Close proximity air carrier-medium large transport flight of 2 military-helicopters.

Attributes
ACN	91386
Time
Date	198807
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : bwi
State Reference	MD
Altitude	msl bound lower : 3000 msl bound upper : 3500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : bwi
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Helicopter
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 125 flight time total : 8000
ASRS Report	91386
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	vertical : 500
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

After receiving a heading of 250 degrees and assigned altitude of 3000' had tuned ILS frequency for runway 10 at bwi. Was checking identification for same. Returned scan to outside cockpit and noticed rotating beacons and navigation lights of 2 slow moving aircraft in very close proximity to our aircraft. Initiated immediate pullup climbing maneuver for evasive action and to avoid what I consider would have been a midair collision. Did not notice any evasive action by other aircraft involved in this incident. The 2 helicopters were on an approximately 180 degree heading and one low at 2500-2700'. The other, higher at 2700-3000', as it appeared to our cockpit reference point, in line with center of forward/right windshield and level with horizon. Evasive action required 500' climb, airspeed 210 KTS assigned. To prevent recurrence, I think a more restricting TCA should be implemented in the bwi, dca, dulles airport areas, requiring exiting aircraft from all groups of aviation to be under positive control.

Original NASA ASRS Text

Title: CLOSE PROX ACR-MLG FLT OF 2 MIL-HELICOPTERS.

Narrative: AFTER RECEIVING A HDG OF 250 DEGS AND ASSIGNED ALT OF 3000' HAD TUNED ILS FREQ FOR RWY 10 AT BWI. WAS CHKING ID FOR SAME. RETURNED SCAN TO OUTSIDE COCKPIT AND NOTICED ROTATING BEACONS AND NAV LIGHTS OF 2 SLOW MOVING ACFT IN VERY CLOSE PROX TO OUR ACFT. INITIATED IMMEDIATE PULLUP CLBING MANEUVER FOR EVASIVE ACTION AND TO AVOID WHAT I CONSIDER WOULD HAVE BEEN A MIDAIR COLLISION. DID NOT NOTICE ANY EVASIVE ACTION BY OTHER ACFT INVOLVED IN THIS INCIDENT. THE 2 HELIS WERE ON AN APPROX 180 DEG HDG AND ONE LOW AT 2500-2700'. THE OTHER, HIGHER AT 2700-3000', AS IT APPEARED TO OUR COCKPIT REFERENCE POINT, IN LINE WITH CENTER OF FORWARD/RIGHT WINDSHIELD AND LEVEL WITH HORIZON. EVASIVE ACTION REQUIRED 500' CLB, AIRSPD 210 KTS ASSIGNED. TO PREVENT RECURRENCE, I THINK A MORE RESTRICTING TCA SHOULD BE IMPLEMENTED IN THE BWI, DCA, DULLES ARPT AREAS, REQUIRING EXITING ACFT FROM ALL GROUPS OF AVIATION TO BE UNDER POSITIVE CTL.

Data retrieved from NASA's ASRS site as of August 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.