 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
An A319 on a coupled ILS approach descended below the GS because the autoplt was slow to respond following a steep descent and deceleration.
| Attributes | |
| ACN | 647603 |
| Time | |
| Date | 200502 |
| Local Time Of Day | 0001 To 0600 |
| Place | |
| Locale Reference | airport : atl.airport |
| State Reference | GA |
| Altitude | agl single value : 1500 |
| Environment | |
| Flight Conditions | VMC |
| Weather Elements | Rain |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : a80.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | A319 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | ils localizer & glide slope : 8l |
| Flight Phase | descent : approach |
| Route In Use | approach : instrument precision |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Experience | flight time total : 10000 flight time type : 3500 |
| ASRS Report | 647603 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Events | |
| Anomaly | aircraft equipment problem : critical non adherence : published procedure non adherence : company policies non adherence : far other anomaly |
| Independent Detector | aircraft equipment other aircraft equipment : pfd glide scope other flight crewa |
| Resolutory Action | flight crew : overcame equipment problem |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Aircraft |
Narrative:
Following a steep arrival descent into atl (landing east) the localizer and GS were intercepted for runway 8L; approximately 8 mi from the airport. At GS interception; the speed brake; flaps; and landing gear were extended to control speed on the approach. After the final flap deceleration; a slowing ground speed required a moderated descent rate as commanded by the flight director. The aircraft was making appropriate corrections but appeared slow to respond to the flight director commands. At an estimated altitude between 200-500 ft above the airport (while flying below the clouds in light rain with 3 mi flight visibility); the aircraft began to sink below the indicated GS. As the deviation approached a 1 DOT deflection; I disconnected the autoplt; gently corrected the descent rate and continued the landing visually. The pitch adjustment was imperceptible to passenger and the flight attendants. The maximum noted deviation from the GS was 1 DOT below the ideal path.
Original NASA ASRS Text
Title: AN A319 ON A COUPLED ILS APCH DSNDED BELOW THE GS BECAUSE THE AUTOPLT WAS SLOW TO RESPOND FOLLOWING A STEEP DSCNT AND DECELERATION.
Narrative: FOLLOWING A STEEP ARR DSCNT INTO ATL (LNDG E) THE LOC AND GS WERE INTERCEPTED FOR RWY 8L; APPROX 8 MI FROM THE ARPT. AT GS INTERCEPTION; THE SPD BRAKE; FLAPS; AND LNDG GEAR WERE EXTENDED TO CTL SPD ON THE APCH. AFTER THE FINAL FLAP DECELERATION; A SLOWING GND SPD REQUIRED A MODERATED DSCNT RATE AS COMMANDED BY THE FLT DIRECTOR. THE ACFT WAS MAKING APPROPRIATE CORRECTIONS BUT APPEARED SLOW TO RESPOND TO THE FLT DIRECTOR COMMANDS. AT AN ESTIMATED ALT BTWN 200-500 FT ABOVE THE ARPT (WHILE FLYING BELOW THE CLOUDS IN LIGHT RAIN WITH 3 MI FLT VISIBILITY); THE ACFT BEGAN TO SINK BELOW THE INDICATED GS. AS THE DEV APCHED A 1 DOT DEFLECTION; I DISCONNECTED THE AUTOPLT; GENTLY CORRECTED THE DSCNT RATE AND CONTINUED THE LNDG VISUALLY. THE PITCH ADJUSTMENT WAS IMPERCEPTIBLE TO PAX AND THE FLT ATTENDANTS. THE MAX NOTED DEV FROM THE GS WAS 1 DOT BELOW THE IDEAL PATH.
Data retrieved from NASA's ASRS site as of January 2009 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.