In this action under the Federal Tort Claims Act, the pilot of a private aircraft alleges that, during his flight from Texas to Indiana, which included a stop in Arkansas, air traffic control personnel employed by the United States at airports in various states negligently failed to warn him of icing conditions that ultimately caused the aircraft to crash while he was attempting to land at an airport in Indiana.1 The controlling issue is whether a determination in a license suspension proceeding by the National Transportation Safety Board that he violated Federal Aviation Rules by flying an aircraft without deicing equipment into known icing conditions establishes contributory negligence by collateral estoppel and precludes recovery. To decide this issue we must determine whether federal common law or state law controls, and, if the latter, which state law. We hold that Indiana law controls, and that under that law, the District Court’s summary judgment for the United States based on collateral estoppel was correct.
Although the district judge conducted a trial, he disposed of the case after the trial by granting the motion of the United States for summary judgment,' which he had taken under advisement before hearing *1314the evidence. The uncontested facts upon which the summary judgment was based were stated in his unpublished decision and order as follows:
. . . On December 22,1972, plaintiff was the pilot and sole occupant of a Bel-lanca Viking aircraft on a flight from Mineral Wells, Texas, to Marion, Indiana, with an intermediate fuel stop at Flippen, Arkansas. He was then the holder of an FAA pilot’s license, with commercial pilot privileges.
Prior to his departure from Mineral Wells, plaintiff did receive and record for his use in the flight certain weather information. The segment of flight to Flippen, Arkansas, was conducted under Visual Flight Rules. While at Flippen, plaintiff contacted an FAA Flight Service Station and obtained a weather briefing for the segment of his flight to Marion. Thereafter he filed an Instrument Flight Rules Plan and received clearance from the Memphis Air Traffic Control Center for his flight to Marion at an assigned altitude of 5000 feet.[2] Throughout substantially all of the Flip-pen-Marion flight segment, plaintiff was flying above cloud cover, extending upward to about 3000 feet above mean sea level. During the course of that segment of his flight, plaintiff was in radio contact with various air traffic control facilities at Memphis, Kansas City and Indianapolis, and air approach control at Grissom Air Force Base for his attempted landing at Marion. He also made contact with Vandalia, Illinois, radio and Terre Haute, Indiana, radio requesting weather information. Plaintiff did receive weather information from certain of those government facilities.
As he neared the termination of the Flippen-Marion IFR segment of his flight, plaintiff contacted Grissom Flight Control for clearance to land at Marion. He was given a summary of the Grissom weather conditions,[3] as no “landing” information for Marion was available. Plaintiff was given clearance for an instrument landing at Marion. Because of the failure of an essential instrument on the aircraft, plaintiff’s first approach to Marion was unsuccessful. Thereafter, he requested and received from Grissom orientation as to his position, after which he attempted a second approach. The second approach terminated about 500 feet to the west from the assigned runway when the aircraft crashed because of ice accumulated thereon.
The aircraft was not equipped with deicing equipment, and operation of the aircraft in “known icing conditions” was prohibited by the approved flight manual therefor.
The complaint is grounded upon the theory that the crash and plaintiff’s injuries sustained therein proximately resulted from the negligent failure of FAA agents and Air Force personnel to advise plaintiff of icing conditions existing in the vicinity of Marion.
On August 10, 1973, the FAA suspended plaintiff’s pilot’s license for a period of thirty days. Upon an appeal from that determination, a hearing was held before an Administrative Law Judge of the NTSB, commencing on December 11, 1973. That hearing was concluded by an order finding that plaintiff had been aware of the possibility of icing conditions before he departed from Mineral Wells, and was further advised thereof in his weather briefing at Flippen, Arkansas, and that he had violated FAA regulations in operating the aircraft in violation of flight limitations placed upon the craft itself and in operating the craft in a careless manner. The order modified the FAA determination by reducing the period of suspension to fifteen days.
An appeal taken to. the NTSB was terminated on May 22, 1974 by an order *1315affirming the suspension, and an order on September 5, 1974 denying a petition for reconsideration. .
