                  FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

SAM MONTALVO; EVELYN                    
MONTALVO,
               Plaintiffs-Appellants,         No. 05-15640
                 v.                            D.C. No.
SPIRIT AIRLINES; THE BOEING                 CV-03-03181-VRW
COMPANY,
             Defendants-Appellees.
                                        

MARY BUXTON; JOSEPH BUXTON,             
               Plaintiffs-Appellants,
                 v.                           No. 05-15703
CONTINENTAL AIRLINES INC., a                   D.C. No.
corporation; THE BOEING COMPANY,            CV-03-05634-VRW
a corporation,
             Defendants-Appellees.
                                        

DAVID WOODS,                            
               Plaintiff-Appellant,
               v.
AMERICAN AIRLINES, INC.,                      No. 05-15723
             Defendant-Appellee,               D.C. No.
              and                           CV-03-05186-VRW
THE BOEING COMPANY; WEBER
AIRCRAFT LP,
                       Defendants.
                                        

                            14737
14738            MONTALVO v. SPIRIT AIRLINES



VARUN GUPTA,                          
               Plaintiff-Appellant,
               v.
AMERICAN AIRLINES, INC.; THE                No. 05-15724
BOEING COMPANY,                              D.C. No.
           Defendants-Appellees,          CV-04-00412-VRW
              and
WEBER AIRCRAFT LP,
                        Defendant.
                                      

RICHARD JAFFE; ELLEN JAFFE,           
             Plaintiffs-Appellants,
                                            No. 05-15726
                v.
                                             D.C. No.
EL AL ISRAEL AIRLINES, LIMITED;           CV-04-01807-VRW
AMERICAN AIRLINES, INC.,
            Defendants-Appellees.
                                      

TERESA STONESTREET,                   
               Plaintiff-Appellant,
                v.                          No. 05-15732
AMERICAN AIRLINES, INC., a                   D.C. No.
Corporation; THE BOEING                   CV-03-03845-VRW
COMPANY, a Corporation,
             Defendants-Appellees.
                                      
                  MONTALVO v. SPIRIT AIRLINES           14739



BARBARA A. HANSEN,                      
                 Plaintiff-Appellant,
                 v.
AMERICAN AIRLINES, INC.; UNITED
AIR LINES, INC.; UAL                          No. 05-15736
CORPORATION,                                   D.C. No.
             Defendants-Appellees,          CV-04-00789-VRW
                and
THE BOEING COMPANY; WEBER
AIRCRAFT LP,
                         Defendants.
                                        

TRUDY HANSCHU; HARRY HANSCHU,           
              Plaintiffs-Appellants,
                v.                            No. 05-15746
AMERICAN AIRLINES, INC., a                     D.C. No.
Corporation; THE BOEING                     CV-03-03849-VRW
COMPANY, a Corporation,
             Defendants-Appellees.
                                        

JAMES VARRIALE,                         
                Plaintiff-Appellant,          No. 05-15889
                 v.                            D.C. No.
JETBLUE   AIRWAYS CORPORATION,              CV-04-04166-VRW
               Defendant-Appellee.
                                        
14740            MONTALVO v. SPIRIT AIRLINES



ANTHONY R. TWARDOWSKI, an               
individual,
               Plaintiff-Appellant,           No. 05-15911
                v.                             D.C. No.
AMERICAN AIRLINES, INC.; AMERICA            CV-05-00237-VRW
WEST AIRLINES, INC.,
            Defendants-Appellees.
                                        

EDWARD STETSER; RACHEL STETSER,         
               Plaintiffs-Appellants,         No. 05-15949
                 v.                             D.C. Nos.
AMERICA WEST AIRLINES, INC., a             CV-03-05144-VRW
corporation; THE BOEING COMPANY,             MDL-04-1606-
a corporation,                                    VRW
             Defendants-Appellees.
                                        

In re: DEEP VEIN THROMBOSIS             
LITIGATION,


RHONDA O. BELL,
               Plaintiff-Appellant,           No. 05-15953
               v.                              D.C. No.
                                            CV-04-05491-VRW
US AIRWAYS, INC., also known as
US Airways a Subsidiary of US
Airways Group, Inc.; US AIRWAYS
GROUP INC.,
            Defendants-Appellees.
                                        
