This сase begins with the crash of an agricultural aircraft in rural Louisiana. The aircraft had been manufactured by Defendants AlliedSignal, Inc., Peter Baker, and Sandy Meour (collectively “Allied”). It had been maintained by Plaintiffs Eugene Shanks, Farm and Ranch Aerial Applicator Services, and Gulf Coast AG, Inc. (collectively “Shanks”). Pursuant to 49 U.S.C. § 1132, the National Transportation Safety Board (“NTSB”) conducted an official investigation to determine the probable cause of the crash. The NTSB designated Allied as а party to the investigation under 49 C.F.R. § 831.11. As a party, Allied participated in the NTSB investigation, which included a tear-down of the aircraft’s engine at Allied’s facility in Houston, Texas.
Following its investigation, the NTSB issued a “Brief of Accident,” as required by federal law. 1 Although the report did not mention Shanks explicitly, it concluded that the probable cause of the accident was the fact that “[t]he airplane was improperly maintained.” 2 Shanks alleges that Allied conspired to manipulate the NTSB investigatiоn and contributed to an accident report that was false and misleading. 3 He also claims that Allied owed him a duty to rectify errors in the NTSB’s report. 4 According to Shanks, the NTSB’s false accident report led to his indictment on eight federal felony counts. Shanks also claims that the Federal *991 Aviation Administration, prompted by the NTSB report, forced him to agree not to reapply for an airman mechanic’s license for one year.
Shanks asserts numerous state law causes of aсtion arising from Allied’s conduct. His complaint alleges “defamation, tortious interference with business relations, intentional infliction of mental distress, common law negligence, unfair trade practices, negligent infliction of mental distress, intentional infliction of emotional distress, fraud and civil conspiracy.” Allied filed a motion for summary judgment on the ground that it was immune from suit for statements made during the NTSB investigation. It argued that Texas law provides absolute immunity for any communications made in connectiоn with judicial, quasi-judicial, or legislative proceedings. ' The district court denied Allied’s motion, finding that the NTSB investigation was not a judicial, quasi-judicial,' or legislative proceeding, nor were statements made during the investigation sufficiently connected to any other judicial, quasi-judicial, or legislative proceedings. Allied now appeals the district court’s order denying its motion for summary judgment. We vacate that order and remand for further proceedings.
I
Shanks argues that we lack jurisdiction over this aрpeal because the order from which Allied appeals is not a final decision. Under 28 U.S.C. § 1291, we have jurisdiction to hear “appeals from all final decisions of the district courts of the United States.” We read this language to encompass interlocutory appeals “from a small category of decisions that, although they do not end the litigation, must nonetheless be considered ‘final.’ ”
Swint v. Chambers County Comm’n,
In
Quirk v. Mustang Engineering, Inc.,
The
Quirk
panel did not, however, specifically address whether an order, denying such an immunity is properly deemed “final” under § 1291 and the collateral order doctrine. Nonetheless, an independent application of our precedent in that area compels the same result. “[Ojrders denying certain immunities are strong candidates for prompt appеal under § 1291.”
Digital Equipment Corp. v. Desktop Direct, Inc.,
We must, however, “view claims of a ‘right not to be tried’ with skepticism, if not a jaundiced eye.”
Digital Equipment,
Allied bases its immunity claim on the rule of Texas law that communications made during the course of judicial, quasi-judicial, or legislative proceedings are “absolutely privileged.”
Reagan v. Guardian Life Ins.,
We are convinced that Texas law regards its privilege for communications made in the context of judicial, quasi-judicial, or legislative proceedings as a complete immunity from suit, not a mere defense to liability. To insist on a final judgment before reviewing a denial of that immunity could deprive Allied of its entitlement to avoid the burdens of trial. Allied may therefore appeal the district court’s rejection of its immunity claim as a collateral order under 28 U.S.C. § 1291.
II
Allied contends that the district court erred in denying its motion for summary judgment. Summary judgment is appropriate when there is no genuine issue as to any material fact and the moving party is entitled to judgment as a matter of law.
See
Fed. R. Civ. P. 56(c). We review a district court’s denial of summary judgment
de novo,
viewing the evidence in the light most favorable to the nonmovant.