* H¡ * * * *
On conflicting testimony, NTSB found that plaintiff had information as to the possibility of icing in a multistate area including Indiana prior to his departure from Mineral Wells; that plaintiff was advised at Flippen of the substance of the then current Chicago weather forecast of occasional moderate and chance of severe mixed icing in clouds in the lower Ohio Valley region, and advisement that the freezing level would be at or near the surface in the Great Lakes states; that he was then advised of the substance of a Chicago aviation warning forecast of isolated severe and mixed icing in clouds in the Indiana area, among others, from 10 a. m. to 3 p. m.; that plaintiff did not receive from any source a Chicago advisory issued at about the time he left Flip-pen, which contained further and extended information regarding possible icing; that, notwithstanding that omission, plaintiff was in possession of weather information which put him on notice that he could expect to encounter icing conditions upon his intended flight path; and that, in the light of that knowledge available to him, plaintiff did violate FAR § 91.9 by operating his aircraft “in a careless or reckless manner,” and FAR § 91.3(a) by entering into the cloud cover when there was known to him the possibility of icing, in violation of FAA operating limitations for his aircraft.
In the context of the latter rule, the Board refused to limit the phrase, “known icing conditions,” to knowledge that icing had, in fact, been encountered. It held that the phrase included a pilot’s knowledge of facts from either reported or forecast conditions which would reasonably lead a prudent person to expect that icing conditions did exist.
Thus the administrative determination rests upon the factual determination that plaintiff had been provided with sufficient information to lead him to anticipate that he would encounter icing conditions in clouds at Marion, and that he did enter into clouds at an altitude of some 3400 feet for his approach to Marion, despite his possession of such information and despite his knowledge that his craft was neither equipped nor approved for operation in icing conditions.
******
Plaintiff having failed to pursue his statutory right to judicial review of the-suspension order under 49 U.S.C. § 1486(a), the NTSB adjudication that the plaintiff had violated the regulations was a final administrative order.
The District Court reasoned that the doctrine of collateral estoppel precluded plaintiff from relitigating the issue of whether he violated the safety regulations by flying his aircraft into known icing conditions, an issue that had been finally determined adversely to him in the administrative proceeding; that the violation amounted to contributory negligence as a matter of law; and that, because under Indiana law, which the court found to be controlling, contributory negligence was an absolute defense, the United States was entitled to summary judgment.
I.
The Federal Tort Claims Act makes the United States liable for injury “caused by the negligent or wrongful act or omission of any employee of the Government while acting within the scope of his office or employment, under circumstances where the United States, if a private person, would be liable to the claimant in accordance with the law of the place where the act or omission occurred.” 28 U.S.C. § 1346(b); see also, 28 U.S.C. §§ 2672 and 2674. The Supreme Court, in Richards v. United States, 369 U.S. 1, 8-10, 82 S.Ct. 585, 7 L.Ed.2d 492 (1962), rejected the argument that the applicable law is that of the state where the operative effect of the act or omission occurred,4 and applied the statutory language *1316literally. Richards also held that the whole law, including choice-of-law rules, of the state where the act or omission occurred was to be applied. Id. at 10-15.
II.
Notwithstanding Richards, plaintiff argues that the federal government’s massive regulation of the nation’s airways has preempted the field of aviation law, and that therefore federal common law, which should include the doctrine of comparative negligence, should be applied. Reliance is placed upon Kohr v. Allegheny Airlines, Inc., 504 F.2d 400 (7th Cir. 1974), cert. denied, 421 U.S. 978, 95 S.Ct. 1980, 44 L.Ed.2d 470 (1975). This argument was concededly not presented to the District Court and therefore need not be considered by us.5 Youker v. Gulley, 536 F.2d 184, 186-187 (7th Cir. 1976).
We do not rest our rejection of the argument on that ground alone, however. Although Kohr held that a federal rule of contribution and indemnity among joint tort-feasors should control in aviation collision cases, and that rule applied to claims of the United States for contribution and indemnity, the court did not have before it the question of whether the law referred to in the Federal Tort Claims Act, viz., “the law of the place where the act or omission occurred,” is federal law or state law.6 The Richards case, which antedated Kohr and involved facts very similar to those in the ease at bar, expressly holds that the law to which the statutory phrase refers is state law.
