RELATIONSHIP OF DATA CONTAINED IN THE BDA AND ERA PROJECT 00.4771, THE RECORD AND POTENTIAL OF AIR ATTACKS IN ATTAINING US OBJECTIVES IN VIETNAM

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78S02149R000100110006-2
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 5
• Document Creation Date: December 15, 2016
• Document Release Date: September 18, 2002
• Sequence Number: 6
• Publication Date: May 10, 1966
• Content Type: MF

Approved For Rgjkasdia 2/1
10 May 1966
MEMORANDUM FOR:
J?ROM:
SUBJECT:
Relationship of Data Contained in "The BDA" and ERA
Project 00.E-771, The Record and Potential of Air
Attacks in Attaining US Objectives in Vietnam
1. In discussing the relationship between data used in Project
00.E+771 and data contained in "the BDA" it is necessary to distinguish
between several imprecisely titled documents issued by the BDA Branch
of DIA. By some people, all a.re regarded as the BDA". We have, how-
(ever, made a distinction between:
(1) the BDA compilation of individual strike reports (tor an
example see Attachment 1),
(2) "Summary of US and VNAF Air Strikes on DRV Since 1/1/65"
(See Attachment 2), and
(3) "DIA Results of Strikes on DRV Targets" (See Attachment 3).
Supplemental sheets to all three publications are issued simultaneously
and are not always in agreement with each other or internally consistent.
Correction sheets also are frequently issued at much later dates. Hence
our use of the term "corrected" individual strike reports.
2. Data pertaining to sorties which were contained in Project 00.J4(
are a summation of data in the BDA individual strike reports, as corrected
through 19 February. They also agree with a summation of data contained
in the "Summary of US and VNAF Air Strikes on DRV Since 1/1/65" as cor-
rected for discrepancies between the "Summary" and the individual BDA
strike reports. In this sense they are in complete agreement with "the
BDA". This agreement was reflected in the following footnote that appear;
on page B-7 of Appendix B, in the printed version of Project 00.4771:
Data in this Appendix were derived from individual strike report;
given in the Bomb Damage Assessment (BDA) and therefore may not
agree with data in other Sections and Appendixes which have been
derived from other sources such as execute messages and pre.Iim-
inary strike reports. The data, however, have been made as con-
sistent as possible, given problems associated with correction
of preliminary data and varied reporting systems.
DIA review(s) completed.
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;. Data in Project 00.3771 do not agree exactly with data
summarized in the "DIA Results of Strikes on DRV Targets". We were in-
formed by a representative of the BDA Branch that, although an attempt
is made to refine the "Results" as more accurate data become available,
in between revisions data are cumulated without correction. Hence the
"Results" are less accurate than the corrected individual strike reports.
Moreover, the "Results" contain data only on Strike plus Flak Suppression
Sorties, include no data on CAP, RESCAP, ECM, Photo or other Support
Sorties, do not allocate aircraft according to Service, and contain no
data on losses. We therefore decided to work with the individual strike
reports and with the "Summary" rather than with the "Results". As indic-
ated by the following tabulation of data through 23 December 1965, the
total carried by the "Results" for Strike plus Flak Suppression Sorties
is only slightly larger (112) than the total derived from the individual
strike reports and the "Surmnary".
Strike Plus Flak Suppression Sorties
2 March - 23 December 1965
"DIA Results"
ERA Project 00.3771,
BDA Individual Strike
Reports, BDA "Summary"
Armed Reconnaissance
16,3166
17,129
Fixed Target
'(, 703
6,9_8
Total
2a-,1 9
23-, 57
The difference in allocation. to armed reconnaissance and fixed target
sorties was greater. Apparently some of the sorties assigned. by the BDA
individual strike reports to Armed Reconnaissance were carried as Fixed
Target sorties in the "Results".