                 MONTALVO v. SPIRIT AIRLINES          14741



In re: DEEP VEIN THROMBOSIS           
LITIGATION,

                                            No. 05-15956
EUGENE VANARSDALE,
              Plaintiff-Appellant,           D.C. No.
                                          CV-04-01606-VRW
               v.
US AIRWAYS, INC.,
             Defendant-Appellee.
                                      

JAMES MOYER,                          
              Plaintiff-Appellant,          No. 05-16730
               v.                            D.C. No.
US AIRWAYS, INC.,                         CV-05-02325-VRW
             Defendant-Appellee.
                                      

JAMES H. ENGLISH,                     
               Plaintiff-Appellant,         No. 05-17180
               v.                            D.C. No.
US AIRWAYS INC.,                          CV-05-03180-VRW
              Defendant-Appellee.
                                      
14742             MONTALVO v. SPIRIT AIRLINES



THOMAS F. HIND,                             No. 05-17181
              Plaintiff-Appellant,             D.C. No.
               v.
                                          CV-05-03181-VRW
SOUTHWEST AIRLINES CO.,                      ORDER AND
             Defendant-Appellee.              AMENDED
                                              OPINION

        Appeal from the United States District Court
          for the Northern District of California
        Vaughn R. Walker, District Judge, Presiding

                   Argued and Submitted
         April 16, 2007—San Francisco, California

                   Filed October 4, 2007
                 Amended November 9, 2007

     Before: Mary M. Schroeder, Chief Circuit Judge,
Stephen S. Trott, Circuit Judge, and Barry Ted Moskowitz,*
                       District Judge.

             Opinion by Chief Judge Schroeder




  *The Honorable Barry Ted Moskowitz, U.S. District Judge for the
Southern District of California, sitting by designation.
14744           MONTALVO v. SPIRIT AIRLINES


                       COUNSEL

Randy Baker, Seattle, Washington, and Brenda D. Posada,
Sterns & Walker, Oakland, California, for the plaintiffs-
appellants.

William J. Boyce, Houston, Texas, for the defendants-
appellees.

Clem C. Trischler, Pittsburgh, Pennsylvania, for the
defendants-appellees.
                     MONTALVO v. SPIRIT AIRLINES         14745
Stephen C. Kenney and Samantha D. Hilton, San Francisco,
California, for the defendants-appellees.


                              ORDER

   The Opinion filed in this matter on October 4, 2007, is
hereby amended to correct a typographical error. The caption
is amended to include the case number for Thomas F. Hind
v. Southwest Airlines, Case No. 05-17181.


                             OPINION

SCHROEDER, Chief Circuit Judge:

I.   Introduction.

  These consolidated appeals arise from fourteen plaintiffs’
negligence claims under California common law against vari-
ous airlines (collectively “the Airlines” or “Airline-
Defendants”) for failing to warn about the danger of develop-
ing deep vein thrombosis and for providing an unsafe seating
configuration on domestic flights.

   This case presents the question of whether and to what
extent the Federal Aviation Act of 1958 (the “FAA”), 49
U.S.C. § 40103, and its corresponding regulations promul-
gated by the Federal Aviation Administration regarding avia-
tion safety, preempt state law standards of care, including any
state-imposed duty to warn about the risks of deep vein
thrombosis (“DVT”). We also address whether Plaintiffs may
recover for injuries sustained due to an allegedly unsafe seat-
ing configuration or whether such claims are preempted by
the Airline Deregulation Act of 1978 (the “ADA”), an eco-
nomic measure designed by Congress to prevent states from
regulating airline prices, routes, and services. See 49 U.S.C.
14746             MONTALVO v. SPIRIT AIRLINES
§ 41713(b)(1) (previously codified at 49 U.S.C. app.
§ 1305(a)(1)).

   The district court found federal preemption in both
instances. It held that the FAA impliedly preempts the field
of preflight warnings, and the court dismissed Plaintiffs’ fail-
ure to warn claim as a matter of law. In re Deep Vein Throm-
bosis Litig., No. 04-1606, 2005 WL 591241, at *35, *47
(N.D. Cal. March 11, 2005). It observed that Congress’ intent
in passing the FAA was to preempt the entire field of air
safety. It also rested its dismissal on the conflict between fed-
eral safety standards governing passenger warnings and any
state-imposed duty to warn. The district court further held that
the ADA preempts Plaintiffs’ unsafe seating configuration
claim, because any seating reconfiguration would impermiss-
ibly affect airline prices. Id.