In addition, dictum more recent than Kohr in Miree v. DeKalb County, 433 U.S. 25, 97 S.Ct. 2490, 2494 n. 4, 53 L.Ed.2d 557 (1977), strongly suggests that the Supreme Court is still of the view that state law governs in aviation tort claims brought under the Federal Tort Claims Act.7 Moreover, the Court’s disposition of one of the arguments made in Miree is significant. The argument was that federal common law rather than Georgia law should control on the issue of whether the contract between the FAA and the county gave third-party beneficiary rights to the public (see note 7, supra), because the United States “has a substantial interest in regulating aircraft travel and promoting air travel safety.” 97 S.Ct. at 2495. The Court re*1317jected this argument, stating that this federal interest was insufficient, “given the narrow question before us, to call into play the rule of Clearfield Trust,” i. e., the rule that federal law controls when the interest of the United States in national uniformity in the law is exceptional, see note 7, supra. The Court then quoted the following passage from Wallis v. Pan American Petroleum Corp., 384 U.S. 63, 68, 86 S.Ct. 1301, 1304, 16 L.Ed.2d 369 (1966):
In deciding whether rules of federal common law should be fashioned, normally the guiding principle is that a significant conflict between some federal policy or interest and the use of state law in the premises must first be specifically shown. It is by no means enough that, as we may assume, Congress could under the Constitution readily enact a complete code of law governing transactions in federal mineral leases among private parties. Whether latent federal power should be exercised to displace state law is primarily a decision for Congress. [Emphasis added by Court in Miree, 97 S.Ct. at 2495.]
Also, the Supreme Court’s unwillingness to extend federal admiralty jurisdiction and the concomitant uniform federal admiralty law to aviation accidents in Executive Jet Aviation, Inc. v. City of Cleveland, 409 U.S. 249, 273-274, 93 S.Ct. 493, 34 L.Ed.2d 454 (1972), is not without significance, especially when considered in the light of Miree.
In the face of these indications of the Supreme Court’s views, we are not free to extend Kohr to an action under the Federal Tort Claims Act. The law referred to in that Act is, as Richards holds, state law.
III.
Richards sheds no light on the question of which state law applies when, as here, the act or omission occurs in more than one state. The District Court found it unnecessary to address this question, because, in its view, applying the law of any of the three states in which it believed the negligence might have occurred, Indiana, Illinois, or Arkansas, would lead to the same result.8 This was so, the court reasoned, even though the substantive law as to the effect of plaintiff’s fault was comparative negligence in Arkansas9 but contributory negligence in both Illinois and Indiana,10 because (a) the whole law of the place where the act or omission occurred, including its choice-of-law rules, is to be applied under Richards; (b) the applicable choice-of-law rule of each of those states, the court believed, was lex loci delicti;11 and under this rule Indiana substantive law governed, including the contributory negligence doctrine.
We reach the same result, but, because of an intervening change in the Arkansas choice-of-law rule, by different reasoning. A recent choice-of-law decision of the Arkansas Supreme Court indicates that the court might apply the substantive law of Arkansas12 rather than Indiana. Thus, if *1318Arkansas is “the place where the act or omission occurred,” the Federal Tort Claims Act, in combination with that state’s “governmental interest” choice-of-law rule, the Arkansas comparative negligence rule may be applicable.
IV.
