Just an old workhorse.

[BFMF]

A Catalina pilot once told me they often had bird strikes on final approach....from the rear.
It didn't need flaps..

Rear ended by a bird while landing...lol

[NickN]

why no flaps?

Wingspan/design did the job

the lift/drag coefficient was designed to allow the pilot the ability to maneuver for landing without flaps

[bushpilot172]

Flaps would just add more weight.  The gain would't out weigh the negative effects of weight and system design complexity.  Plus the catalina was designed as a flying boat for ocean use primarily, so takeoff length wasn't a factor.  Nice screenshots by the way, I have the alphasim PBY, i love the black cat versions the best.  

[Hagar]

Regarding the lack of flaps; This book suggests it was more a matter of cost. The XP3Y-1 was the prototype Catalina.

[NickN]

Well of course it was the cost

why add something to an aircraft during a time where design budgets were tight when its really not needed and would act as more of a convenience than provide any real advantage. The wingspan was huge for that aircraft already and it could be easily stalled just over the water in the event a short landing was required. If flaps were something that would have made the aircraft much more productive for its use then the cost would be justified.