A fatigued B747 crew began an early descent to their destination in VFR conditions after believing t...

Attributes
ACN	827290
Time
Date	200903
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZZ.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Visual Approach Other Instrument Precision
Flight Plan	IFR
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 8000 Flight Crew Type 2000
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 16000 Flight Crew Type 3200
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Other Fatigue

Narrative:

I was the pilot flying on a vector for approach to runway 21 in ZZZZ. It was around XA00L and we were at 5;000 ft on a vector to intercept the localizer for ILS 21. The intercept vector was at such a high angle to the localizer that even with a 30 degree bank turn we flew through the course. This high rate of needle swing lead me to believe we were inside the IAF which lead me to believe we were well above the glide path. I responded to my belief that I was high on the glide path by configuring the aircraft early to slow down and get back on glide path. I had the airfield in sight and my visual references made me believe I was high on glide path; so I started my descent early. We proceeded below glide path and when I referenced my position with my instruments; we were still 12-13 miles out and approximately 1;000 ft low which we immediately corrected once we established our position on the approach. We maintained VFR flight conditions but we were still on an IFR clearance even though we had the airfield in view. The landing was completed without incident and no other traffic was affected nor were there any GPWS alerts. In conclusion; I believe that fatigue was a factor in the long duty day cycle. It was the first day back at work and I had to shift my sleeping schedule. The second item was the good VFR conditions at the destination lead to a less than standard IFR briefing. I think a few things that could have prevented this from happening would be more time preparing for a sleep cycle change as well as a shorter duty day or maybe a rest period during the transatlantic flight. The next item that could have prevented the situation would have been more due diligence in the approach briefing even in good VFR condition to help develop better situational awareness. In conclusion; no other aircraft were involved; and the flight ended without incident.

Original NASA ASRS Text

Title: A fatigued B747 crew began an early descent to their destination in VFR conditions after believing the aircraft was high on glide path.

Narrative: I was the pilot flying on a vector for approach to Runway 21 in ZZZZ. It was around XA00L and we were at 5;000 FT on a vector to intercept the LOC for ILS 21. The intercept vector was at such a high angle to the LOC that even with a 30 degree bank turn we flew through the course. This high rate of needle swing lead me to believe we were inside the IAF which lead me to believe we were well above the glide path. I responded to my belief that I was high on the glide path by configuring the aircraft early to slow down and get back on glide path. I had the airfield in sight and my visual references made me believe I was high on glide path; so I started my descent early. We proceeded below glide path and when I referenced my position with my instruments; we were still 12-13 miles out and approximately 1;000 FT low which we immediately corrected once we established our position on the approach. We maintained VFR flight conditions but we were still on an IFR clearance even though we had the airfield in view. The landing was completed without incident and no other traffic was affected nor were there any GPWS alerts. In conclusion; I believe that fatigue was a factor in the long duty day cycle. It was the first day back at work and I had to shift my sleeping schedule. The second item was the good VFR conditions at the destination lead to a less than standard IFR briefing. I think a few things that could have prevented this from happening would be more time preparing for a sleep cycle change as well as a shorter duty day or maybe a rest period during the Transatlantic flight. The next item that could have prevented the situation would have been more due diligence in the approach briefing even in good VFR condition to help develop better situational awareness. In conclusion; no other aircraft were involved; and the flight ended without incident.

Data retrieved from NASA's ASRS site as of April 2012 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.