2 Senators Charge Rockwell Failing to Find Shuttle Cracks : Aerospace: NASA says it will assign re-investigations at Rocketdyne. Firm calls the allegations untrue.

Rockwell International is failing to find cracks on the space shuttle’s main engines, posing potentially catastrophic safety hazards, two U.S. senators charged Wednesday.

Sen. William V. Roth Jr. (R-Del.), chairman of the Senate Governmental Affairs Committee, said documents obtained by his committee raise serious questions about inspection procedures on the engine’s high-pressure turbo pumps at Rockwell’s Rocketdyne plant in Canoga Park.

In a letter to NASA chief Daniel Goldin, Roth and Sen. Charles Grassley (R-Iowa) called for an investigation into the alleged safety problems.

“If these allegations are true, this could result in the catastrophic loss of the shuttle,” the lawmakers said.

In light of the latest questions, a NASA spokesman said Wednesday that the agency will assign both its safety and shuttle offices to re-investigate whether Rocketdyne’s inspection procedures are adequate.

Dave Geiger, Rocketdyne’s safety director for shuttle engines, said allegations that the company is failing to find cracks are not true and that prior investigations have “uncovered no evidence for concern.”

Shuttle engines are inspected after each flight and are rebuilt periodically. Cracks are carefully monitored, Geiger said, but not every one is repaired. So far, he said, no engine has ever failed or lost a part for any reason.

The turbo pumps have long been regarded an engineering marvel, but also the highest-risk equipment aboard the vehicle. The pumps, roughly the size of an automobile engine, produce 75,000 horsepower.

The devices pump liquid oxygen and liquid hydrogen from the shuttle’s large external tank to engine combustion chambers. If hooked up to a back-yard swimming pool, the pumps would suck it dry in seconds.

Concerns about the pumps, which operate under enormous internal pressure, first emerged last year when former Rocketdyne inspector Dave Vancil alleged in letters to NASA that Rocketdyne’s inspection system had failed to detect cracks along weld joints.

A NASA investigation disputed Vancil’s allegations, though some other flaws in welds were detected. Vancil was “an employee in good standing,” but left last year as part of a general layoff, Geiger said.

Geiger said Vancil, as well as others, do not understand that the procedures in question represent just one of many rounds of inspection. But Roth’s letter to Goldin disputes that contention, saying Rocketdyne’s own procedures limit redundant inspections.

Even while NASA has defended itself recently, it has paid close attention to any safety problems posed by cracks, documents show.

The Times separately obtained a report under the Freedom of Information Act about another turbo pump crack issue, involving a part called a volute liner.

The NASA report, issued last February, said the agency had found a 1.7-inch crack in the liner of an engine used for ground testing. The report concluded that it was unlikely such a large crack would occur in engines actually used for launching the shuttle.

Roth also released a 1993 Pentagon report harshly critical of Rocketdyne, issued by the Defense Contract Management Command, the agency that administers military rocket engine contracts at an office inside Rockwell’s Rocketdyne plant.

The Pentagon report, a demand for corrective action, asserted that Rocketdyne was experiencing a “quality system breakdown” and that “all hardware is considered suspect.” The defense report, known as a Method C, is the most severe demand for improvement.

Geiger said the problem stemmed from a new computer system used to monitor the certification status of inspectors. Rocketdyne fixed the problem within a few months by getting rid of the computer and going back to a manual system using printed cards, he said.