 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Sjc local controller observes PA28 off course and issues corrective instructions. Controller concerned that MSAW did not incident alert in a timely fashion.
| Attributes | |
| ACN | 452496 |
| Time | |
| Date | 199910 |
| Day | Mon |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | navaid : sjc.vor |
| Altitude | msl bound lower : 800 msl bound upper : 1700 |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : sjc.tower |
| Operator | general aviation : personal |
| Make Model Name | PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior |
| Operating Under FAR Part | Part 91 |
| Navigation In Use | other vortac |
| Route In Use | approach : instrument non precision |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : local |
| Qualification | controller : radar |
| Experience | controller limited radar : 2.5 controller radar : 10 controller time certified in position1 : 2.1 |
| ASRS Report | 452496 |
| Person 2 | |
| Affiliation | other |
| Function | flight crew : single pilot |
| Qualification | pilot : instrument |
| Events | |
| Anomaly | altitude deviation : overshoot inflight encounter : weather non adherence : clearance non adherence : published procedure other spatial deviation |
| Independent Detector | atc equipment : msaw atc equipment other atc equipment : radar other controllera |
| Resolutory Action | controller : issued alert controller : issued new clearance flight crew : returned to intended or assigned course |
| Supplementary | |
| Problem Areas | Navigational Facility ATC Human Performance Flight Crew Human Performance ATC Facility |
| Primary Problem | Flight Crew Human Performance |
Narrative:
The GS at sjc has been OTS at san jose for several weeks. So, we have been using the localizer DME runway 30L approach. The cherokee (X) was on a normal approach until 1 mi inside of ironn intersection, whereat the step-down altitude is 1700 ft MSL. At 4 mi final, the PA28 started to diverge left of final and continue descent. By the time I noticed, the PA28 was 1 mi left of course of 1000 ft MSL and diverging. I issued the low altitude alert, including the minimum vectoring altitude which is 2000 ft MSL. The MSAW did not sound the alarm until the PA28 was 1 1/2 mi off course at 800 ft, at which point he started climbing. Additionally, since we started using the localizer/DME approach, I've observed numerous instances where the MSAW alarmed even though the aircraft were above the published descent altitudes of 1700 ft MSL until ironn and 700 ft MSL until the MDA. It seems like a review of the program parameters may be in order.
Original NASA ASRS Text
Title: SJC LCL CTLR OBSERVES PA28 OFF COURSE AND ISSUES CORRECTIVE INSTRUCTIONS. CTLR CONCERNED THAT MSAW DID NOT INCIDENT ALERT IN A TIMELY FASHION.
Narrative: THE GS AT SJC HAS BEEN OTS AT SAN JOSE FOR SEVERAL WKS. SO, WE HAVE BEEN USING THE LOC DME RWY 30L APCH. THE CHEROKEE (X) WAS ON A NORMAL APCH UNTIL 1 MI INSIDE OF IRONN INTXN, WHEREAT THE STEP-DOWN ALT IS 1700 FT MSL. AT 4 MI FINAL, THE PA28 STARTED TO DIVERGE L OF FINAL AND CONTINUE DSCNT. BY THE TIME I NOTICED, THE PA28 WAS 1 MI L OF COURSE OF 1000 FT MSL AND DIVERGING. I ISSUED THE LOW ALT ALERT, INCLUDING THE MINIMUM VECTORING ALT WHICH IS 2000 FT MSL. THE MSAW DID NOT SOUND THE ALARM UNTIL THE PA28 WAS 1 1/2 MI OFF COURSE AT 800 FT, AT WHICH POINT HE STARTED CLBING. ADDITIONALLY, SINCE WE STARTED USING THE LOC/DME APCH, I'VE OBSERVED NUMEROUS INSTANCES WHERE THE MSAW ALARMED EVEN THOUGH THE ACFT WERE ABOVE THE PUBLISHED DSCNT ALTS OF 1700 FT MSL UNTIL IRONN AND 700 FT MSL UNTIL THE MDA. IT SEEMS LIKE A REVIEW OF THE PROGRAM PARAMETERS MAY BE IN ORDER.
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.