Near midair collision.

Attributes
ACN	281148
Time
Date	199408
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : sac
State Reference	CA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute airway : sac
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	Other
Function	observation : observer
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 20 flight time total : 210 flight time type : 20
ASRS Report	281148
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Events
Anomaly	conflict : nmac non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : anomaly accepted other
Consequence	Other
Miss Distance	horizontal : 0 vertical : 150
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were IFR cnc to S9C. I was safety pilot. The control called 'traffic 1 mi 12 O'clock, northbound, 5400 ft descending, descend to 4000 ft.' I began to look for the traffic, I noticed the pilot was not descending. I asked why not. He said he thought the phrase 'descend to 4000 ft' was describing the other aircraft's (C-172) intentions. He tried to get back to approach but the frequency was occupied. During my debate with the pilot my scanning got sloppy. Out from behind the windshield mounted compass came the other aircraft. There was no time to change course. Had I been moving my head while scanning I would have seen the conflict sooner.

Original NASA ASRS Text

Title: NMAC.

Narrative: WE WERE IFR CNC TO S9C. I WAS SAFETY PLT. THE CTL CALLED 'TFC 1 MI 12 O'CLOCK, NBOUND, 5400 FT DSNDING, DSND TO 4000 FT.' I BEGAN TO LOOK FOR THE TFC, I NOTICED THE PLT WAS NOT DSNDING. I ASKED WHY NOT. HE SAID HE THOUGHT THE PHRASE 'DSND TO 4000 FT' WAS DESCRIBING THE OTHER ACFT'S (C-172) INTENTIONS. HE TRIED TO GET BACK TO APCH BUT THE FREQ WAS OCCUPIED. DURING MY DEBATE WITH THE PLT MY SCANNING GOT SLOPPY. OUT FROM BEHIND THE WINDSHIELD MOUNTED COMPASS CAME THE OTHER ACFT. THERE WAS NO TIME TO CHANGE COURSE. HAD I BEEN MOVING MY HEAD WHILE SCANNING I WOULD HAVE SEEN THE CONFLICT SOONER.

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.