Modern day noise measurement techniques provide more sophisticated means of drawing the dividing line between compensability and noncompensability. [FN 8]

[FN 8] This point is forcefully made in the trial court's memorandum opinion as follows: "Since the noise from jet aircraft is capable of acceptable and recognized measurement in terms of its annoyance effect, no reasonable basis exists for making a legal difference between the effects caused by flyby aircraft and the same effects caused by flyover aircraft. Recognition of this principle of equal treatment for the same effects from jet noise is the basis upon which NEF Area 'C' has been designated as the area in which the Effective Perceived Noise Level is such that a substantial interference with residential living results from jet aircraft noise caused by the landings and takeoffs in the vicinity of Los Angeles International Airport. "It is suggested that unless recovery in inverse condemnation is limited to landowners suffering from flyover aircraft, there will be no reasonable way to draw a line to distinguish between those landowners who would have a cause of action and those who would not. The development of the NEF contour areas provides a good means of drawing a reasonable line between those landowners who may establish a cause of action for inverse condemnation and those who may not. All landowners who suffer from substantially the same noise level are treated on an equal basis. Thus, all landowners located in NEF Area 'C' are subjected to noise from jet aircraft which substantially interferes with residential comfort, enjoyment and use of their property and which is substantiated by the Effective Perceived Noise Level rating in decibels used to delineate NEF Area 'C.' To the extent that they are able to establish that jet aircraft noise has diminished substantially the market value of their property, they should be entitled to recover damages in inverse condemnation. Those owners whose property is located outside of NEF Area 'C' would not ordinarily be entitled to recover because the jet noise in areas outside of NEF Area 'C' does not constitute normally a substantial interference with residential comfort, enjoyment and use of their property."

[FN 9] A collection of commentaries critical of Batten may be found in Berger, supra, footnote 4, 9 Cal. Western L.Rev. at pages 236-238.

[FN 10] Although we reject the application of strict notions of trespass to the instant case, it may be noted that there is precedent for liability for damage caused by vibrations emitted through the air or the ground. (E.g., Smith v. Lockheed Propulsion Co., 247 Cal.App.2d 774, 784 [56 Cal.Rptr. 128, 29 A.L.R.3d 538]; McGrath v. Basich Brothers Const. Co., 7 Cal.App.2d 573, 576 [46 P.2d 981].)

The City contends that plaintiffs did not prove there was damage to the property in a substantial amount. (Lombardy v. Peter Kiewit Sons' Co., 266 Cal.App.2d 599, 602-603 [72 Cal.Rptr. 240], app. dism., 394 U.S. 813 [22 L.Ed.2d 748, 89 S.Ct. 1486], overruled on another ground, Southern Cal. Edison Co. v. Bourgerie, 9 Cal.3d 169, 175 [107 Cal.Rptr. 76, 507 P.2d 964].) However, Lombardy was a case which was decided upon the pleadings alone, in which the plaintiffs merely claimed to have sustained damages to real property and person in the amount of $5,000, and therefore it was impossible to tell to what extent the property itself was damaged.

In this case, however, the trial court found that the noise from the jet aircraft severely and substantially interfered with the residential use and enjoyment of the properties and found measurable reductions in market value in the amounts indicated in the judgment. Whether the damage was substantial enough to be compensable is a mixed question of fact and law for the trial court to determine, and the court's implied findings on factual issues will be upheld on appeal if there is substantial evidence to support them. (Riverside County Flood etc. Dist. v. Halman, supra, 262 Cal.App.2d 510, 517.) In the absence of specific legislative standards (see Van Alstyne, supra, fn. 5, 16 U.C.L.A. L.Rev. at pp. 535-539) we cannot say the damage was insubstantial in this case.

The City contends that it should not be liable because it does not build or fly the jet aircraft which make the noise and therefore the City's conduct is not the proximate cause of plaintiffs' damage. (Albers v. County of Los Angeles, 62 Cal.2d 250, 263 [42 Cal.Rptr. 89, 398 P.2d 129].) This argument is without merit. The fact that the City plans, builds and operates the airport is sufficient to impose liability. (Griggs v. Allegheny County, supra, 369 U.S. 84, 89 [7 L.Ed.2d 585, 589].) The City's operation of the airport need not be the sole cause of the damage. It need only be one substantial cause. (Holtz v. Superior Court, supra, 3 Cal.3d 296, 304, fn. 9; Blau v. City of Los Angeles, 32 Cal.App.3d 77, 84-85 [107 Cal.Rptr. 727].)

