OFFICE OF THE AssisTANT SECRETARY 

Approved for Release: 2018/11/16 C05114702T!TAGBOARD .1 vi 0L\Jf\ [,1 VACl-Ut 

DEPARTMENT OF THE AIR FORCE 

WASHINGTON 20330 

MEMORANDUM FOR DR. BROWN 

SUBJECT: SR-71 Aircraft Attrition 

Colonel Gunderson's note to me of 26 October stated 

that you desired a determination of how many SR-71 attrition 

aircraft we think we will need (and their cost) in order to 

maintain a 25 UE SR-71 force through FY 1977. 

There are a number of considerations related to SR-71 

"requirements" and attrition which should be outlined (and 

your reactions obtained) before we proceed with these 

determinations: 

1. SR-71 attrition is running considerably ahead 

of that forecast by OSD when they previously rejected an 

attrition buy of 9 aircraft. OSD's forecast was two losses ~,w~ 

every three years. We have experienced four losses in the :; ,,:,'- , last 21 months, of which three have been in the last 9 months. 

Accordingly, we are now at an inventory point which OSD forecast would not result until FY 1972. 

2. However, another factor in the decision not to 

buy attrition SR-71's at the time was Mr. McNamara's personal 

reaction to the JCS that OXCART aircraft would be available 

for mission coverage if needed. 

3. In last year's BOB-OSD study of the OXCART and 

SR-71, which led to the President's decision to place the 

OXCART in storage, three particular factors are pertinent to 

your concern: 

a. The OXCART were to be stored, rather than 

destroyed, with the principal reason for storing being that 

they would be available to replace heavier-than-expected attrition of SR-7l's. (A secondary possibility of higher mission 

reqUirements was recognized.) The OXCART would be removed 

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from storage under the attrition replacement circumstances in 

lots (lllre4 or 5), rather than individually. All of our OXCART 

storage planning has been on this basis. At the moment, there 

are six operationally-configured OXCART, and two test aircraft 

could be readily-configured to operational type (one is now in 

storage). The one OXCART trainer could be used for SR-7l training, but could not be modified to an operational configuration 

at reasonable cost. There is one other A-12, now in storage, 

which accrued from the old TAGBOARD drone program. This was 

modified extensively, and would require major rework to be useable 

for SR-7l attrition replacement--for all practicable purposes, 

it should not be considered as an additional aircraft source. 

b. BOB-OSD did not, in the final analysis, 

rationalize a finite number of OXCART/SR-7l type aircraft required for missions. They indicated that the maximum need was 

for 30 aircraft, but that mission interchangeability could apply 

to reduce this number. Their approach, then, in the selected 

alternative was to forecast an inventory at end FY 1970 (26 

operational/test and 2 trainer SR-7l's), and reflect the possible 

mission coverage of this inventory. No projections beyond FY 1970 

were included. 

c. Satellites and drones (particularly the TAGBOARD) 

could cover a significant portion of target requirements. 

4. At present, there are 25 test and operational SR-7l's 

(the test are planned for operational use) and two trainers. We 

recently received OSD approval to modify one YF-12 to serve as a 

third trainer. 

5. If we take a "worst case" situation that we could 

expect two SR-7l losses per year to continue, the SR-7l would 

be down to 6 operational aircraft by end FY 1977. If we used all 

8 OXCART for attrition replacement, we would still have only 14 

by that time, which would indicate a need to buy 11 more SR-7l's 

to maintain 25 operational. 

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6. If we assumed one SR-71 loss per year, the SR-71's 

would be down to 16 by end FY 1977, but with 8 OXCART, could be 

an inventory of 24. In this instance, it would be difficult to 

make a case for buying more SR-71's. 

7. One aspect we should consider is that if we made 

an open move to propose the procurement of additional SR-71's, 

the BOB (and probably OSD) would object to procurement until we 

had fully considered the 8 OXCART availability. This would delay 

facing up to SR procurement until FY 1970 or 1971 on the "worst 

case" basis. Also, we might expect a move by CIA to retain the 

OXCART in a flying status, to keep the aircraft ready, introduce 

improvements, etc. (No funds are budgeted in FY 1969 for OXCARTa minimum program for flying would be $50 million a year, and 

could go up to $80 million, depending on the program choices.) 

8. Another aspect is the TAGBOARD Drones (and possibly 

the Compass Arrow type drones). Amidst the ExCom discussions on 

the OXCA~T!SR-71 Kadena operations discussions, Dr. Hornig raised 

a questi~n as to the feasibility of reducing the FY 1968 TAGBOARD 

procurement to offset the OXCART extension costs. The general 

reaction was that if the OXCART or SR-71 became severely vulnerable 

to enemy action, the TAGBOARD might be the system to use. Accordingly, the TAGBOARD was not reduced. 

9. Still another consideration developed on 27-28 October. 

This was the idea of modifying the A-12's for interceptor use. If 

this course were followed, it would result in some "F-12 type" aircraft at relatively-low cost, but delete the stated purpose for 

storing the A-12's (replacement of higher than expected SR-71 attrition), and more importantly, while saving on F-12 type of funding, 

create a situation of either accepting all future SR-71 attrition 

without replacement, or buying more SR-71's (which would probably 

cost more for investment than the F-12's). 

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The preceding is furnished to bring you up-to-date on 

the principal considerations involved. The chances for 

approval of additional SR-71's in the FY 68/69 time period 

are probably extremely small. If we ordered 11 in either 

year (or in both years by lot buy), the investment cost 

could be at least $275 million, and subject to the full 

funding rules). 

exander H. Flax 

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