                      United States Court of Appeals
                           FOR THE EIGHTH CIRCUIT
                                    ___________

                                    No. 06-3855
                                    ___________

Sammie Sappington; Evelyn                *
Sappington; Justin Sappington,           *
                                         *
             Plaintiffs - Appellants,    *
                                         * Appeal from the United States
      v.                                 * District Court for the Western
                                         * District of Missouri.
Skyjack, Inc., A Division of Linamar     *
Corp., A Canadian Corporation; Rental *
Services Corporation, Inc.,              *
                                         *
             Defendants - Appellees.     *
                                    ___________

                              Submitted: October 15, 2007
                                 Filed: January 4, 2008
                                  ___________

Before BYE, BOWMAN, and SMITH, Circuit Judges.
                           ___________

BYE, Circuit Judge.

      Sammie Sappington, Evelyn Sappington, and Justin Sappington (plaintiffs)
appeal the district court's order excluding the testimony of their retained experts and
granting summary judgment in favor of Skyjack, Inc., and Rental Services
Corporation, Inc. (RSC). We reverse.
                                            I

       This strict products liability action arises out of the death of Doyle Sappington,
a carpenter employed by a general contractor performing work on a parking garage
construction project in Kansas City, Missouri. On the day of the accident, Sappington
was operating a scissors lift,1 Model SJII 4626 (SJII), manufactured by Skyjack. The
lift was owned by RSC and had been leased to a subcontractor on the construction
project.

        The Skyjack SJII, and the later manufactured Skyjack SJIII 4626 lift (SJIII), are
forty-six inches wide and can be elevated to a working height of twenty-six feet. The
Skyjack SJIII differs from the SJII primarily because Skyjack incorporated "pothole
protection" into its design. Pothole protection is an industry term of art, referring to
design features intended to enhance stability in the event a lift is driven into a
depression or pothole. Pothole protection, as the phrase is used here, refers
specifically to a system of drop-down stabilizing bars located at the bottom sides of
the lift platform, which, when deployed, reduce the lift's ground clearance. When
activated, the pothole protection design on the SJIII reduces ground clearance from
3 1/4 inches to 3/4 inches, thereby increasing stability by reducing the distance the
SJIII drops if it enters a depression.

        Both models have controls located on the work platform which allow the
operator to raise and lower the work platform, and drive the lift forward and backward
without lowering the platform. At the time of the accident, Sappington was operating
the lift on a smooth concrete surface with a slope of approximately 0.07 percent, and
the work platform was raised to at or near its maximum level of twenty-six feet. The

      1
       A scissors lift is a mobile work platform commonly used on construction sites
as an alternative to stationary scaffolding. It takes its name from the operating
mechanism used to elevate the work platform which resembles and operates like a
scissors.

                                          -2-
accident occurred when he drove the lift in reverse and the rear wheels dropped off
the concrete floor into a hole created earlier in the day when a portion of the concrete
floor was removed. When the rear wheels dropped off the edge of the walkway, the
lift became unstable, pitched backwards, and tipped over. Sappington fell from the
lift and later died from his injuries.

        Plaintiffs, (Evelyn (Doyle's mother), Sammie (Doyle's daughter), and Justin
(Doyle's son)), brought a strict products liability claim against the manufacturer of the
lift, Skyjack, and the lift owner/lessor, RSC.2 Plaintiffs allege the SJII was defective
and unreasonably dangerous because it was not sufficiently stable to remain upright
when its wheels dropped into the hole. They contend Skyjack should not have
manufactured the lift without pothole protection, and all lifts currently manufactured
are so equipped, including the SJIII, the successor to the SJII. Plaintiffs argue the
pothole protection technology incorporated into the design of the SJIII, manufactured
two years after the SJII lift involved in the accident, was available and feasible in
1995 when the subject SJII lift was manufactured. Plaintiffs contend 1) the SJIII
design would have prevented the tip-over accident, 2) the design was available at the
time the SJII was manufactured, i.e., economically and technologically feasible, and
3) the safer design should have been used by Skyjack instead of the SJII design.
Plaintiffs also allege RSC had both SJII and SJIII lifts available for lease and the SJII
it leased to the subcontractor was defective and unreasonably dangerous.

      To support their strict products liability claims, plaintiffs hired two experts.
The first, Bryan Johnson, was hired to perform testing on an SJIII lift to determine
whether, under conditions similar to those at the accident scene, it would remain
upright. Johnson placed the SJIII on a wooden platform, sloped at approximately two
degrees, which raised the lift seven inches off the road surface. He loaded the lift's


      2
       The original complaint alleged additional causes of action which have been
dismissed and are not relevant to this appeal.

