AT-11 Kansan

A Dutch warbird rarity

Photo by Dean Wingard

First Impressions:  The AT-11 possesses all the characteristics and appeal of a mini WWII bomber; glass nose, bomb bay, top turret and ventral gun.  Although not as well-known as the B-17, B-24, B-25, or the B-29, the “Kansan” trained 90% of the bombardiers that flew in these larger machines.  This particular AT-11 has a unique history from WWII and as a test aircraft in later years. 

Background:  The AT-11 (Advanced Trainer) is built off the venerable Beechcraft Model 18 airframe, first produced in 1937.  By 1941, the Beech 18 had already proven itself as a highly versatile platform.  This modern and streamlined medium-sized aircraft quickly received the attention of the Army Air Forces and Navy for use as trainers and utility aircraft.   The first military variant of the Beech 18 was the AT-7 “Navigator”, developed pre-WWII as a navigational trainer.  The main feature is the addition of an astrodome on the top of the fuselage, used by student navigators for celestial navigation.  The AT-11, named “Kansan” for the rugged Midwesterners who built them in Wichita, Kansas, was further adapted with a glass bombardier’s nose, internal bomb bay, top turret, and a ventral “tunnel” gun.  The AT-11’s bomb bay holds ten M38A-2, 100-lb. practice bombs or ten 100-lb HE (High Explosive) bombs loaded on two racks immediately behind the cockpit.  For a bombardier training mission, the crew typically consisted of the pilot, instructor bombardier, and two student bombardiers.  The pilot was in the left seat, the instructor bombardier in the right cockpit seat, and a student bombardier positioned in the nose to utilize either a Norden or Sperry bombsite.  The other student bombardier filmed the bomb drops with a 35mm motion picture camera through a hole in the rear cabin compartment for debrief purposes.  Each student was given five passes over the target.  The aircraft flight controls were coupled to the C-1 autopilot on each pass, releasing a single bomb on each pass, before swapping positions with the other student.  The copilot rudder pedals are removable, and the right-side yoke can be moved out of the way by unlocking a floorboard latch to allow for crews-shifts during flight.  The U.S. Navy also used the “Kansan” as a trainer and named it the SNB-1.

 The AT-11 was designed to replicate the experience of the large bombers (e.g. B-17, B-24), and many included a foldable navigator’s table in the rear of the fuselage.  Oxygen masks were worn for high altitude employment training, further adding to the realism of actual combat missions. Because crew coordination is vital in heavy bombers, the AT-11 taught bombardier students critical pilot, navigator and gunner communications in the AT-11. 

Gunnery training missions involved a gunnery instructor and two student gunners.  Early AT-11s used a Beechcraft electric glass turret with a single Browning AN/M2 .30-caliber machine gun. Later AT-11 models used the Crocker Wheeler A-8 turret, which had twin Brownings, identical to what most large bombers featured.  A single, flexible .30 AN/M2 Browning “tunnel” or “ventral” gun was mounted on the belly facing aft. 

Mike Allen of Star, NC, has owned serial no. 42-3069 (Dutch serial number), for 30 years; his son Preston has flown it now for over a decade.  Their AT-11 was originally built for the Royal Netherlands Navy for use in the Dutch East Indies as a trainer and bomber.  The Netherlands had been invaded by German forces in May 1940, so when the Dutch East Indies fell to Japanese Forces in March 1942 (the same month Mike and Preston’s AT-11 was hot off the production line in Wichita), all 24 Dutch AT-11s were immediately appropriated by the U.S. Army Air Forces.  The remaining Dutch forces that were able to escape had no place to call home but were eager to rejoin the fight against the Axis powers.  The United States gave these “Flying Dutchmen” a home base for their Royal Netherlands Military Flying School (RNMFS) at Jackson Army Air Base in Mississippi.  Eventually, the AT-11s were transferred back to the U.S. Army Air Forces.  As far as Mike Allen knows, this is the only former Dutch AT-11 still flying. 

