**Source:** This document taken from the Report of Apollo 204 Review Board--NASA Historical Reference Collection, NASA History Office, NASAHeadquarters, Washington, DC.

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**The Accident**

## 3. Events From Initiation Of The T-10 Minute Hold At 23:20 GMT Until The Report Of Fire

From the start of the T-10 minute hold at 23:20 GMT until about 23:30 GMT there are no events that appear to be related to the fire. The major activity during this period was routine troubleshooting of the communications problem. The records show that except for the communications problem all systems were operating normally during this period. There were no voice transmissions from the spacecraft from 23:30:14 GMT until the transmission reporting the fire which began at 23:31:04.7 GMT (6:31:04.7 p.m. EST).

During the period beginning about 30 seconds before the report there are indications of crew movement. These indications are provided by the data from the Biomedical Sensors, the Command Pilot's live mike, the Guidance and Navigation System and the Environmental Control System.

There is, however, no evidence as to what this crew movement was or that it was related to the fire.

The biomedical data indicate that just prior to the fire report the Senior Pilot was performing essentially no activity (or was in the baseline "rest" condition) until about 23:30:21 GMT when a slight increase in pulse and respiratory rate was noted. At 23:30:30 GMT the electrocardiogram indicates some muscular activity for several seconds. Similar indications are noted at 23:30:39 GMT. The data show increased activity but are not indicative of an alarm type of response. By 23:30:45 GMT, all of the biomedical parameters had reverted to the baseline "rest" level.

Beginning at about 23:30 GMT, the Command Pilot live microphone transmitted brushing and tapping noises which are indicative of movement. The noises were similar to those transmitted earlier in the test by the live mike when the Command Pilot is known to have been moving. These sounds end at 23:30:58.6 GMT.

Any significant crew movement results in minor motion of the Command Module. This motion is detected by the Guidance and Navigation System and is indicative of crew movement; however, the type of movement cannot be determined. Data from this system indicate a slight movement at 23:30:24 GMT with more intense activity beginning at 23:30:39 GMT. More movement begins at 23:31:00 GMT and continues until loss of data transmission during the fire.

 Increases of oxygen flow rate to the crew suits also indicate movement. All suits have some small leakage. This leakage rate varies with crew positions. Earlier in the Plugs-Out Test, the crew reported that a particular movement, the nature of which was unspecified, provided increased flow rate. This is also confirmed from the flow rate data records. The flow rate shows a gradual rise at 23:30:24 GMT which reaches the limit of the sensor at 23:30:59 GMT.

There is a variation at 23:30:50 GMT in the signal output from the gas chromatograph cable (the gas chromatograph was not installed in the Command Module). When the gas chromatograph is not connected, the cable acts as an antenna. Thus, changes in the electromagnetic field within the spacecraft are sensed when the cable is approached closely, touched or moved or voltage fluctuations occur in other equipment. Variations found in the signal level from the gas chromatograph cable at earlier times in the test have been correlated with either crew movement or voltage transients when equipment was turned off or on at these earlier times. The variation at 23:30:50 GMT, may have resulted because it was touched or approached by the crew since there does not appear to be any voltage transient condition at this time which could have given the observed signal.

A significant voltage transient was recorded at 23:30:54.8 GMT. The records show a surge in the AC Bus 2 Voltage.

Several other parameters being measured also showed anomalous behaviour at this time. There was a 1.7-second dropout in signal from the C-band decoder and transmitter outputs, a brief dropout of the VHF-FM carrier, a fluctuation in the rotation controller null outputs and a fluctuation in the gas chromatograph signal.

## 4. Events From The Report Of Fire Until Crew Removal

The events that occurred during this period can be comprehended most readily by examination of Enclosures 2, Enclosures 3, Enclosures 4, Enclosure 5 and Enclosure 6. These enclosures show a sketch of Launch Complex 34, the Space Vehicle in the service tower and the interior of a mock-up of a Command Module detailed reconstruction of Spacecraft 012.

Beginning at 23:31:04.7 GMT (6:31:04.7 P.M. EST), the crew gave the first verbal indication of an emergency -- a fire in the Command Module was reported.

Emergency procedures called for the Senior Pilot, occupying the center couch, to unlatch and remove the hatch while retaining his harness buckled. A number of witnesses who observed the television picture of the Command Module hatch window during this stage of the fire discerned motion that suggests that the Senior Pilot was reaching for the inner hatch handle. The Senior Pilot's harness buckle was found unopened after the fire, indicating that he initiated the standard hatch-opening procedure. Data from the Guidance and Navigation System indicate considerable activity within the Command Module after the fire was discovered. This activity is consistent with movement of the crew prompted by proximity of the fire or with the undertaking of standard emergency egress procedures.

