Old 29th Jul 2010, 10:59
  #95 (permalink)  
Join Date: Jul 2009
Location: France - mostly
Age: 80
Posts: 1,689
Stall testing of transport category airplanes

Originally Posted by PBL
You think people have been going out doing stalls in Airbuses to see what happens?
The aerodynamic characteristics of a modern commercial jet are determined in wind tunnels, mostly for certification purposes.
For type certification of Transport Category airplanes the 'applicant' (manufacturer) must conduct an extensive stall test programme. Details and objectives can be found in reference 1. Wind tunnel testing does not produce the evidence required for certification, but is primarily a design tool and assists in preparing the flight test crew for the more critical conditions to be tested, as explained in reference 1.
Originally Posted by PBL
So what data is it that a given manufacturer didn't have, that they would have gone back up to get because the regulators were worried again about LOC? Can anybody here say?
The major manufacturers contributing to an industry-wide effort to improve pilot training aids for upset recovery, including recovery from stalls, drew on their extensive experience. They did not have to 'go back' to get it. A detailed reply to your question 'straight from the horse's mouth' can be found in ref.2.
Originally Posted by PBL's blog
Another, Airclues, replied In the early 80ís I was co-pilot on several C[ertificate] of A[irworthiness] air tests on the Boeing 747 when a full stall was completed (I believe that the UKCAA was the only authority that required this) and described his experiences. In other words, actually high-alpha-stalling large commercial aircraft, even for certification, is ancient history.
Perhaps you are confusing (type) certication with the UK CAA practice for periodic renewal (from memory: every 5 years) of the C of A of individual 'Performance Group A' aircraft on the UK Register. The UK ARB (later CAA) requires a performance flight test as a condition for renewal of the CofA. The flight test includes stalls and verification of climb performance with simulated engine failure (2nd and 4th TO climb segments). To my knowledge, the CAA is the only authority to require these tests, but possibly some former 'Commonwealth' countries follow CAA practice. The CAA requirement for CofA renewal performance testing has nothing to do with type certification testing.

Reference 1: Advisory Circular no.AC-25-7A Flight Test Guide for Certification of Transport Category Airplanes.

Reference 2: Airbus Flight Test views on Upset Recovery Training

Last edited by HazelNuts39; 31st Jul 2010 at 19:52. Reason: The CAA apparently sill requires these tests
HazelNuts39 is offline