SA-363 File No
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SA-363 File No. 1-0011 CLVTL AERONAUTICS BOARD AIRZFWT ACCIDENT REPORT TRANS W3RJ 3 A 1’ HLlfJES I” INC , , LOCKHFED CONSTELLATION MODEL, 049, N 86511, MIDWAY AIRPORT CHICAGO ILLINOIS SEPTEMBER 1, 1961 SYNOPSIS Trans World Airlines Flight 529, a model 049 Loikheed Constellation, N 86511, ;rash-.d aboat nine miles west of Midway Airport, Chicago, illinois, on September 1, 1961, af, 0205 c-d t,, killing all 78 occupants. The flight originated at Boston, Massachusetts, destination San Fran-islo, Saliforaia, with intermediate stops schedded at New York, New York; Fitrsbwgh, Pennsylvania; Chicago, Tllinois; Las Vegas, Nevada; and Los Angeles, California, The flight to Chicago was routine. A scheduled crew change was made at Chicago and the flight departed there at 0200 :.d.+..-Approximately five minutes later, during good weather, while clinibing on the intended course, the a.ircraft experienced loss of longitudinal control and crashed, All occupants died instantly and the air- craft was cornplrtely destroyed. Invt.st8igst,ion dis:losed that a 5/16 inch AN-175-21 nickel steel bolt from the elevator boost mechanism vas missing, There was evidence that the bolt vas not in place at the time of impact The proper posj-tioning of this bolt is vital to the 2ontrol of the aircraft and must therefore have been in place until inmdiately prior to the loss of ecntrol. -2- ... The Board determines that the probable cause of this accident was the loss of an AN-175-21 nickel steel bolt from the parallelogram linkage of .- the elevator boost system, resulting in loss of control of the aircraft. -3- Investigation At approximately 0205 Ll September 1, 1961, a Trans World Airlines Lockheed Constellat ion 049, N 86511, crashed approximately- nine miles west of Midway Airport, Chicago, Illinois, following takeoff from Midway Airport. The crew of 5 md all 73 passengers were fatally injured. TWA Flight 529 was a scheduled flight originating at Boston, Massachusetts, with intermediate stops at New York, Pittsburgh, Chicago, Las Vegas, Los Angeles, and terminating at San Francisco, California. Discrepancies noted prior to the Boston departure were an inoperable white navigation light located in the aircraft's tail cone, and a leaking fuel drain valve on the No. 3 main fuel tank sump, These two discrepancies were corrected by the ground crew prior to the flight's departure from Boston. One carry-over discrepancy from the previous flight was a malfunction of the cabin refrigeration system during ground operation. Since this was not con- sidered necessary to the safety of flight, it was carried over to prevent a delay at Boston. Because of this discrepancy, the cabin was unpressurized I during climbout until reaching 6,000 feet, at which time the cabin was pres- surized to the field elevation of the next stop. This procedure was repeated after each en route stop\tO cool the cabin for passenger comfort. The flight from Boston to Midway Airport, Chicago, was routine and it arrived there at 0118. -1/ All times herein unless otherwise noted are Central Daylight based'on the 24-hour clock. ..- -4- The crew originating the flight at Boston terminated their portion at I Chicago. The new crew consisted of Captain James H. Sanders, First Officer Dale Tarrant, Flight Engineer James C. Newlin, and Stewardesses Barbara Jane Pearson and Nanette G. Fidger. The incoming captain and flight engineer briefed Captain Sanders and Flight Engineer Newlin on the carry-over discrepancy and it was agreed that the aircraft was airworthy. At Midway, oil and fuel were added. Total fuel on board at departure was 3,240 gallons. The gross takeoff weight was 94,794 pounds - well below the maximum allowable gross takeoff weight of 96,000 pounds, and the center of gravity was within allowable limits. A flight plan to Las Vegas was filed for the flight in accordance with Instrument Flight Rules (IFR) via Victor Airway 8 to Akron, Colorado, Victor Airway 1512 to Kremmling, Colorado, Victor Airway 1522 to Moqon, Nevada, and Victor Airway 8-North to Las Vegas. The estimated time en route was six hours and twenty- three minutes, at a+ue airspeed of 223 knots. When the aircraft departed the passenger loading gate, Captain Sanders was observed by a TWA passepger agent to have been seated in the left seat. During engine runup, Flight 529 was given its air traffic control clearance which was: "cleared to the Las Vegas Airport via Victor 6 Naperville, Victor 8 flight plan route, maintain 5,000 feet." The clearance was acknowledged cor- rectly and TWA Flight 529 departed on runway 22L at 0200, making a right turn out of traffic. The 0200 Midway Airport weather was: scattered clouds at 10,000 feet; high overcast, visibility three miles in haze and smoke; wind south eight knots. -5- The Chicngo O'Hare Ah-port weather at 0200 was: partial obscuration; scattered clouds 15,000 feet; high overcast; visibility two and one-half miles in ground - fog and smoke; wind south six knots. .