THE PA WHILE THE OTHER IS TALKING ON TWR FREQ. THIS ASSURES THAT THE FREQ IS ALWAYS MONITORED AND I CANNOT THINK OF A BETTER DIVISION OF TASKS WHICH WOULD BE SAFER THAN THIS ONE. IF I HAD VERIFIED THAT TWR CLRED US FOR TKOF, THEN THE CAPT MAY HAVE RESPONDED WITH SOME OTHER ANSWER ASIDE FROM 'YES.' THIS QUICK QUERY MAY HAVE PREVENTED OUR NEAR MISS.

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.