Paul Phelan’s article in The Australian on Fri 10 Aug.
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Paul Phelan’s article in The Australian on Fri 10 Aug.
Paul Phelan’s article in The Australian on Fri 10 Aug.
As an aviator for many years I have been a reader of Paul’s articles in various publications over the years and have met him on a number of occasions as he, unlike other aviation journalists frequents airports, aero club lounges and aviation gatherings. I have always been impressed in his efforts to bring some of the regulators habits and actions out in the open in an effort to get a better deal for the industry. As a pilot, he often writes of his first hand experiences and in an interesting and informative manner.
Having said that, I was most surprised and somewhat disappointed to read his article titled “Crashed Shrikes were overweight” last Friday. It is not an article that I would expect from Paul, but one that might come from a non-savvy junior journalist with little or no knowledge of the subject matter.
In very basic terms I believe the article is a sensational beat up following the recent tragic accident in Victoria which killed one of the most knowledgeable Shrike engineers in Australia, if not the world.
Let’s start with the headline:
I don’t think so! If the article is pointed at the accident in Tasmania and the recent one it is wrong! The Tasmanian Shrike had just one pilot on board and the recent accident had two occupants – far below MTOW.
To my knowledge the increased AUW for the Shrike which was approved by the Australian regulator (DCA) in the late 60’s/early 70’s has not been a factor in any Shrike loss in Australia.
The subject aircraft in the recent crash I understand had quite low hours for the type (less than 5000) and had only been in Australia for a short time, which means that for most of its life has been operated at the FAA MTOW. Besides, the investigation has some way to go and to presume at this early stage that fatigue was a factor is drawing a very long bow.
True. However the STC which permitted the increase was two fold in that there was a difference in the MTOW weight for IFR and VFR operations – brought about by the need to achieve a specific climb gradient for IFR ops – which it did (I participated in some of the test flights and saw the performance first hand!). The STC was issued to an organization operated by very experienced aviation professionals and to my knowledge not only was performance tested, but also fatigue issues investigated and considered. (That, at a time when the wing issues were well known) Initially the STC was available only to that operator, but due to circumstances which are not relevant to this discussion was extended to all Shrikes in Australia.
There is no mention of the VFR/IFR differences in the article.
Quoting what Gulfstream people might say or the contents of a dated report sound fine, but there are many other factors applicable and a broad and simple investigation will reveal that there are many aircraft modified by STC or otherwise from the manufacturer’s status. All such modifications are undertaken by persons approved for the purpose and it must be assumed in such cases that the applicable issues including fatigue are considered at the time. What the manufacturer might choose to do or not do is irrelevant to the discussion.
Wrong Paul! The Shrike is a popular aircraft because it is a good airframe, simple to operate and maintain with normally aspirated engines with a good airfield performance and a high reliability factor. The increase in the Australian MTOW gives a good aircraft some additional flexibility and to say that the majority of the hours flown are “at unusually heavy weights” is just pure bunkum!
Certainly there are some high time Shrikes about (many aircraft are these days) but to give the impression that the fleet average is 25,000 hours is nothing but a dramatic guess.
Yes, and those aircraft would have to be the best maintained Shrikes anywhere in the world for a fleet that size. Steve (RIP) was the Shrike Guru and over the past 30 years or so he has maintained Shrikes in a manner not normally seen in GA. He was also very much aware of the fatigue issues and spared no effort in conducting inspections in his fleet and often far in excess of the manufacturers recommendations or the regulators requirements.
Paul, you can do better than this and have done in the past. Are you short on work and need to take some of Steve Creedy's sensational pills to earn a quid? I for one hope that you can retain your professional standards in your future writings in supporting a struggling industry and not as you have in this article succumbed to the need to write such sensational uninformed dribble whilst seemingly taking advantage of a tragedy.
As an aviator for many years I have been a reader of Paul’s articles in various publications over the years and have met him on a number of occasions as he, unlike other aviation journalists frequents airports, aero club lounges and aviation gatherings. I have always been impressed in his efforts to bring some of the regulators habits and actions out in the open in an effort to get a better deal for the industry. As a pilot, he often writes of his first hand experiences and in an interesting and informative manner.
