II
98
of theprojects, however, were terminated in March 1958 and otbera in Aprily
but the delays, while vexatious, did not hinder the beginning of the operational phase of HARDTACK,
.
Adreraft Modification. The major Task Group 7.4 modification tes
for HARDTACK was that involving B-57 sampler aircraft.
Four B-57B aircraft
of the 4926th Test Squadron (Sampling) entered Warner Robins Air Matertel
Area in July 1957 to be changed from conventional configuration to sampler
configuration and to undergo installation of TACAN equipment.
All eed
one of these 5-578 aircraft, approaching their IRAN inspection dates, werd \
similtaneously being subjected to the IRAN requirement.
The last of tie
aircraft from Warner Robins was returned to the 4926th in late January
1958, Six other B-57B's, already modified, were in use by the 4926th.
All ten of these aircraft were earmarked for use on Oparation HARDTACK,
To augment the sampling effort for HARDTACK, six B-57D aircraft of
the 4025th Strategic Reconnaissance Squadron at Laughlin Air Force Base,
Texas, were also designated for HARDTACK use.
These six Strategic Air
Command aircraft were entered in the modification process at the Glenn L.
Martin plant at Baltimore, Maryland, in October 1957.
process in January 1958.
They completed the
This modification consisted primarily of the ad-
ditionof sampler tanks and compressor platforms not necessitating major
chagesto the basic configuration of the aircraft. After sampler modification the B-57D aircraft were still in such a configuration that