Maneuvering speed

Implications

It has been widely misunderstood that flight below maneuvering speed will provide total protection from structural failure. In response to the destruction of American Airlines Flight 587, a CFR Final Rule was issued clarifying that "flying at or below the design maneuvering speed does not allow a pilot to make multiple large control inputs in one airplane axis or single full control inputs in more than one airplane axis at a time". Such actions "may result in structural failures at any speed, including below the maneuvering speed."

Design maneuvering speed V_A

VA is the design maneuvering speed and is a calibrated airspeed. Maneuvering speed cannot be slower than V_s \sqrt{n} and need not be greater than Vc.

If V_A is chosen by the manufacturer to be exactly V_s \sqrt{n} the aircraft will stall in a nose-up pitching maneuver before the structure is subjected to its limiting aerodynamic load. However, if V_A is selected to be greater than V_s \sqrt{n}, the structure will be subjected to loads which exceed the limiting load unless the pilot checks the maneuver.

The maneuvering speed or maximum operating maneuvering speed depicted on a cockpit placard is calculated for the maximum weight of the aircraft. Some Pilot's Operating Handbooks also present safe speeds for weights less than the maximum.

The formula used to calculate a safe speed for a lower weight is \scriptstyle V_A \sqrt{W_2 \over W_1}, where VA is maneuvering speed (at maximum weight), W2 is actual weight, W1 is maximum weight.

Maximum operating maneuvering speed V_O

Some aircraft have a maximum operating maneuvering speed VO. Note that this is a different concept than design maneuvering speed. The concept of maximum operating maneuvering speed was introduced to the US type-certification standards for light aircraft in 1993. The maximum operating maneuvering speed is selected by the aircraft designer and cannot be more than V_s \sqrt{n}, where Vs is the stalling speed of the aircraft, and n is the maximal allowed positive load factor.

References

References

1. [[Federal Aviation Administration]], [http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/d1a4060f22939f36862572eb0061ca3f/$FILE/AC%2023-19A.pdf Advisory Circular 23-19A, ''Airframe Guide for Certification of Part 23 Airplanes'', Section 48 (p.27)] {{Webarchive. link. (December 7, 2016 Retrieved 2012-01-06)
2. [https://web.archive.org/web/20110927154821/https://www.cnatra.navy.mil/pubs/folder5/NFO_SNFO/P-821(2).PDF CNATRA P-821 (Rev. 01-08) "Flight Training Instruction, Advanced Naval Flight Officer (T-45C)".] ''Department of the Navy'', 2008.
3. Federal Aviation Administration, [http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFinalRule.nsf/0/395c3f064247018a862577b200495b5a!OpenDocument 14CFR §25.1583 Final Rule] Retrieved 2012-01-06
4. [http://www.ecfr.gov/cgi-bin/retrieveECFR?gp=1&SID=0eb6ca22ab5efa94f23f757d30af7726&h=L&n=14y1.0.1.3.10&r=PART&ty=HTML#14:1.0.1.3.10.3.70.9 14 CFR §23.335(c)(2)] Definition of Maneuvering Speed
5. (2000). "Jeppesen Instrument/Commercial Manual". Jeppesen Sanderson.
6. [http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/0/2A0AA756267EFE8F85256687007232CC?OpenDocument USA 14 CFR §23.1507] {{Webarchive. link. (February 12, 2017 Retrieved 2012-01-06)