Walt has basically a BINGO!

I thank you for the photo as it will help in elaboration of a couple of your answers. De Havilland of the U.K. in 1936 by A.E. Haag designed a fast mailplane or passenger version with more windows to be capable of trans-Atlantic flights. The D.H.91 Albatross built in 1938 and 1939 had a certain smooth beauty that belied its substantial problems. The wooden monocoque fuselage was comprised of a sandwich of outer cedar ply with balsa wood core and inner cedar ply, where the skin bore all flight loads. The fuselage proved to be not very strong as on the second aircraft's third landing, the fuselage broke in two-(I am NOT making this up!). The landing gear gave constant problems also, not lowering, collapsing and having brake failures. Two mail version and five passenger version were the total built. The last two were scrapped in 1943 because of rotting wing spars.

The streamlined engines' cowling prevented direct airflow to cool the piston engines, so holes in the wings routed cooling air via tubing to each engine-(I an NOT making this up!).

In the 22 passenger version the passenger entry/exit door was just 39 inches high, with the tapered rear fuselage very cramped. The ride was reported to be noisy and uncomfortable.

About the twin tail problem: the first vertical twin tails were set so close to the fuselage that directional instability (yaw) required them to be moved to the ends of the horizontal stabilizer, as shown in the photo. That gave a moment arm to work the rudders, correcting the initial instability.

Here are my answers.

1a. De Havilland, 1b. DH.91, 1c. Albatross.

2a. Four de Havilland Gipsy 12 piston engines, 2b. 525 hp each, 2c. Engine cooling was via routed air to each engine from holes in the wing.

3. Seven total, two as mail planes, one for Imperial Airways and one for BOAC and five as passenger planes initially for Imperial Airways, then reorganized and moved to/operated by BOAC.

Specs and performance

Crew: Four

Passenger version: 22 passengers.

Powerplant: Four de Havilland Gipsy 12 piston engines, 525 hp each.

Length: 71' 6"

Height: 22' 3"

Wingspan: 105'

Wing area: 1,078 sq. ft.

Weight max: 29,500 lbs.

Max speed: 225 mph

As an aside, please consider this wooden ply aircraft compared with the contemporary and successful Douglas DC-3 twin engine all aluminum 21 passenger airliner of 1935. The DC-3 wing spars are so strong that our FAA has given the aircraft an unlimited wing hours life! It has been said that there will be a DC-3 flying somewhere in the world, forever.

I thank all who viewed this quiz..