Help needed -For a long time this issue has been on my mind!

Help needed
For a long time this issue has been on my mind!

On the 15 March 1968, six new General Dynamics F-111A’s were deployed to Thailand, for combat missions and evaluations against targets in North Vietnam, under the Combat Lancer program.
But by 22nd April, after fifty-five night bombing missions flown, the USAF had lost three of their state-of-the art strike aircraft that was the pride of the United States military and their aviation industries know how and technology, which had resulted in the halt of F-111 combat ops.
It turned out that the three F-111A losses were not due to enemy action but were caused by wing and tail structural defects. One of the Combat Lancer crashes had been traced to a malfunction of the aircraft’s tail servo actuator. The USAF later discovered (as a later returning prisoner of war would confirm) that a tailplane problem could cause a sudden and uncontrollable pitch-up and roll. This failure in the flying controls system caused the aircraft to break up in flight. The other two crashes in Vietnam were traced to poor mounting of the M61A1 cannon and to pilot error.

These F-111 losses caused a storm of controversy back in the United States. To the point that a Senator William Proxmire denouncing the F-111A as an unsafe and defective plane. The aircraft became known as “McNamara’s Flying Edsel”, and was accused of being a potential “technological gold mine for the Reds”.

My question to the Forum and members is this –
Were these three lost F-111A’s located?
If so were these aircraft ever recovered?
or destroyed in situ by other U.S means to preserve their advanced state-of-the-art avionics, radars, EW/ECM sytems secrets, so as to not fall into Soviet and Chinese hands for assessment, evaluation and copying, via the North Vietnamese as war booty?

I have always thought the Soviet GRU, would have found this advanced technology of its enemy a ‘crown jewel’, and a big contributor to the Soviets own then own Sukhoi T-6-2I (later designated Su-24 ‘Fencer’) program, which would become the Soviets equivilant to the F-111 itself.

Regards
Pioneer