Personnel located on adjustable level 8 (A-8) adjacent to the Command Module responded to the report of the fire. The Pad Leader ordered crew egress procedures to be started and technicians started toward the White Room which surrounds the hatch and into which the crew would step upon egress. Then the Command Module ruptured.

All transmission of voice and data from the spacecraft terminated by 23:31:22.4 GMT, three seconds after rupture. Witnesses monitoring television showing the hatch window report that flame spread from the left to the right side of the Command Module and shortly thereafter covered the entire visible area.

Flames and gases flowed rapidly out of the ruptured area, spreading flames into the toroidal space between the Command Module pressure vessel and heat shield, through access hatches and into levels A-8 and A-7 of the service structure. These flames ignited combustibles, endangered pad personnel, and impeded rescue efforts. The burst of fire, together with the sounds of rupture, caused several pad personnel to believe that the Command Module had exploded or was about to explode. Pad personnel fled from the immediate area.

The immediate reaction of all personnel on level A-8 was to evacuate the level. This reaction was promptly followed by a return to effect rescue. Upon running out on the swing arm from the umbilical tower, several personnel obtained a fire extinguisher and returned along the swing arm to the White Room to begin rescue efforts. Others obtained fire extinguishers from various areas of the service structure and rendered assistance in fighting the fires.

The time interval between exit to the swing arm and return to the White Room is estimated variously by the participants. Persons viewing television monitors could not see movement early in the White Room because of heavy smoke. Approximately one minute and thirty seconds after the first crew report of the fire the Pad Leader reported over his headset that attempts had been started to remove the hatches. This report was made after the Pad Leader had gone out on the swing arm, returned and entered the White Room one or two times and left to reach breathable air and his headset. It is therefore estimated that attempts to remove the hatches began one minute after the fire was first reported.

Three hatches were installed on the Command Module. The outermost hatch, called the boost protective cover (BPC) hatch, is part of the cover which shields the Command Module during lauch and is jettisoned prior to orbital operation. The middle hatch is termed the ablative hatch and becomes the outer hatch when the BPC is jettisoned after launch. The inner hatch closes the pressure vessel wall of the Command Module and is the first hatch to be opened by the crew in an unaided crew egress.

The outer or BPC hatch was in place but not fully latched because of distortion in the BPC caused by wire bundles temporarily installed for the test. The middle hatch and inner hatch were in place and latched after crew ingress.

Although the BPC hatch was not fully latched it was necessary to insert a specially-designed tool into the hatch in order to provide a hand-hold for lifting the hatch from the Command Module. At this time the White Room was filling with dense, dark smoke from the Command Module interior and from secondary fires throughout level A-8. While some personnel were able to locate and don operable gas masks others were not. Some proceeded without masks while others attempted without success to render masks operable. Even operable masks were unable to cope with the dense smoke present because they were designed for use in toxic rather than dense smoke atmospheres.

Visibility in the White Room was virtually zero. It was necessary to work essentially by touch since visual observation was limited to a few inches at best. A hatch removal tool was in the White Room. Once the small fire near the BPC hatch had been extinguished and the tool located the Pad Leader and an assistant removed the BPC hatch. Although the hatch was not latched, removal was difficult.

The personnel who removed the BPC hatch could not remain in the White Room because of the smoke. They left the White Room and passed the tool which was necessary to open each hatch to other individuals. A total of five individuals took part in opening the three hatches and each made several trips into the White Room and out for breathable air.

The middle hatch was removed with less effort than was required for the outer or BPC hatch.

The inner hatch was unlatched and an attempt was made to raise it from its support and to lower it to the Command Module floor. The hatch could not be lowered the full distance to the floor and was instead pushed to one side. When the inner hatch was opened intense heat and a considerable amount of smoke issued from the interior of the Command Module.

When the Pad Leader ascertained that all hatches were open, he left the White Room, proceeded a few feet along the swing arm, donned his headset and reported this fact. From a voice tape it has been determined that this report came approximately five minutes, twenty-seven seconds after the first report of the fire. The Pad Leader estimates that his report was made no more than thirty seconds after the inner hatch was opened. Therefore, it is concluded that all hatches were opened and the two outer hatches removed approximately five minutes after the report of fire or at about 23:36 GMT. A log maintained by a person monitoring voice transmissions from level A-8 sets the time of the Pad Leader's report at 23:36 GMT. All records in this log are noted in minutes with no indication of seconds. Medical opinion, based on autopsy reports, has concluded that chances of resuscitation decreased rapidly once consciousness was lost and that resuscitation was impossible by 23:36 GMT.

Visibility within the Command Module was extremely poor. Although the lights remained on, they could be perceived only dimly. No fire was observed. Initially, the crew was not seen. The personnel who had been involved in removing the hatches attempted to locate the crew without success.