Having said that, I was most surprised and somewhat disappointed to read his article titled “Crashed Shrikes were overweight” last Friday. It is not an article that I would expect from Paul, but one that might come from a non-savvy junior journalist with little or no knowledge of the subject matter.
In very basic terms I believe the article is a sensational beat up following the recent tragic accident in Victoria which killed one of the most knowledgeable Shrike engineers in Australia, if not the world.
Let’s start with the headline:
Crashed Shrikes were overweight
“Flying at heavier weights increases the risk of structural failure, and the deadly mix of turbulence and latent fatigue can trigger in-flight break-up.”
The subject aircraft in the recent crash I understand had quite low hours for the type (less than 5000) and had only been in Australia for a short time, which means that for most of its life has been operated at the FAA MTOW. Besides, the investigation has some way to go and to presume at this early stage that fatigue was a factor is drawing a very long bow.
“In the US, their country of origin, Shrikes are limited to a 3062kg maximum takeoff weight, but when they were imported here as used aircraft, the (then) Department of Aviation issued a "supplemental type certificate" allowing them to fly at up to 3357kg, the equivalent of three extra passengers."
There is no mention of the VFR/IFR differences in the article.
Quoting what Gulfstream people might say or the contents of a dated report sound fine, but there are many other factors applicable and a broad and simple investigation will reveal that there are many aircraft modified by STC or otherwise from the manufacturer’s status. All such modifications are undertaken by persons approved for the purpose and it must be assumed in such cases that the applicable issues including fatigue are considered at the time. What the manufacturer might choose to do or not do is irrelevant to the discussion.
“The Shrike remains popular with commercial operators because of the weight concession, but its pilots are now worried that the average aircraft in Australia has flown about 25,000 hours at unusually heavy weights."
Certainly there are some high time Shrikes about (many aircraft are these days) but to give the impression that the fleet average is 25,000 hours is nothing but a dramatic guess.
“…about 50 Shrike Commanders are still flying in Australia. More than half are registered to General Aviation Maintenance Pty Ltd, the operators of the crashed plane, and they are still certified to fly here at a 10 per cent heavier MTOW than the US regulator allows."
Paul, you can do better than this and have done in the past. Are you short on work and need to take some of Steve Creedy's sensational pills to earn a quid? I for one hope that you can retain your professional standards in your future writings in supporting a struggling industry and not as you have in this article succumbed to the need to write such sensational uninformed dribble whilst seemingly taking advantage of a tragedy.
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Triadic - why don't you copy and paste your post into an email back to The Australian? Of course your reply is not as sensational but it would be great if the paper would print the other side of their story...
Between this and the dribble fed from QF management it is no wonder the public has no idea and that pollies make stupid decisions regarding aviation
Between this and the dribble fed from QF management it is no wonder the public has no idea and that pollies make stupid decisions regarding aviation
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What a load of crap.........
Typical journalist rubbish.
Seems a media sport to make an accusation without any knowledge of fact and a very tenuous link to recent events...
Typical journalist rubbish.
Seems a media sport to make an accusation without any knowledge of fact and a very tenuous link to recent events...
Having delved into this issue myself many years ago, I think he has hit the nail fairly and squarely on the head. There has never been to my knowledge any meaningful flight testing done at the higher (VFR) takeoff weight 3357kg or at the higher IFR wt of 3243kg. The reason for the increase would seem political in that when HC Sleigh imported the aircraft for the coastwatch contract, they needed the extra weight for payload/range specifications. The lack of climb performance at higher weights was more acute because of the added bubble windows and ~7 extra antennas. Also this category of aircraft is only required to maintain 5000' on one engine at ISA conditions. Not indicative of the aussie environment.
Certainly he article title is misleading and the timing is in poor taste; possibly not relevant to this crash. It must however be addressed
Certainly he article title is misleading and the timing is in poor taste; possibly not relevant to this crash. It must however be addressed
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illusion
Your history is a bit out.... the increased MTOW was in place well prior to HCSleigh having anything to do with coastwatch, which was not until the later '70's. Sleigh's in fact imported very few of the Shrikes, having inherited them in a takeover. They all had the STC applied at that time.
