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Widebody transport flight crew slows aircraft to achieve final approach speed. Controller says had to vector aircraft behind.
| Attributes | |
| ACN | 154033 |
| Time | |
| Date | 199008 |
| Day | Sun |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : lga |
| State Reference | NY |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| 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 |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : cfi pilot : flight engineer |
| Experience | flight time last 90 days : 100 flight time total : 16000 flight time type : 40 |
| ASRS Report | 154033 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument pilot : atp |
| Events | |
| Anomaly | non adherence : clearance other anomaly other anomaly other |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | none taken : detected after the fact |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Light traffic, ATC assigned 170 KTS to OM runway 4 ILS lga. Previous assigned speed was 180 KTS. I slowed to 170 KTS. Then prior to LOM I slowed to about 160 KTS. Final flap speed on widebody transport is 162 KTS. Company policy is to be stable and on speed. As it was a coupled approach, the autothrottles slowed the aircraft prior to LOM. I saw an problem in slowing back from 170 KT slightly outside the OM. Widebody transport is difficult to go down and slow down at the same time. After landing, the ground controller asked me to call TRACON. I did so and ATC controller said he had an aircraft behind me on approach that required vectors due to me slowing below assigned speed of 180 KTS. I reminded him we had been assigned 170 KTS and he did not realize that we had received 170 KTS. I told him that I was sorry for any conflict, but the widebody transport is difficult to slow down and that I probably had not dropped below 160 KTS prior to OM. My feeling is that if ATC had another aircraft so close behind a 'heavy' that a 10 KT (170-160=10) speed change for about 3 mi or 1 min makes a difference, then he had that aircraft too close to me. A pleasant discussion followed. ATC was not aware of the 162 KT final flap speed on widebody transport aircraft. I would not have slowed down if I knew someone was that close behind me. I suspect the aircraft behind me was faster than assigned speed.
Original NASA ASRS Text
Title: WDB FLT CREW SLOWS ACFT TO ACHIEVE FINAL APCH SPEED. CTLR SAYS HAD TO VECTOR ACFT BEHIND.
Narrative: LIGHT TFC, ATC ASSIGNED 170 KTS TO OM RWY 4 ILS LGA. PREVIOUS ASSIGNED SPD WAS 180 KTS. I SLOWED TO 170 KTS. THEN PRIOR TO LOM I SLOWED TO ABOUT 160 KTS. FINAL FLAP SPD ON WDB IS 162 KTS. COMPANY POLICY IS TO BE STABLE AND ON SPD. AS IT WAS A COUPLED APCH, THE AUTOTHROTTLES SLOWED THE ACFT PRIOR TO LOM. I SAW AN PROB IN SLOWING BACK FROM 170 KT SLIGHTLY OUTSIDE THE OM. WDB IS DIFFICULT TO GO DOWN AND SLOW DOWN AT THE SAME TIME. AFTER LNDG, THE GND CTLR ASKED ME TO CALL TRACON. I DID SO AND ATC CTLR SAID HE HAD AN ACFT BEHIND ME ON APCH THAT REQUIRED VECTORS DUE TO ME SLOWING BELOW ASSIGNED SPD OF 180 KTS. I REMINDED HIM WE HAD BEEN ASSIGNED 170 KTS AND HE DID NOT REALIZE THAT WE HAD RECEIVED 170 KTS. I TOLD HIM THAT I WAS SORRY FOR ANY CONFLICT, BUT THE WDB IS DIFFICULT TO SLOW DOWN AND THAT I PROBABLY HAD NOT DROPPED BELOW 160 KTS PRIOR TO OM. MY FEELING IS THAT IF ATC HAD ANOTHER ACFT SO CLOSE BEHIND A 'HVY' THAT A 10 KT (170-160=10) SPD CHANGE FOR ABOUT 3 MI OR 1 MIN MAKES A DIFFERENCE, THEN HE HAD THAT ACFT TOO CLOSE TO ME. A PLEASANT DISCUSSION FOLLOWED. ATC WAS NOT AWARE OF THE 162 KT FINAL FLAP SPD ON WDB ACFT. I WOULD NOT HAVE SLOWED DOWN IF I KNEW SOMEONE WAS THAT CLOSE BEHIND ME. I SUSPECT THE ACFT BEHIND ME WAS FASTER THAN ASSIGNED SPD.
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.