# NTSB Safety Recommendation P-73-052

**Citation:** P-73-052  
**Type / status:** guidance / guidance  
**Agency:** National Transportation Safety Board  
**Effective:** 1973-11-13  
**Published:** 1973-11-13

THE NTSB RECOMMENDS THAT THE PHILLIPS PIPE LINE COMPANY: AMEND ITS MAINTENANCE OPERATING MANUAL TO INCLUDE A SECTION ON STRESS CONCENTRATION AS A RESULT OF IMPROPER REPAIR WELDING.

## Document text

NTSB safety recommendation P-73-052.

THE NTSB RECOMMENDS THAT THE PHILLIPS PIPE LINE COMPANY: AMEND ITS MAINTENANCE OPERATING MANUAL TO INCLUDE A SECTION ON STRESS CONCENTRATION AS A RESULT OF IMPROPER REPAIR WELDING.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1973-11-13

Adopted Date: 1973-11-07

Overall Date Closed: 1976-07-20

Synopsis: ON FEBRUARY 22, 1973, NATURAL GAS LIQUIDS LEAKED FROM A RUPTURED 10-INCH PIPELINE AT A PUMP STATION IN AUSTIN, TEXAS, FLOWED INTO DITCHES ALONGSIDE A ROAD ADJACENT TO THE STATION, AND VAPORIZED. A DODGE VAN DROVE INTO THE VAPOR-RICH ZONE AND STALLED. WHEN THE DRIVER ATTEMPTED TO RESTART THE ENGINE, THE VAPOR IGNITED, AND THE DRIVER AND SEVEN PASSENGERS WERE ENGULFED IN FLAMES. SIX OF THESE PERSONS DIED AND TWO WERE CRITICALLY BURNED.

Ntsbnumber: PLD73XR005

Report Number: PAR-73-04

Addressee Name: Phillips Petroleum Company

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Organization Type: P-Private Industry

Communication Date: 1974-08-28

Communication Type: Official Correspondence

Communication Contents: LETTER FROM PHILLIPS PIPE LINE COMPANY: PHILLIPS' MAINTENANCE OPERATING MANUAL HAS BEEN AMENDED TO INCLUDE 'PROCEDURES THAT MUST BE FOLLOWED TO AVOID STRESS CONCENTRATIONS' DURING MAINLINE REPAIR AND MAINTENANCE.

## Provenance

- Official: Yes
- Source: <https://data.ntsb.gov/carol-main-public/sr-details/P-73-052>
- Source ID: `ntsb-pipeline`
- SHA-256: `410eb8d80f7c7520fc6997ae2db3599e38d9763f943b8ed6357c830f1d8a1ed1`
- Retrieved: 2026-08-20T04:57:24.741Z
- Exported: 2026-08-24T13:15:37.621Z
- Document slug: `ntsb-recommendation-p-73-052`

### Source metadata

```json
{
  "recordKind": "ntsb_safety_recommendation",
  "safetyRecommendationNumber": "P-73-052",
  "recommendationMode": "Pipeline",
  "topicMode": "Pipeline",
  "ntsbNumber": "PLD73XR005",
  "priority": "CLASS II",
  "overallStatus": "Closed - Acceptable Action",
  "overallStatusAcronym": "CAA",
  "overallDateClosed": "1976-07-20",
  "lastModifiedDate": "2016-11-15",
  "reportNumber": "PAR-73-04",
  "reportUrl": "https://www.ntsb.gov/investigations/Pages/PLD73XR005.aspx",
  "transmittalLetterUrl": "http://www.ntsb.gov/safety/safety-recs/recletters/P73_47_54.pdf",
  "addressees": [
    {
      "addresseeName": "Phillips Petroleum Company",
      "addresseeStatusAcronym": "CNLA",
      "addresseeStatus": "Closed--No Longer Applicable",
      "addresseeDateClosed": "1976-07-20",
      "addresseeDetails": [
        {
          "addresseeAcronym": null,
          "addresseeOrganizationType": "P-Private Industry",
          "isFromNtsb": false,
          "communicationDate": "1974-08-28",
          "communicationType": "Official Correspondence",
          "communicationContents": "LETTER FROM PHILLIPS PIPE LINE COMPANY: PHILLIPS' MAINTENANCE OPERATING MANUAL HAS BEEN AMENDED TO INCLUDE 'PROCEDURES THAT MUST BE FOLLOWED TO AVOID STRESS CONCENTRATIONS' DURING MAINLINE REPAIR AND MAINTENANCE."
        }
      ]
    }
  ],
  "jurisdiction": "US"
}
```