As well as cheap flights from Edinburgh or Belfast to New York State from £99, there are ten long-haul destinations in the sale with London Gatwick departures starting from £129 one-way. These routes include Boston, Las Vegas, Seattle, Orlando, New York and the UK's only low-cost service to Singapore.
Travellers looking to head to Europe can enjoy bargain flights too, with prices from London starting from just £29 one-way. The nine European destinations in the sale are Malaga, Alicante, Barcelona, Madrid, Palma, Oslo, Stavanger, Copenhagen and Aalborg.
Norwegian's Chief Commercial Officer Thomas Ramdahl said: "To help celebrate 15 years of affordable flights with Norwegian, we're delighted to offer holidaymakers further savings on 28 routes from the UK and Ireland.
"With affordable fares to the US, Singapore and Europe, our birthday sale has something to offer all travellers. We're very grateful for the loyal support our passengers have shown us over the last 15 years, and we look forward to welcoming them on board for many more years to come."
Coolest gadgets for flights
Coolest gadgets for flights
It may be one of the most anti-social in-flight accessories around, but the B-tourist is ideal for eating, sleeping and reading while pretending no-one on the plane exists. Made from stretchy fabric, it loops around the seat backs and features plastic rings on the sides to adjust the width of your privacy. The B-tourist is yet to hit the market.
Designed to keep you extra warm and comfortable on long-haul flights, the Duvet Suit comes in a carry bag that is condensed and can be used as a pillow and detachable hood. The suit is a two-piece outfit that can be worn as separates if you get too warm on the plane.
Having trouble getting comfy in your seat? The Ostrich Pillow was invented for power naps and allows you to comfortably rest your head on any surface (even the plane window), while blocking out visual and aural distractions. There's just one catch - it doesn't look good and you'll certainly attract a few stares with this quirky pillow that makes you appear to be wearing a padded balaclava.
It might not be the most fashionable jacket, but if you want to stay cool on a plane, the Kuchofuku Air Conditioned Jacket may be the answer. The jacket features two cooling fans on its back which waft a refreshing breeze around the wearer. The fans are powered by AA batteries or can be plugged into a computer using a USB cable.
One of the most controversial travel gadgets to date, the Knee Defender has caused quite a stir and has even diverted flights. The gadget works by helping you stop reclining seats on planes. It clips onto your meal tray and prevents the person in front from reclining. The plastic gadget, which has been criticized as being a passive aggressive product, even comes with a 'Courtesy Card' which you can present to the passenger in front asking them not to recline their seat. The creators of the product say that if this is not effective, the Knee Defender acts as your 'Plan B'.
Need help falling asleep on a plane? SleepPhones provide restful, audio-assisted relaxation without bulky headphones or uncomfortable earbuds. The wearable technology works as pyjamas for your ears, using smooth fleece material and helping you fall asleep on a flight while reducing ambient noise, conversations and snoring.
Conscious of plane germs? The trayGUARD is a tray table cover that provides an instant hygienic surface for flyers. The inventors say it is food contact safe and incorporates a chemical-free antimicrobial technology that is effective for the duration of your trip. Just slip it over your tray and you won't have to worry about catching flu germs. There is even a kids' version which comes with crayons for children to decorate their trayGUARD.
Does dozing on a flight leave you with neck pain? For those not getting enough support from U-shaped neck pillows, the NapAnywhere head support could be the answer. The pillow was developed by physician Dr. Shamaiengar to make travelling a more comfortable experience and is a minimalist device providing head support while in a seated position. The top part of the NapAnywhere features a shelf which sits below the chin and back of the head with a design to cradle your head.
Aero-Tray allows you to make the most of your space on a flight with its two-tier system which can separate food and drinks from your electronic items. It features an extendable pull-out shelf and cup support while counteracting the angle of a reclined seat in front, elevating your computer screen to relax neck, wrists and eye strain.
Part pillowcase, part hoodie, part iPhone case, the HoodiePillow promises ultimate Cocoonification™ to help you tuck away your stresses and relax on a flight. The travel pillowcase offers warmth, quiet and a healthy sleep environment while keeping the light out to give you uninterrupted shut-eye on a plane. It fits standard bed pillows and is made from premium sweatshirt material, which features two drawstrings for you to adjust it to your head size.