Flight Test: The Avro Arrow and a Career in Aeronautical Engineering

The published literature on the Arrow’s highest-speed flight has included some inaccurate and incomplete information, in part because the project was initially classified and pertinent data was withheld from the press. And until recently, the government-ordered destruction of Arrow documents prevented access to engineering flight test reports that could resolve discrepancies. However, the acquisition of the Ralph Waechter Fonds by LAC, and the inclusion of selected excerpts in Flight Test, has removed the latter problem. Some of the matters that are revealed by material in the Fonds include engine parameters during the high-speed run, the correct identification of those Mach numbers that were achieved in level flight vs. diving flight, and calibration data showing error bounds for Machmeter measurements. The latter information can explain small variations in published Mach number estimates. The engine data shows that the rpm values for the high pressure compressors were at 99.8% for the port engine and 100% for the starboard engine, while both engines still had a little room to spare before reaching the recommended temperature limit. Statements made in some press reports and books that the high-speed run was carried out at less than full throttle have little significance since it is not unusual for an aircraft to reach an operational limit while still short of full throttle. The distinction between level flight and diving flight had to be correctly recorded in the flight test report because the rate of change of altitude was used in the report's aerodynamic drag calculations.   

Ralph Waechter's Avro Papers at
Library and Archives Canada 

Ralph Waechter's Avro papers and other material from his career in aeronautical engineering were acquired by Library and Archives Canada (LAC) in 2016. ​ Click here for further details.

Book Reviews

R. Isinger, CAHS Journal, Vol. 53/No.3 (2015) p. 84.
​T.F.J. Leversedge, Airforce Magazine, Vol. 39/No. 3 (2016) p. 42.

Recent Publications

David Waechter, "The Highest Speed of the Avro Arrow: Reconciling Assorted Claims" 
CAHS Journal, Vol. 55/No.2 (2017) pp. 64-67. 

David Waechter, "Aeroballistics Range Tests of the Avro Arrow: A Lesser-known Investigation" 
CAHS Journal, Vol. 55/No.4 (2017) pp. 150-153.

David Waechter, "Jet Aircraft Operation: Early Work on Cruise Control and Computer Flight Planning"
CAHS Journal, Vol. 56/No.2 (2018) In Press.

​Events in 2019
Nov 27: Presentation for Elmira Radio Club (Elmira, Ontario)​
May 22 - 25: Presentation for CAHS National Convention (Saint Anne de Bellevue, Quebec).​​


Events in 2018

April 18: Presentation for Kenneth Molson Lecture Series (Ottawa, ON).
May 30 - June 3: Presentation for CAHS National Convention (Calgary, AB).

October 18: Presentation for ELO: Extended Learning Opportunities  (Erin, ON)
Events in 2017

January 12: Presentation for Retired Business and Professional Men's Club (Waterloo, ON).
February 4: Presentation for CAHS Toronto Chapter. Event photos at Gusair.com
May 18: Presentation for CAHS Montreal Chapter.
​June 8-11: Presentation for CAHS National Convention (London, ON).

Events in 2016

Western Tour
September 15: Presentation for CAHS Calgary Chapter.
September 20: Presentation for CAHS Regina Chapter.

September 21: Presentation for University of Saskatchewan Aero Design Team.

Ontario Events
June 25 & 26: Book Sales at the Quinte International Air Show.
April 28: Presentation for CAHS Ottawa Chapter.​