The City contends that because Congress has declared a public freedom of transit through the navigable air space, and has defined navigable air space to include air space needed to insure safety in takeoff and landing (49 U.S.C.A. ss 1301, 1304) the City is immune from liability. This is also without merit. The fact that the flights are within the navigable air space does not immunize the owner and operator of an airport for failure to appropriate the land and air space necessary to provide an adequate approach way. (Griggs v. Allegheny County, supra, 369 U.S. 84, 88 [7 L.Ed.2d 585, 588]; Loma Portal Civic Club v. American Airlines, Inc., supra, 61 Cal.2d 582, 591-594; City of Oakland v. Nutter, supra, 13 Cal.App.3d 752, 763, fn. 12; Martin v. Port of Seattle, supra, 391 P.2d 540, 544-545; Thornburg v. Port of Portland, supra, 376 P.2d 100, 108.) [FN 11]

[FN 11] City attempts to distinguish Griggs on the ground that the fact situation there arose prior to the 1958 amendment defining navigable air space to include the air space necessary to insure safe takeoff and landing. This is not persuasive. Even prior to 1958 the air space necessary to insure safe takeoff and landing was controlled by federal regulations. (Allegheny Airlines v. Village of Cedarhurst (2d Cir. 1956) 238 F.2d 812, 815; City of Newark, New Jersey v. Eastern Airlines (D.N.J. 1958) 159 F.Supp. 750, 756.) The flights in Griggs were not in violation of any CAA regulations, yet relief against the county as owner and operator of the airport was granted. (Loma Portal Civic Club v. American Airlines, Inc., supra, at p. 594.) The question is considered settled by the authorities cited in the text.

The City contends that the extensive pattern of federal regulation of air transportation preempts the field and that "[s]ince it is the Federal Government which controls the airspace it should be their responsibility for what happens as a result of its use." The contention that federal preemption precluded all state activity in aircraft noise control was rejected by our Supreme Court in Loma Portal Civic Club v. American Airlines, Inc., supra, at pages 591-594. The court found that the maintenance of an action for damages by the property owners, such as this one, would not conflict with federal law. The court said: "Moreover, we note that noise abatement is a federal as well as a state aim, and when not inconsistent with safety, the enforcement of a damage remedy under a nuisance theory, for example, would not necessarily present a conflict with federal law but might well reinforce it. ... [P] Only a compelling federal interest, e.g., where the state-created liability would clearly frustrate federal purposes, justifies our implying an intent on the part of Congress to nullify common-law rights normally in the state-law sphere." (Id., at p. 592.) The City relies on Allegheny Airlines v. Village of Cedarhurst (2d Cir. 1956) supra, 238 F.2d 812, affg. (E.D.N.Y. 1955) 132 F.Supp. 871; and City of Newark, New Jersey v. Eastern Airlines (D.N.J. 1958) supra, 159 F.Supp. 750, cases in which municipal ordinances attempting to regulate the altitude at which aircraft flew over the city were invalidated. As noted in Loma Portal Civic Club, supra, at pages 593-594, in both of those cases there was a direct conflict with federal flight control and the courts expressly stated that their decision did not affect the right of property owners to sue for damages.

In American Airlines, Inc. v. Town of Hempstead (2d Cir. 1968) 398 F.2d 369, affg. (E.D.N.Y. 1967) 272 F.Supp. 226, cert. den., 393 U.S. 1017 [21 L.Ed.2d 561, 89 S.Ct. 620], the court struck down a municipal ordinance which prohibited the operation of any mechanism which created a noise within the town exceedng a certain level. The court invalidated the ordinance on the ground there was a direct conflict with federal regulations controlling flight patterns and procedures because it was impossible to comply with the ordinance without changing altitudes, flight paths, traffic patterns, and safety margins regulated by the federal government. But the court noted that the case had nothing to do with the question of landowners' rights to compensation for overflights which constituted a taking of property. (398 F.2d at p. 372.)

In City of Burbank v. Lockheed Air Terminal (1973) 411 U.S. 624 [36 L.Ed.2d 547, 93 S.Ct. 1854], the Supreme Court invalidated a municipal ordinance which prohibited pure jet landings and takeoffs from Hollywood-Burbank Airport between 11 p.m. and 7 a.m. The ordinance was invalidated because such curfews, if enacted upon a widespread basis, would result in bunching of flights which would be inconsistent with the federal regulatory scheme. (Id., at pp. 627, 639-640 [36 L.Ed.2d at pp. 550, 557].) The majority opinion went further, however, to declare that section 611 of the Federal Aviation Act, as amended by the Noise Control Act of 1972 (49 U.S.C.A. s 1431) impliedly preempted the field of aircraft noise control. (Id., at pp. 628-640 [36 L.Ed.2d at pp. 551-557].) Nothing in Burbank or Hempstead suggests, however, that the City of Los Angeles, as owner and operator of LAX, should be absolved of all responsibility for the substantial interference with plaintiffs' use and enjoyment of their property which results from use of the airport. The legislative history of section 611 expressly indicates that it is not intended to "affect the rights of a State or local public agency, as the proprietor of an airport, from issuing regulations or establishing requirements as to the permissible level of noise which can be created by aircraft using the airport." [FN 12]