Inasmuch as the legal quality of conduct alleged to have caused injury to the plaintiff is not determined until the end of the trial, and the trier of fact must know which law is applicable in order to make that determination, the statutory phrase “the place where the act or omission occurred” necessarily refers to the situs of conduct that is asserted to be actionable, rather than the situs of the part of that conduct that is ultimately determined to be actionable.13 No cases deciding which state law is to be applied when the allegedly negligent conduct occurred in more than one state have been called to our attention, and we have found none.14
The choice is limited at the outset by the words of the Act, which as Richards held, preclude the borrowing of the place-of-impact rule that has evolved as part of the traditional rule of lex loci delicti. The Act’s focus upon only the acts or omissions themselves also rules out the significant contacts rule of the Restatement (Second) Conflict of Laws or any variant of that rule.15 Excluding possibilities that would appear to be wholly arbitrary leaves the alternatives of the place of the last act or omission having a causal effect, or the place of the act or omission having the most significant causal effect. The former would have the advantage of certainty, as does the traditional conflicts rule of lex loci delicti, but the latter seems to us to be more consistent with the statutory language and Congress’ intent. In this case, however, the law of Indiana governs if either interpretation is adopted, for the acts or omissions in Indiana were not only the last in time but had a more significant causal relationship to the injury than those occurring in any other state.
The relative importance of the Indiana events becomes apparent when it is recalled that flight control personnel in that state were responsible for giving plaintiff the information he would need to complete his journey by landing there. It was they who gave him clearance for an instrument landing at Marion and a summary of weather conditions at Grissom Air Force Base, with the further information that they had “no landing information for Marion.” They also gave him orientation as to his position before his attempt at a second approach.16 At least the acts or omissions that occurred in other states had no more causal significance than those that occurred in Indiana, and the close relationship of the Indiana events to the crash itself and the fact that what was said there could have prevented the crash seem to us to give that state the edge as the situs of the acts or omissions having the greatest causal significance.17
*1319V.
Having determined that the Federal Tort Claims Act refers us to Indiana law, and remembering that under Richards the whole of that law, including choice-of-law rules, is to be applied, the next step is the application of the Indiana choice-of-law rule. The District Court held that rule to be lex loci delicti. Plaintiff does not question this ruling in his brief, and the brief of the United States proceeds on the assumption that it is correct. With the case in this posture, we make the same assumption,18 noting that the result would be the same even if the significant contacts rule of the Restatement (Second) were applied.19 In either event, the applicable substantive law is that of Indiana, which includes the rule that contributory negligence is an absolute defense. See note 10, supra. Accordingly, if plaintiff was collaterally estopped from denying contributory negligence, summary judgment for the United States was proper.
VI.
The issue of whether the final administrative determination of plaintiff’s negligence can be asserted as a bar under the doctrine of collateral estoppel in a subsequent judicial proceeding is a question of Indiana law divisible into two parts: First, was plaintiff’s negligence established in the administrative proceeding?20 Second, if it was, is the administrative agency’s determination a proper basis for collateral estop-pel? 21
A.
The District Court did not, nor need we, decide whether flying an aircraft not equipped for deicing into known icing conditions and attempting to land in those conditions is, standing alone, contributory negligence as a matter of law. That conduct was found by the NTSB to be a violation of regulations promulgated for safety purposes. Compare 49 U.S.C. § 1348(c) with F.A.R. 91.9, 91.31(a); 14 C.F.R. §§ 91.9, 91.31(a) (1977). Indiana has, by statute, incorporated federal air safety regulations as its own standards of care. Cf. Ind.Code § 8-21-4-8 (1976). Finally, under Indiana law violation of a safety-oriented *1320statute or regulation is negligence per se.22 Contributory negligence as a matter of law was therefore established.
B.
The final question that must be answered to complete our analysis is whether under Indiana law the NTSB’s final decision is a proper basis for collateral estoppel. In Amann v. Tankersley, 149 Ind.App. 501, 273 N.E.2d 772 (1971), the Indiana Appellate Court outlined the essential elements which are “generally required” for the application of the doctrine of collateral estoppel:
(a) a suit and an adversary proceeding
(b) a final judgment
(c) a decision on the merits
(d) rendered by a court of competent jurisdiction
(e) identity of parties
(f) identity of subject matter or issues
(g) capacity of parties
(h) mutuality of estoppel.
