No positive answer has been found for this incident. Detail inspection of the cable tension regulator has shown it to be normal in all respects. Engineers from NAA have informed us that the design of this cable tension regulator is such that it may be expected to run out of travel with the X-15 subjected to extreme heat conditions. If this occurs, very large frictional loads and binding of the control handle will result. Since the handle seizure disappeared following the high heat portion of the flight profile it appears that such was the case. NAA Engineers have been requested to redesign the regulator to provide additional travel.

B. SAS notch filter case replaced with original (no-notch) case.

Failure of the notch filter case occurred during preflight alignment. The case was returned to the laboratory and a "non-notch" case installed for flight.

B. Failure of the SAS Pump

Failure of the SAS emergency hydraulic pump to operate properly on command occurred during preflight. This pump and its selector valve were rejected and replaced.

B. Smoke was reported as originating in the forward lower floor area of the cockpit as on previous heat flights. This nuisance item will probably recur whenever the forward bulkhead becomes hot enough to sear the paint and sealant. It is tentatively planned to strip the paint from this area during the lay-up for the star tracker modification.

G. The Hycon cameras failed to operate again. The trouble was traced to a poorly insulated light bulb inside the Hycon package, which blew the main fuse. Rework is being made at the Hycon factory.

D. Slight cabin pressure dropoff occurred immediately after burnout. Cabin altitude rose to approximately 43,000. This phenomenon is not new and is suspected to be caused by "G" effects on the cabin regulator. Cabin pressure recovered completely after the dropoff.

E. Alpha indicator oscillations were reported by the pilot. The indicator is under suspicion since the oscillations did not appear on the recorder. Lab investigations are not complete as of date of this report.

F. The lower ventral was not recovered due to parachute riser failure. Subsequent inspection shows that an obsolete deployment bag and riser assembly was installed. Steps are being taken to insure against a repetition of this error. All spares in the warehouse have been inspected and no additional obsolete bags have been found.

G. Except as noted above, subsystem operation was normal. Some rippling of the canopy skirt was noted after the flight, apparently due to heat. Other than this no new wrinkles or cracks were found.