   We affirm the district court’s dismissal of the failure to
warn claim, but remand the seating configuration claim for
further factual development. The FAA and the relevant fed-
eral regulations preempt Plaintiffs’ failure to warn claim,
because the FAA preempts the entire field of aviation safety
through implied field preemption. The FAA and regulations
promulgated pursuant to it establish complete and thorough
safety standards for air travel, which are not subject to supple-
mentation by, or variation among, state laws. Some circuits
have considered whether federal law preempts discrete
aspects of air safety. See, e.g. French v. Pan Am Express, Inc.,
869 F.2d 1, 6-7 (1st Cir. 1989) (holding that the FAA governs
issues of pilot suitability, including submission to drug test-
ing). The Third Circuit has gone one step further. See Abdul-
lah v. American Airlines, Inc., 181 F.3d 363, 367-68 (3d Cir.
1999). We adopt the Third Circuit’s broad, historical
approach to hold that federal law generally establishes the
applicable standards of care in the field of aviation safety. Id.;
cf. Witty v. Delta Airlines, 366 F.3d 380, 384-86 (5th Cir.
2004). Because the FAA preempts the entire field of aviation
safety from state and territorial regulation, the Airlines are
                  MONTALVO v. SPIRIT AIRLINES               14747
under no obligation to warn of the risk of developing DVT,
absent a federal mandate to do so. Because there are no fed-
eral regulations requiring the Airlines to warn about the risks
of DVT, we affirm the district court’s dismissal of Plaintiffs’
failure to warn claim.

   The Airlines’ preemption argument on the seating configu-
ration claim presents a closer question. The Airlines argue
that any reconfiguration of airplane seating would decrease
the number of seats and thus require a significant increase in
ticket prices to offset the loss in revenue. They assert that trig-
gering this increase would amount to an indirect regulation of
airline fares, which is precluded by the ADA. While the Air-
lines may ultimately be correct, we remand this claim to the
district court for further development, because on the basis of
the record before us, there is an insufficient factual basis on
which to conclude that any seat reconfiguration would have
what the Supreme Court has described as the “forbidden sig-
nificant effect” on airline ticket prices. See Morales v. Trans
World Airlines, Inc., 504 U.S. 374, 388 (1992).

II.   Background.

   Plaintiffs filed this suit on April 14, 2003, in state court
against Spirit Airlines, Northwest Airlines, El Al Limited,
American Airlines, Continental Airlines, America West Air-
lines, U.S. Airways, and Jetblue Airlines. The facts underly-
ing each of plaintiffs’ claims are largely identical. Each
plaintiff allegedly developed DVT after taking a trans-
continental or mid-continental flight. Each also claims that
prolonged, cramped seating during flight was the proximate
cause of his DVT. DVT is a medical condition that occurs
when a blood clot forms in a deep vein, usually in the leg. It
can cause serious complications if the clot breaks off and trav-
els to an organ, most commonly to the lungs or brain. See
Witty, 366 F.3d at 382. Some of the plaintiffs in this litigation
are in fact deceased as a result of the clots spreading to a vital
organ.
14748             MONTALVO v. SPIRIT AIRLINES
   In their initial complaint, Plaintiffs raised common law per-
sonal injury claims against the Airlines, as well as breach of
warranty claims against various airplane manufacturers (the
“Manufacturer-Defendants”). They claimed that the Airline-
Defendants failed to warn about the risk of developing DVT,
and that the Airlines failed to inform passengers about steps
they could have taken during flight to mitigate any risk. Plain-
tiffs argued that at the time they took the flights on which they
developed DVT, the Airlines were aware or reasonably
should have been aware that long-distance air travel can cause
DVT and that resulting blood clots can sometimes result in
serious injury or death. Plaintiffs asserted that the Airlines
were aware of several measures that could prevent passengers
from incurring DVT, such as walking around the cabin, exer-
cising the legs while seated, or wearing special stockings.
Despite this alleged knowledge, the Airlines gave no warn-
ings regarding DVT.

   In addition to the failure to warn claim, Plaintiffs alleged
that the Airlines provided an unsafe seating configuration by
limiting each passenger’s legroom. Apart from the claims
against the Airlines, Plaintiffs also brought suit against the
Manufacturer-Defendants, claiming they provided a seat
design that was defective for the same reason.