fib. Apart from the differences in totals and in allocation to Fixed
Target or Armed Reconnaissance, data shown in the "Results" for sorties
against individua~_rFixed Target Systems differ from data contained in the
graphic summariesnattacks on individual target systems in Appendix B of
Project 00.3771. For example, the "Results" show 210 strike sorties
against "Power Plants" through 23 December 1965. The Project 00.3771
graphic summary of attacks on powerplants shows 229. This is explained
by a footnote to the graphic summary which states "included 19 aircraft
that also attacked fixed targets of other types on mission." Such in-
clusion was desired to determine the total number of planes over various
types of targets as an aid to analyzing losses and vulnerability of
planes engaged in different types of missions. (The DIA "Results" assigns
aircraft striking multiple targets to the principal target only.) No
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double counting resulted in Project 00.771 from the inclusion of
planes engaged in multiple missions in more than one graphic summary,
because the total of sorties and their allocation to Fixed Target, Armed
Reconnaissance, Strike plus Flak Suppression, or Support, was derived
:independently on the basis of the BDA. individual strike reports.
5. In addition to the correction sheets issued by the BDA Branch
of DIA, some further correction, or at least selection, of data contained
in the BDA individual strike reports was necessary. The total number of
sorties shown in such reports does not always agree with the sum of the
.individual aircraft reported for the strike, as is illustrated by the
following tabulation of discrepancies in strike reports during 5-19
February.
Strike
Number
Total Aircraft
Credited. to
Strike in
BDA Strike
Date Report
Sum of Individual
Aircraft Listed
in BDA Strike
Report
Deviation of
Total from
Sum of
Individual
Lircraft
1126 2/5/66
64
62
+2
113+ 2/6/66
116
46
+70
1136 2/7/66
93
92
+1
1139 2/8/66
1[5
46
-1
1151 2/11/66
101
100
+1
-L163 2/16/66
93
100
-I
1167 2/17/66
88
90
-2
1175 2/19/66
61
71
-10
'T'otal for 8
Strikes Shown
661
607
+54
Where the BDA report for an individual strike was internally inconsistent-
the sum of the individual aircraft reported was used in Project 00.4771, 1
preference to the total number of aircraft shown for the strike. The rea-
son for this choice was that the more detailed data selected were in agre e
ment with data contained in the "Summary" and permitted a distinction be-
-tti,Teen Strike plus Flak Suppression and Support Aircraft.
6. In addition to the data originating in the BDA Branch of 1IA,
there are other Armed Service documents (such as the STAG, Assessment of
the Air Effort in Vietnam and Laos, and certain series issued by MMCC PAC
that contain data pertaining to sorties which have been based on execute
messages or other preliminary data, rather than on the actual BDA reports
of individual strikes.
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 App 6-2
r ved R wR -2~O t~tg~ Ir 3D#WS?O2449~19864A0110
UNCLASSIFIED ONFIDENTIAL gy SECRET
CENTRAL INTELLIGENCE AGENCY
OFFICIAL ROUTING SLIP
25X1
App
TO
NAME AND ADDRESS
DATE
INITIALS
I
- i
l tAr _~
2
3
4
5
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ACTION
DIRECT REPLY
PREPARE REPLY
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DISPATCH
RECOMMENDATION
COMMENT
FILE
RETURN
CONCURRENCE
INFORMATION
SIGNATURE
Remarks:
Data in Project 00.4771 agree with the BDA indi-
vidual strike reports and with the "Summary of US
& VNAF Air Strikes on DRV Since 1/l/65." They do
not agree exactly with the "DIA Results of Strike
on DRV Targets", which is a compilation of rela-
tively uncorrected data pertaining only to Strike
plus Flak Suppression Sorties.
In March the BDA Branch of DIA planned to revise
the "Results" to reflect corrections in the indi-
vidual BDA strike reports. We supplied them with
copies of worksheets from Project 00.4771 to ass-
ist in the process. The personnel of the Branch
changed at about that time and I don't know
whether revision was undertaken or not.
FOLD HERE TO RETURN TO SENDER
FROM: NAME, ADDRESS AND PHONE NO.
DATE
-G-46
FORM b 237 Use previous editions
(40)
< U.S. GOVERNMENT PRINTING OFFICE : 1961 0-587282