And yes, flight testing was undertaken in regard to the performance issues and the results satisfied the DCA of the day.
Coast watch was a very different environment and in fact a few Shrikes were scrapped during that period, mainly due to corrosion I recall.
I am sure the latest investigation will cover off these issues. However my issue is the article.
The reason for the increase would seem political in that when HC Sleigh imported the aircraft for the coastwatch contract, they needed the extra weight for payload/range specifications.
And yes, flight testing was undertaken in regard to the performance issues and the results satisfied the DCA of the day.
Coast watch was a very different environment and in fact a few Shrikes were scrapped during that period, mainly due to corrosion I recall.
I am sure the latest investigation will cover off these issues. However my issue is the article.
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Mr Phelan: Give credit where credits due
Triadic, an excellant posting. 
Yes I agree, Mr Phelans article was poorly timed and ill informed. Yes I agree, SK would of forgotten more on those airframes than most engineers would of known and Yes most of those aircraft are a absolute credit to him and his organisation. Interesting to note however that these crashes both involved female crew operating in turbulant conditions and at similar heights. 
Please Mr Phelan, now isn't the time to vent your spleen or opinion on a company you know so well. I hope to see GAM's continue to operate into the future, as I feel that with some better check/training put in place it'd be the GA example of a great company operation! 
Yes I agree, Mr Phelans article was poorly timed and ill informed. Yes I agree, SK would of forgotten more on those airframes than most engineers would of known and Yes most of those aircraft are a absolute credit to him and his organisation. Interesting to note however that these crashes both involved female crew operating in turbulant conditions and at similar heights. Please Mr Phelan, now isn't the time to vent your spleen or opinion on a company you know so well. I hope to see GAM's continue to operate into the future, as I feel that with some better check/training put in place it'd be the GA example of a great company operation!
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Triadic has the right information with respect to HC Sleigh...
I extremely disappointed that someone supposedly in the know with aviation chooses this time to publish that sort of crap when the industry lost the person who owns more Shrikes than any other person, at least in this country...
It is poor form, tacky and entirely bad manners...
Any one with any industry understanding would know this without being told!
I extremely disappointed that someone supposedly in the know with aviation chooses this time to publish that sort of crap when the industry lost the person who owns more Shrikes than any other person, at least in this country...
It is poor form, tacky and entirely bad manners...
Any one with any industry understanding would know this without being told!
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Yes poor timing, but look behind Paul to the editor. Would this article caused the same responses in two or three months. The issues will be researched and over time, our ever so clever regulator will come up some whizz bang scheme that is similar to 400 series sids, PA31 spars etc, that no one else in the world does or thinks necessary.
I extremely disappointed that someone supposedly in the know with aviation chooses this time to publish that sort of crap ..........It is poor form, tacky and entirely bad manners...
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????
Thank god we have Paul Phelan writing in aviation newspapers and magazines. He is one of the few writers who is game to write about what he sees, and says what he thinks. Most of the other aviation stuff we read in Australia is just promotional rubbish. Nice warm and fuzzy stuff that will not upset anyone, or achieve anything.
Maybe the timing was unfortunate on this occasion, but the matter should be discussed and thoroughly investigated. It's starting to look as if there really is a problem.
I do not think Paul was saying that this aircraft was overloaded on the fatal flight, or that any particular operator was knowingly overloading them, beyond normal Australian flight manual limits.
But I think we should have a good look at the logic of what comes from our authorities.
I remember, a long time ago, when the coastwatch contract was awarded to a company that was not able to carry it out. The media told us that this company was not licenced to do the work, did not have aircraft, or crews. Other tenderers that did have these things were unsucessful. The sucessful tenderer started to operate, but could not meet the requirements and major changes were made. (another operator)
It would have been about this time that the STC for a 300 kg overload of shrikes surfaced.
Let's look at other aircraft.
The Piper PA32 aircraft has to have it's wing main spar "retired from service" at 11,000 hours because of an Australian airworthiness directive, unless it can be inspected by an inspection scheme "that is approved by CASA". There is no inspection scheme that is approved by CASA. This is not required in other countries. The aircraft manufacturer says the wing spar should be inspected at 70,000 hours (yes seventy thousand hours), and there is an inspection scheme for this. CASA will not accept it.