- Radar contact was. established with -the flight one minute and 34 seconds after the flight acknowledged takeoff clearance,and as the aircrafl; prGceeded outbound in a right turn, At 0204, Flight 529 was observed on radar by the de- parture controller tobe five miles west of Midway Airport proceeding on course, Northwest Airlines Flight lo5 was cleared for takeoff on runway 22L at Midway, and took off immediately. The ground controller observed a flash west of Midway I Airport at this time and asked Flight lo5 if he had seen a flash. Flight lo5 advised that they had seen a flash fire and would fly over the area. As Flight 105 reported over the fire, the radar range was noted to be nine miles west of Midway Airport and the radar return of WA Flight 529 had disappeared from the scope. It was later determined that Flight' 529 had crashed at this site and that the observed ground fire was the result of the accident. - At approximately 0204, American Airlines Flight 805, an air 'freighter, also observed the flash as they were about to land at Midway Airport. They abandoned their landing approach and proceeded to the fire area on a westerly course at an altitude of 2,000 feet with their landing lights on. I A door-to-door inquiry by members of the Civil Aeronautics Board witness , group was acconplished over a localized are& along the probable flightpath, resulting in approximately 150 interviews. Witnesses who observed Flight 529 indicated that it was heading in a wester- ly direction and was apparently proceeding normalAh.until less than two miles / from the scene of the accident. A witness located one mile south-southwest of the -b- scene stated that the aircraft was flying low at that point on a northerly heading, No witnesses were found who saw the aircraft at the moment of impact; - however, a few witnesses located near the accident scene said that they heard a change in engine noise volune, but that this change in engine sound did not indicate to them either distress or failure. Other witnesses were confused by the presence of other aircraft flying in the area immediately following the .- accident and therefore were unable to determine definitely if they had seen Flight 529. TWA Flight 529 crashed in an open field near Hinsdale, DuPage County, Illinois. The aircraft struck the ground in a slightly left-wing-low and nosedown attitude on a heading of approximately true North. The aircraft dis- integrated, leaving debris over an area 200 feet wide and 1,100 feet long. Five craters were made, each approximately three to four feet deep, as a result of the four engines and fuselage striking the ground. Investigation revealed that the portion of the horizontal stabilizer to which the right vertical fin is attached had separated from the aircraft prior to impact, having landed approximately 400 feet south of the main impact craters. The stabilizer failure occurrdd at Stabilizer Stations 240R and 23OR of the front and rear spars, respectively. There was no evidence of fatigue on the spar i caps, spar webs, skin material, or stringers, Examination did disclose that I there had been oscillatory loads applied to the four spar caps md the two spar webs prior to and during separation.. The $ront-.spar upper and lower caps lied failed in tension and the 4! nterconnecting spar web had experienced a tensile tear from top to bottom. The fracture faces of to 11 rear spar caps were brinelled by recontact after failure. -7- There were several indications that the elevator had beer, at its maximum * upward travel. The most significant evidence of this was in the deformation pattern impressed in the right rudder by the elevator outboard closing ri.b in a manner and position such that the elevator had to be full up at the time the rignt rildder was forced into it during the stabilizer separation. The landing gear was determined to be in the up and locked position at impact. Th.e flaps and landing lights were retract.ed, and all filght controls and their comterbalances were accounted for, There was no evidence of in-flight fire; however, there was considerable evidence of ground fire on portions of the wreckage which also showed severe impact damage e Exan5nation of the wreckage revealed no evidence of an in-flight explosion or colllsim with foreign objects. No evidence of electrical overheating of the D(: and AC units was found. Measurements and readings were made of all trim actuators and their asso- ciated cockpit, position indicators. The variations of readings within each of the trim systems prevented any determination of in-f1igh.t trim positions, The two aileron boost assemblies were found in the boost-off posit:on as was the aileron boost cutoff valve, The shift handle in the cockpit, however, 0 was found in the boost-on position.