On this page (5 sections)
The route in one look
Two airports called Belfast, and only one of them flies here.
The route runs between George Best Belfast City Airport (BHD) and London Heathrow (LHR), and takes about an hour and 25 minutes gate to gate. That is British Airways' own figure for the route, and it is the only airline on it. The great-circle distance is roughly 313 miles, or 503 kilometres.
Belfast has two airports and they are not interchangeable. Belfast City (BHD) sits three miles from the city centre, close enough that the airport describes it as a five minute hop and its own taxi partner quotes ten minutes to City Hall. Belfast International (BFS) is out at Aldergrove, about 13 miles north-west of the city. Heathrow services use Belfast City only. Belfast International has no Heathrow route at all, and it never appears on this city pair however you search for it.
The page works in both directions. Heathrow to Belfast is the same aircraft, the same terminal and the same flight time, and the Belfast City end is the same short run into town whichever way you are going. Only the check-in end changes.
Who flies it
British Airways, alone, and that is the whole answer.
British Airways is the only airline flying Belfast to Heathrow. There is no low-cost competition on the route, and that single fact explains most of what people find surprising about it: fares sit above the other Belfast to London routes, and there is no second carrier to fall back on when a flight goes wrong. Belfast City Airport lists British Airways as serving two London airports from Belfast, Heathrow and London City, so if you want a BA flight to a more central London airport, that alternative comes from the same Belfast terminal.
The other Belfast City carriers go elsewhere. easyJet flies Belfast City to Gatwick and Luton, Aer Lingus Regional covers the English and Scottish regional cities including Birmingham, Manchester and Edinburgh, and KLM and Loganair handle Amsterdam and the Scottish mainland, Loganair flying to Aberdeen and Inverness. None of them fly to Heathrow. Over at Belfast International, the airline list is easyJet, Jet2, Ryanair and TUI, and the London flying from there goes to Gatwick, Luton and Stansted.
Every Belfast to Heathrow flight is direct. There is no sensible connecting version of this route, because a connection would mean routing through another UK airport to reach one that Belfast City already serves non-stop. The airlines flying from Heathrow page sets British Airways' domestic operation against the rest of the airport, and the live departures board is the right place for today's Belfast times and gates rather than a schedule printed on a page that does not change.
Flying versus the alternative
There is no train, and that changes the whole calculation.
On every other British Airways domestic route into Heathrow, the honest question is whether the train beats the plane. Here it does not arise. There is no rail link between Northern Ireland and Great Britain, so the surface alternative is a ferry and a long drive: a little over two hours at sea from Belfast to Cairnryan, which lands you in south-west Scotland with most of Britain still ahead of you. Against an hour and 25 minutes in the air, that is an overnight undertaking, and it only makes sense if you need your own car at the far end.
So the real comparison is not flying against not flying. It is which London airport you fly to, and there the answer genuinely varies:
- Heathrow wins if you are connecting onward, or if west London, Heathrow's own corridor or the Thames Valley is your destination.
- London City, also British Airways from Belfast City, is closer to the financial districts and quicker to clear on arrival, and it is the better pick for a same-day meeting in the City or Canary Wharf.
- Gatwick, Luton and Stansted are usually cheaper, because that is where the low-cost carriers fly, but most of them go from Belfast International rather than Belfast City, which adds a longer trip at the Belfast end.
The case for Heathrow specifically is connecting traffic, and it is a strong one. Heathrow's domestic network exists largely to feed the long-haul departures: around 90 percent of the airport's passenger flights are international, and the domestic services are mostly British Airways runs from Terminal 5 to Edinburgh, Glasgow, Aberdeen, Manchester, Newcastle and Belfast. If your Belfast flight is the first leg of something longer, no other London airport offers the same onward choice, and the ferry is not a substitute in any form. See connecting flights at Heathrow for how tight a connection you can safely book.
At Heathrow
Terminal 5, in both directions, with a domestic arrival's shortcuts.
Belfast flights use Terminal 5 at Heathrow, arriving and departing. That follows from the airline rather than the route: Terminal 5 is British Airways' home at Heathrow, and the domestic operation runs from there alongside the long-haul. The practical effect on the way out is that you check in, drop bags and clear security in the same building you fly from, and the Terminal 5 guide covers the layout, while the Terminal 5 map shows where the gates and satellites sit. Allow for the satellite buildings: some departures leave from B or C gates, reached by an underground transit that adds time you need to have budgeted.
Arriving from Belfast, you land as a domestic arrival, so there is no border control and no immigration queue. You walk off, collect bags if you checked any, and you are out. It is one of the quicker arrivals at Heathrow, and worth knowing if you are judging how much time to leave before an onward train or meeting.
If you are connecting, staying inside Terminal 5 is the good case and it covers most British Airways onward flights. A connection to Terminal 2, 3 or 4 means a transfer between terminals, which is signposted and free but eats time. The Terminal 5 lounges page covers what is available airside if you have a wait, and the inter-terminal transfer page has the timings if your onward flight is not in Terminal 5.
Who it suits, honestly
A strong route for two groups, and an expensive habit for everyone else.
Fly Belfast to Heathrow if you are connecting. This is the case the route is built for. Belfast City to Terminal 5, then onward on British Airways from the same terminal, is about as clean as a domestic-to-long-haul connection gets in the UK, and no ferry or other London airport competes for that job.
Fly it if Belfast City's location earns its keep. Three miles from the city centre, with a ten minute taxi and a shuttle bus to Belfast Grand Central Station, the city airport can save an hour of door-to-door time against Belfast International. On a short trip that saving is real, and it can outweigh a cheaper headline fare from Aldergrove.
Think again if you are simply going to London and paying for it yourself. With one airline and no competition, this is the most expensive way to fly Belfast to London, and Heathrow is not the most convenient London airport for most of the city. If your destination is central or eastern London, British Airways to London City from the same Belfast airport is usually the better trip. If price is what matters, the Belfast International routes to Gatwick, Luton and Stansted are the ones to price up, and you accept a longer run to the airport in Belfast in exchange.
Do not fly it to reach Scotland or the north of England. Flying to Heathrow to travel back north is a common and expensive mistake. Belfast City has direct Aer Lingus Regional and easyJet services to Edinburgh, Glasgow, Manchester, Leeds Bradford and Birmingham, and one of those will almost always beat a London connection on both time and cost.