Unwanted Cartesian

CREATE TABLE Aircraft (
AircraftId CHAR(6),
Status CHAR(1),
Type CHAR(4),
PRIMARY KEY (AircraftID) );

CREATE TABLE Routes (
Origin CHAR(3),
Destination CHAR(3),
FlyingTime REAL,
PRIMARY KEY (Origin, Destination) );

CREATE TABLE Flights (
FlightCode CHAR(6),
Origin CHAR(3),
Destination CHAR(3),
AircraftId CHAR(6),
FlightDate DATE,
DepartureTime REAL,
ArrivalTime REAL, 
PRIMARY KEY (FlightCode),
FOREIGN KEY (Origin, Destination) REFERENCES Routes,
FOREIGN KEY (AircraftId) REFERENCES Aircraft);

CREATE TABLE Passengers (
PassengerName CHAR(30),
FFFlag CHAR(1),
PRIMARY KEY (PassengerName) );

CREATE TABLE Bookings (
PassengerName CHAR(30),
FlightCode CHAR(6),
Status CHAR(1),
PRIMARY KEY (PassengerName, FlightCode),
FOREIGN KEY (PassengerName) REFERENCES Passengers,
FOREIGN KEY (FlightCode) REFERENCES Flights);

Query:
select flights.Origin, distinct flights.flightcode, flights.Destination, Aircraft.AircraftID, aircraft.Type
From Flights, Aircraft 
where FlightDate > sysdate and flightdate < sysdate +7;