Apparent loss of separation between 2 aircraft holding at the same altitude.

Attributes
ACN	392112
Time
Date	199801
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bov
State Reference	FO
Altitude	msl bound lower : 9000 msl bound upper : 9000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lhr
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Flight Phase	cruise other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	392112
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe non adherence : clearance non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 12000 vertical : 9
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Approaching bovington VOR on bov 1A arrival into lhr at FL090. Within 1 mi of VOR we were told to enter hold at bov. Passed over VOR and entered hold. During initial outbound leg ATC told us to proceed direct to bov and depart VOR on 120 degree heading. During our right turn to VOR we received a TA from another aircraft approaching the VOR at our 7 O'clock position, distance 2 NM. ATC immediately asked our altitude then told us to expedite descent to FL080. This was the first call we had heard concerning a descent to FL080. Certainly we had not acknowledged a descent clearance for the hold. This was revealed to ATC upon listening to their tape. Contributing factors: a previous ATC controller had told us to expect not to have to hold at bnn, holding clearance was issued nearly on top of the holding fix and apparently the descent clearance was not heard and acknowledged due to the workload at the time.

Original NASA ASRS Text

Title: APPARENT LOSS OF SEPARATION BTWN 2 ACFT HOLDING AT THE SAME ALT.

Narrative: APCHING BOVINGTON VOR ON BOV 1A ARR INTO LHR AT FL090. WITHIN 1 MI OF VOR WE WERE TOLD TO ENTER HOLD AT BOV. PASSED OVER VOR AND ENTERED HOLD. DURING INITIAL OUTBOUND LEG ATC TOLD US TO PROCEED DIRECT TO BOV AND DEPART VOR ON 120 DEG HDG. DURING OUR R TURN TO VOR WE RECEIVED A TA FROM ANOTHER ACFT APCHING THE VOR AT OUR 7 O'CLOCK POS, DISTANCE 2 NM. ATC IMMEDIATELY ASKED OUR ALT THEN TOLD US TO EXPEDITE DSCNT TO FL080. THIS WAS THE FIRST CALL WE HAD HEARD CONCERNING A DSCNT TO FL080. CERTAINLY WE HAD NOT ACKNOWLEDGED A DSCNT CLRNC FOR THE HOLD. THIS WAS REVEALED TO ATC UPON LISTENING TO THEIR TAPE. CONTRIBUTING FACTORS: A PREVIOUS ATC CTLR HAD TOLD US TO EXPECT NOT TO HAVE TO HOLD AT BNN, HOLDING CLRNC WAS ISSUED NEARLY ON TOP OF THE HOLDING FIX AND APPARENTLY THE DSCNT CLRNC WAS NOT HEARD AND ACKNOWLEDGED DUE TO THE WORKLOAD AT THE TIME.

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.