Northwest Airlines v. Glenn L. Martin Company

• Decision Date: 31 May 1955
• Docket Number: No. 12130.,12130.
• Citation: 224 F.2d 120
• Parties: NORTHWEST AIRLINES, Inc., The British Aviation Insurance Company, Ltd., The Institute of London Underwriters, R. Walker Roylance and A. J. Whittall, Fidelity & Casualty Company of New York, Appellants, v. GLENN L. MARTIN COMPANY, Appellee.
• Court: U.S. Court of Appeals — Sixth Circuit

224 F.2d 120 (1955)

NORTHWEST AIRLINES, Inc., The British Aviation Insurance Company, Ltd., The Institute of London Underwriters, R. Walker Roylance and A. J. Whittall, Fidelity & Casualty Company of New York, Appellants, v. GLENN L. MARTIN COMPANY, Appellee.

No. 12130.

United States Court of Appeals Sixth Circuit.

May 31, 1955.

Craig Spangenberg, Cleveland, Ohio, argued, M. C. Harrison, Harrison, Spanggenberg & Hull, Cleveland, Ohio, Francis D. Butler, St. Paul, Minn., on the brief for appellants.

Edward D. Crocker and C. M. Horn, Cleveland, Ohio, argued, Arter, Hadden, Wykoff & Van Duzer, Victor DeMarco, Jones, Day, Cockley & Reavis, Cleveland, Ohio, on the brief for appellee.

Before SIMONS, Chief Judge, and McALLISTER and STEWART, Circuit Judges.

STEWART, Circuit Judge.

This was an action for damages brought by appellant, hereinafter referred to as "Northwest," a commercial airline company, against appellee, hereinafter referred to as "Martin," a manufacturer of airplanes.¹ The action was based upon Martin's alleged negligence in the design and manufacture of five "Model 202" airplanes purchased by Northwest, resulting in the loss of one of the planes and the temporary loss of use of four others. No questions of warranty are involved, since the purchase agreement in effect limited Martin's liability to that imposed on it by law for its negligence.

The trial lasted approximately three months. The jury deliberated for ten days before returning general verdicts in favor of Martin.² The appendices on appeal number more than two thousand pages. We are told that the case is one of great importance not only because of its immediate impact upon the rights and liabilities of the parties, but perhaps even more so because of its supposed impact upon the airline and aircraft industries, and the relationships between them. Yet the case remains a negligence action, involving for the most part issues of fact, prolix and technical though they be. From this thick overlay of factual controversy emerge familiar questions of ordinary care, proximate cause, contributory negligence and assumption of risk.

Martin is a Maryland corporation, with its plant and offices near Baltimore. It has been engaged in the design and manufacture of airplanes since 1909. Throughout World War II Martin devoted its efforts completely to the designing and building of military planes, as did the entire aircraft industry. It became apparent in the closing days of the war that the post-war period would provide a large potential market for modern, economical commercial transport planes. Martin decided to enter this market, and accordingly embarked upon the design of the "202," a fast, two-engine airplane which would incorporate many of the engineering and manufacturing advances made during the war period. Commencing early in 1945 the project moved ahead until by 1946 more than five hundred of Martin's designing engineers were working on the "202."

Some time in the summer of 1946, Northwest decided to purchase ten Martin 202's. The formal contract was not signed until February 24, 1947, but it was dated August 31, 1946, and the evidence shows that Northwest's decision to purchase the planes had been made in June of 1946. These ten airplanes were delivered to Northwest in 1947, and they proved so satisfactory that Northwest decided to buy three more 202's and signed the contract for their purchase on December 23, 1947. Northwest made subsequent purchases, so that it owned and was operating a fleet of twenty-five Martin 202's on August 29, 1948, the date on which occurred the dramatic events which provide the immediate background of this case.

At 3:50 p. m. on that day a Northwest 202 airplane, identified hereinafter as "No. 44," took off from Chicago on a regularly scheduled non-stop flight for Minneapolis. It carried thirty-three passengers, a pilot, co-pilot and stewardess. No. 44 was one of the original ten 202's purchased from Martin, and, at the time of taking off, had flown a total of 1,321 hours, or about five per cent of its expected service life. So far as was then known, the airplane was in perfect condition.

