Hi everyone,
whilst I appreciate the following relates to the first simulation, it's worthwhile taking note of both the date of the question and the written reply, and the paragraphs following the list of the three simulations:
QUESTION IN THE HOUSE
27 July 2000
Mr O’Neill: To ask the Secretary of State for Defence
(1) if he will provide a detailed description of the simulator used by Boeing as part of the Board of Inquiry investigation into RAF Chinook ZD 576
(2) If he will provide a detailed description of the simulator used by the Defence Evaluation and Research Agency during the Board of Inquiry investigation into RAF Chinook ZD576
(3) If the Boeing simulation undertaken as part of the Board of Inquiry investigation into the crash of RAF Chinook XZ576 was able to determine the precice (a) speed and (b) height of the aircraft prior to the last five seconds before impact.
Mr Spellar: I will write to my hon. Friend and a copy of my letter will be placed in the library of the House.
____________________________
WRITTEN REPLY
MoD Headed Paper
D/MIN(AF)/
JS/2878K/2879K/2880K/00/Y Dated 31 October 2000
Dear Martin,
I undertook to write (Official Report 27 July 2000, Written Answers column 749 refers) in response to your questions concerning the flight simulations undertaken following the Chinook accident on the Mull of Kintyre.
Three different simulations were used by Boeing to explore the last five seconds of flight, modelling the response of a Chinook to full up collective control inputs, combined with large aft longitudinal stick inputs. There were:
a. A mathematical model of the flight characteristics of a Chinook was hosted in a flight simulator, and a pilot’s control movements were input by moving flying controls. The electronic responses of the simulator to those movements were plotted and related in aircraft attitude. These inputs and responses were used as a baseline for further investigations.
b. Using the Chinook flight simulator mathematical model in a non-real time model, the mathematical equivalent of various combinations of pilots control inputs were computer generated, and fed into the mathematical model. The responses of the model to those inputs were plotted and related to aircraft attitude.
c. A further refinement was to use a mathematical model, known as the B-29 model of tandem rotor flying qualities transient analysis, as it had a greater fidelity to Chinook characteristics than the model used in the flight simulator at the time.
The extensive data from all three simulations was correlated and validated, but it gave no insight into the precise speed and height of Chinook ZD576 prior to the last five seconds before impact. However, an approximation of the height and speed prior to the last five seconds of impact can be made. A report summarising all the data from these simulations was submitted to the Board of Inquiry into the accident.
With regard to the Defence Research Agency (DERA) simulation, their computer based work used a relatively simple mathematical model, from which were obtained estimates of the flight path changes that might be achieved following abrupt pilot control inputs. Engineering data to configure the model were obtained from Chinook operating manuals and open literature sources. Additional information was obtained during a visit to RAF Odiham, and a short visit to the RAF’s Chinook flight simulator at Farnborough. Full details of DERA’s methodology were submitted to the Board of Inquiry.
I hope this helps clarify the position.
Signed – John Spellar MP
The document clearly states that the simulations gave no insight into the precise speed and height of ZD576. Yet during the evidence to the Select Committee, the Air Marshals constantly said that they knew 'for a fact' heights and speeds.
I'm currently reading the documentation relating to the latest simulations so will post something on them soon. However, I doubt it provides facts that conclude that two highly trained pilots were negligent.
Regards as always
Brian
"Justice has no expiry date" - John Cook