Reported loss of separation when an MD11 descends through the altitude of a B727 at FL330.

Attributes
ACN	383857
Time
Date	199710
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : unz
State Reference	GU
Altitude	msl bound lower : 33000 msl bound upper : 33000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	383857
Person 2
Affiliation	Other
Function	other personnel other
Qualification	other other : other
Events
Anomaly	non adherence : required legal separation non adherence : published procedure other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 30000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

2 MD11's were converging in toyk and naha fir's at FL350. Tried to move one to FL310. Because of HF radio problems, clearance was delivered 30 mins late. The MD11 made the descent through a B727 at FL330, head on, approximately 60 mi lateral (need 100 mi). Several other aircraft were contacted to deliver/relay clearance to the MD11. There was confusion as to whether the aircraft got the clearance because of the bad radios.

Original NASA ASRS Text

Title: RPTED LOSS OF SEPARATION WHEN AN MD11 DSNDS THROUGH THE ALT OF A B727 AT FL330.

Narrative: 2 MD11'S WERE CONVERGING IN TOYK AND NAHA FIR'S AT FL350. TRIED TO MOVE ONE TO FL310. BECAUSE OF HF RADIO PROBS, CLRNC WAS DELIVERED 30 MINS LATE. THE MD11 MADE THE DSCNT THROUGH A B727 AT FL330, HEAD ON, APPROX 60 MI LATERAL (NEED 100 MI). SEVERAL OTHER ACFT WERE CONTACTED TO DELIVER/RELAY CLRNC TO THE MD11. THERE WAS CONFUSION AS TO WHETHER THE ACFT GOT THE CLRNC BECAUSE OF THE BAD RADIOS.

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.