Air carrier medium large transport premature descent on approach when crossing fix misidentified.

Attributes
ACN	104037
Time
Date	198901
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : pit
State Reference	PA
Altitude	msl bound lower : 4400 msl bound upper : 5000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : pit
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
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 2600 flight time type : 450
ASRS Report	104037
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Chart Or Publication
Air Traffic Incident	Pilot Deviation
Situations
Airport	procedure or policy : unspecified
Publication	Unspecified

Narrative:

Pit was conducting simultaneous ILS approachs to runways 28L and 28R. Our aircraft was on the ILS 28R approach. The captain was at the controls and the first officer was reading the specifics of the approach to the captain. As first officer, I apparently misread the caution on the approach plate and told the captain he was at kerrs intersection when I saw 13 DME from mmj VOR. At this time the captain vacated 5000' and started down to 4000' which is a mandatory crossing altitude for cofee intersection. We were at 4400' MSL when pit approach control called us on the radio and said we should still be at 5000'. We climbed back up to 5000' and continued the approach. The captain on the approach plate states that kerrs intersection is 11.2 DME from mmj VOR and 13 DME from the runway. By telling the captain we were at kerrs intersection when we were really only at 13 DME from mmj VOR resulted in us starting out of 5000' 1.8 DME too soon.

Original NASA ASRS Text

Title: ACR MLG PREMATURE DESCENT ON APCH WHEN CROSSING FIX MISIDENTIFIED.

Narrative: PIT WAS CONDUCTING SIMULTANEOUS ILS APCHS TO RWYS 28L AND 28R. OUR ACFT WAS ON THE ILS 28R APCH. THE CAPT WAS AT THE CONTROLS AND THE F/O WAS READING THE SPECIFICS OF THE APCH TO THE CAPT. AS F/O, I APPARENTLY MISREAD THE CAUTION ON THE APCH PLATE AND TOLD THE CAPT HE WAS AT KERRS INTXN WHEN I SAW 13 DME FROM MMJ VOR. AT THIS TIME THE CAPT VACATED 5000' AND STARTED DOWN TO 4000' WHICH IS A MANDATORY XING ALT FOR COFEE INTXN. WE WERE AT 4400' MSL WHEN PIT APCH CTL CALLED US ON THE RADIO AND SAID WE SHOULD STILL BE AT 5000'. WE CLBED BACK UP TO 5000' AND CONTINUED THE APCH. THE CAPT ON THE APCH PLATE STATES THAT KERRS INTXN IS 11.2 DME FROM MMJ VOR AND 13 DME FROM THE RWY. BY TELLING THE CAPT WE WERE AT KERRS INTXN WHEN WE WERE REALLY ONLY AT 13 DME FROM MMJ VOR RESULTED IN US STARTING OUT OF 5000' 1.8 DME TOO SOON.

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.