                                          -3-
work platform with 205 pounds, raised it to its maximum height of twenty-six feet,
and drove it at a top speed forward and backward until the wheels dropped off the
edge of the platform. On each occasion, the lift remained upright.

       The second expert, Dr. James Blundell, is an associate professor of mechanical
engineering with the undergraduate mechanical engineering school at the University
of Missouri, Kansas City. He holds a PhD in mechanical engineering and teaches
courses in machine design and design safety. In connection with his work on the case,
Dr. Blundell reviewed depositions (including testimony detailing stability testing of
the SJIII conducted by Skyjack), accident scene photographs, photographs from
Skyjack's post-accident investigation, reports authored by Johnson and Ken Zimmer
(plaintiffs' previous expert witness), the OSHA investigation file, documents produced
under seal by Skyjack, the SJII and SJIII operating manuals, American National
Standards Institute (ANSI) standards A92.6-1990 and 1999 for "Self Propelled
Elevating Work Platforms," and a video created by Mayville Engineering Company
(MEC), entitled Pot Hole Protection Can You Live Without It? Dr. Blundell did not
conduct independent testing, but instead relied on stability testing of the SJIII lift
performed by Johnson and Skyjack.

       Dr. Blundell stated the SJII operated by Sappington was defective and
unreasonably dangerous because it did not remain upright when its wheels dropped
into the depression. He further opined the pothole protection would have prevented
the unit from overturning. Dr. Blundell concluded, based on his review of current
ANSI standards, that elevated lifts are now required to withstand the instability
encountered in Sappington's accident. He further stated the SJIII was technically and
economically feasible when the SJII was manufactured in 1995,3 and complies with

      3
        When discussing feasibility, Dr. Blundell used the term interchangeably with
"state of the art." By doing so, he created some confusion because state of the art is
also used to describe a defense which may be offered by a manufacturer to a claim of
negligence based on products liability. By state of the art, Dr. Blundell means the

                                         -4-
the current ANSI standard. See ANSI Standard A92.6 (American National Standard
for Self-propelled Elevating Work Platforms) (promulgated 1999 and replacing ANSI
Standard A92.6 promulgated 1990). In other words, according to Dr. Blundell, the
SJIII could and should have replaced the SJII by 1995, and the accident would not
have occurred had Sappington been using an SJIII lift.4

       As evidence of feasibility, Dr. Blundell's report indicated other lift
manufacturers, e.g., MEC, Snorkel, and Upright, recognized the need for and
incorporated pothole protection into their designs before the SkyJack II involved in
the accident was manufactured; in MEC's case, as early as 1987. Additionally, he
identified internal Skyjack memoranda, dated beginning January 1995, discussing the
need to implement pothole protection, and reflecting plans to do so as of August 1995.



       After discovery, Skyjack and RSC moved to exclude the testimony of both
experts, and for summary judgment, arguing that without expert testimony plaintiffs
could not prove the SJII lift was defective and unreasonably dangerous. The district
court, relying on Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993),
held the experts' testimony was neither relevant or reliable and excluded the evidence.
It further held plaintiffs could not prove their claims without expert testimony and
granted summary judgment. On appeal, plaintiffs argue the district court abused its
discretion when it excluded the expert testimony, and summary judgment was
inappropriate.


technology was available and economically feasible.
      4
       The applicable ANSI standard does not explicitly mention pothole protection.
Dr. Blundell, however, testified the testing mandated by the standard requires lifts to
remain stable when tested under drop off conditions. According to Dr. Blundell, to
meet the standard's testing requirements, all manufacturers have incorporated pothole
protection. Thus, Dr. Blundell opined the effect of the standard is to require pothole
protection.

                                         -5-
                                          II

       We review a grant of summary judgment de novo, applying the same standard
as the district court. Jaurequi v. Carter Mfg. Co., Inc., 173 F.3d 1076, 1085 (8th Cir.
1999). Summary judgment is proper if there exists no genuine issue as to any material
fact and the moving party is entitled to judgment as a matter of law. Fed. R. Civ. P.
56(c). When ruling on a summary judgment motion, a court must view the evidence
"in the light most favorable to the nonmoving party." Dush v. Appleton Elec. Co.,
124 F.3d 957, 962-63 (8th Cir. 1997) (citing F.D.I.C. v. Bell, 106 F.3d 258, 263 (8th
Cir. 1997)). However, a "nonmovant must present more than a scintilla of evidence
and must advance specific facts to create a genuine issue of material fact for trial."
F.D.I.C., 106 F.3d at 263 (citing Rolscreen Co. v. Pella Prods. of St. Louis, Inc., 64
F.3d 1202, 1211 (8th Cir. 1995)).