[FN 12] This language is that of the Secretary of Transportation quoted in the Senate Report on the bill adding section 611 to the Federal Aviation Act. In more detail the report states as follows: "The bill is an amendment to a statute describing the powers and duties of the Federal Government with respect to air commerce. As indicated earlier in this report, certain actions by State and local public agencies, such as zoning to assure compatible land use, are a necessary part of the total attack on aircraft noise. In this connection, the question is raised whether this bill adds or subtracts anything from the powers of State or local governments. It is not the intent of the committee in recommending this legislation to effect any change in the existing apportionment of powers between the Federal and State and local governments.

"In this regard, we concur in the following views set forth by the Secretary in his letter to the committee of June 22, 1968: 'The courts have held that the Federal Government presently preempts the field of noise regulation insofar as it involves controlling the flight of aircraft. Local noise control legislation limiting the permissible noise level of all overflying aircraft has recently been struck down because it conflicted with Federal regulation of air traffic. American Airlines v. Town of Hempstead. 272 F.Supp. 226 (U.S.D.C., E.D., N.Y., 1966). The court said, at 231, "The legislation operates in an area committed to Federal care, and noise limiting rules operating as to those of the ordinance must come from a Federal source." H.R. 3400 would merely expand the Federal Government's role in a field already preempted. It would not change this preemption. State and local governments will remain unable to use their police powers to control aircraft noise by regulating the flight of aircraft.

'However, the proposed legislation will not affect the rights of a State or local public agency, as the proprietor of an airport, from issuing regulations or establishing requirements as to the permissible level of noise which can be created by aircraft using the airport. Airport owners acting as proprietors can presently deny the use of their airports to aircraft on the basis of noise considerations so long as such exclusion is nondiscriminatory.

'Just as an airport owner is responsible for deciding how long the runways will be, so is the owner responsible for obtaining noise easements necessary to permit the landing and takeoff of the aircraft. The Federal Government is in no position to require an airport to accept service by larger aircraft and, for that purpose, to obtain longer runways. Likewise, the Federal Government is in no position to require an airport to accept service by noisier aircraft, and for that purpose to obtain additional noise easements. The issue is the service desired by the airport owner and the steps it is willing to take to obtain the service. In dealing with this issue, the Federal Government should not substitute its judgment for that of the States or elements of local government who, for the most part, own and operate our Nation's airports. The proposed legislation is not designed to do this and will not prevent airport proprietors from excluding any aircraft on the basis of noise considerations.'

"Of course, the authority of units of local government to control the effects of aircraft noise through the exercise of land use planning and zoning powers is not diminished by the bill.

"Finally, since the flight of aircraft has been preempted by the Federal Government, State and local governments can presently exercise no control over sonic boom. The bill makes no change in this regard." (Sen.Rep. No. 1353, 90th Cong. 2d Sess. (1968) 2 U.S. Code Cong. & Admin. News (1968) pp. 2693-2694.)

[FN 13] "... But, we are concerned here not with an ordinance imposed by the City of Burbank as 'proprietor' of the airport, but with the exercise of police power. While the Hollywood-Burbank Airport may be the only major airport which is privately owned, many airports are owned by one municipality yet physically located in another. For example, the principal airport serving Cincinnati is located in Kentucky. Thus, authority that a municipality may have as a landlord is not necessarily congruent with its police power. We do not consider here what limits, if any, apply to a municipality as a proprietor." (City of Burbank v. Lockheed Air Terminal, supra, 411 U.S. at p. 636, fn. 14 [36 L.Ed.2d at p. 555, fn. 14].)

[FN 14] For one discussion of the multiple strategies available to attack the problem of jet noise see Comment, supra, footnote 2, 6 Harv. Civ. Rights-Civ. Lib. L.Rev. 61. See also Larsen, Improving the Airport Environment: Effect of the 1969 FAA Regulations on Noise (1970) 55 Iowa L.Rev. 808.

[FN 15] The record in the instant case does not present the issue as to whether the City has any cause of action against any other parties such as the airlines, aircraft manufacturers, or the federal government.

The City contends that plaintiffs did not timely file claims within one year from the time the cause of action arose. (Gov. Code, s 911.2; Mosesian v. County of Fresno, 28 Cal.App.3d 493, 495 [104 Cal.Rptr. 655].) The claims were filed in January and February of 1964. The City contends that the cause of action arose sometime in 1962 and therefore the claims were not timely. The trial court determined that for purposes of Government Code section 911.2 the cause of action arose in May 1963 and thus the statute was satisfied.