   Defendants collectively removed the actions to federal dis-
trict court on the basis of diversity jurisdiction in July 2003.
On June 22, 2004, the Judicial Panel on Multidistrict Litiga-
tion transferred all actions to Judge Vaughn Walker of the
Northern District of California for coordinated pre-trial pro-
ceedings. In re Deep Vein Thrombosis Litig., 323 F. Supp. 2d
1378, 1380-81 (J.P.M.L. 2004).

  The Manufacturer-Defendants moved for summary judg-
ment on the defective seat design claim, and the district court
granted the motion. Deep Vein Thrombosis Litig., No. 04-
1606, 2005 WL 591241, *14-15. With respect to the remain-
ing state law claims, the Airline-Defendants filed a Joint
                  MONTALVO v. SPIRIT AIRLINES             14749
Report and Case Management Statement arguing that federal
law preempts the failure to warn and unsafe seating configu-
ration claims. The district court treated the report as a motion
to dismiss under Federal Rule of Civil Procedure 12(b)(6) and
requested briefing from the parties. After considering the
arguments, the district court entered judgment for the Airlines
under Federal Rule of Civil Procedure 54(b). Id. It held that
the Airline Deregulation Act expressly preempts the unsafe
seating configuration claim, because any required recon-
figuration of seats would impermissibly affect prices. Id. at
*4-10. It also held that the Federal Aviation Act impliedly
preempts the failure to warn claim, because Congress
intended to occupy exclusively the field of passenger warn-
ings. Id. at *10-14.

  Plaintiffs pursue on appeal only the district court’s dis-
missal of their failure to warn claim and their unsafe seating
configuration claim. They do not appeal the district court’s
grant of summary judgment in favor of the Manufacturer-
Defendants for the defective seat design claim.

III.   Preemption of the Failure to Warn Claim.

   [1] It is well-established that Congress has the power to
preempt state law. U.S. CONST. ART. VI, cl. 2; Cipollone v.
Liggett Group, Inc., 505 U.S. 504, 516 (1992). It may do so
expressly or impliedly. Cipollone, 505 U.S. at 516. Congress’
intent may be “explicitly stated in the statute’s language or
implicitly contained in its structure and purpose.” (quoting
Jones v. Rath Packing Co., 403 U.S. 519, 525 (1997)) Id.
Nothing in the FAA expressly preempts state regulation of air
safety, so preemption, if any, must be implied.

  [2] There are two types of implied preemption: conflict pre-
emption and field preemption. Courts may find conflict pre-
emption when a state law actually conflicts with federal law
or when a state law stands as an obstacle to the accomplish-
ment and execution of the full purposes and objectives of
14750             MONTALVO v. SPIRIT AIRLINES
Congress in enacting the federal law. See Shaw v. Delta Air-
lines, Inc., 463 U.S. 85, 95 (1983) (holding that a state law
was preempted by ERISA insofar as the state law prohibited
practices that were lawful under ERISA); Crosby v. Nat’l
Foreign Trade Council, 530 U.S. 363, 373 (2000). Implied
preemption exists when federal law so thoroughly occupies a
legislative field “as to make reasonable the inference that
Congress left no room for the States to supplement it.” Cipol-
lone, 505 U.S. at 516 (citing Fidelity Fed. Sav. & Loan Ass’n
v. de la Cuesta, 458 U.S. 141, 153 (1982)). Thus, field pre-
emption occurs when Congress indicates in some manner an
intent to occupy a given field to the exclusion of state law.
Cipollone, 505 U.S. at 516. In this case, we conclude that
Congress has indicated its intent to occupy the field of avia-
tion safety.

   While the comprehensiveness of a statute is one indication
of preemptive intent, it alone is generally not sufficient to find
that Congress intended to occupy the entire field. Skysign Int’l
Inc. v. Honolulu, 276 F.3d 1109, 1117 (9th Cir. 2002) (citing
Geier v. American Honda Motor Co., 529 U.S. 861, 884
(2000)). We may, however, also look to the pervasiveness of
the regulations enacted pursuant to the relevant statute to find
preemptive intent. Fidelity Fed. Sav. & Loan Ass’n, 458 U.S.
at 153 (“Federal regulations have no less preemptive effect
than statutes.”). This is because “[w]here . . . Congress has
entrusted an agency with the task of promulgating regulations
to carry out the purposes of a statute, as part of the pre-
emption analysis we must consider whether the regulations
evidence a desire to occupy a field completely.” R.J. Reynolds
Tobacco Co. v. Durham County, 479 U.S. 130, 149 (1986)
(citation omitted). As a result, a regulation’s preemptive force
does not depend on express Congressional authorization to
displace state law. Id. Instead, when an agency administrator
promulgates pervasive regulations pursuant to his Congressio-
nal authority, we may infer a preemptive intent unless it
appears from the underlying statute or its legislative history
that Congress would not have sanctioned the preemption. Id.
                  MONTALVO v. SPIRIT AIRLINES             14751
Here, the regulations enacted by the Federal Aviation Admin-
istration, read in conjunction with the FAA itself, sufficiently
demonstrate an intent to occupy exclusively the entire field of
aviation safety and carry out Congress’ intent to preempt all
state law in this field.