      This is a diversity action and is governed by state substantive law. Erie R.R.
v. Tompkins, 304 U.S. 64, 78 (1938). The parties agree Missouri substantive law
controls.

                                          A

      Under Missouri law,

      [T]he term "products liability claim" means a claim or portion of a claim
      in which the plaintiff seeks relief in the form of damages on a theory that
      the defendant is strictly liable for such damages because:

      (1) The defendant, wherever situated in the chain of commerce,
      transferred a product in the course of his business; and
      (2) The product was used in a manner reasonably anticipated; and
      (3) Either or both of the following:
      (a) The product was then in a defective condition unreasonably
      dangerous when put to a reasonably anticipated use, and the plaintiff was

                                         -6-
      damaged as a direct result of such defective condition as existed when
      the product was sold; or
      (b) The product was then unreasonably dangerous when put to a
      reasonably anticipated use without knowledge of its characteristics, and
      the plaintiff was damaged as a direct result of the product being sold
      without an adequate warning.

Mo. Rev. Stat. § 537.760.

       To prove a claim of strict products liability, a Missouri plaintiff "must prove
that the product was defective and dangerous when put to a reasonable use anticipated
by the manufacturer and that the plaintiff sustained damage as a direct result of the
defect." Peters v. Gen. Motors Corp., 200 S.W.3d 1, 17 (Mo. Ct. App. 2006)
(citations omitted); see also Nesselrode v. Executive Beechcraft, Inc., 707 S.W.2d
371, 375 (Mo. 1999) (en banc) ("[T]he primary inquiry in a design defect case is
whether the product – because of the way it is designed – creates an unreasonable risk
of danger to the consumer or user when put to normal use.").

       In Missouri, "the concept of 'unreasonable danger' is to be treated as an ultimate
issue for the jury." Rodriquez v. Suzuki Motor Corp., 996 S.W.2d 47, 65 (Mo. 1999)
(en banc) (citing Nesselrode, 707 S.W.2d at 378). Missouri courts have consistently
refused to impose any "judicial definition [of unreasonably dangerous] whether
derived from consumer expectations, risk-utility, or otherwise." Id. Instead, juries
"give the concept of unreasonable danger content by applying their collective
intelligence and experience to the broad evidentiary spectrum of facts and
circumstances presented by the parties." Thompson v. Brown & Williamson Tobacco
Corp., 207 S.W.3d 76, 90 (Mo. Ct. App. 2006) (citations and quotations omitted).
The parties are "entitled to assist the jury in defining the term 'unreasonably
dangerous' by presenting evidence that the utility of a design outweighs its risks, or
that consumer expectations were violated, or any other theory of unreasonable
dangerousness supported by the evidence." Id. (citations and quotations omitted).


                                          -7-
Such evidence, however, is not required and a plaintiff is not, for example, "required
to prove the existence of a reasonable alternative design in order to make a
submissible case." Id. at 90-91. Further, a plaintiff has no burden to prove a product
failure or malfunction, Stinson v. E.I. DuPont De Nemours and Co., 904 S.W.2d 428,
431 (Mo. Ct. App. 1995) (citation and quotations omitted), and "[t]he existence of a
defect may be inferred from circumstantial evidence with or without the aid of an
expert witness," Klein v. General Elec. Co., 714 S.W.2d 896, 900 (Mo. Ct. App.
1986).

       For summary judgment purposes, the evidence plaintiffs offer shows the SJII
lift Sappington was operating was manufactured and leased by defendants. Further,
the alleged defect, i.e., the failure of the lift to remain stable during an encounter with
a drop off, existed at the time the lift was manufactured and leased. Neither defendant
contends the subject lift had been altered in any manner. Finally, there is no dispute
Sappington's death was the direct result of injuries he sustained when the lift
overturned.

       Additionally, there has been no evidence offered to suggest Sappington was
using the SJII lift in a manner not reasonably anticipated. Skyjack hints Sappington
was at fault for the accident because he failed to observe the depression, and
Sappington caused the accident when he drove the lift into the pothole. Using lifts at
constructions sites, where depressions or potholes are common, does not constitute an
unforeseeable misuse of the product. Furthermore, even assuming the depression
constituted an open and obvious hazard, and Sappington's fault contributed to the
accident, "[e]vidence that the defect was readily apparent would not bar plaintiffs'
recovery, but could be properly considered in apportioning fault." Miller v. Varity
Corp., 922 S.W.2d 821, 826 (Mo. Ct. App. 1996).

