Potter v. Hartzell Propeller, Inc.

• Decision Date: 13 August 1971
• Docket Number: Nos. 42520,42957,s. 42520
• Citation: 189 N.W.2d 499,291 Minn. 513
• Parties: L. A. POTTER, agent for the shareholders of LFD Company, formerly known as the Louis F. Dow Company, Respondent, v. HARTZELL PROPELLER, INC., Respondent. MAXWELL AIRCRAFT SERVICE, INC., defendant and third-party plaintiff, Appellant, v. GOPHER AVIATION, INC., third-party defendant, Respondent.
• Court: Minnesota Supreme Court

Page 499

189 N.W.2d 499

291 Minn. 513

L. A. POTTER, agent for the shareholders of LFD Company, formerly known as the Louis F. Dow Company, Respondent, v. HARTZELL PROPELLER, INC., Respondent.

MAXWELL AIRCRAFT SERVICE, INC., defendant and third-party plaintiff, Appellant, v. GOPHER AVIATION, INC., third-party defendant, Respondent.

Nos. 42520, 42957.

Supreme Court of Minnesota.

Aug. 13, 1971.

Coulter, Nelson & Sullivan, Minneapolis, for appellant.

Meagher, Geer, Markham & Anderson and M. J. Coyne and O. C. Adamson, II, Minneapolis, for L. A. Potter.

Carroll, Cornan, Roth & Austin, Minneapolis, for Hartzell Propeller, Inc.

Faegre & Benson, and W. James Fitzmaurice, Minneapolis, for Gopher Aviation, Inc.

Heard before KNUTSON, C.J., and NELSON, OTIS, PETERSON, and KELLY, JJ.

OPINION

PER CURIAM.

Plaintiff's aircraft crashed on a flight from Florida on January 3, 1965, resulting in total loss of the aircraft. Plaintiff recovered from defendant Maxwell Aircraft Service, Inc., the sum of $66,000, plus interest from the date of loss.

The aircraft, a 1957 model E--18--S twin-engined Beechcraft, was purchased by plaintiff on February 6, 1963. It was equipped at that time with Pratt & Whitney Model R--985--AN--14B engines and Hamilton Standard propellers. Plaintiff purchased from defendant Maxwell new three-bladed propellers, manufactured by defendant Hartzell Propeller, Inc., to replace the original propellers; and on April 29, 1963, these were modified by defendant Maxwell to improve synchronization of the propellers on this twin-engined aircraft. A blade on one of the modified Hartzell propellers fractured during the flight on January 3, 1965, causing the left engine to be wrenched from its mountings and, thereby, causing the accident. The last major overhaul of this left engine was performed on August 14, 1963, by defendant Gopher Aviation, Inc.

The jury, by special verdict, found that the converted propeller which fractured and resulted in the loss of the engine was defective as a result of defendant Maxwell's negligent performance of the work of modification. The other defendants were exonerated from negligence or other responsibility for the crash.

Defendant Maxwell's appeal from the order denying a new trial and from the judgment raises issues concerning the admissibility of certain expert testimony as to the cause of the crash; the claimed concurrent negligence of defendants Hartzell and Gopher, as a matter of law; the admissibility, on the issue of damages, of testimony as to the purchase price of the aircraft; and the right of plaintiff to collect interest on the verdict from the date of loss.

1. Defendant Maxwell's first contention is that it is entitled to a new trial on the issue of liability because the trial court committed prejudicial error in permitting plaintiff's expert to express his opinion on the cause of the accident and in refusing to permit Maxwell's expert to express his opinion on that issue. Maxwell contends that the court imposed inconsistent foundational requirements for reception of testimony by opposing experts.

The record on the issue of causation is both long and complicated, but a short summary of the testimony and proposed testimony of the expert witnesses produced by the parties, together with their asserted qualifications, will suffice for purposes of this narrow issue.

Plaintiff's expert, Dr. Kenneth Packer, was without doubt qualified to give expert testimony. He holds a doctorate in industrial engineering, master of science and bachelor of science degrees in metallurgical engineering, and a bachelor of science degree in chemical engineering. Packer was a Marine Corps pilot during World War II, compiling 1,500 hours of flying time, and also served as acting engineering officer at Cherry Point Marine Air Station. Packer has a commercial pilot's license and is an active pilot. He is president of Packer Engineering Associates, which provides consulting service to industry in materials and manufacturing processes. This company has done work for a number of clients, including evaluation of skin materials for the trisonic transport aircraft for the Department of Transportation, and work in the failure analysis of components of the timing mechanism for space craft retrorockets for N.A.S.A.

Packer's testimony is long, complex, and detailed, culminating in an opinion that the manner in which defendant Maxwell modified the Hartzell propellers caused the propeller blade to fracture which in turn caused the airplane to crash. One of the blades was broken at the shank, about 4 1/16 inches from the butt end of the blade. The separated portion of the blade was not found, but Packer examined the fractured propeller shaft on November 10, 1966. He found, among other things, that the pilot tube hole in the fractured blade was not, after modification, concentric with the blade. He noted, additionally, that there were machining marks on the surface of the bore and that the bronze bushing and needle bearing were improperly seated, permitting the blade to wobble on the pilot tube.

David Biermann, president of defendant Hartzell, testified that there were two contributing causes of the propeller stress which resulted in the engine loss and crash: The condition of the blade shank (which plaintiff's expert, Packer, testified caused the accident), and damper wear (which defendant Maxwell contends caused the crash). Biermann testified that he had no opinion as to which was the primary and which the secondary cause, although the trial court did admit earlier deposition testimony in which Biermann expressed his opinion that the condition of the dampers was the primary cause and that the condition of the blade shank was possibly a secondary cause of unknown magnitude. Biermann's qualifications, which include bachelor's degrees in mechanical and aeronautical engineering and years of practical experience in propeller research and design, are unchallenged.

Defendant Maxwell's expert was its president, Kenneth Maxwell. Maxwell is not an engineer but has been involved in the aviation industry in some capacity since 1933. For a number of years he did 'engine work,' and in 1946 he started overhauling propellers, which is his present specialty. Maxwell holds an F.A.A. certification as a properller repair station operator and is familiar with propellers in the Hartzell line. He testified that he is 'quite familiar' with the Pratt & Whitney R--985--AN--14B engine, but admitted that he had never overhauled the engine and that this familiarity had been acquired through contacts with people who had overhauled such engines and to a limited degree from observing the overhaul process. In an attempt to demonstrate his knowledge of engines, Maxwell explained the location of various engine parts. He also testified that in his business of overhauling and repairing propellers he has occasion to see propellers from damaged aircraft and makes a point of trying to ascertain causes of propeller failure.

Had the trial court permitted Maxwell to give his opinion as to the cause of the propeller failure, he would have testified that the propeller failure was due to the condition of the flyweight liners, dampers, and internal engine parts. The trial court, however, did permit Maxwell to testify as to the effect of the worn condition of the flyweight liners and the flyweights and the galling on the parting surfaces and butt end of the crankshaft. He stated that 'with the balancers out of limits, this puts the propeller and the engine in the critical vibration harmonics which are not compatible, as I understand the approval for the propeller on the engine.'

Defendant Maxwell contends that the trial court applied inconsistent foundational requirements in permitting Packer, on the one hand, to testify that the use of a boring tool to modify the Hartzell propellers was improper, and in not permitting Maxwell, on the other hand, to testify as to the cause of the propeller failure. More specifically, it is contended that Packer should not have been...