Page:CAB Accident Report, TWA Flight 891.pdf/42

 -42- 11.34.? Inspections and bench tests, made on the premises of sp_ec1alized firms, on various parts, accessories and equipment belonging to

the i‘ ll-fated plane.

These inspections and tests were undertaken in order to ascertain whether the parts, accessories and equipment in question were in proper working order at the time of the crash.

The result was positive in the sense that no eVidence of abnormal conditions was found.

11.1.1.8 Static tests on fuel tank caps P.N. 750433-13

The purpose of these tests was the same as that mentioned in par. ll.h.3.

The tests, conducted on used caps, brought out that the breakage of the 1nleldual component parts of the caps occurs under

loads corresponding to pressures ranging between 126 and 1h1 p.s.i., namely, pressures far greater than those required to cause the tank structure to give way and the fuel intake pipe (an. h78301) of tank No. 7 to crack.

ll.h.9 Statistical lng_u11"y into the trouble encountered in the practical use of submerged pumps in the fuel tanks

This impiry was undertaken in order to examine the typical defects encountered in pumps of this type and to ascertain whether such defects, if found present in the submerged pumps of wrecked plane 7313 C, might have directly or indirectly caused the gasoline vapors in the tanks to ignite and explode.

It was established that the pumps of the wrecked aircraft had no such defects.

11.14.10 Tests on the highest temperature that the body [ca51ng] of a submerged pump can attain when the pump is, by mistake, kept operating for a long time in a practically empty tank

These tests were made in order to asoertain whether, under the conditions in question, the result would be an explosion of the gasoline vapors contained in the tanks.

The tests showed that the highest temperature reached Imder the conditions cited would be about 120°.

1.1.th Statistical inquiry into the replaCing of P.N. 750138-13 caps and m. l817h2-fdigsticks on he planes at some _past time

Since it was found from the wreckage of the ill-fated plane that the caps of tanks Nos. 6 and 7 and the dipsticks of tanks Nos. 1 and 6 (these caps and sticks are screwed onto the top surface of the mg) were missing, an inquin was made in