   [3] We begin with Congress’ intent, because our analysis
of the scope of the statute’s preemption is guided by the oft-
repeated comment that the purpose of Congress is the ultimate
touchstone in every preemption case. Id.; Cipollone, 505 U.S.
at 516. The Congressional purpose must be clear, for we are
mindful of the adage that Congress does not cavalierly pre-
empt state law causes of action. Medtronic, Inc. v. Lohr, 518
U.S. 470, 485 (1996). In this case, however, we are address-
ing an area of the law that has long been dominated by federal
interests. As we have observed, regulation of this country’s
airspace has “a history of significant federal presence.” Sky-
sign Int’l Inc., 276 F.3d at 1116; Fidelity Fed. Sav. & Loan
Ass’n, 458 U.S. at 153 (holding that preemptive intent is more
readily inferred when the statute governs an area of the law
where the federal interest is dominant).

   The purpose, history, and language of the FAA lead us to
conclude that Congress intended to have a single, uniform
system for regulating aviation safety. The catalytic events
leading to the enactment of the FAA helped generate this
intent. The FAA was drafted in response to a series of fatal
air crashes between civil and military aircraft operating under
separate flight rules. See United States v. Christensen, 419
F.2d 1401, 1404 (9th Cir. 1969). To avoid future disasters
and, as we have expressed it, “to promote safety in aviation
and thereby protect the lives of persons who travel on board
aircraft,” In re Mexico City Aircrash of October 31, 1979, 708
F.2d 400, 406 (9th Cir. 1983), Congress enacted the FAA,
“the whole tenor [of which was] to create and enforce one
unified system of flight rules.” Christensen, 419 F.2d at 1404;
see also World Airways, Inc. v. Int’l Brotherhood of Team-
sters, Airline Div., 578 F.2d 800 (9th Cir. 1978). In discussing
14752             MONTALVO v. SPIRIT AIRLINES
the impetus for the FAA, the Supreme Court has also noted
that regulating the aviation industry requires a delicate bal-
ance between safety and efficiency. It is precisely because of
“the interdependence of these factors” that Congress enacted
“a uniform and exclusive system of federal regulation.” City
of Burbank v. Lockheed Air Terminal Inc., 411 U.S. 624, 638-
39 (1973) (citations omitted); see also id. at 644 (J. Rehn-
quist, dissenting) (“The paramount substantive concerns of
Congress in enacting the FAA were to regulate federally all
aspects of air safety, . . . and, once aircraft were in ‘flight,’
air-space management . . . .”); Northwest Airlines, Inc. v. Min-
nesota, 322 U.S. 292, 303 (1944) (J. Jackson, concurring)
(“Planes do not wander about in the sky like vagrant clouds.
They move only by federal permission, subject to federal
inspection, in the hands of federally certified personnel and
under an intricate system of federal commands.”).

   [4] The legislative history of the FAA further illustrates
Congress’ intent to make the Federal Aviation Administration
the sole arbiter of air safety. The House Report for the FAA
explained in a section entitled “Purpose of Legislation,” that
“the administrator of the new Federal Aviation Agency (1)
would be given full responsibility and authority for the . . .
promulgation and enforcement of safety regulations . . . .”
H.R. REP. NO. 2360, 85th Cong., 2d Sess., 22, reprinted in
1958 U.S.C.C.A.N. 3741, 3741. In a letter to the House Com-
mittee on Interstate and Foreign Commerce, included as part
of the House Report, a representative of the Executive Branch
wrote:

    It is essential that one agency of government, and
    one agency alone, be responsible for issuing safety
    regulations if we are to have timely and effective
    guidelines for safety in aviation.

