Gull wing

 Originally 2 crew, redesigned for 1

 Redesigned due to shift in intended role

 Less then 50 built

 1 known be left

 Was a follow up to a successful design

  And led to a very successful aircraft of the same type

  Had an internal bomb bay

  Predecessor was slow, and the follow on plane was a "dog"

 Gull wing

 Originally 2 crew, redesigned for 1

 Redesigned due to shift in intended role

 Less then 50 built

 1 known be left

 Was a follow up to a successful design

  And led to a very successful aircraft of the same type

  Had an internal bomb bay

  Predecessor was slow, and the follow on plane was a "dog"

  Radial engine 

 Gull wing

 Originally 2 crew, redesigned for 1

 Redesigned due to shift in intended role

 Less then 50 built

 1 known be left

 Was a follow up to a successful design

  And led to a very successful aircraft of the same type

  Had an internal bomb bay

  Predecessor was slow, and the follow on plane was a "dog"

  Radial engine 

  Tricycle landing gear used for first time on deck

  Douglas BTD 1 Destroyer

  First production aircraft to use tricycle gear on a carrier deck.

  designed to replace the SBD (Slow but deadly) Dauntless

  Redesigned  overnight to become the AD series 

  30 built, never to see combat with 1 left in a museum

  You are up

 Allen

Alright here we go, flipped to a random page out of my big aircraft book.

- Entered service in 1938

- Twin Radial Engine

- Used by 6 Nation, not USA

- Crew of 3

- Predominantly flew night missions