Narrative:

Captain flying. Departed off of runway 4 at mdw with climb to 3000 ft and initial heading (?). Switched to departure and was given a turn to 090 degrees. Climbing through 1900 ft and passing 070 degree heading, TCASII alert with 'monitor vertical speed' callout. Power had been pulled back below cutback EPR since only 1000 ft to go in climb and climbing at approximately 1500 FPM. Plane climbed to 2100 ft. TCASII alert 'descend, descend' as copilot commented '300 ft above.' descended to 1900 ft and checked TCASII for other aircraft. I saw converging aircraft symbol pass over aircraft. Copilot commented that he 'did not pick up the other aircraft visually.' he saw converging aircraft appear on TCASII screen from 1-2 O'clock position. The altitude of other aircraft changed from 500 ft above to 400/300/200 ft and finally 100 ft above our aircraft. Ord departure was informed of the RA and near miss. They informed me that 'mdw tower was controling the other aircraft and that the aircraft had us visually.' I spoke with mdw tower supervisor on duty may/xa/98. He informed me that the converging traffic was a government helicopter on a surveillance flight. The government helicopter was supposed to remain clear of an ascending and converging aircraft. The minimum vertical distance of the near miss, 100 ft, demonstrates that this was not possible. If the priority of air traffic was the government surveillance, then I should have not been cleared for takeoff. If departure aircraft had the priority clearance then the helicopter should have been given an altitude above my clearance altitude, 3000 ft. Neither the ord departure nor mdw tower recognized the impending collision and neither took action. It is imperative that a review of air traffic priorities in regards to government surveillance be accomplished.

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Original NASA ASRS Text

Title: NMAC BTWN A DC9-39 CLBING IN CLASS E AIRSPACE JUST OUTSIDE OF CLASS C AND BELOW CLASS B AIRSPACE, AND A GOV HELI DSNDING. THE GOV HELI ADVISED THAT THE DC9 WAS SIGHTED AND ATC INSTRUCTED PLT TO REMAIN CLR OF THE ASCENDING AND CONVERGING TFC.

Narrative: CAPT FLYING. DEPARTED OFF OF RWY 4 AT MDW WITH CLB TO 3000 FT AND INITIAL HDG (?). SWITCHED TO DEP AND WAS GIVEN A TURN TO 090 DEGS. CLBING THROUGH 1900 FT AND PASSING 070 DEG HDG, TCASII ALERT WITH 'MONITOR VERT SPD' CALLOUT. PWR HAD BEEN PULLED BACK BELOW CUTBACK EPR SINCE ONLY 1000 FT TO GO IN CLB AND CLBING AT APPROX 1500 FPM. PLANE CLBED TO 2100 FT. TCASII ALERT 'DSND, DSND' AS COPLT COMMENTED '300 FT ABOVE.' DSNDED TO 1900 FT AND CHKED TCASII FOR OTHER ACFT. I SAW CONVERGING ACFT SYMBOL PASS OVER ACFT. COPLT COMMENTED THAT HE 'DID NOT PICK UP THE OTHER ACFT VISUALLY.' HE SAW CONVERGING ACFT APPEAR ON TCASII SCREEN FROM 1-2 O'CLOCK POS. THE ALT OF OTHER ACFT CHANGED FROM 500 FT ABOVE TO 400/300/200 FT AND FINALLY 100 FT ABOVE OUR ACFT. ORD DEP WAS INFORMED OF THE RA AND NEAR MISS. THEY INFORMED ME THAT 'MDW TWR WAS CTLING THE OTHER ACFT AND THAT THE ACFT HAD US VISUALLY.' I SPOKE WITH MDW TWR SUPVR ON DUTY MAY/XA/98. HE INFORMED ME THAT THE CONVERGING TFC WAS A GOV HELI ON A SURVEILLANCE FLT. THE GOV HELI WAS SUPPOSED TO REMAIN CLR OF AN ASCENDING AND CONVERGING ACFT. THE MINIMUM VERT DISTANCE OF THE NEAR MISS, 100 FT, DEMONSTRATES THAT THIS WAS NOT POSSIBLE. IF THE PRIORITY OF AIR TFC WAS THE GOV SURVEILLANCE, THEN I SHOULD HAVE NOT BEEN CLRED FOR TKOF. IF DEP ACFT HAD THE PRIORITY CLRNC THEN THE HELI SHOULD HAVE BEEN GIVEN AN ALT ABOVE MY CLRNC ALT, 3000 FT. NEITHER THE ORD DEP NOR MDW TWR RECOGNIZED THE IMPENDING COLLISION AND NEITHER TOOK ACTION. IT IS IMPERATIVE THAT A REVIEW OF AIR TFC PRIORITIES IN REGARDS TO GOV SURVEILLANCE BE ACCOMPLISHED.

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.