Id. at 3761. Congress thus intended to ensure that the agency
alone would have the power, if it chose to exercise it, to frame
the rules for the safe and efficient use of the nation’s airspace.
                  MONTALVO v. SPIRIT AIRLINES              14753
Air Line Pilots Ass’n, Int’l v. Quesada, 276 F.2d 892, 894 (2d
Cir. 1960).

   [5] The language of the Act itself also illustrates that Con-
gress “left open the door” for the Administrator to choose to
preempt subfields of air commerce, including but not limited
to aviation safety, “through the use of its authority to develop
regulations. . . .” Skysign Int’l Inc., 276 F.3d at 1116 (citing
49 U.S.C. § 40103(b)(1)-(2) (1994)). The FAA not only
authorizes but affirmatively directs the Administrator of the
Federal Aviation Administration to promulgate regulations for
the “safe flight of civil aircraft in air commerce.” 49 U.S.C.
§ 44701. Congress also wrote into the FAA a catch-all provi-
sion, which directs the Administrator to regulate any “other
practices, methods, and procedure the Administrator finds
necessary for safety in air commerce and national security.”
Id.

   [6] Thus, when we look to the historical impetus for the
FAA, its legislative history, and the language of the Act, it is
clear that Congress intended to invest the Administrator of the
Federal Aviation Administration with the authority to enact
exclusive air safety standards. Moreover, the Administrator
has chosen to exercise this authority by issuing such pervasive
regulations that we can infer a preemptive intent to displace
all state law on the subject of air safety. See Fidelity Fed. Sav.
& Loan Ass’n, 458 U.S. at 153. These regulations codified in
Title 14 of the Code of Federal Regulations, cover, inter alia,
airworthiness standards, crew certification and medical stan-
dards, and aircraft operating requirements. The regulations
also include a general federal standard of care for aircraft
operators, requiring that “no person may operate an aircraft in
a careless or reckless manner so as to endanger the life or
property of another.” 14 C.F.R. § 91.13(a) (2003). Most perti-
nently, a number of specific federal regulations govern the
warnings and instructions which must be given to airline pas-
sengers. See 14 C.F.R. pt. 25 (2005); 14 C.F.R. pt. 121
(2005). These regulations require, for example, that “no
14754             MONTALVO v. SPIRIT AIRLINES
smoking” placards be placed in lavatories, id. § 25.791(d)
(2004), that “no smoking” signs be illuminated during the
entire flight on non-smoking flights, id. § 121.317(c) (2003),
and that the “fasten seat belt” sign “shall be turned on during
any movement on the surface, for each takeoff, for each land-
ing, and at any other time considered necessary by the pilot
in command,” id. § 121.317(b). In addition, the Federal Avia-
tion Administration has published regulations, id. §§ 121.571,
121.585, and an advisory circular setting out in detail the oral
briefings, familiar to all domestic air travelers, which flight
attendants or other flight personnel must give passengers, as
well as the information that must be included in passenger
safety briefing cards. These briefings include warnings for
passenger safety, such as “seat backs [must be] in an upright
position before takeoff and landing.” Id. § 125.327(a)(3). The
comprehensiveness of these regulations demonstrates that the
Administrator has exercised his authority to regulate aviation
safety to the exclusion of the states.

   If the FAA did not impliedly preempt state requirements
for passenger warnings, each state would be free to require
any announcement it wished on all planes arriving in, or
departing from, its soil, or to impose liability for the violation
of any jury’s determination that a standard the jury deems rea-
sonable has been violated. Such a “patchwork of state laws in
this airspace . . . would create a crazyquilt effect.” French,
869 F.2d at 6. Congress could not reasonably have intended
an airline on a Providence-to-Baltimore-to-Miami run to be
subject to certain requirements in, for example Maryland, but
not in Rhode Island or in Florida. See id. It is equally as
doubtful that Congress would have intended the sufficiency of
the Airlines’ warnings to hinge on where each passenger on
each flight was likely to file suit. As the district court noted,
such a result would be an anathema to the FAA. In re Deep
Vein Thrombosis Litig., No. 04-1606, 2005 WL 591241, at
*13.