       The defendants also suggest the absence of evidence of other accidents is fatal
to plaintiffs' claims. "Evidence of the absence of other accidents has been held

                                           -8-
relevant and admissible in a product liability case." Savant v. Lincoln Eng'g, 899
S.W.2d 120, 122 (Mo. Ct. App. 1995). A defendant offering such evidence, however,
must show "no accidents occurred when the product was used under conditions
substantially similar to those faced by plaintiff and that an adequate number of those
situations occurred to make the absence of accidents meaningful." Id. Even assuming
a lack of other accident evidence could, as a matter of law, bar plaintiffs' claims, there
has been no such evidence offered in this case.

     In considering defendants' arguments, the district court, relying on Morrison v.
Kubota Tractor Corp., 891 S.W.2d 422 (Mo. Ct. App. 1994), noted:

      [W]here the perilous nature of the product and the danger of using it is
      obvious and not concealed; where its normal functioning creates no
      danger not known or appreciated by the user; where it is properly
      manufactured to accomplish the function for which it is designed, the
      manufacturer has satisfied the law's demands and is under no duty to
      make it "more" safe by providing a built-in safety device.

Dist. Ct. Order, p. 20.

       Morrison, however, is inapposite, and offers no support for the district court's
erroneous decision to grant summary judgment. In Morrison, the Missouri court of
appeals was asked to determine whether a trial court erred in directing verdicts on
plaintiffs' negligence claims. 891 S.W.2d at 427-28. The court of appeals held a
manufacturer cannot be held liable under a negligent design theory when the defect
or danger is open, obvious and apparent. Id. The holding of Morrison, however, was
specifically limited to negligence claims. Id. at 427-28 n.5. Since Morrison, the court
of appeals has confirmed the open and obvious nature of a hazard does not bar
recovery by a plaintiff in a strict products liability claim, but may be considered in
apportioning fault. Miller, 922 S.W.2d at 826.



                                           -9-
       The district court ultimately concluded, and the defendants assert on appeal,
that plaintiffs cannot maintain a submissible claim for strict products liability without
the excluded expert testimony. We disagree. A claim of strict products liability may
be based solely upon circumstantial evidence and does not require expert testimony.
Klein, 714 S.W.2d at 900. Moreover, a Missouri plaintiff is not required to present
evidence "that the utility of a design outweighs its risks, or that consumer expectations
were violated, or any other theory of unreasonable dangerousness supported by the
evidence." Thompson, 207 S.W.3d at 90. In this case, the contested issue on
summary judgment is whether the lift was unreasonably dangerous, and is an issue
which resides solely within the province of the jury. Rodriguez, 996 S.W.2d at 65.
Plaintiffs contend Sappington was killed because the lift failed to remain upright when
it encountered the depression – a common workplace hazard. According to plaintiffs,
the propensity for lifts to tip over when driven into drop offs was a concern within the
industry before the subject lift was manufactured. Plaintiffs have offered evidence
tending to show the technology exists, and indeed existed in 1995, to manufacture
more stable lifts – including a lift which would not have overturned under the
conditions presented by this accident. This evidence does not require the testimony
of experts, and we are not able to say, under Missouri's law of strict products liability,
there is no conceivable way for plaintiffs to convince a jury the lift was unreasonably
dangerous.

      It is true that manufacturers need only build "reasonably safe" [products],
      and that when plaintiffs fail to prove otherwise they do not make a
      submissible case. Nevertheless, this determination is normally made
      after plaintiff puts on evidence. Unless there is no conceivable way for
      plaintiff to prove the ultimate facts alleged, plaintiff should be allowed
      to proceed.

Threats v. Gen. Motors Corp., 890 S.W.2d 327, 329 (Mo. Ct. App. 1994) (emphasis
in original) (citation omitted).



                                          -10-
      Accordingly, we determine summary judgment was improvidently granted.

                                            B

      We next consider – and reject – the district court's bases for excluding the
testimony of plaintiffs' experts.

       The district court's exclusion of expert testimony is reviewed for an abuse of
discretion. Turner v. Iowa Fire Equip. Co., 229 F.3d 1202, 1207 (8th Cir. 2000).

        The admissibility of expert testimony is governed by Federal Rule of Evidence
702; under Rule 702 the trial judge acts as a "gatekeeper" screening evidence for
relevance and reliability. Daubert, 509 U.S. at 589. "Rule 702 reflects an attempt to
liberalize the rules governing the admission of expert testimony. The rule clearly is
one of admissibility rather than exclusion." Lauzon v. Senco Prods., Inc., 270 F.3d
681, 686 (8th Cir. 2001) (internal quotations and citations omitted). "The exclusion
of an expert's opinion is proper only if it is so fundamentally unsupported that it can
offer no assistance to the jury." Wood v. Minn. Mining & Mfg. Co., 112 F.3d 306,
309 (8th Cir. 1997) (internal quotations and citation omitted).

