EU261 / UK261 · No win, no fee
AY3778 flight compensation
Finnair flight AY3778 is a scheduled service operating from General Edward Lawrence Logan International Airport to London Heathrow Airport.
Check your AY3778 flightQuick facts
- Flight number
- AY3778
- Airline
- AY
- ICAO airline code
- FIN
- Origin airport
- General Edward Lawrence Logan International Airport
- Destination airport
- London Heathrow Airport
- Distance category
- Long-haul
- EU261 protection
- No
- UK261 protection
- Yes
- Aircraft
- B772
- Schedule snapshot
- 2 Sept 2026, 00:05 – 2 Sept 2026, 07:00
About AY3778
Passengers travelling on Finnair flight AY3778 between Boston and London may be entitled to compensation if the flight was delayed, cancelled or heavily disrupted.
How much compensation can you receive?
Under UK261 the amounts are £220, £350 or £520 depending on distance.
Passenger rights under EU261
UK261 can provide a fixed amount for a long delay, some cancellations, or denied boarding when its conditions are met.
When are you entitled to compensation?
Eligible passengers travelling on AY3778 may receive compensation when the disruption was within the airline's control and the legal requirements for the Boston to London route are met.
AY3778 compensation statistics
The statistics below summarise the passenger-rights framework that may apply to AY3778.
Under UK261 the amounts are £220, £350 or £520 depending on distance.
Arrival delay normally required.
Applies on eligible European flights.
What happens after you submit your claim?
Once your AY3778 claim has been submitted, FlightClaimly guides you through the compensation process.
- 1
Submit your claim
You check your flight, add your passenger details and upload the documents needed to start the case.
- 2
FlightClaimly reviews the case
We review the information and prepare the claim before contacting the airline.
- 3
The airline responds
The airline reviews the claim and may approve, reject or request additional information.
- 4
You receive your payout
If the claim is successful, FlightClaimly helps complete the payout process.
How the claim process works
- 1Check your flight details and tell us what happened.
- 2Confirm whether the disruption may qualify under EU261 or UK261.
- 3Add your passenger details and booking reference.
- 4Sign the authority form so FlightClaimly can handle the claim.
- 5Upload your supporting documents.
- 6FlightClaimly submits the claim and follows up with the airline.
Common AY3778 disruption types
- ✓ Flight delayed more than 3 hours
- ✓ Flight cancelled
- ✓ Missed connection
- ✓ Denied boarding
- ✓ Technical problems
- ✓ Operational disruption
- ✓ Crew shortage
- ✓ Strike
- ✓ Bad weather
Frequently asked questions
Can I claim compensation for a delayed flight?
Yes. If your flight arrived at least three hours late and the disruption was within the airline's control, you may be entitled to compensation under EU261 or UK261.
How much compensation can I receive?
Under UK261 the amounts are £220, £350 or £520 depending on distance.
What documents do I need?
Usually your booking confirmation or boarding pass is enough to get started. In some cases we may request additional documentation.
How long does the claim process take?
Every airline is different. Some claims are resolved within a few weeks, while others may take several months if they are disputed.
Do I pay anything upfront?
No. FlightClaimly works on a no win, no fee basis. You only pay if we successfully recover compensation for you.
- Finnair (AY)
- Boston (BOS) → London (LHR)
- approx. 5,240 km · Long-haul (over 3,500 km)
- £520 (UK261), depending on the airline · UK261 depending on the airline · B772 · Helsinki Airport (HEL)
AY 3778 (AY3778) is sold by Finnair. On a codeshare another airline may operate the flight, and the operating airline determines which rules apply.
AY3778 departs from United States and lands in United Kingdom. If Finnair also operates the flight, UK261 may apply, as Finnair is an EU airline. If another airline operates it, that airline decides.
With about 5,240 km between BOS and LHR (long-haul (over 3,500 km)), compensation may be £520 (UK261), depending on the airline, if you are entitled to it. All amounts
Does EU261 apply to Finnair flight AY 3778?
No, but UK261 may apply if the operating airline is a UK or EU airline.
Who operates Finnair flight AY 3778?
In our data, Finnair is the airline selling AY3778. Who actually operates the flight is shown on your ticket or booking confirmation.
Was AY 3778 part of a connecting flight? How is compensation calculated?
Your booking shows this, not the flight number. If AY3778 was part of a connecting journey on one booking, distance is counted from the first departure airport to the final destination, and the delay is counted on arrival at the final destination. The distance band (short-, medium- or long-haul) follows that distance and may then differ from this leg (£520 (UK261), depending on the airline).