Herein, in spite of low military budgets, aircraft capabilities were enhanced, most requiring a flight navigator. The B-12, B-17, B-24, B-25, B-26, and B-29 would all require well-trained specialists, i.e., navigators and bombardiers. Good nav-methodologies for the bubble-sextant with an averager and the trained employment of celestial navigation methods such as the Air Almanac with Sight Reduction Tables allowed for dependable worldwide Navigator flight navigation. Navigator Harold Gatty at the urging of the US Army's pioneer navigator Capt. Hegenberger in 1932 taught the Army Air Corps Experimental Unit at Bolling Field in Washington, D.C. precision Dead Reckoning. Gyro-assisted compass systems, Norden integrated-autopilot bombsights and optics-gyrostabilized driftmeters came in to being. And too the capabilities of radar were discovered. Precision plotters notably Weems, dividers, accurate maps and celestial tables with a bubble-sextant became the navigator's basic trade tools. The Army Air Corps developed some eight planes during this time.

Navigator developments in this period:

• Using a direction finder radio beacon for an all-gyro-instrument-flight, Lt. Jimmy Doolittle assisted by Lt. Albert Hegenberger of Army Engineering Labs executed a completely blind flight and landing, that led to the development of the civilian airliner employed ILS, Instrument Landing Systems and the military SCS-51. Ref. Aviation History by Anne Millbrooke, Published by Jeppesen-Sanderson 1999, Pages 6-45/46 and 8-10.
  
• Code-transmitter receivers, Morse code sets, telegraph radios, and wireless telegraphs became well developed for aircraft in the 1930s. These tube-transmitters and receivers, weighed 30 to 40 pound a piece and required long wire (approximately 250 feet) trailing wire antennas that were reeled in and out of the plane in flight. Ref. Aviation History by Anne Millbrooke, Published by Jeppesen-Sanderson 1999, Page 6-46/47
  
• Carl. J. Norden demonstrated to the U.S Navy and later the Army Air Corps his tachometric bombsight which was first installed in the Martin B-10 and then B-12. Ref. One Hundred years of Flight by Daniel L Haulman, Air Force History and Museums Program, 2003, Page 29 and Splendid Vision, Unswerving Purpose: by HO/ASC AFMC, AFHMP, USAF, W-P AFB, Ohio. Pages 152 & 153.
  
• Fairchild F-1 becomes the first designated photographic aircraft, with camera and observer camera-operator, a mission flown to this day.. Splendid Vision, Unswerving Purpose: by HO/ASC AFMC, AFHMP, USAF, W-P AFB, Ohio. Page 160
  
• Precision Dead Reckoning with the navigator accomplishing accurate calibrations of the compass and air speed indicator and integrating precise drift and ground speed readings, with the meticulous use of a pre-formatted log, was introduced to the US Army Air Corps, Experimental Unit at Bolling Field, Washington, D.C. by Tasmanian born Royal Australian Navy navigator Harold Gatty. Ref. Path Finders The Origins of Air Navigation by Col. Ray L. Bowers http://airpower.maxwell.af.mil/airchronicles/aureview/1971/jul-aug/bowers.html
  
• Special Air Almanac for the year 1933 was issued by the U.S. Naval Observatory, the first complete air-almanac for flight navigators was Greenwich Hour Angle based, easing the computational effort required of the navigator in shooting celestial fixes. Ref History of Air Navigation by Arthur J. Hughes, Chapter III Historic Flights 1919-1930, published by George Allen and Unwin LTD, London England 1946. Pages 71 and 72.
  
• Remote, repeater and gyro-compasses developed for aircraft use were integrated with autopilots, and for the military coupled with the Norden and Sperry bombsights. Ref History of Air Navigation by Arthur J. Hughes, Chapter Compasses published by George Allen and Unwin LTD, London England 1946.
  
• B-10, B-12, B-15 and Boeing aircraft Model 299 created a crew position for the navigator and navigator/bombardier. The bomb-aimer/bombardier was now a necessary crewmember. Ref. Splendid Vision,Unswerving Purpose: Bombardment Airplanes; by HO/ASC AFMC, AFHMP, USAF, W-P AFB, Ohio. Pages 165-176 and Ref. Training to Flight Training by Rebecca (Hancock Cameron) Welch of the Air Force History and Museums Program, 1999, Chapter 12, Not Just a Pilot's War: Individual Training of Navigators, Bombardiers and Gunners. Pages 421-450.