149 Ind.App. at 509, 273 N.E.2d at 777.
Apart from the fact that the prior decision was by an administrative agency rather than a court, all these essential elements are satisfied: (a) The proceedings were adversary in nature, (b) the functional equivalent of (c) a final decision on the merits (d) was entered by a tribunal of competent jurisdiction, and (g) the parties had capacity to litigate the issues. Also, (f) the pertinent issues are the same in both cases, viz., whether plaintiff received weather information that should have alerted a reasonably prudent pilot that icing conditions would be encountered, and, if so, whether plaintiff violated F.A.R. 91.9 and 91.31(a) by thereafter acting as he did. In addition, (e) the identity of parties requirement is satisfied, because the United States and its agency are in privity for collateral estoppel purposes. Sunshine Coal Co. v. Adkins, 310 U.S. 381, 402-403, 60 S.Ct. 907, 84 L.Ed. 1263 (1940); Mathis v. Laird, 457 F.2d 926, 927 (5th Cir. 1972). Finally, (h) the mutuality of estoppel requirement is satisfied. There is no reason that the United States would not likewise have been estopped had the relevant facts been adjudicated in favor of plaintiff in the administrative proceeding.23
We turn now to the more difficult question of whether Indiana would accord collateral estoppel effect to the decision of an administrative agency. The reported Indiana cases involve judgments of courts; we have found no decision either way dealing with an administrative determination.24 In the absence of controlling Indiana decisions, we are to decide the question as we believe the Indiana courts would decide it. Huff v. White Motor Corp., 565 F.2d 104, 106 (7th Cir. 1977); D’Ambra v. United States, 396 F.Supp. 1180, 1181 (D.R.I.1973); aff’d, 518 F.2d 275 (1st Cir. 1975).
The policy underlying the doctrine of res judicata, of which collateral estoppel is a part,25 is stated in § 1 of the Restatement of Judgments (1942):
Where a reasonable opportunity has been afforded to the parties to litigate a claim before a court which has jurisdiction over the parties and the cause of action, and *1321the court has finally decided the controversy, the interests of the State and of the parties require that the validity of the claim and any issue actually litigated in the action shall not be litigated again by them.
The time when courts were unwilling to extend the doctrine to administrative determinations, Pearson v. Williams, 202 U.S. 281, 284-285, 26 S.Ct. 608, 50 L.Ed. 1029 (1906), has long since passed. By 1958, Professor Kenneth Culp Davis was able to say that “[t]he courts generally follow this sound view,” which he stated as follows:
The reasons against a second litigation between the same parties of the same claims or issues are precisely the same for some administrative determinations as they are for most judicial determinations. The sound view is therefore to use the doctrine of res judicata when the reasons for it are present in full force, to modify it when modification is needed, and to reject it when the reasons against it outweigh those in its favor. [Footnote omitted.]
2 K. Davis, Administrative Law Treatise 548 (1958).26 In 1966 the Supreme Court applied the doctrine to an administrative determination, stating
When an administrative agency is acting in a judicial capacity and resolves disputed issues of fact properly before it which the parties have had an adequate opportunity to litigate, the courts have not hesitated to apply res judicata to enforce repose.
United States v. Utah Construction & Mining Co., 384 U.S. 394, 422, 86 S.Ct. 1545, 1560, 16 L.Ed.2d 642 (1966). Relitigation of factual issues determined by the Advisory Board of Contract Appeals was precluded in that case because “the Board was acting in a judicial capacity” when it considered those issues, the issues were “relevant to issues properly before” the Board, “and both parties had a full and fair opportunity to argue their version of the facts and an opportunity to seek court review of any adverse findings.” The Court concluded,
There is, therefore, neither need nor justification for a second evidentiary hearing on these matters already resolved as between these two parties.