      A district court should apply a three-part test when screening testimony under
Rule 702.

      First, evidence based on scientific, technical, or other specialized
      knowledge must be useful to the finder of fact in deciding the ultimate
      issue of fact. This is the basic rule of relevancy. Second, the proposed
      witness must be qualified to assist the finder of fact. Third, the proposed
      evidence must be reliable or trustworthy in an evidentiary sense, so that,
      if the finder of fact accepts it as true, it provides the assistance the finder
      of fact requires.



                                           -11-
Lauzon, 270 F.3d at 686 (internal citations and quotations omitted).

       In Daubert, the Supreme Court provided a non-exhaustive list of factors a
district court should consider when performing its gatekeeper function, including,

      1) whether the theory or technique can be (and has been) tested; 2)
      whether the theory or technique has been subjected to peer review and
      publication; 3) the known or potential rate of error; and 4) whether the
      theory has been generally accepted.

Lauzon, 270 F.3d at 686.

      Subsequent cases have proposed additional factors, including, whether
      the expertise was developed for litigation or naturally flowed from the
      expert's research; whether the proposed expert ruled out other alternative
      explanations; and whether the proposed expert sufficiently connected the
      proposed testimony with the facts of the case.

Id. at 686-87.

                                           1

       The district court excluded the results of Johnson's testing finding them
irrelevant and unreliable. In so holding, the court relied on what it perceived to be
numerous important dissimilarities between the test conditions and the accident
conditions. We discuss each below.

       The district court focused on the fact Johnson's testing involved the SJIII,
instead of the SJII, and apparently concluded Johnson's testing would only have been
relevant and reliable had it been conducted using an SJII lift retrofitted with pothole
protection. The district court's reasoning on this issue, and in other portions of its
order, reflects a fundamental misunderstanding of plaintiffs' theory of the case and the

                                         -12-
arguments advanced by the plaintiffs. Plaintiffs do not argue the SJII lift should have
been retrofitted with pothole protection. Instead, they contend the accident would not
have happened had Sappington been operating an SJIII lift, which in 1995 was a
reasonable alternative design to the SJII lift. Because plaintiffs offer the SJIII as a
reasonable alternative to the SJII, testing of the SJIII is highly relevant. Assuming
plaintiffs prove the SJIII design was feasible at the time the SJII was manufactured,
they still must prove the SJIII would not have tipped over under conditions similar to
those present at the tip-over site. While the district court viewed Johnson's tests as an
attempt to reconstruct the accident using the wrong lift, Johnson performed the tests
to show the proffered reasonable alternative design (the SJIII) would not have tipped
under similar conditions. Thus, Johnson's testing of the SJIII is highly relevant,
whereas testing on an SJII would have been irrelevant.

       The district court also focused on the difference in overall weight between the
SJII and the SJIII. The SJII lift is approximately 700 pounds lighter than the SJIII,
giving the SJIII a lower center of gravity. Because center of gravity affects stability,
the district court found the weight difference between the machines made testing of
the SJIII irrelevant and unreliable. Plaintiffs do not argue an SJII lift retrofitted with
pothole protection would have prevented the accident. If they did, testing on a
modified SJII machine would be necessary and weight differences between the SJII
and SJIII would be relevant. Instead, plaintiffs argue the SJIII lift should have
replaced the SJII lift and the SJII should not have been manufactured in 1995. Once
plaintiffs' theory of the case is cast in the proper light, Johnson's testing to determine
the stability parameters of the SJIII becomes highly relevant, and weight differences
between it and the SJII are irrelevant.

       Next, the district court focused on differences between the conditions under
which Johnson conducted his testing and those which existed at the accident scene.
In particular, the district court found the platform off which Johnson drove the lift
varied from the slope of the concrete flooring on which Sappington was driving the

                                          -13-
lift. Additionally, the court found Sappington was driving on concrete and Johnson
tested the SJIII by driving it off a wooden platform. Neither of these differences are
relevant.

       The slope at the accident scene was approximately 0.07 percent. The slope of
the platform used by Johnson was approximately two percent. Thus, the difference
was minimal. More importantly, to the extent there was a difference, Johnson's testing
involved a greater degree of slope, thereby presenting conditions more adverse than
those present at the accident. If the lift could remain stable under more adverse
conditions, Johnson's testing suggests it would have remained stable during the
accident.

       As for the difference in surface material, i.e., concrete versus wood, the record
offers no explanation for why the differences would undermine the relevance or
reliability of Johnson's tests, and we will not speculate on a matter more appropriately
reserved for cross examination.

