-61-
‘ -6l-' Milan Control: "Roger, report on leaving Saronno." The plane confirms.
(6) 11:32 The plane reports to Milan Control that at 32‘ is leanng Saronno at 10,000 ft. and is proceeding toward Biella.
Milan Control: “Roger, report on reaching 18,500 ft. and estimated time for Biella."
l 14:32- The plane replies: "Wait one moment - I estimate Biella at 2 hS' - hS' ."
h:33 The plane: "Roger...Roger.“
h:35 On the basis of the statements made by the Witnesses and the time shown by the watches of the victims, the plane crashed to the ground at about 1:35 p.m.
Pomt (7) indicates the position of the plane at the time when the right Wing presumably broke off, at an altitude below 11,000 ft.
Pomt (8) indicates the position on the ground of the main piece of wreckage: fuselage With the left wing and engine No. 2.
M15 Milan Control attempts to conunun1cate with the plane, repeating its call letters without success. The First Officer of a SABELBIA Airline DC-613 plane, which at that time had taken off and was over Mt. Ceneri at 16,000 ft., joined in the call, twice.
CAUSES
The breaking up in flight of Super Constellation plane type lam-A, No. 7313-0, at the points described in Chapter III, was due to the explosion of the fuel vapors contained in tank No. 7, followed inunediately by either an excess of pressure or a further explosmn in tank No. 6.
In the absence of other Significant and concrete eVidence, taking into account the stormy weather conditions, With frequent electric discharges, existing in the area. at the time of the crash, it may be assumed that the explosmn of the fuel vapors contained in tank No. 7 was set off , through the outlet pipes, by the igniting of the gasoline vapors issuing from these ipes as a consequence of static electricity discharges (streamer corona which developed on the vent outlets.
The Board feels that the hypothesis mentioned shave presents the highest- degree of plausibility as compared with all the others taken under examination-