Id. With the Utah Construction decision leading the way, the courts have continued to extend the doctrine of res judicata to the decisions of administrative agencies in appropriate cases. See K. Davis, Administrative Law 1970 Supplement 609-623 (1971); K. Davis, Administrative Law of the Seventies 427-434 (1976) (“As of 1975, the main contours of the law of administrative res judicata are precisely what the 1958 Treatise proposed.”) and 1977 Supplement 144-146; and see Note, The Collateral Estoppel Effect of Administrative Agency Actions in Federal Civil Litigation, 46 Geo.Wash.L. Rev. 65 (1977).27
In dealing with prior judicial adjudications, the courts have not hesitated in recent years to expand the application of the collateral estoppel, or issue preclusion, *1322branch of the doctrine of res judicata, with which we are concerned here, to better serve the underlying policy on which the doctrine is based, viz., that one opportunity to litigate an issue fully and fairly is enough. See, e. g., Blonder-Tongue Laboratories, Inc. v. University of Illinois Foundation, 402 U.S. 313, 91 S.Ct. 1434, 28 L.Ed.2d 788 (1971); Samuel C. Ennis & Co. v. Woodmar Realty Co., 542 F.2d 45, 49 (7th Cir. 1976); Speaker Sortation Systems, Division of A-T-O Inc. v. United States Postal Service, 568 F.2d 46, 48 (7th Cir. 1978); Restatement (Second) Judgments § 88 (TentDraft No. 2, 1975).28 At the same time, however, there is an increasing recognition that the rules of issue preclusion should not be inexorably applied when a fair opportunity to litigate the issue in the prior proceeding was lacking. Restatement (Second) Judgments § 68.1 (Tent.Draft No. 4, 1977).
In attempting, without any discernible doctrinal trend in the reported decisions of the courts of a state, to predict how those courts will decide an issue of state law when it is presented to them, a federal court may reasonably assume that they will follow the rule that appears best to effectuate the policies that underlie the rule. Here the underlying policy, viz., that one fair opportunity to litigate an issue is enough, is best served by the rule that issue preclusion applies to a final administrative determination of an issue properly before an agency acting in a judicial capacity when both parties were aware of the possible significance of the issue in later proceedings and were afforded a fair opportunity to litigate the issue and to obtain judicial review.29
In hearing the testimony on the fact issues here, the NTSB was performing a judicial function. The critical question in the administrative hearing was credibility of witnesses. The administrative law judge believed the FAA personnel who testified that they had advised plaintiff of the likelihood of icing conditions in Indiana, and rejected plaintiff’s testimony to the contrary, performing the same role of weighing and evaluating conflicting testimony that a trier of fact would have performed in a judicial proceeding involving the same fact issues. As Professor Davis points out, the doctrine of collateral estoppel performs “at its best” in the kind of situation presented here. 2 Davis, supra, § 18.03 at 559.
Although the rules of evidence are somewhat relaxed in proceedings before the NTSB, with the result, as plaintiff points out, that some hearsay may be admissible, that alone should not be determinative. The question is ultimately one of fairness. Plaintiff has not pointed to any significant evidence admitted in the administrative proceedings that would not have been admissible in court. Similarly, although the limitations on the opportunities for discovery in the administrative proceeding might produce such unfairness in a given case that issue preclusion should be denied, cf. Restatement (Second) Judgments § 68.-1(c) (“differences in the quality or extensiveness of the procedures followed”), plaintiff here has not pointed to any specific prejudice resulting from limitations on discovery. We are satisfied that plaintiff was afforded a full and fair opportunity in the administrative proceeding to litigate the fact issues that were controlling in both proceedings.30
An additional factor remains to be considered. If, because the significance an *1323administrative determination would have in later court proceedings is not reasonably foreseeable, a party does not choose to litigate the common issues in the administrative proceeding, it would be unfair to hold him bound by the administrative determination. Compare Restatement (Second) Judgments § 68.1(e)(ii) and (iii). That is not the case here, however. Not only is suspension of a license ordinarily a matter of importance to the pilot, but the plaintiff here retained counsel and vigorously litigated the issues in the license suspension proceeding. Here, as in Utah Construction, 384 U.S. at 422, 86 S.Ct. at 1560, “[tjhere is . neither need nor justification for a second evidentiary hearing” on issues already determined between the parties.
We therefore conclude that, under Indiana law, the plaintiff was estopped from relitigating the issue of whether his conduct violated Federal Aviation Regulations and the underlying fact issues. Because, under that law, the determination of these issues adversely to plaintiff requires the conclusion that he was negligent, and contributory negligence is an absolute bar to recovery, plaintiff could not succeed in his Federal Tort Claims Act suit. The judgment is therefore affirmed.
AFFIRMED.