Altitude deviation altitude excursion as air carrier PIC descends medium large transport below LOM c...

Attributes
ACN	246130
Time
Date	199307
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : avp
State Reference	PA
Altitude	msl bound lower : 2300 msl bound upper : 3900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : avp
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : straight in approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 180 flight time total : 8700 flight time type : 4000
ASRS Report	246130
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 17000 flight time type : 5000
ASRS Report	246131
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	atc equipment other atc equipment : unspecified other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

With good VFR conditions we reported the airport in sight and were cleared for a visual approach to runway 4. At this time we were about 20 NM out and slightly high on the GS. The last altitude assigned was 4000 ft. The captain set 2300 ft in the altitude, continued his descent below the GS to 2300 ft, and leveled off to slow to approach speed. I should have questioned his choice of altitude because he was still outside of cye NDB. There are antennas and ridges between 2000 ft and 2949 ft and the approach calls for 3900 ft until cye. We had the antennas visually but looking back we should have operated more conservatively. I should have pointed out to the captain that there are obstructions to consider. And I should have done this during the approach briefing portion of the preliminary landing checklist. Also, the fact that this approach has 2 NDB's should have been borne out in the briefing to eliminate confusion. I should have also immediately asserted myself (good cockpit resource management) that the GS should be used even though we were VFR. Supplemental information from acn 246131: since we were below normal IFR vectoring altitude, approach control called us with a warning about the towers ahead. We maintained legal VFR separation altitude at all times, but we would have caused less stress on the controller if we would have maintained 4000 ft MSL until on final and completely clear of all obstructions.

Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION AS ACR PIC DSNDS MLG BELOW LOM XING ALT PRIOR TO LOM ON A VISUAL APCH. CFIT. MSAW ALERT.

Narrative: WITH GOOD VFR CONDITIONS WE RPTED THE ARPT IN SIGHT AND WERE CLRED FOR A VISUAL APCH TO RWY 4. AT THIS TIME WE WERE ABOUT 20 NM OUT AND SLIGHTLY HIGH ON THE GS. THE LAST ALT ASSIGNED WAS 4000 FT. THE CAPT SET 2300 FT IN THE ALT, CONTINUED HIS DSCNT BELOW THE GS TO 2300 FT, AND LEVELED OFF TO SLOW TO APCH SPD. I SHOULD HAVE QUESTIONED HIS CHOICE OF ALT BECAUSE HE WAS STILL OUTSIDE OF CYE NDB. THERE ARE ANTENNAS AND RIDGES BTWN 2000 FT AND 2949 FT AND THE APCH CALLS FOR 3900 FT UNTIL CYE. WE HAD THE ANTENNAS VISUALLY BUT LOOKING BACK WE SHOULD HAVE OPERATED MORE CONSERVATIVELY. I SHOULD HAVE POINTED OUT TO THE CAPT THAT THERE ARE OBSTRUCTIONS TO CONSIDER. AND I SHOULD HAVE DONE THIS DURING THE APCH BRIEFING PORTION OF THE PRELIMINARY LNDG CHKLIST. ALSO, THE FACT THAT THIS APCH HAS 2 NDB'S SHOULD HAVE BEEN BORNE OUT IN THE BRIEFING TO ELIMINATE CONFUSION. I SHOULD HAVE ALSO IMMEDIATELY ASSERTED MYSELF (GOOD COCKPIT RESOURCE MGMNT) THAT THE GS SHOULD BE USED EVEN THOUGH WE WERE VFR. SUPPLEMENTAL INFO FROM ACN 246131: SINCE WE WERE BELOW NORMAL IFR VECTORING ALT, APCH CTL CALLED US WITH A WARNING ABOUT THE TWRS AHEAD. WE MAINTAINED LEGAL VFR SEPARATION ALT AT ALL TIMES, BUT WE WOULD HAVE CAUSED LESS STRESS ON THE CTLR IF WE WOULD HAVE MAINTAINED 4000 FT MSL UNTIL ON FINAL AND COMPLETELY CLR OF ALL OBSTRUCTIONS.

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.

Altitude deviation altitude excursion as air carrier PIC descends medium large transport below LOM crossing altitude prior to LOM on a visual approach. CFIT. MSAW alert.