During its flight the plane maintained routine operational radio contact with the ground, and at 4:55 p. m. it reported that it was over La Crosse, Wisconsin and estimated that it would arrive over the Hastings marker (near Minneapolis) at 5:21 p. m. The plane was authorized to commence its descent so as to pass over the Hastings marker at an altitude of 2,500 feet and was directed to report when it passed through the 7,000 foot level on its descending path. At 4:56 p. m. the pilot radioed that he was beginning his descent and at 4:59 p. m. he advised that he was passing through the 7,000 foot level. No further messages were received from No. 44.

At about this time the plane was observed by witnesses on the ground proceeding into a violent thunderstorm. A few minutes later, at approximately 5:05 p. m., the left wing tore off, and the airplane crashed near Fountain City, Wisconsin, a few miles to the northeast of Winona, Minnesota. All of the passengers and crew were killed. Subsequent investigation revealed that the immediate cause of the crash was the breaking of a front wing spar in the left wing at the point where the outer section of the wing was attached.

Later the same day, when all that was known of No. 44 was that it was overdue, another Northwest 202, hereinafter referred to as "No. 42," was flown on a regularly scheduled round-trip flight from Minneapolis to Duluth. No. 42 was also one of the original ten 202's purchased from Martin by Northwest. It too had flown only a small fraction of its expected service life. The weather was fair, the air smooth, and the trip uneventful, except that the pilot noticed that in order to keep the plane in level flight, it required a somewhat unusual amount of extra "trim tab." After the pilot landed No. 42 in Minneapolis, he made a routine report, including a statement about the unusual trim conditions which he had encountered, and then got into his automobile to drive home. Fortunately, however, he changed his mind and returned to the ramp where No. 42 was parked. He located the head of the Northwest inspection crew, told him in detail what he had noticed on the trip to Duluth, and urged that the plane be carefully examined before being allowed to depart on its next trip. Accordingly, the inspectors did make a thorough examination and found that a joint in the right wing of No. 42 was completely broken, and that the wing was being held in place only by its "skin." It was the same side of the same step of the same joint that had broken in No. 44.

By this time Northwest had learned of the crash of No. 44, and its remaining twenty-three 202 airplanes were immediately grounded and thoroughly inspected. The inspection of these airplanes was made jointly by Northwest and Martin. The wings of the airplanes were all disassembled, and it was discovered that of the four remaining airplanes which had flown in excess of 1,200 hours, all had fatigue cracks in the wing joints, exactly where the wings of 44 and 42 had broken. Of the fifteen airplanes which had flown between 500 and 1,200 hours, seven were found to have fatigue cracks in the same wing joint. Of the four airplanes which had flown less than 500 hours, no such fatigue cracks were found. It is conceded that the broken parts of the wing joints of Nos. 44 and 42 which caused the loss of the first plane and damage to the second were caused by failures which began and developed as fatigue cracks. It is further conceded that the expected safe service life of the 202 had been between twenty-five and thirty thousand hours. All of Northwest's 202's were subsequently rebuilt in two successive phases, and the danger of premature fatigue failures in the wing joints was successfully eliminated.

Northwest then brought this action for damages resulting from the loss of No. 44 and for the loss of use of No. 42 and three other 202's during the time they were being repaired. It was Northwest's contention that the fatigue cracks were the direct result of Martin's negligence in a number of different respects in the design and manufacture of the 202 airplanes.

In order properly to understand this contention, it is necessary to review briefly the evidence as to the cause and nature of fatigue in metal. Fatigue is the phenomenon by virtue of which a metal part will eventually crack and break under repeated loads, each one of which is less than its tensile strength for one load. Three of the factors which affect fatigue life are, first, the kind of metal; second, the amount of repeated load as related to the strength of the metal for one load; and third, the configuration and surface condition of the metal.

It is known that a metal which is smooth and highly polished is less subject to fatigue than one with a rough finish or the surface of which is marred by a scratch or notch. A rough surface is called a "stress raiser." Abrupt changes of section in the metal are also "stress raisers," as are notches and bolt holes. It is stress concentration which is the fundamental cause of fatigue failure.

The fatigue life of some metals seems to be much more affected by stress raisers than does that of others. Those metals are said to be "notch sensitive." The Martin 202 was made from an aluminum alloy called 75ST, which was known to be much more notch sensitive than the alloy 24ST which had been used before 75ST was developed.

It was Northwest's contention that the wing joints which cracked and broke in Nos. 42 and 44, and which cracked in the other airplanes, had a number of unnecessary stress raisers which were the result of Martin's negligence in design and manufacture, and that it was these stress raisers which caused the premature fatigue failure at the bottom of the fourth step at the outer end of the front spar of the center wing. Northwest alleged...