       The final dissimilarity noted by the district court relates to the load on the work
platform at the time of the accident, compared to the load on the platform during the
testing. The parties agree the platform load at the time of the accident was
approximately 305 pounds. Johnson, however, believed the load was approximately
84 pounds less. Thus, he did not test the SJIII under the same load conditions as were
present at the time of the accident.

       As the load on the work platform increases, the center of gravity changes and
reduces stability. The 84 pound difference in work platform load between the
accident and the testing, however, is not sufficient in our view to render Johnson's
testing inadmissible. "As a general rule, the factual basis of an expert opinion goes
to the credibility of the testimony, not the admissibility." Triton Corp. v. Hardrives,



                                          -14-
Inc., 85 F.3d 343, 347 (8th Cir. 1996) (quoting Loudermill v. Dow Chem. Co., 863
F.2d 566, 570 (8th Cir.1988)).5

       We conclude it was an abuse of discretion to exclude the results of Johnson's
testing because the purported dissimilarities offered by the district court are not
relevant or sufficient to render Johnson's opinions inadmissible.

                                            2

       The district court also excluded the opinions of Dr. Blundell, finding them
irrelevant and unreliable. As with Johnson's opinions, the reasons articulated by the
district court for excluding Dr. Blundell are considered below.

       The district court noted Dr. Blundell relied on Johnson's testing to form part of
the factual basis for his opinions, i.e., because the SJIII remained stable during testing
it would not have tipped under the circumstances present during the accident. The
district court, having mistakenly concluded Johnson's testing was designed to show
the SJII would not have tipped over if retrofitted with pothole protection, concluded
Dr. Brundell's opinions were based on irrelevant and unreliable information. As
noted, Johnson's testing should not have been rejected and the district court erred in
excluding Dr. Brundell's opinions because they rely in part on Johnson's testing.

      The district court also refused to allow Dr. Blundell to rely on testing Skyjack
performed on the SJIII lift. Even assuming Johnson's testing was sufficiently flawed
to warrant its rejection, plaintiffs argue the stability testing conducted by Skyjack to
ensure the SJIII complied with the current ANSI standard can be used to prove the


      5
       As will be explained later, stability testing conducted by Skyjack strongly
suggests the 84 pound weight difference did not significantly affect the test results.


                                          -15-
SJIII would not have overturned in the accident. According to plaintiffs, Skyjack
drove the SJIII into a drop off 30-50 times and on every occasion it remained stable,
thereby proving it would not have tipped in the accident. The district court rejected
the argument, finding the testimony from Skyjack's in-house expert did not explain
under what conditions the testing was performed, i.e., height of the work platform,
slope, and the amount of load on the work platform.

       The deposition testimony of Skyjack's in-house expert does not include
information about the height of the platform, slope, or the amount of load on the work
platform during Skyjack's testing. Skyjack, however, concedes its SJIII lift complies
with the current ANSI standard and has passed the testing requirements imposed by
the standard. Therefore, as explained below, it was unnecessary for Skyjack's expert
to testify about the conditions under which its testing was performed, i.e., platform
height, workload, slope, etc., because those testing conditions are dictated by the
ANSI standard.

       The current ANSI standard requires self-propelled lifts to undergo several
stability tests and to remain stable under "the most adverse stability condition(s)."
ANSI Standard A92.6-1999, subpart 4.7 (Stability Testing). Most adverse stability
condition(s) is defined as

      The permitted configuration of the aerial platform most likely to cause
      instability while maintaining stability. Factors to be considered shall
      include:

             1. With zero load to maximum test load.
             2. Up to and including maximum platform height.
             3. All positions and configurations of the platform(s).
             4. All wheel and axle positions.
             5. Forward and backward configurations of the elevating
             assembly.



                                        -16-
             6. All other moveable features which affect the stability of
             the aerial platform.

Id. at subpart 3 (Definitions) (emphasis added).

        Among the stability tests required by the ANSI standard is a vertical load test
to determine the forward to backward stability of the lift under "most adverse stability
condition(s)." See subpart 4.7.2 (Vertical load test). This test, in addition to requiring
the lift be tested at maximum platform height (26 feet), requires the work platform to
be loaded at 1.50 times its rated capacity with the load placed 12 inches back from the
guardrail. The rated workload for the SJIII is 850 pounds. To comply with the
stability testing mandated by ANSI, the lift must remain vertically stable when fully
elevated to 26 feet and carrying a load of 1275 pounds.

       The standard also requires stability testing on a slope. See subpart 4.7.3 (Static
load test on slope). For this test, the work platform is loaded to 1.33 times the rated
workload of 850 pounds (1130.5 pounds), with the load placed 12 inches back from
the guardrail, and testing is performed on a slope 5 degrees greater than the slope for
which the lift is rated by the manufacturer. The record indicates the accident
happened at 0.07 percent slope and Johnson's testing was performed at approximately
2 degrees of slope. Thus, absent evidence to the contrary, it is reasonable to conclude
the degree of slope present at the accident scene and during testing were well within
the SJIII's operating capabilities required by the ANSI standard.

