Page:CAB Accident Report, Braniff Airways Flight 542.pdf/3

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Investlgatlon also dlsclosed that there was no known trafflc whlch could accoun ,Eor a vlolent evaSlve maneuver 1n the medlate Vlclnlty of N 97050 at the tlme of the accldent, nor were there any mealles or unmanned aircraft in the region, according to the Department of Defense.

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Surface weather charts for the late evening of September 29, 1959, and early morning hours of September 30, 1959, show a very weak preSSure gradlent from south— western Texas east—northeastward to western Alabama. A diffuse quaszL—statlonery front along the Appalachlans reached 1nto central ‘0351851pp1 and extended along a lme runnlng from near Shreveport, Lou151ana, to Fort Worth, Texas, thence south— westward to Junctlon, Texas, and west—Southwestward to the Mexlcan border. The leadlng edge of this front was some 125 rules to the north of the crash 511.39 at the

time of the crash.

The route from Houston to Dallas was 60 rules or more east of an area :m winch if. 3. Weather Bureau forecasts called for severe thunderstorm actlvlty. For thls route the anatlon area forecast, lssued at 1852 by the U. 3. Weather Bureau at San Antonlo, 1ndacated scattered clouds at 14,000 to 5,000 feet and a broken celllng at 10,000 feet 1n the Vlcinlty of a few lsolated dlssszatang cumulonmbus, mostly over extreme southern Texas, untll 2100 and broken to scattered clouds above 10,000 feet elsewhere on the route. Addltlonally, the forecast 1nd1cated that low stratusv scattered to broken at 1,500 feet Hath 1ts tops at 5,000 feet along the coast, was expected to spread 1nland and lower to broken to overcast 1,000 to 2,000 feet by 2200 locally 800 to 1,000 feet, overcast; v151b111ty f1ve rules 1n fog over luterlo‘

jectlons after 0200 September 30, 1959.

During the early evenlng of September 29, 1959, weather reports show that over southeastern Texas there was generally 1/10 to 5/ 10 of altocumulus clouds at 12,000 feet; 6/10 to 9/10 of c1rrus clouds above 20,000 feet; and a few isolated d1531pat1 clmmlonlmbus with bases around h,OOO feet. A small area of locally heavy thunder- storms, whlch developed near San Angelo at 1500 and moved east—southeastward, had reached the v1c1n1ty of Kerrville and Frederlcksburg, Texas, by 2200 decreasmg to 10 to 15 sales 1n dlameter and was disalpating 1n the Vlclnlty of Blanca, Texas, around 2200. At 2200 algnlflcant, but 1solated, radar echoes were reported southea of Shreveport, Loulslana, and thunderstorms were v151ble from Lufkm, Texas. At the same tlme, llghtnlng from the thunderstorm area near Blanco was v151ble from Waco and Austln. College Statlon, Tyler and Gregg County were clear wlth v151b111t 15 miles, whlle Houston reported only hlgh thln c1rrus clouds above 20,000 feet. Dallas had scattered clouds at 12,000 feet :In addition to the hlgh thm clrrus deck

By 2300, surface observatlons and radar reports showed almost all thunder— storms to be d1551patlng except for an area extendmg from 25 males north-northeast to 25 rules north—northWest of Waco. A second area shoszng on the radar scope at TMace was flve miles mde and extended from 30 mles west southwest of Palestlne, Texas, to 30 mles east—southeast of Waco. The latter report places a radar echo approxmately elght miles northwest of Buffalo, Texas, and 15 1nterpreted as bemg a rainfall echo, most likely the 1ntermed1ate and higher level remnants of earher thunderstoms mov1ng from the westnsouthwest. A Grumman Mallard pllot en route from Dallas to Houston later reported encounterlng 1nterm1ttent llght rain and moderate turbulence at 7,000 feet northwest of Buffalo, Texas, and observed shallm