Narrative:

ATC issued descent from 6000 ft to 4000 ft MSL, with no TA. Pilot initiated a slow/momentary delay during descent for aircraft confign to prevent overspd during flap extension. ATC questioned aircraft descent implying 'why are you climbing, you were cleared to 4000 ft.' aircraft was not climbing, we had descended out of 6000 ft and momentarily slowed descent at 5800 ft for speed reduction. ATC was informed that we were configuring and ATC's response suggested that ATC had additional traffic. Remainder of descent was expedited to 4000 ft. Contributing factors was ATC's failure to give traffic information and the necessity for aircraft to expedite our descent from 6000-4000 ft. (Normally a required call.) ATC also seemed unfamiliar with the aircraft characteristics of the DC8, requiring an almost level pitch attitude to reduce speed to allow flap extension without an overspd. Even with ATC failing to issue traffic information, if cargo carriers were required to have TCASII the crew may have possibly seen any potential traffic and expedited descent. Supplemental information from acn 362611: we momentarily leveled off at 5800 ft while the flaps moved to their initial position. At this point, the socal approach controller said, 'why are you climbing? You are cleared to 4000 ft.' he stated that 'you need to descend for traffic.' this was the first time he had mentioned a traffic conflict. I looked out the left window and saw position lights above and to the left of us. We continued descent and landed uneventfully. I explained to the socal controller that we had extended the flaps and may have climbed a maximum of 100 ft due to ballooning of the aircraft during flap extension.

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Original NASA ASRS Text

Title: APCH CTLR QUESTIONS ALT AND RATE OF DSCNT OF DC8 FREIGHTER AS ACFT IS SLOWED FOR FLAP EXTENSION. POTENTIAL CONFLICT WITH ACFT Y WAS A POSSIBILITY WITH NO FURTHER RATE OF DSCNT. ACFT X HAD NO TCASII AND WAS NOT AWARE OF OTHER TFC IN AREA.

Narrative: ATC ISSUED DSCNT FROM 6000 FT TO 4000 FT MSL, WITH NO TA. PLT INITIATED A SLOW/MOMENTARY DELAY DURING DSCNT FOR ACFT CONFIGN TO PREVENT OVERSPD DURING FLAP EXTENSION. ATC QUESTIONED ACFT DSCNT IMPLYING 'WHY ARE YOU CLBING, YOU WERE CLRED TO 4000 FT.' ACFT WAS NOT CLBING, WE HAD DSNDED OUT OF 6000 FT AND MOMENTARILY SLOWED DSCNT AT 5800 FT FOR SPD REDUCTION. ATC WAS INFORMED THAT WE WERE CONFIGURING AND ATC'S RESPONSE SUGGESTED THAT ATC HAD ADDITIONAL TFC. REMAINDER OF DSCNT WAS EXPEDITED TO 4000 FT. CONTRIBUTING FACTORS WAS ATC'S FAILURE TO GIVE TFC INFO AND THE NECESSITY FOR ACFT TO EXPEDITE OUR DSCNT FROM 6000-4000 FT. (NORMALLY A REQUIRED CALL.) ATC ALSO SEEMED UNFAMILIAR WITH THE ACFT CHARACTERISTICS OF THE DC8, REQUIRING AN ALMOST LEVEL PITCH ATTITUDE TO REDUCE SPD TO ALLOW FLAP EXTENSION WITHOUT AN OVERSPD. EVEN WITH ATC FAILING TO ISSUE TFC INFO, IF CARGO CARRIERS WERE REQUIRED TO HAVE TCASII THE CREW MAY HAVE POSSIBLY SEEN ANY POTENTIAL TFC AND EXPEDITED DSCNT. SUPPLEMENTAL INFO FROM ACN 362611: WE MOMENTARILY LEVELED OFF AT 5800 FT WHILE THE FLAPS MOVED TO THEIR INITIAL POS. AT THIS POINT, THE SOCAL APCH CTLR SAID, 'WHY ARE YOU CLBING? YOU ARE CLRED TO 4000 FT.' HE STATED THAT 'YOU NEED TO DSND FOR TFC.' THIS WAS THE FIRST TIME HE HAD MENTIONED A TFC CONFLICT. I LOOKED OUT THE L WINDOW AND SAW POS LIGHTS ABOVE AND TO THE L OF US. WE CONTINUED DSCNT AND LANDED UNEVENTFULLY. I EXPLAINED TO THE SOCAL CTLR THAT WE HAD EXTENDED THE FLAPS AND MAY HAVE CLBED A MAX OF 100 FT DUE TO BALLOONING OF THE ACFT DURING FLAP EXTENSION.

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.