Flight crew of helicopter attempting IFR-ILS approach at lga runway 13 made 2 missed approachs accou...

Attributes
ACN	110674
Time
Date	198905
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lga
State Reference	NY
Altitude	msl bound lower : 1100 msl bound upper : 2000
Environment
Flight Conditions	IMC
Aircraft 1
Controlling Facilities	tracon : n90
Operator	general aviation : corporate
Make Model Name	Helicopter
Navigation In Use	Other
Flight Phase	descent : approach descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 140 flight time total : 11000 flight time type : 110
ASRS Report	110674
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial
Events
Anomaly	other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance none taken : anomaly accepted other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

After being held and delayed en route to the nyc heliports due to a radar outage, we were offered the ILS to 13, the departure runway. This is done fairly frequently to ease congestion, as the pattern and missed approach do not conflict with runway 4. We were vectored to the final approach course 1 1/2 mi outside the marker, and cleared for the approach, to maintain 2000' till established. I elected to shoot a coupled approach, due to the high winds and turbulence. We intercepted the localizer and G/south, and were proceeding down, when just inside the marker (approximately 1 mi) we went into a steep turn to the right and a 2000 FPM dive. I disengaged the autoplt and initiated a left turn and climb back to course. As I stabilized the aircraft, I noticed a left turn and climb back to course. As I stabilized the aircraft, I noticed that the track bar on the localizer was oscillating 1 1/2 dots either side of center. I thought this might be the reason for the erratic autoplt. The controller then called and said he showed us well south of course, and at 1100'. We said we showed close to course,but then the track bar went to full deflection. At that time I initiated a missed, as I no longer was sure of my position. We were vectored for another ILS 13, which I hand flew, with the same problem. This time we were on G/south, inside the marker, when we again lost the localizer.I leveled off until the needle settled down, and had to shoot another missed because we were too high to get back on G/south and course. At that time we requested the ILS to 4, because of the erratic localizer. The controller handed us off to another controller, and we made the same request. He insisted on the ILS 13, and assumed us that it was showing normal. We reluctantly agreed, and the third approach was completed uneventfully. I think the problem may have been caused by a failure to clear the ILS critical zone, and my failure to request that it be checked after the first occurrence. We are checking on the actions of the autoplt and suspect a problem with the air data sensor. The combination could have been disastrous.

Original NASA ASRS Text

Title: FLT CREW OF HELICOPTER ATTEMPTING IFR-ILS APCH AT LGA RWY 13 MADE 2 MISSED APCHS ACCOUNT NAVIGATION AIDS ERRONEOUS. THIRD APCH SUCCESSFUL WITH NO INSTRUMENT MALFUNCTION.

Narrative: AFTER BEING HELD AND DELAYED ENRTE TO THE NYC HELIPORTS DUE TO A RADAR OUTAGE, WE WERE OFFERED THE ILS TO 13, THE DEP RWY. THIS IS DONE FAIRLY FREQUENTLY TO EASE CONGESTION, AS THE PATTERN AND MISSED APCH DO NOT CONFLICT WITH RWY 4. WE WERE VECTORED TO THE FINAL APCH COURSE 1 1/2 MI OUTSIDE THE MARKER, AND CLRED FOR THE APCH, TO MAINTAIN 2000' TILL ESTABLISHED. I ELECTED TO SHOOT A COUPLED APCH, DUE TO THE HIGH WINDS AND TURB. WE INTERCEPTED THE LOC AND G/S, AND WERE PROCEEDING DOWN, WHEN JUST INSIDE THE MARKER (APPROX 1 MI) WE WENT INTO A STEEP TURN TO THE RIGHT AND A 2000 FPM DIVE. I DISENGAGED THE AUTOPLT AND INITIATED A LEFT TURN AND CLB BACK TO COURSE. AS I STABILIZED THE ACFT, I NOTICED A LEFT TURN AND CLB BACK TO COURSE. AS I STABILIZED THE ACFT, I NOTICED THAT THE TRACK BAR ON THE LOC WAS OSCILLATING 1 1/2 DOTS EITHER SIDE OF CENTER. I THOUGHT THIS MIGHT BE THE REASON FOR THE ERRATIC AUTOPLT. THE CTLR THEN CALLED AND SAID HE SHOWED US WELL S OF COURSE, AND AT 1100'. WE SAID WE SHOWED CLOSE TO COURSE,BUT THEN THE TRACK BAR WENT TO FULL DEFLECTION. AT THAT TIME I INITIATED A MISSED, AS I NO LONGER WAS SURE OF MY POS. WE WERE VECTORED FOR ANOTHER ILS 13, WHICH I HAND FLEW, WITH THE SAME PROB. THIS TIME WE WERE ON G/S, INSIDE THE MARKER, WHEN WE AGAIN LOST THE LOC.I LEVELED OFF UNTIL THE NEEDLE SETTLED DOWN, AND HAD TO SHOOT ANOTHER MISSED BECAUSE WE WERE TOO HIGH TO GET BACK ON G/S AND COURSE. AT THAT TIME WE REQUESTED THE ILS TO 4, BECAUSE OF THE ERRATIC LOC. THE CTLR HANDED US OFF TO ANOTHER CTLR, AND WE MADE THE SAME REQUEST. HE INSISTED ON THE ILS 13, AND ASSUMED US THAT IT WAS SHOWING NORMAL. WE RELUCTANTLY AGREED, AND THE THIRD APCH WAS COMPLETED UNEVENTFULLY. I THINK THE PROB MAY HAVE BEEN CAUSED BY A FAILURE TO CLEAR THE ILS CRITICAL ZONE, AND MY FAILURE TO REQUEST THAT IT BE CHKED AFTER THE FIRST OCCURRENCE. WE ARE CHKING ON THE ACTIONS OF THE AUTOPLT AND SUSPECT A PROB WITH THE AIR DATA SENSOR. THE COMBINATION COULD HAVE BEEN DISASTROUS.

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.

Flight crew of helicopter attempting IFR-ILS approach at lga runway 13 made 2 missed approachs account navigation aids erroneous. Third approach successful with no instrument malfunction.