   The uniqueness of the aviation industry further mandates
the need for a centralized authority. See, e.g., S. REP. NO.
                  MONTALVO v. SPIRIT AIRLINES              14755
1811, 85th Cong., 2d Sess. 5 (1958) (“Aviation is unique
among transportation industries in its relation to the federal
government—it is the only one whose operations are con-
ducted almost wholly within federal jurisdiction, and are sub-
ject to little or no regulation by States or local authorities.”).
Aviation transportation requires more national coordination
than any other public transportation and also poses the largest
risks. Id. Regulation on a national basis is required because air
transportation is a national operation.

   For all of these reasons, the Third Circuit became the lead-
ing circuit to recognize that federal law preempts the entire
field of aviation safety. Abdullah, 181 F.3d at 367-68. The
plaintiffs in that case were passengers who were injured when
an airline encountered turbulence. They sued the airline for
negligence for failing to warn the passengers about the turbu-
lence. In determining whether the plaintiffs’ claims were pre-
empted, the Third Circuit concluded that “because of the need
for one, consistent means of regulating aviation safety, the
standard applied in determining if there has been careless or
reckless operation of an aircraft, should be federal; state or
territorial regulation is preempted.” Id. at 372. The plaintiffs
could therefore recover only if they could prove that the air-
lines violated a federal standard of care. Id.

   [7] We similarly hold that federal law occupies the entire
field of aviation safety. Congress’ intent to displace state law
is implicit in the pervasiveness of the federal regulations, the
dominance of the federal interest in this area, and the legisla-
tive goal of establishing a single, uniform system of control
over air safety. This holding is fully consistent with our deci-
sion in Skysign, 276 F.3d 1109, where we considered whether
federal law preempted state regulation of aerial advertising
that was distracting and potentially dangerous to persons on
the ground. In upholding the state regulations, we held that
federal law has not “preempt[ed] altogether any state regula-
tion purporting to reach into the navigable airspace.” Id. at
1116. While Congress may not have acted to occupy exclu-
14756             MONTALVO v. SPIRIT AIRLINES
sively all of air commerce, it has clearly indicated its intent
to be the sole regulator of aviation safety.

   [8] The FAA, together with federal air safety regulations,
establish complete and thorough safety standards for interstate
and international air transportation that are not subject to sup-
plementation by, or variation among, states. The district court
correctly held that because there is no federal requirement that
airlines warn passengers about the risk of developing DVT,
Plaintiffs’ negligence claim fails as a matter of law.

IV.   Preemption of the Unsafe Seating Configuration Claim.

   Plaintiffs’ second claim is that the Airlines were negligent
in providing an unsafe seating configuration, which caused
blood clots to form in Plaintiffs’ bodies from a lack of ade-
quate legroom. The district court dismissed the claim under
Federal Rule of Civil Procedure 54(b), holding that it was pre-
empted by the Airline Deregulation Act, 49 U.S.C.
§ 41713(b)(1). In re Deep Vein Thrombosis Litig., No. 04-
1606, 2005 WL 591241, at *4-8. The court accepted the posi-
tion of the Airlines, who posited that to provide more leg-
room, they would have to reduce the number of seats per
aircraft and then materially increase ticket prices to offset the
decreased revenue. The court found that there would be a
price increase and it would amount to a forbidden indirect
regulation of the aviation industry under the ADA. Id. at *8-
10.

   [9] The ADA, unlike the FAA, contains an express preemp-
tion provision. See 49 U.S.C. § 41713(b)(1). It prohibits states
from indirectly regulating air commerce by enacting laws that
have a significant effect on airline prices, routes, or services.
 Id. Preemption provisions are narrowly and strictly con-
strued. Charas v. Trans World Airlines, Inc., 160 F.3d 1259,
1265 (9th Cir. 1998). In deciding whether the ADA expressly
preempts Plaintiffs’ claim, we must first “ascertain and give
effect to the plain meaning of the language used.” Id. at 1264
                   MONTALVO v. SPIRIT AIRLINES               14757
(quoting Hughes Air Corp. v. Public Utils. Comm’n, 644 F.2d
1334, 1337 (9th Cir. 1981)). We may then “look to the provi-
sions of the whole law[ ] and to its object and policy.” Id.
(quoting Kelly v. Robinson, 479 U.S. 36, 43 (1986)). And, as
always, we must keep in mind that Congress’ intent is the ulti-
mate touchstone of every preemption case. Id. at 1265.

