TOP SECRET-
INTELLIGENCE AGENCY. C.
5
6
Copy t?
MEMORANDUM FOR: Director. National Reconnaissance Office
Report of Major Aircraft Accident Resulting in the Loss2,5
1. In response to your verbal request of Generalummary report on the analysis, findings, andtakenesult of the loss of aircraft number
onecember
TOP SCCftCT-
aircraft wai taxied to the runway and the
Before Takeoff checklist completed. Compressor stall waswhile trimming the left engine. This enginetrimmed slightly to correct this condition and allcompleted
aircraft was cleared for takeoff and4 PST. Gross weight was% CG. Takeoff distance was computedfeet. The takeoff appeared normal, however,indicated that the ground rollittle longer This could not be ascertained and is notto the accident. Rotation begannotsoccurred atnots. Immediatelymain gear left the ground, the aircraft yawed toitch maneuver. erieB of violent yawingactions followed very rapidly with the aircraft The pilot attempted to regain control ofwith no apparent response to stick and rudderejected at the top of the maneuver as the aircraft went Into
the final pitchdown from which the crash occurred. Estimated altitude at the point of ejection iseet above the ground. Estimated elapsed time from lift-off to impact was Ubs thaneconds. The aircraft Impacted first on the left wing and broke into many segments as It slid across the frozen lake bed for approximately one mileoot wide path. The pilot landed to the left of the aircraft wreckage track and received only minor Injuries.
b. Inveatigation and Analysis
(1) Immediately after the accident General Ledford appointed an Accident Investigation Board consisting of qualified personnel from the Office of the Aerospace Safety Division, Inspector General, ' United States Air Force,!
fter detailed examination and analysis of all the available data and evidence, It was determined that the only area of
Investigation whichirect involvement with the cause of this accident was in the maintenance and materiel fields.
by the pilot, chase pilot, mobileand many other witnesses were studied;mof the takeoff was reviewed; data extracted from theexamined; and crash recorder data was checked. all Information showed fairly conclusively that thea series of violent and uncontrollable yawing andimmediately after lift-off. The pilot ejectedthe last possible moment before the aircraft crashed.
response to the maintenance and materielof the Incorrect rate gyro wiringhe pilot and two otheraken to Beale AFB where all three accomplishedruns in thelight simulator. Each pilotnormal and unannounced malfunction takeoffs in whichand pitch rate gyro functions to the stability(SAS) were reversed. Results of these tests showedthat the aircraft was completely uncontrollable underconditions. The gyratione of the simulatoridentical to those experienced by the pilot2
ust before the crash.
(5) The sequence of events and subsequent Investigation of the wreckage pinpointed the cause of the accident as being due to the SAS pitch gyros being connected to the yaw servos and vice versa. The results of Incorrect connection are two-fold. First thein this situation does not have any stability augmentation In the pitch and yaw axes. Secondly, every input into one axisommand into the other axis in the following manner:
Pitch Up commands Left Yaw Pitch Down commands Right Yaw Left Yaw commands Pitch Up Right Yaw commands Pitch Down
Thus, when he pilot applied aft stick fores to rotate the aircraft,
HANDLE VTAIIH'J'M i| ill ht
the pitch rate gyroarge rudder input which produced left yaw. This evidenced on the aircraft only upon elimination of the gear restraining force at lift-off. The left yaw commanded additional pitch up which in turn commanded left yaw, etc. Pilot corrective action for either of these motions is augmented by the servo Inputs action upon the wrong gyro signals resultedevere right yaw and nose down motion. When the pilot corrected for this motion he pitchednd yawed left.
Findings
Cause. The primary cause of thismaintenance error inlight line electricianin performing his duty. He connected thefor the yaw and pitch rate gyros of thesystem in reverse.
Causes.
A contributing cause was supervisory errors by the electrical supervisor and the Inspector, both of whom failed to perform their duties properly,
A second contributing causeesign deficiency which made it possible to physically connect the wiring harnesses to the yaw and pitch rate gyros in reverse.
d. Corrective Action
I
the accident, General Ledford conveneda contractors meeting on field inspection/maintenance
In attendance were representatives
of nu tne primary contractors associated with the OXCART vehicle.
General Ledford set the tone of the meeting by requiring all contractors to redouble their efforts at workingero defects level of maintenance.
esult of this meeting, and in compliance with the recommendations of the Accident Investigation Board, the
TOP SECRiT ,
following specific actions havo been taken or are in the process of being accomplished:
Mr. Kelly Johnson of Lockheed Aircraft Corporation Is making necessary arrangements for Improving LAC personnel supervision and training. He is also Improving the techniques of distribution of technical material to LAC maintenance personnel.
Other contractors are implementing end-to-end checks and more deflnitized procedures ln the Lockheed/ other contractor equipment Interface areas.
Renewed detailed attention will be given to compliance with Service Bulletins.
Types and numbers of checklists are being expanded as rapidly as possible. Two engineers are working full time to develop the required checklists and/or expand the existing lists.
anourse tor mechanics and a
for supervisors and inspectors to insure adequate maintenanc training at all-levels. raining record system has been developed to insure that all maintenance personnel receive this training as well as refresher courses at periodic intervals.
(f)reliminary inspection of all areas where possible "Murphy's Law" conditions might exist has been completed. LAC isetailed review of the entire aircraft design to discover any possible similar conditions. This review Is to be completed Provision has also been
made for Inspection of all aircraftew "Murphy"
Item is discovered,
HANDLE VIA
SYSTEM
. -7
ystemsupervisory technical monitors. Headquartersthe additional Detachment personnel required.
improve the quality of supervisors, acoordinated organizational changes are beingthe DCM and contractor personnel iitructure at
changes to lines of responsibility and
functional areas.
omplete and detailed report of the accident investigation Is on file In the office of Brigadier General Leo P. Geary.
director of Reconnaissance, CIA
in nYFintrrural
Joack C. rigadier General USAF Director of Special Activities
Distribution:
RO
- DCIE
-
IA
A
S
A
- Chrono
- RB
HANDLEo iMEM
Original document.
Comment about this article, ask questions, or add new information about this topic: