Aircraft on ILS approach descends below GS. Cleared approach lights by only 50 ft.

Attributes
ACN	224359
Time
Date	199210
Day	Fri
Place
Locale Reference	airport : jfk
State Reference	NY
Altitude	agl bound lower : 50 agl bound upper : 2000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	tracon : n90
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : private pilot : instrument pilot : cfi pilot : atp
Experience	flight time last 90 days : 100 flight time total : 6000 flight time type : 1000
ASRS Report	224359
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	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:

I was PNF with a new captain. On approach he joined the runway 4R localizer but stayed 1 DOT below GS. I asked him about this and he said he wanted to stay low. We crossed the OM 200 ft below intercept altitude. I advised him of this, he didn't respond. At 700 ft AGL he went 1 1/4 to 1 1/2 dots low. I was getting really nervous. I told him again and told him to watch the approach lights. We crossed over the approach lights and I yelled at him to watch the lights. If we had been any lower, I would have taken the airplane from him. We just cleared the approach lights by about 50 ft maximum. The landing was uneventful. I don't know if he was too tired, too far behind the airplane or if he had negative transfer of training. I do know that medium large transport to widebody transport upgrading pilots have a tendency to duck under. This could get really hectic in the longer-legged widebody transport.

Original NASA ASRS Text

Title: ACFT ON ILS APCH DSNDS BELOW GS. CLRED APCH LIGHTS BY ONLY 50 FT.

Narrative: I WAS PNF WITH A NEW CAPT. ON APCH HE JOINED THE RWY 4R LOC BUT STAYED 1 DOT BELOW GS. I ASKED HIM ABOUT THIS AND HE SAID HE WANTED TO STAY LOW. WE CROSSED THE OM 200 FT BELOW INTERCEPT ALT. I ADVISED HIM OF THIS, HE DIDN'T RESPOND. AT 700 FT AGL HE WENT 1 1/4 TO 1 1/2 DOTS LOW. I WAS GETTING REALLY NERVOUS. I TOLD HIM AGAIN AND TOLD HIM TO WATCH THE APCH LIGHTS. WE CROSSED OVER THE APCH LIGHTS AND I YELLED AT HIM TO WATCH THE LIGHTS. IF WE HAD BEEN ANY LOWER, I WOULD HAVE TAKEN THE AIRPLANE FROM HIM. WE JUST CLRED THE APCH LIGHTS BY ABOUT 50 FT MAX. THE LNDG WAS UNEVENTFUL. I DON'T KNOW IF HE WAS TOO TIRED, TOO FAR BEHIND THE AIRPLANE OR IF HE HAD NEGATIVE TRANSFER OF TRAINING. I DO KNOW THAT MLG TO WDB UPGRADING PLTS HAVE A TENDENCY TO DUCK UNDER. THIS COULD GET REALLY HECTIC IN THE LONGER-LEGGED WDB.

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.