   Congress enacted the ADA in 1978 as an amendment to the
FAA. The Act’s purpose was to encourage airlines to compete
in the marketplace by deregulating the aviation industry.
Morales, 504 U.S. at 378. Before deregulation, Congress had
authorized the Civil Aeronautics Board to regulate entry into
the interstate airline industry, set routes that airlines could fly,
and choose rates that the airlines could charge consumers. Id.
Congress terminated this practice to encourage the airlines to
be more autonomous competitors in our capitalist society.

   Congress feared, however, that states would attempt to
undo federal deregulation with regulation of their own. Id.;
see also Charas, 160 F.3d at 1265. To prevent states from
doing indirectly what Congress proscribed directly, Congress
included an express preemption provision in the ADA. The
provision provides, subject to certain exceptions not relevant
here, that:

    A State . . . may not enact or enforce a law, regula-
    tion, or other provision having the force and effect
    of law related to a price, route, or service of any air
    carrier that may provide air transportation under this
    subpart.

49 U.S.C. § 41713(b)(1).

   The Supreme Court has twice addressed the scope of this
preemption clause, first in Morales, 504 U.S. 374, and again
in American Airlines v. Wolens, 513 U.S. 219 (1995). The
Court in Morales held that the ADA preempted the attempts
of several state attorneys general to enforce state laws prohib-
14758             MONTALVO v. SPIRIT AIRLINES
iting deceptive advertising by airlines, because advertising
fostered competition, which in turn affected airline prices. In
so holding, the Court paid particular attention to the use of the
phrase “related to.” The Court interpreted the phrase to mean
any state regulation “having a connection with, or reference
to, airline ‘rates, routes, or services.’ ” Morales, 504 U.S. at
384. The Court, however, was careful to limit the reach of the
preemptive effect to regulation that has some long-term mate-
rial impact. It emphasized that only those regulations that
have “the forbidden significant effect” upon rates, routes, or
services are preempted. Id. at 388.

   We have applied Morales and Wolens to an ADA preemp-
tion case in order to address whether certain state tort claims
that related to the negligent performance of in-flight duties by
flight attendants were preempted. See Charas, 160 F.3d 1259.
We noted that the Supreme Court has held preempted only
state regulation that has a significant effect on prices, routes,
and services, because Congress’ intent in deregulating the avi-
ation industry was to “encourage the forces of competition,”
not to obviate all tort claims under state law that might in
some peripheral way impact the airlines. See id. at 1266. We
held that state claims that do not “significantly impact federal
deregulation” are not preempted. Id. at 1265-66. Clarifying
some confusion in our cases, we held that preemption of regu-
lation related to “services” refers to the regularity or fre-
quency of flights between given destinations, not to the
onboard services rendered by a flight crew.

   In Witty, 366 F.3d 380, which presented the same legal
issues before us now, the Fifth Circuit dismissed the plain-
tiffs’ seating configuration claim on preemption grounds,
observing that the plaintiffs effectively conceded that any seat
reconfiguration would materially affect costs, leading to a sig-
nificant increase in airfares. Id. at 383. In this case, however,
Plaintiffs have not conceded that any seating reconfiguration
would result in a significant effect on airline ticket prices or
would interfere with the forces of competition. The Airlines
                   MONTALVO v. SPIRIT AIRLINES           14759
have not yet produced any evidence on this issue, and we
have no factual basis on which to judge the effect of any seat-
ing reconfiguration on prices. We thus cannot determine
whether a seat reconfiguration would materially impact fed-
eral deregulation, which this court has determined is a prereq-
uisite for finding preemption. See Charas, 160 F.3d at 1265-
66.

   [10] The Supreme Court has instructed that only those state
laws that have a significant effect on prices are preempted by
the ADA. Morales, 504 U.S. at 384. Without more factual
development, we cannot determine whether the preemptive
reach of Morales extends as far as the seating configuration
issue presented in this case. We therefore remand the recon-
figuration claim to the district court for further proceedings.

V.   Conclusion.

   [11] We hold that Plaintiffs’ failure to warn claim is pre-
empted by the Federal Aviation Act, which together with the
regulations promulgated by the Federal Aviation Administra-
tion, exclusively governs the entire field of aviation safety.
We thus affirm the district court’s judgment in favor of the
Airlines on this claim. The judgment in favor of the Airlines
on the seating configuration claim is reversed, and that claim
is remanded for further factual development, because on the
basis of the record before us, we are unable to determine to
what extent seat reconfiguration would affect airline prices.
Each party shall bear its own costs.

  AFFIRMED IN PART; REVERSED AND REMANDED
IN PART.
