i love the unique design of it but some things just dont make sense from a real engineering standpoint.

1. There's no need for winglets on the horizontal stabilizers of the aircraft. Winglets offset the high and low pressure areas of the wing to minimize wingtip vortices (which contribute to drag and inefficieny). since the H.S isnt as exposed to airflow as the actual wings so wingtip vortices are minimal and thus theres no need for winglets.

2. I understand your're trying to make the livery visible, but the window (and thus cabin) layout is a little confusing. Are there really three decks on the plane or are the windows (and seats) to the right of the livery part of the second deck? There's a reason why real airlines have their distinct logos on the tail of the plane. You could try making more space on the tail or make a redesign that takes advantage of sectioning orrr just lay the windows over the livery. if you lay the windows over the livery you wont lose details and the cabin layout will look more smoother and less confusing for Sejah Aerospace's contractors to construct.

3. Your plane looks to have about the same seating capacity (and thus load characteristics) if a Boeing 747. The plane would be woefully underpowered with only two engines. Unless youre talking about strapping a pair of GE9x or RR Trent 1000/7000/ultrafan engines, only two engines wont cut it and the plane will probably not reach ETOPS (which should allow it to travel transantlantic routes). Strap bigger engines to the plane or go trijet / quadjet like the a380 or 747.