CREATE TABLE 'airlines' (
	uid INTEGER PRIMARY KEY, 
	Airline TEXT, 
	Abbreviation TEXT, 
	Country TEXT
)

CREATE TABLE 'airports' (
	City TEXT, 
	AirportCode TEXT PRIMARY KEY, 
	AirportName TEXT, 
	Country TEXT, 
	CountryAbbrev TEXT
)

CREATE TABLE 'flights' (
	Airline INTEGER, 
	FlightNo INTEGER, 
	SourceAirport TEXT, 
	DestAirport TEXT, 
	PRIMARY KEY(Airline, FlightNo),
	FOREIGN KEY (SourceAirport) REFERENCES airports(AirportCode),
	FOREIGN KEY (DestAirport) REFERENCES airports(AirportCode)
)
SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid  =  T2.Airline WHERE T2.DestAirport  =  "AHD"
Which airlines have a flight with destination airport AHD?