Air carrier medium large transport on a VOR arc descended below FAF altitude before reaching the FAF...

Attributes
ACN	116470
Time
Date	198907
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gdm airport : orh
State Reference	MA
Altitude	msl bound lower : 3000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bdl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 161 flight time total : 9000 flight time type : 3600
ASRS Report	116470
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 13000 flight time type : 10000
ASRS Report	116256
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac non adherence : clearance non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared to go outbnd on the center 104 degree right to intercept the gdm 28 DME arc for the VOR DME runway 33 approach into orh (worcester, ma). I reported arc interception and we were cleared for the approach. The captain had briefed that upon interception we were cleared to 2500'. Distracted by WX concerns (we had already deviated quite a bit and the radar was really lit up), I rechecked the approach plate, saw '2500', and responded, '2500 looks good'. After rolling out on the arc, the captain started his descent and I reported, 'out of 4000, on the approach'. The IAF was at the intersection of the gdm 179 degree right and the 28 DME arc which I failed to recognize until the sharp controller told us to stop our descent at 3000'. After hearing something unexpected I looked more closely and figured out my mistake. After reaching the IAF we made the approach but missed due to poor flight visibility. The mistake: incorrect reading of the approach plate and subsequent descent before the IAF. Contributing factors: 1) bad WX, i.e., thunderstorms, 2) crew fatigue, i.e., next to last leg on the 4TH day of a 4 day trip, 3) inadequate approach briefing. Corrective actions: slow down the operation to insure proper preparation for a demanding approach, especially when fatigue is a factor.

Original NASA ASRS Text

Title: ACR MLG ON A VOR ARC DESCENDED BELOW FAF ALT BEFORE REACHING THE FAF.

Narrative: WE WERE CLRED TO GO OUTBND ON THE CTR 104 DEG R TO INTERCEPT THE GDM 28 DME ARC FOR THE VOR DME RWY 33 APCH INTO ORH (WORCESTER, MA). I REPORTED ARC INTERCEPTION AND WE WERE CLRED FOR THE APCH. THE CAPT HAD BRIEFED THAT UPON INTERCEPTION WE WERE CLRED TO 2500'. DISTRACTED BY WX CONCERNS (WE HAD ALREADY DEVIATED QUITE A BIT AND THE RADAR WAS REALLY LIT UP), I RECHECKED THE APCH PLATE, SAW '2500', AND RESPONDED, '2500 LOOKS GOOD'. AFTER ROLLING OUT ON THE ARC, THE CAPT STARTED HIS DSCNT AND I REPORTED, 'OUT OF 4000, ON THE APCH'. THE IAF WAS AT THE INTXN OF THE GDM 179 DEG R AND THE 28 DME ARC WHICH I FAILED TO RECOGNIZE UNTIL THE SHARP CTLR TOLD US TO STOP OUR DSCNT AT 3000'. AFTER HEARING SOMETHING UNEXPECTED I LOOKED MORE CLOSELY AND FIGURED OUT MY MISTAKE. AFTER REACHING THE IAF WE MADE THE APCH BUT MISSED DUE TO POOR FLT VISIBILITY. THE MISTAKE: INCORRECT READING OF THE APCH PLATE AND SUBSEQUENT DSCNT BEFORE THE IAF. CONTRIBUTING FACTORS: 1) BAD WX, I.E., TSTMS, 2) CREW FATIGUE, I.E., NEXT TO LAST LEG ON THE 4TH DAY OF A 4 DAY TRIP, 3) INADEQUATE APCH BRIEFING. CORRECTIVE ACTIONS: SLOW DOWN THE OPERATION TO INSURE PROPER PREPARATION FOR A DEMANDING APCH, ESPECIALLY WHEN FATIGUE IS A FACTOR.

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.