Throughout this period, other pad personnel were fighting secondary fires on level A-8. There was considerable fear that the launch escape tower, mounted above the Command Module, would be ignited by the fires below and destroy much of the launch complex.

Shortly after the report of fire, a call was made to the fire department. From log records, it appears that the fire apparatus and personnel were dispatched at about 23:32 GMT. After hearing the report of the fire, the doctor monitoring the test from the blockhouse near the pad proceeded to the base of the umbilical tower.

The exact time at which firemen reached Level A-8 is not known. Personnel who opened the hatches unanimously state that all hatches were open before any firemen were seen on the level or in the White Room. The first firemen who reached Level A-8 state that all hatches were open, but that the inner hatch was inside the Command Module, when they arrived. This places arrival of the firemen after 23:36 GMT. It is estimated on the basis of tests, that seven to eight minutes were required to travel from the fire station to the launch complex and to ride the elevator from the ground to Level A-8. Thus, the estimated time of firemen arrival at level A-8 is shortly before 23:40 GMT.

When the firemen arrived, the positions of the crew couches and crew could be perceived through the smoke but only with great difficulty. An unsuccessful attempt was made to remove the Senior Pilot from the Command Module.

Initial observations and subsequent inspection reveal the following facts. The Command Pilot's couch (the left hand couch) was in the "170 degree position," in which it is essentially horizontal throughout its length. The foot restraints and harness were released and the inlet and outlet oxygen hoses were connected to the suit. The electrical adapter cable was disconnected from the communications cable. The Command Pilot was lying supine on the aft bulkhead or floor of the Command Module, with his helmet visor closed and locked and with his head beneath the Pilot's head rest and his feet on his own couch. A fragment of his suit material was found outside the Command Module pressure vessel five feet from the point of rupture. This indicates that his suit had failed prior to the time of rupture (23:31:19.4 GMT) allowing convection currents to carry the suit fragment through the rupture.

The Senior Pilot's couch (the center couch) was in the "96 degree" position in which the back portion is horizontal and lower in the raised position. The buckle releasing the shoulder straps and lap belts was not opened. The straps and belts were burned through. The suit oxygen outlet hose was connected but the inlet hose was disconnected. The helmet visor was closed and locked. The Pilot was supine on his couch. 

From the foregoing it has been determined that in all probability the Command Pilot left his couch to avoid the initial fire, the Senior remained in his couch as planned for emergency egress, attempting to open the hatch until his restraints burned through and the Pilot remained in his couch to maintain communications until the hatch could be opened by the Senior Pilot as planned. With a slightly higher pressure inside the Command Module than outside, opening the inner hatch is impossible because of the resulting force on the hatch. Thus the inability of the pressure relief system to cope with pressure increase due to the fire made opening of the inner hatch impossible until after cabin rupture, and after rupture the intense and widespread fire together with rapidly increasing carbon monoxide concentrations further prevented egress.

Whether the inner hatch handle was moved by the crew cannot be determined because the opening of the inner hatch from the White Room also moves the handle within the Command Module to the unlatched position.

Immediately after the firemen arrived, the Pad Leader on duty was relieved to allow treatment for smoke inhalation. He had first reported over the headset that he could not describe the situation in the Command Module. In this manner he attempted to convey the fact that the crew was dead to the Test Conductor without informing the many people monitoring the communication channels. Upon reaching the ground the Pad Leader told the doctors that the crew was dead. The three doctors proceeded to the White Room and arrived there shortly after the arrival of the firemen. The doctors estimate their arrival to have been at 23:45 GMT. The second Pad Leader reported that medical support was available at approximately 23:43 GMT. The three doctors entered the White Room and determined that the crew had not survived the heat, smoke, and thermal burns. The doctors were not equipped with breathing apparatus, and the Command Module still contained fumes and smoke. It was determined that nothing could be gained by immediate removal of the crew. The firemen were directed to stop removal efforts.

When the Command Module had been adequately ventilated, the doctors returned to the White Room with equipment for crew removal. It became apparent that extensive fusion of suit material to melted nylon from the spacecraft would make removal very difficult. For this reason it was decided to discontinue efforts at removal in the interest of accident investigation and to photograph the Command Module with the crew in place before evidence was disarranged.

Photographs were taken, and the removal efforts resumed at approximately 5:30 GMT (12:30 a.m. EST) on January 28. Removal of the crew took approximately 90 minutes and was completed about seven and one-half hours after the accident.

**Description of Test Sequence And Objectives | History Of The Accident | Investigation And Analysis | Findings, Determinations And Recommendations**
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Updated February 19, 2009    Steve Garber, NASA History Web Curator     For further information E-mail histinfo@hq.nasa.gov
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