Altitude deviation during approach.

Attributes
ACN	123420
Time
Date	198909
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mmu
State Reference	NJ
Altitude	msl bound lower : 1500 msl bound upper : 2000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other cruise other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 150 flight time total : 8500 flight time type : 1500
ASRS Report	123420
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 1900 flight time type : 200
ASRS Report	123423
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On sep/mon/89, at approximately mid pm local, at 2000'. We were being vectored for an NDB T approach to mmu, nj. Approach questioned our altitude. Copilot reported 2000' which was where we were. Apparently the #1 transponder, which had given us problems before, was not indicating 2000'. The copilot switched to #2 transponder and ny approach said that it was then reading 2000'. Supplemental information from acn 123423: we were cleared out of 3000' down to 2000'. PNF (me) reset altitude selector but failed to arm the altitude select feature on the flight director. The aircraft was on autoplt. The captain and I had our eyes outside the cockpit looking for traffic, sightseeing, etc. At around 1500' the approach controller reminded us of our altitude assignment. We adjusted our altitude and that's it.

Original NASA ASRS Text

Title: ALT DEVIATION DURING APCH.

Narrative: ON SEP/MON/89, AT APPROX MID PM LOCAL, AT 2000'. WE WERE BEING VECTORED FOR AN NDB T APCH TO MMU, NJ. APCH QUESTIONED OUR ALT. COPLT REPORTED 2000' WHICH WAS WHERE WE WERE. APPARENTLY THE #1 XPONDER, WHICH HAD GIVEN US PROBLEMS BEFORE, WAS NOT INDICATING 2000'. THE COPLT SWITCHED TO #2 XPONDER AND NY APCH SAID THAT IT WAS THEN READING 2000'. SUPPLEMENTAL INFORMATION FROM ACN 123423: WE WERE CLRED OUT OF 3000' DOWN TO 2000'. PNF (ME) RESET ALT SELECTOR BUT FAILED TO ARM THE ALT SELECT FEATURE ON THE FLT DIRECTOR. THE ACFT WAS ON AUTOPLT. THE CAPT AND I HAD OUR EYES OUTSIDE THE COCKPIT LOOKING FOR TFC, SIGHTSEEING, ETC. AT AROUND 1500' THE APCH CTLR REMINDED US OF OUR ALT ASSIGNMENT. WE ADJUSTED OUR ALT AND THAT'S IT.

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.