The question of when a cause of action arises in a case such as this is a difficult one and the answer necessarily depends upon a number of factors. In Jensen v. United States (1962) 305 F.2d 444, 447 [158 Ct.Cl. 333], the court stated, "There is, unfortunately, no simple litmus test for discovering in all cases when an avigation easement is first taken by overflights. Some annoyance must be borne without compensation [citations]. The point when that stage is passed depends on a particularized judgment evaluating such factors as the frequency and level of the flights; the type of planes; the accompanying effects, such as noise or falling objects; the uses of the property; the effect on values; the reasonable reactions of the humans below; and the impact upon animals and vegetable life." The determination necessarily depends upon the facts of each case.

The City points to certain evidence that individual plaintiffs were annoyed by the jet noise in 1962 and that they hired attorneys and appraisers in that year. But the cause of action did not accrue at the point the homeowners first became annoyed. As pointed out in Jensen some annoyance must be borne without compensation. It is only when the flights substantially interfered with the use and enjoyment of plaintiffs' properties and resulted in a diminution of their market value that a cause of action arose. (Aaron v. United States (1963) 311 F.2d 798, 800 [160 Ct.Cl. 295], second appeal (1964) 340 F.2d 655, 658-659 [167 Ct.Cl. 818].)

Moreover, under the decision in Pierpont Inn, Inc. v. State of California, 70 Cal.2d 282, 291-293 [74 Cal.Rptr. 521, 449 P.2d 737], which relies in turn upon United States v. Dickinson (1947) 331 U.S. 745, 747-749 [91 L.Ed. 1789, 1793-1794, 67 S.Ct. 1382], plaintiffs were not required to sue as soon as the damaging flights began but were entitled to some extent to wait until the situation became stabilized. (See also Nestle v. City of Santa Monica, supra, 6 Cal.3d 920, 937.)

In the instant case, the trial court carefully weighed a variety of circumstances including the increase in the number of jet aircraft landings, the increase in the number of fan jet aircraft (which are greatly more annoying than pure jet aircraft), and the effect upon the residents, and determined that the statute of limitations began to run in May 1963. Many of the individual plaintiffs testified that although they were annoyed by the noise in 1962, the frequency of the flights and the damage caused by the noise jumped markedly in 1963. (See Jensen v. United States, supra.) There was substantial evidence to support the trial court's ruling that plaintiffs' claims were timely filed.

Since we uphold the trial court's finding that for purposes of the statute of limitations the taking or damaging of plaintiffs' property occurred as of May 1963, there is no merit to the City's contention that the testimony of plaintiffs' appraisers was defective in failing to distinguish decreases in market value which the City contends occurred in 1962. (See Pierpont Inn, Inc. v. State of California, supra, 70 Cal.2d 282, 290-294.) [FN 16]

[FN 16] Another contention raised by the City as to the appraisal testimony is that it should have been stricken as based on speculation. This contention is based on a single remark of one appraiser which he later corrected. There were many days of testimony by the appraisers explaining the reasons for their opinions. The trial court properly denied the motion to strike. (MCA, Inc. v. Universal Diversified Enterprises Corp., 27 Cal.App.3d 170, 178-179 [103 Cal.Rptr. 522].)

Admissibility of NEF Area Study

The City argues that the trial court should have excluded from evidence the Bolt, Beranek and Newman study of noise exposure forecast areas for LAX, because the earliest portion of that study was for the year 1965, whereas the taking or damaging in the instant case occurred in May 1963. The City contends that the study was therefore irrelevant. This argument is without merit. The NEF area contours were based upon a number of factors including frequency of jet flights, timing of such flights by day and by night, types of jet aircraft, operating conditions and procedures, and flight patterns. Although the number of flights increased between 1963 and 1965, the City points to no evidence that the types of aircraft, operating procedures, or flight patterns were substantially different in 1965. That NEF area C was the neighborhood of the most severe impact on land use was substantiated by the testimony of the appraisers. The trial court took the date of the study into account in determining the weight of the evidence. The study was relevant. (Evid. Code, s 210.)

In summary we hold that the municipal operator of an airport is liable for a taking or damaging of property when the owner of property in the vicinity of the airport can show a measurable reduction in market value resulting from the operation of the airport in such manner that the noise from aircraft using the airport causes a substantial interference with the use and enjoyment of the property, and the interference is sufficiently direct and sufficiently peculiar that the owner, if uncompensated, would pay more than his proper share to the public undertaking. Whether the interference is substantial enough to meet this standard is a mixed question of fact and law for the trial judge to determine. The owner need not prove there were direct overflights of the property. The fact that the federal government controls the flight of aircraft does not relieve the airport owner and operator of liability where the operation of the airport is a substantial cause of the property owner's damage.

The judgment is affirmed.

Kaus, P. J., and Stephens, J., concurred.

Appellant's petition for a hearing by the Supreme Court was denied August 28, 1974.