Loss of separation between 2 ar aircraft on simultaneous ILS approachs to parallel runways at ord.

Attributes
ACN	144909
Time
Date	199005
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 3000 msl bound upper : 4000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : private pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 18000 flight time type : 150
ASRS Report	144909
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe inflight encounter : weather non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

We were intercepting the ILS to 27R at 4000' with moderate turbulence and heavy rain. We were directed to immediately descend to 3000' and then were told it was ok, that the other aircraft was back in his airspace (approach to 27L) simultaneous approachs. We caught fleeting glimpses of the other aircraft correcting to course. Do not allow simultaneous approachs during turbulence and heavy WX conditions. On approach other aircraft Y reported a 300' loss due to moderate turbulence on base leg and at that time we had to divert our course in order to avoid a magenta area on our radar. The controller chastised air carrier Y for not answering a call.

Original NASA ASRS Text

Title: LOSS OF SEPARATION BETWEEN 2 AR ACFT ON SIMULTANEOUS ILS APCHS TO PARALLEL RWYS AT ORD.

Narrative: WE WERE INTERCEPTING THE ILS TO 27R AT 4000' WITH MODERATE TURB AND HEAVY RAIN. WE WERE DIRECTED TO IMMEDIATELY DSND TO 3000' AND THEN WERE TOLD IT WAS OK, THAT THE OTHER ACFT WAS BACK IN HIS AIRSPACE (APCH TO 27L) SIMULTANEOUS APCHS. WE CAUGHT FLEETING GLIMPSES OF THE OTHER ACFT CORRECTING TO COURSE. DO NOT ALLOW SIMULTANEOUS APCHS DURING TURB AND HEAVY WX CONDITIONS. ON APCH OTHER ACFT Y RPTED A 300' LOSS DUE TO MODERATE TURB ON BASE LEG AND AT THAT TIME WE HAD TO DIVERT OUR COURSE IN ORDER TO AVOID A MAGENTA AREA ON OUR RADAR. THE CTLR CHASTISED ACR Y FOR NOT ANSWERING A CALL.

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.