        Finally, the most relevant ANSI standard for this case requires stability testing
be conducted while the lift is being driven. In particular, subpart 4.7.4.2 (Depression
test) requires

      A dynamic stability test shall be performed on the maximum slope for
      which the aerial platform is rated by the manufacturer up to and
      including maximum travel height [26 feet]. The platform shall carry a

                                          -17-
      test load(s) whose center of gravity is located 6 inches (0.15m) above the
      platform floor(s) and distributed over the leading half of the platform(s)
      and equal to the rated workload [850 pounds]. The machine shall be
      driven into a 24 inch (0.60m) square hole with a vertical drop of 4 inches
      (0.10m) at its maximum attainable forward speed for that configuration
      with one front wheel aligned perpendicular to the edge of the test hole.
      The test shall also be performed at the maximum attainable reverse speed
      for that configuration with one rear wheel aligned perpendicular to an
      edge of the test hole.

Id. (emphasis added).

       The testing conditions imposed by the ANSI standard are clearly set forth and
equal or exceed those present during the accident and the testing performed by
Johnson. The standard requires drop off testing be performed at maximum rated
slope, with the work platform extended to its maximum height, under maximum load
conditions, and at full operating speed. Thus, it was an abuse of discretion for the
district court to refuse to allow Dr. Blundell to rely on Skyjack's own testing, which
it concedes was done in compliance with the ANSI standard. Moreover, this testing
strongly suggests Johnson's failure to account for an additional 84 pounds of load
when he conducted his testing is not significant. To comply with the ANSI standard,
the SJIII must remain stable when driven into a depression while loaded with nearly
three times the weight present at the time of the accident.

        The district court also refused to allow Dr. Blundell to rely on Skyjack's testing
because it was performed to ensure compliance with an ANSI standard promulgated
after the SJII lift was manufactured. The district court believed an ANSI standard
would only be relevant to prove the manufacturer's product was not in compliance
with industry standards or the "state of the art" at the time the product was
manufactured. A state-of-the-art argument would be relevant if this was a products
liability claim based on negligence, where the plaintiff might offer the then existing
ANSI standard to argue the manufacturer knew or should have known about the

                                          -18-
industry standard. Here, however, the ANSI standard is not being offered to show the
SJII did not comply with a standard yet to be written. Instead, Plaintiffs argue 1) the
SJIII could and should have been manufactured in 1995, 2) the SJIII meets the testing
requirements imposed by the current ANSI standard, 3) the conditions required by the
current ANSI standard equal or exceed the conditions present at the accident scene,
and 4) the SJIII was a reasonable alternative design and would have prevented the
accident.

      The district court next concluded the SJII met the requirements of the 1990
ANSI standard which was in effect when it was manufactured in 1995, and therefore,
reference to the 1999 ANSI standard is irrelevant. The 1990 ANSI standard is only
relevant if a state-of-the-art defense could be asserted.

       The district court also found Dr. Blundell's opinions unreliable because he
based his opinion as to feasibility of manufacturing the SJIII in 1995, in part, on the
fact another manufacturer (MEC) began outfitting its lifts with pothole protection as
early as 1987. The district court found this information unreliable because Dr.
Blundell 1) had no personal knowledge of MEC's earlier use of pothole protection, 2)
did not test the MEC lift for stability, and 3) the MEC lift needed pothole protection
to comply with the 1990 ANSI standard's stability requirements but the SJII lift did
not. None of these contentions are relevant.

        First, it does not matter from what source Dr. Blundell discovered MEC was
utilizing pothole protection as early as 1987. The defendants do not dispute the fact
and the information would be no less accurate if Dr. Blundell had actually observed
the lift as opposed to having read about it in the literature and observed its operation
in a videotape.

     Second, stability testing on the MEC is irrelevant. Plaintiffs are not offering the
MEC lift as a reasonable alternative. Instead, Plaintiffs argue pothole protection was

                                         -19-
available as early as 1987, but not incorporated by Skyjack until 1997, which would
have prevented the accident.

       Third, it is irrelevant why MEC used pothole protection in 1987. The evidence
is offered to prove pothole protection was available in 1987 and could have been in
use by Skyjack when the SJII was manufactured in 1995.

       Next, the district court reasoned Dr. Blundell's opinions were irrelevant and
unreliable because "it is illogical to conclude that because a design is made today it
could have been made in 1995." This argument is both factually and legally incorrect.
The relevant time period to consider is whether a lift manufactured in 1997 could have
been manufactured in 1995. Plaintiffs need not prove a lift manufactured in 2007 was
feasible in 1995.