See Smith v. Brenoettsy,
Allied argues that it is absolutely immune undеr Texas law from any suit based on its communications with the NTSB. It claims immunity on the grounds that (1) the NTSB investigation was a quasi-judicial proceeding, (2) communications made during the NTSB investigation were preliminary to other quasi-judicial or judicial proceedings, and (3) communications made to the NTSB were connected to legislative proceedings. Shanks *993 responds that the immunities provided by Texas law do not apply to communications made during NTSB investigations. Shanks also argues that a party to an NTSB investigаtion is precluded from claiming immunity in connection with litigation arising from that investigation. 6
A
We first address whether a defendant is entitled to absolute immunity for communications made in connection with accident investigations by the NTSB. Where, as here, a federal court exercises jurisdiction over state law causes of action based on diversity of citizenship,
see
28 U.S.C. § 1332, we must apply state substantive law.
See Rogers v. Corrosion Prods., Inc., 42 F.3d
292, 295 (5th Cir.1995) (citing
Erie R.R. Co. v. Tompkins,
Although the Texas Supreme Court has never specifically decided whether communications during NTSB investigations are immune from suit, it has provided strong guidance to predict how it would rule on this particular issue. The immunity asserted by Allied “attaches only to a limited and select number of situations which involve the administration of the functions of thе branches of government, such as statements made during legislative and judicial proceedings.”
Hurlbut,
These cases provide solid grounds to predict that the Texas high court would find that NTSB accident investigations are quasi-judicial proceedings, from which it would follow that any communications made during such investigations are absolutely immune from suit. The Texas courts of appeal provide further support. 7 Texas courts have *994 rеcognized six factors that are relevant to whether proceedings are quasi-judicial for purposes of absolute immunity:
(1) the power to exercise judgment and discretion;
(2) the power to hear and determine or to ascertain facts and decide;
(3) the power to make binding orders and judgments;
(4) the power to affect the personal or property rights of private persons;
(5) the power to examine witnesses, to compel the attendance of witnesses, and to hear’ the litigation of issues on a hearing; and
(6) the power to enforce decisions or impose penalties.
Village of Bayou Vista v. Glaskox,
Admittedly, NTSB investigations lack other indicia of quasi-judicial proceedings. Such investigations, for example, “are not conducted for the purpose of determining the rights or liabilities of any person.” 49 C.F.R. § 831.4. However, a proceeding need not meet all of the above criteria to be considered quasi-judicial.
See Parker,
Taking a more comprehensive look at the ease law, we find only two situations in which Texas courts have found that communications to government agencies are not entitled to absolute immunity. The first involves unsolicited communications to law enforcement officials. In
Hurlbut v. Gulf Atlantic Life Insurance Co.,
Texas courts have. also denied absolute immunity where the challenged communications are made to agencies that issue merely recommendations or preliminary findings. One case concerned a regional council of county governments charged with making rеcommendations to federal agencies on requests for health services grants.
See Parker,
Furthermore, it would be nonsensical to characterize the NTSB’s investigation as *995 “preliminary” to litigation over an aircraft accident, because by federal statute, no part of an NTSB report may be “used in a civil action for damages resulting from a matter mentioned in the report.” 49 U.S.C. § 1154(b). Although the NTSB’s conclusions are not relevant to any party’s legal rights, Congress has deemed the NTSB’s findings sufficiently important that its investigations have “priority over any investigation by another department, agency, or instrumentality of the United States Government.” 49 U.S.C. § 1131(a)(2). Therefore, we find in-apposite Texas cases suggesting that absolute immunity does not apply to government agencies whose conclusions are merely preliminary.
For these reasons, we hold that an NTSB accident investigation would qualify as a quasi-judicial proceeding under Texas law. Thus Texas law grants absolute immunity from suit for statements made during such investigations. 8 The district court erred in finding the NTSB investigation was not a quasi-judicial proceeding for purposes of Texas immunity law.
B
Shanks also argues that NTSB policy precludes Allied’s immunity claim. Specifically, *996 Shanks points out that parties to an accident investigation are required to sign a “Statement of Party Representatives” See .49 C.F.R. § 831.11(b). The statement provides, among other things: “By placing their signatures hereon all participants agreе that they will neither assert nor permit to be asserted on their behalf, any privilege in litigation, with respect to information or documents obtained during the course of and as a result of participation in the NTSB investigation.”
Shanks’s argument fails for several reasons. First, Allied never signed the Statement of Party Representatives or any other document containing such language. In fact, the provision requiring parties to sign the Statement of Party Representatives was not added to the NTSB regulations until 1997, four years after the NTSB’s initial investigation into this matter had concluded.
