Pilot suggests use of transponder in class east airspace near pdx.

Attributes
ACN	443683
Time
Date	199907
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : pdx.airport
State Reference	OR
Altitude	msl bound lower : 1200 msl bound upper : 1500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	general aviation : personal
Make Model Name	Robinson R22
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	arrival : vfr
Flight Plan	None VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 25 flight time total : 550 flight time type : 550
ASRS Report	443683
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Supplementary
Problem Areas	Airport
Primary Problem	Airport

Narrative:

When pdx is landing to the west, heavy jets on base are just a few hundred ft over traffic at or below the 1700 ft altitude under the class C airspace. Terrain in this area goes to 1000 ft. The proximity of controled and uncontrolled traffic -- especially at night -- is disconcerting. The pdx tower has not said anything back other than to 'avoid class C airspace' so establishing contact does not seem to help. Perhaps the use of mode C transponder should be required in this area at all altitudes so that the tower could at least advise the pdx traffic of the exact altitudes of the private traffic below them.

Original NASA ASRS Text

Title: PLT SUGGESTS USE OF XPONDER IN CLASS E AIRSPACE NEAR PDX.

Narrative: WHEN PDX IS LNDG TO THE W, HVY JETS ON BASE ARE JUST A FEW HUNDRED FT OVER TFC AT OR BELOW THE 1700 FT ALT UNDER THE CLASS C AIRSPACE. TERRAIN IN THIS AREA GOES TO 1000 FT. THE PROX OF CTLED AND UNCTLED TFC -- ESPECIALLY AT NIGHT -- IS DISCONCERTING. THE PDX TWR HAS NOT SAID ANYTHING BACK OTHER THAN TO 'AVOID CLASS C AIRSPACE' SO ESTABLISHING CONTACT DOES NOT SEEM TO HELP. PERHAPS THE USE OF MODE C XPONDER SHOULD BE REQUIRED IN THIS AREA AT ALL ALTS SO THAT THE TWR COULD AT LEAST ADVISE THE PDX TFC OF THE EXACT ALTS OF THE PVT TFC BELOW THEM.

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.