      Additionally, the argument continues to rely on the fact the current ANSI
standard did not become effective until 1999. According to the district court, the
design and manufacture of a lift produced in 1995 could not be guided by a standard
which did not yet exist. We agree, but as has been repeatedly noted, the 1999 ANSI
standard is not being offered as evidence of the state of the art existing in 1995.
Rather, plaintiffs offer the standard to aid in proving the feasibility of the pothole
protection design.

       As a further basis for rejecting Dr. Blundell's opinions, the district court found
the current ANSI standard does not require pothole protection, and therefore, it does
not support Plaintiffs' argument that pothole protection should have been used in
1995. The current ANSI standard requires lifts to remain stable under drop off
conditions. Dr. Blundell testified every manufacturer today meets the requirement by
outfitting their lifts with pothole protection. Thus, while the ANSI standard does not
speak directly to pothole protection, it imposes requirements which have led all
manufacturers to use pothole protection.

                                          -20-
       Finally, the district court and the defendants cite Milanowicz v. The Raymond
Corp., 148 F. Supp. 2d 525 (D. N.H. 2001), as authority for the district court's
rejection of Plaintiffs' experts. Milanowicz, however, is easily distinguishable.

        In Milanowicz, the plaintiff was injured while adjusting forks on a lift truck.
Id. at 526. The plaintiff's expert testified powered fork positioners should have been
incorporated into the truck's design. Id. at 538. The district court excluded the
expert's testimony, because, among other things, the expert conceded the ANSI
standard in effect at the time of the accident did not require such devices. Id. at 537.
Furthermore, the expert could not identify any industry standard or literature which
required his suggested alternative design, or any consumer or industry group which
endorsed the alternative. Id. at 537-38. And finally, the expert did not test his
proposed alternative design nor was he aware of any other testing which had been
performed to determine the feasibility of his proposed design. Id. at 538-39.

       As in Milanowicz, the SJII lift complied with the then existing ANSI standard,
and based on this single similarity the district court and defendants conclude
Milanowicz requires exclusion of plaintiffs' experts. In this case, however, unlike
Milanowicz, the expert's proposed alternative design is supported by industry
standards, literature, and testing. Dr. Blundell's testimony draws support from the
1999 ANSI standard which fully supports his proffered alternative design. Dr.
Blundell testified his proposed alternative design comports with the current ANSI
standard which imposes stability requirements which have led to the incorporation of
pothole protection by every manufacturer of lifts. Furthermore, the industry standards
and practices reflected in compliance with the ANSI standard support Dr. Blundell's
opinions, i.e., pothole protection should be incorporated into lift designs to prevent
overturning in drop off conditions. Finally, as evidenced by Skyjack's successful
incorporation of pothole protection into the SJIII's design, Dr. Blundell's suggested
alternative design has been fully tested.



                                         -21-
        Nonetheless, the district court, relying on several additional factors suggested
in Milanowicz, found Dr. Blundell's opinions unreliable. See id. at 541 (suggesting
a district court consider additional factors in its gatekeeping role, including, 1) federal
standards, 2) standards established by independent organizations, 3) relevant
literature, 4) industry practice, 5) product design and accident history, 6) charts and
diagrams, 7) scientific testing, 8) feasibility of alternative design, and 9) risk utility
of proposed alternative design). To the extent these factors are relevant to the current
inquiry, we are satisfied Dr. Blundell's opinions comport with the additional
requirements. While no party has offered any federal standards for consideration, Dr.
Blundell's opinions take the relevant ANSI standards into account. Dr. Blundell also
reviewed relevant literature and the current industry practices and concluded every
manufacturer uses pothole protection. He also specifically considered stability testing
of the SJIII, and the feasibility and risk utility of implementing the design in 1995.

      We are satisfied Dr. Blundell's opinions survive review under Daubert. The
proposed alternative design has been thoroughly tested and subjected to peer review
and publication. Further, the known or potential rate of error has been considered and
the theory has been widely accepted and implemented throughout the industry.
Therefore, it was an abuse of discretion to exclude Dr. Blundell's testimony.

                                            III

      We reverse the order of the district court granting summary judgment and
excluding the testimony of plaintiffs' experts, and remand for further proceedings
consistent with this opinion.6
                        ______________________________

      6
        RSC argues it is a seller of goods and should be dismissed under Mo. Rev.
Stat. § 537.762 which protects sellers of goods when the manufacturer is sued in a
strict products liability claim. Because the district court did not reach this issue, we
decline to consider it on appeal.

                                           -22-