See
62 Fed.Reg. 3806, 3808 (1997) (adding current language in 49 C.F.R. § 831.11(b)). Second, even if the statement binds Allied nonetheless, its language does not .cover the kind of substantive immunity asserted by Allied in this case. Its terms merely prohibit parties from asserting a privilege “with respect to information or documents obtained” during NTSB investigations. Thus the statement focuses on evidentiary matters, that is, the disclosure of “information or documents.” The Tenth Circuit has described it as a
“discovery
waiver[ ],” by which parties “g[i]ve up
discovery
privileges рotentially assertable in a tort liability case.”
Thomas Brooks Chartered v. Burnett,
For these reasons, we find that the NTSB’s Statement of Party Representatives applies only to evidentiary privileges from the disclosure of information, not to substantive immunities from suit. It therefore does not prevent Allied from claiming that its conduct during the NTSB investigation is immune from suit under Texas law. Nor has Shanks identified any NTSB policy independent of the Statement of Party Representatives that would preclude Allied from asserting immunity.
Ill
Accordingly, we VACATE the district court’s order denying Allied’s motion for summary judgment and REMAND for further proceedings not inconsistent with this opinion.
Notes
. The NTSB is obliged to "report on the facts and circumstances of each accident investigated by it.” 49 U.S.C. § 1131(e). Its conclusions must be "issued in the form of a report or 'brief' of the incident or accident." 49 C.F.R. § 831.4.
. The section of the report entitled "Probable Cause” read:
The National Transportation Safety Board determines that the Probable Cause(s) of this accident was: A loss of control during a propeller underspeed condition which resulted in a stall. The underspeed condition was caused by a speeded spring failure as a result of a binding bogus propeller pitch control cam. The airplane was improperly maintained.
. After filing this lawsuit, Shanks petitioned the NTSB for reconsideration. In response, the NTSB issued a revised accident report, which found that the probable cause of the accident was pilot error. The revised report concluded that the probable cause of the accident was "the pilot’s failure to maintain adequate airspeed, resulting in an inadvertent stall.”
.In addition, Shanks contends that Defendant Sandy Meour made a defamatory statement many months after the NTSB investigation. His complaint also alleges that Allied’s conduct "is continuing in nature and that such acts are not complete in themselves.” On appeal, Shanks argues that this language refers to acts by Allied outside the NTSB investigation. As explained below, claims based on conduct other than communications made during the NTSB investigation are not properly before us on appeal. See infra at n. 6.
. When the district court denies a defendant’s immunity-based summary judgment motion because of disputed factual issues, we do not have appellate jurisdiction under 28 U.S.C. § 1291.
See Johnson v. Jones,
. Shanks makes two additional arguments that are not properly before us. First, Shanks's brief devotes four sentences to the argument that federal law preempts the state law immunities on which Allied relies. This claim was raised for the first time on appeal, and we shall not address it. See Quenzer v. United States (In re Quenzer), 19 F.3d 163, 165 (5th Cir.1993) (“Typically, we will not consider on appeаl matters not presented to the trial court.”).
Second, Shanks contends that Allied committed actionable conduct outside the scope of the NTSB investigation, for which the immunity claimed by Allied would not apply. We decline to examine these claims, because the district court never addressed whether any actionable conduct took place outside of the NTSB investigation. “It is the general rule that a federal appellate court does not consider an issue not passed upon below.”
Americans Disabled for Accessible Pub. Transp. v. Skinner,
. When making an "Bríe-guess” as to how a state’s high court would decide an issue, it is proper to look to the decisions of lower state courts.
See Hill v. London, Stetelman, & Kirkwood, Inc.,
. Absolute immunity unquestionably applies to Shanks’s defamation claim.
See Reagan,
The Texas Supreme Court has intimated that absolute immunity applies only to defamation actions.
See Bird v. W.C.W.,
Lower Texas courts have also struggled with whether absolute immunity applies to causes of action other than defamation. Some courts have addressed whether absolute immunity applies to particular non-defamation causes of action.
See Rose v. First Am. Title Ins. Co.,
Allied raises this issue cursorily, arguing in a footnote that although absolute immunity "was first developed in the context of defamation claims, ... it is now clear that it applies to all theories of recovery based on the immunized communications." The district court never addressed this question, however, and we decline to examine it for the first time on appeal. We leave it for the district court to determine on remand whether absolute immunity applies to Shanks’s other causes of action.
