Near midair collision in proximity of approach route.

Attributes
ACN	281531
Time
Date	199408
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : hnk
State Reference	NY
Altitude	msl bound lower : 16500 msl bound upper : 17500
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tower : boi
Operator	common carrier : air carrier
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute airway : zny
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 15000 flight time type : 2000
ASRS Report	281531
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : excursion from assigned altitude conflict : nmac non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

In the area of helon intersection we received clearance to descend from 18000-13000 ft. On passing through about 17000 ft captain and first officer noticed traffic on TCASII/radar screen at 12 O'clock about 600 ft below. Captain suggested and first officer shallowed descent. Just when traffic appeared to be past or passing under our aircraft (on TCASII screen) RA commanded a climb. First officer executed a climb of approximately 2000-2500 FPM (whatever ivsi called for) controller warned of traffic at 16500 ft and I believe commanded climb as we leveled at 17500 ft (after RA stopped). Problem probably brought on by peak traffic and possible low experience on part of controller. There also seems to be a lack of consistent corridors and descent altitudes, ie, we were given syr at 27000 ft (cruise altitude 41000 ft) then given sax 25 DME at 8000 ft from a distance and altitude that we could not meet the restr from. Too low at syr is bad for our fuel burn. Too late for the crossing restr is bad planning and messes up both pilots and controllers. In this case the crossing restr was made impossible by the RA but it is usually tight due to late descent clearance.

Original NASA ASRS Text

Title: NMAC IN PROX OF APCH RTE.

Narrative: IN THE AREA OF HELON INTXN WE RECEIVED CLRNC TO DSND FROM 18000-13000 FT. ON PASSING THROUGH ABOUT 17000 FT CAPT AND FO NOTICED TFC ON TCASII/RADAR SCREEN AT 12 O'CLOCK ABOUT 600 FT BELOW. CAPT SUGGESTED AND FO SHALLOWED DSCNT. JUST WHEN TFC APPEARED TO BE PAST OR PASSING UNDER OUR ACFT (ON TCASII SCREEN) RA COMMANDED A CLB. FO EXECUTED A CLB OF APPROX 2000-2500 FPM (WHATEVER IVSI CALLED FOR) CTLR WARNED OF TFC AT 16500 FT AND I BELIEVE COMMANDED CLB AS WE LEVELED AT 17500 FT (AFTER RA STOPPED). PROB PROBABLY BROUGHT ON BY PEAK TFC AND POSSIBLE LOW EXPERIENCE ON PART OF CTLR. THERE ALSO SEEMS TO BE A LACK OF CONSISTENT CORRIDORS AND DSCNT ALTS, IE, WE WERE GIVEN SYR AT 27000 FT (CRUISE ALT 41000 FT) THEN GIVEN SAX 25 DME AT 8000 FT FROM A DISTANCE AND ALT THAT WE COULD NOT MEET THE RESTR FROM. TOO LOW AT SYR IS BAD FOR OUR FUEL BURN. TOO LATE FOR THE XING RESTR IS BAD PLANNING AND MESSES UP BOTH PLTS AND CTLRS. IN THIS CASE THE XING RESTR WAS MADE IMPOSSIBLE BY THE RA BUT IT IS USUALLY TIGHT DUE TO LATE DSCNT CLRNC.

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.