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Airtours C404 crash report

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Airtours C404 crash report

Old 13th Aug 2001, 02:09
  #81 (permalink)  
 
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Compressor Stall:

>> Damned if you do and damned it you don't. <<

More like "dead if you do, and with some explaining to do if you don't".

Very unlikely a pilot would wear the blame for a "land straight ahead" unless you can prove conclusively that the aircraft was well able to climb away.... in which case, why would the pilot elect to land straight ahead???
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Old 13th Aug 2001, 03:59
  #82 (permalink)  
 
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I would like to see you try to prove in court that the aircraft would not climb on one engine (cos it's old, and not flown by the Cessna test pilots etc.) when the books say it will.

Pilot's word against the Manufacturer's books. I know what the layperson (read judge and jury) would think.
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Old 14th Aug 2001, 14:41
  #83 (permalink)  
 
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Hmmm, not sure I'd agree with that. The basic premise of UK law is "innocent until proven guilty".

There are lots of reasons why an aircraft might not be able to meet the published performance minima, ie weather, turbulence/windshear, etc.

It has long been realised that the published performance data of light twins is usually very optimistic, there is plenty of precedent around for that view to be shared by a court.
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Old 14th Aug 2001, 14:54
  #84 (permalink)  

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Sorry chaps but the crack test pilot in a new aircraft routine doesn't play.

FAR 23.45 General.

(a) Unless otherwise prescribed, the performance requirements of this part must be met for --

(1) Still air and standard atmosphere; and

(2) Ambient atmospheric conditions, for commuter category airplanes, for reciprocating engine-powered airplanes of more than 6,000 pounds maximum weight, and for turbine engine-powered airplanes.

(b) Performance data must be determined over not less than the following ranges of conditions --

(1) Airport altitudes from sea level to 10,000 feet; and

(2) For reciprocating engine-powered airplanes of 6,000 pounds, or less, maximum weight, temperature from standard to 30 C above standard; or

(3) For reciprocating engine-powered airplanes of more than 6,000 pounds maximum weight and turbine engine-powered airplanes, temperature from standard to 30 C above standard, or the maximum ambient atmospheric temperature at which compliance with the cooling provisions of 23.1041 to 23.1047 is shown, if lower.

(c) Performance data must be determined with the cowl flaps or other means for controlling the engine cooling air supply in the position used in the cooling tests required by 23.1041 to 23.1047.

(d) The available propulsive thrust must correspond to engine power, not exceeding the approved power, less --

(1) Installation losses; and

(2) The power absorbed by the accessories and services appropriate to the particular ambient atmospheric conditions and the particular flight condition.

(e) The performance, as affected by engine power or thrust, must be based on a relative humidity:

(1) Of 80 percent at and below standard temperature; and

(2) From 80 percent, at the standard temperature, varying linearly down to 34 percent at the standard temperature plus 50 F.

(f) Unless otherwise prescribed, in determining the takeoff and landing distances, changes in the airplane's configuration, speed, and power must be made in accordance with procedures established by the applicant for operation in service. These procedures must be able to be executed consistently by pilots of average skill in atmospheric conditions reasonably expected to be encountered in service.

(g) The following, as applicable, must be determined on a smooth, dry, hard-surfaced runway --

(1) Takeoff distance of 23.53(b);

(2) Accelerate-stop distance of 23.55;

(3) Takeoff distance and takeoff run of 23.59; and

(4) Landing distance of 23.75.

Note: The effect on these distances of operation on other types of surfaces (for example, grass, gravel) when dry, may be determined or derived and these surfaces listed in the Airplane Flight Manual in accordance with 23.1583(p).


(h) For commuter category airplanes, the following also apply:

(1) Unless otherwise prescribed, the applicant must select the takeoff, enroute, approach, and landing configurations for the airplane.

(2) The airplane configuration may vary with weight, altitude, and temperature, to the extent that they are compatible with the operating procedures required by paragraph (h)(3) of this section.

(3) Unless otherwise prescribed, in determining the critical-engine-inoperative takeoff performance, takeoff flight path, and accelerate-stop distance, changes in the airplane's configuration, speed, and power must be made in accordance with procedures established by the applicant for operation in service.

(4) Procedures for the execution of discontinued approaches and balked landings associated with the conditions prescribed in 23.67(c)(4) and 23.77(c) must be established.

(5) The procedures established under paragraphs (h)(3) and (h)(4) of this section must --

(i) Be able to be consistently executed by a crew of average skill in atmospheric conditions reasonably expected to be encountered in service;

(ii) Use methods or devices that are safe and reliable; and

(iii) Include allowance for any reasonably expected time delays in the execution of the procedures.


[Doc. No. 27807, 61 FR 5184, Feb. 9, 1996]


go here for the details.
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Old 14th Aug 2001, 20:05
  #85 (permalink)  
 
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US FARs, or Aussie FARs?
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Old 15th Aug 2001, 04:44
  #86 (permalink)  
 
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The above are US FARs: Gaunty - thanks!

I agree with your comments re "innocent until proven guilty" Raw Data, but I could still imagine an insurer or a regulatory authority (esp. our CASA!) wanting to prove the pilot acted negligently in order to obivate itself of responsibilities associated with the incident.

In the absence of proof from the investigators of any other reason that the aircraft would not climb, the shoulder of blame could, unfairly, be put on the pilot.

I know that this has diverted the thread from the facts about the inital tragedy, but it is a related and important issue, possibly deserving of a thread of its own?

[ 15 August 2001: Message edited by: compressor stall ]
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Old 15th Aug 2001, 11:28
  #87 (permalink)  
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AAIB seem to have gone to considerable lengths to prove the plane could have climbed ok that day. However, worryingly, it showed that it could only survive a failure shortly after take off if the failed engine was feathered otherwise you lost 200 feet per minute and they were not much higher than that. In other words there was considerable pressure to do something quickly contrary to my suggestion of how pilots should handle emergencies.

I am quite concerned after reading the report. The pilot was very familiar with this aircraft and was highly qualified. He'd also done an engine failure practice very recently. Did he make a mistake or was there a coincidental minor problem with the second engine?

We learn also there was a surplus pilot on the flight deck. There was no recommendation along the lines of let the pilot flying concentrate on maintaining control and declaring the candidate failed engine (from control pressure) but leave the engine untouched until the second pilot confirms the engine by checking instruments and engine appearance etc.

Twisted's First Law:
With a two engine plane if you have one fail, and you switch one off, you risk having zero.
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