If this history isn’t interesting enough, this AT-11 was sold to Mississippi State College (later University) in 1956, where it was used as a test bed for their Aerophysics Department until 1980.  During various experimental test modifications, their AT-11 was fitted with both a U.S.N. Goodyear blimp model on top of the fuselage and later, a Boeing Vertol 107 mast and rotor system.  If you have trouble envisioning a blimp or rotor system on top of an AT-11, you can join me!  After many modifications during its years as a test aircraft, it is now reconfigured to appear as it did during service with the Royal Netherlands Air Force (minus the bomb bay and tunnel gun).

Photo from the David J. Gauthier Collection

Design:  The AT-11 is most easily distinguished from a standard Beech 18 by the glass bombardier nose and the turret on the top rear of the fuselage.  The Top Secret bombsites (either Norden or Sperry) were loaded from the ground via a trap door under the nose.  This trap door was the main reason student bombardiers were required to wear parachutes while in the nose.

Powerplants: The AT-11 uses two 9-cylinder, supercharged Pratt & Whitney R-985 Wasp Junior radial engines to turn its original 2-bladed Hamilton Standard 2D30 constant speed, non-feathering propellers.  The original engines of the Allens’ AT-11 were actually the Jacobs-built R-985-1, under license from Pratt & Whitney.  Four fuel tanks (2 main and 2 auxiliary) supply a total of 206 gallons.  AT-11s (and early Beech 18 models) feed both engines from only one tank at a time.  A fuel indicator gauge (with associated selector switch) display the fuel remaining in only one tank at a time but is surprisingly accurate. 

Flight Characteristics: The AT-11, like the other Beech 18 models, is easily flown by one pilot.  Take-off is accomplished by lining up on the runway, ensuring the tailwheel is locked, advancing the throttles while ensuring that manifold pressure does not exceed 37-inches.  Hold the tail on the ground until airflow over the twin rudders is adequate for directional control (approximately 30-40 mph).  Once the tail is raised slightly, simply allow the Kansan to take flight when it’s ready.  During retraction, the main landing gear swings aft and, when fully stowed, the bottom of the tires protrude from the underside of the engine nacelle, which provides some protection in the event of a gear-up landing.  Matt Younkin, who flies his black and red AT-7C in an amazing and agile airshow routine, describes the aircraft as an honest airplane that will do what you ask it; no more and no less.  It’ll also let you know early if you’re asking too much of it.  The yokes are small, but the plane can still be easily maneuvered with one hand.  Some rudder inputs are required but not excessive.  Even though an AT-11 lacks the conical Beech 18 nose and carries the extra drag of a top gun turret, Mike Allen swears that his AT-11 walks away from other Beech 18s with the same power settings. 

Landing:  Most actively flying Beech 18 models have been converted to Cleveland brakes, but the Allen’s AT-11 still has the original “doghouse” forked gear legs with 33” main tires.  The main landings gear is electro-mechanically actuated and is verified down and locked with a single green light on the instrument panel.  There is no cockpit indication that the tailwheel is down.  Emergency extension of the landing gear is accomplished by the pilot lifting a covered “kick pedal” on the floor, then kicking it to disengage the electric motor from the gear drive.  The landing gear will freefall down and the pilot can then pull out a hand crank below the pilot’s seat and cranking the gear down.  The flaps can also be manually cranked down with the same lever by simply not pulling the crank outwards first.  For landing, lower the gear and deploy the flaps incrementally by recentering the flap switch.  Trim for 100 mph on final with full flaps (40˚) and flare to settle on the runway in a slightly tail low attitude.  

During training missions, AT-11s were typically flown by one pilot, but if you happen to be landing from the right seat, you will enjoy a fantastic, unobstructed view of the runway in front of you.  As the aircraft slows and the pilot lowers the tail to the ground, the twin tails make their money by continuing to provide adequate directional control, unhindered by the fuselage. 

Wrap-up: The AT-11 Kansan is a true war hero, cut from the same cloth as the PT-17 Stearman and the AT-6 Texan.  Although somewhat rare these days, there are a handful of AT-11s still flying and it’s a great way to own a glass-nosed WWII bomber!

Photo by Dean Wingard