DELTA AIR LINES, INC. - Collections

1 N A T I 0 N A L T R A N S P 0 R T A T I 0 N S A F E T Y 3 3 4 3 2 ! DELTA AIR LINES, INC. DOUGLAS DC 9-32, N3329L LOUISVILLE, KENTUCKY SEPTEMBER 8,1970 TABLE OF CONTENTS Page 1 Analysis 4 Probable Cause .. 5 1. Synopsis i ! Investigation 1 ! Corrective Action 5 .. I .. Appendices A. Investigation and Hearing .. 7 B. Crew Information .. 9 C. Aircraft Information .. 11 1. Louisville, Kentucky, Approach Chart (Standiford Field) .. 13 2. Plan and Profile View of Runway 29 .. 15 3. Flight Recorder Data Graph .. 17 Attachments r File No. 1-0016 NATIONAL TRANSPORTATION SAFETY BOARD AIRCRAFT ACCIDENT REPORT WASHINGTON, D. C. 20591 Adopted: November 17,1971 DELTA AIR LINES, INC.

2 DOUGLAS DC-9-32, N3329L LOUISVILLE, KENTUCKY SEPTEMBER 8,1970 SYNOPSIS INVESTIGATION At approximately 2114 eastern daylight time DELTA Air Lines Fhght 439 was a scheduled September 8, 1970, DELTA Air Lines Flight 439, domestic flight from Chicago, Illinois (O'Hare a Douglas Model DC-9-32, N3329L, touched ' Field), to Atlanta, Georgia, with intermediate down 156 feet short of Runway 29 at Standi.' ' ,8tops at Louisville and Lexington, Kentucky. ford Field, Louisville, Kentucky, during a a Flight 439 of September 8, 1970, departed landing ~visual approach. In the area of initial( Chicago at 2013 eastern daylight time en route contact, the&b*w-d the to Louisville, Kentucky, on an Instrument Flight runway threshold at a measurea 2 44' or an ap.)

3 Rules (IFR) flight plan. proximate 5 percent gradient. At 2 101 ,' Louisville Approach Control The aircraft made firm contact on the main established radar with Flight 439. gear , rolled 73 feet in the direction of the run- vectors and altitude infomation were given the and then became airborne. It crew until the flight was turned to a heading touched down a second time On the i that would intercept the inkdc* localizer 262 feet beyond the runway threshold. From course to R~~~~~ 29 at standiford gild. The the Point Of second touchdown) ground marks flight was subsequently cleared for an ILS ap- continued approximately 4,457 feet to where proach.

4 (Attachment l.) the aircraft came to rest. The aircraft was sub- stantially damaged by the initial ground contact landing weight had been computed to be but there was no fire. 92,000 pounds, which established an approach The 89 passengers and five crewmembers on reference airspeed of 123 knots. Flaps had been board deplaned safely; however, onedss extended to 500. The stated that the 14,eassenge~i~~s. approach appeared normal in all respects, and The ~~~i~~~l ~~~~~~~~~i~~ safety ~~~~d that the last time he observed the airspeed determines that the probable of this , indication it was 130 to 132 knots. H'&eJieved accident was the &ot's misi aircraft did not flare properly for land- due to- the absmre~~of su ing, w&h resulted in hard landing and a , misleading information Rroduced.

5 Ounce. 6y deceptive sloEinm did not position the aircraft on the Iwide ' anda_thepila %'e ?d?i!d!! ___ Was %!.ah!&& the final- daylight, based on the 24-hour clock. proach p& __-- 'Instrument landing System. -~ b ~.. -___ 'Unless otherwise noted, all times used herein are eastern - c 1 The first officer thought that the approach had been normal in all respects, and that an air- speed of 130 knots had been maintained. All instrument indications were normal as he checked them when the aircraft was about 2,500 feet from the end of the runway. A witness who sd heard the aitad&& P assed over a toll rou .Am0 feet ~ ~e9, thought the~aiK&was . stated.

6 ".I-kave seen many airplanes_comein~-lowbef~rs-lancting on the runway. Usually the airplanes rhat~ in low increase the engine that." over. thdl_r0ad,hu~ ..& 'ZlW feet :de. The airport elevation is 497 Runway 29 at Standiford Field is 7,200 feet feet and the elevation at the ap9- of 29 is-47-e accident. -nt indled. The threshold is marked with standard green lights. When Flight 439 made the amroach which .- ter&eA in th& the h&- medium h; set-ar 3, was 7 -unway 29 did not have a prepared , the threshold slopes upward 2"44', a gradient of underrun/overrun area. The ground leading to '5 approximately 5 percent. Flight 439 made initial ground contact on this inclin -the run -b- b-The aircraft then contas&huunxay ir- feetbTeyond_the.

7 *hreshalband-ceo ..on the .runway ,..came.. 4,457 feetheyond . (See Attach- ment 2.) I Runway .. ' uisihil$y Y- received_Illinnr.~~~ ~~-the hard lank. Bowe-vvly. The aircraft was damaged substantially, but 1 ' there was no fire. Wreckage examination showed that the fuse- lage had fractured and buckled in the area between fuselage stations 737 and 794. The 2 fracture path was almost identical on each side of the fuselage. The seat track on the right side of the cabin separated at row 32 and the left track separated at row 31. There was no visible damage to the landing gear components or to any support or mounting structure. The left main landing gear tires revealed flat spots on both tires.

8 Holes in these areas penetrated through the tire tread and casing. The tail cone rested on the runway. The underside of the cone had been worn flat, and heat discoloration was visible on the sides. belt attachments. There was no separation of seat belts or seat from N3329L for testing: The following components were removed Speed command of attitude and thrust computer Speed command of attitude and thrust indicator Altimeters - two Vertical speed indicators - two Air data computer Anti-skid control box < Anti-skid wheel speed transducers - two ' Functional testing of these components was 1 \conducted in accordance with the specific over.

9 Haul requirements. These tests revealed that the components were operational within the require- ments and/or limitations set forth by the manu- facturer. The captain's airspeed indicator was checked at indicated speeds of 123 knots and 128 knots, and was within the prescribed tolerance. checked with a field test unit. This check did The aircraft pitot and static systems were not reveal any systems discrepancies. The aircraft had been maintained in accord- ance with Federal Aviation Administration and company procedures. A special airframe inspec- tion for turbulence encounters or for hard or overweight landings had never been required.

10 The Douglas Aircraft Company computed the loads and forces necessary to cause fuselage separation at stations 737 to 794, as well as the effe 'i' 7 2 :al on each side de of the cabin track separated to the landing ut or mounting es revealed flat n these areas and casing. runway. The worn flat, and he sides. :at belts or seat were removed ie and thrust .e and thrust lcers - two mponents was ,ealed that the ! specific over- lin the require- by the manu- r was checked nd 128 knots, rance. systems were his check did kzd in accord- nistration and :frame inspec- lr for hard or I required. computed the ause fuselage as well as the t vxlce recorder were recovered.