Last time I read the notice about the CESSNA SID program on the CASA web site it concluded by saying that this would give non cessna operators a commercial advantage, and they seemed to be trying to find a way to apply similar things to operators of other aircraft, purely for commercial reasons, to even things up.
I thank god for writers like Paul Phelan, who are game to challenge the integrity of some of the things our regulator does. Most people in aviation are afraid to upset our regulator, as they are mindful of their next renewal, and/or dispensation.
(Edited only to include para breaks.)
Maybe the timing was unfortunate on this occasion, but the matter should be discussed and thoroughly investigated. It's starting to look as if there really is a problem.
I do not think Paul was saying that this aircraft was overloaded on the fatal flight, or that any particular operator was knowingly overloading them, beyond normal Australian flight manual limits.
But I think we should have a good look at the logic of what comes from our authorities.
I remember, a long time ago, when the coastwatch contract was awarded to a company that was not able to carry it out. The media told us that this company was not licenced to do the work, did not have aircraft, or crews. Other tenderers that did have these things were unsucessful. The sucessful tenderer started to operate, but could not meet the requirements and major changes were made. (another operator)
It would have been about this time that the STC for a 300 kg overload of shrikes surfaced.
Let's look at other aircraft.
The Piper PA32 aircraft has to have it's wing main spar "retired from service" at 11,000 hours because of an Australian airworthiness directive, unless it can be inspected by an inspection scheme "that is approved by CASA". There is no inspection scheme that is approved by CASA. This is not required in other countries. The aircraft manufacturer says the wing spar should be inspected at 70,000 hours (yes seventy thousand hours), and there is an inspection scheme for this. CASA will not accept it.
Last time I read the notice about the CESSNA SID program on the CASA web site it concluded by saying that this would give non cessna operators a commercial advantage, and they seemed to be trying to find a way to apply similar things to operators of other aircraft, purely for commercial reasons, to even things up.
I thank god for writers like Paul Phelan, who are game to challenge the integrity of some of the things our regulator does. Most people in aviation are afraid to upset our regulator, as they are mindful of their next renewal, and/or dispensation.
(Edited only to include para breaks.)
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WRONG!!
I do not think Paul was saying that this aircraft was overloaded on the fatal flight
Crashed Shrikes were overweight
The sucessful tenderer started to operate, but could not meet the requirements and major changes were made. (another operator)
It would have been about this time that the STC for a 300 kg overload of shrikes surfaced.
It would have been about this time that the STC for a 300 kg overload of shrikes surfaced.
It is also interesting to note that the number of in-flight failures of the model 500 worldwide are minimal (2), and the Australian STC applied to the 500S & 500U's, where there have not, to my knowledge, been any failures to date identified with the known wing problems
I agree that there is a place for writers like Paul, but to maintain his credibility he has to get it right and not stick unjustified knives into the industry that gives him work!
Last edited by triadic; 14th Aug 2007 at 12:40. Reason: Insert further detail
Minimal?
In June 1991, seventeen senior engineers met in Seattle to discuss the safety of AeroCommanders after the twenty-third in-flight wing failure. Lawyers watchedcarefully over their shoulders. The meeting had been called by the United StatesFederal Aviation Administration (FAA) to discuss ‘wing loads, flutter, corrosion,cracking, and possible corrective action.’ How was it that such fundamental structural problems were still unresolved after forty years?
The Aero Commander typifies the practicalities of controlling fatigue in smallcommuter aircraft. The purpose of this paper is not to criticise Aero Commandersor those involved, but to draw lessons for the future - for designers, operators, regulators and all who have an interest in structural durability.
Not that I am suggesting this has anything to do with this particular acident, but the figure is concerning. I am not aware of a single Cessna 300 series that has had an inflight break up world wide, and Cessna have brought in the SID's programme.
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Writer's response
Most people who regularly read newspapers understand that it’s not journalists, but subeditors, who write the headlines. Their quite valid purpose is to attract the reader’s attention, which works, and they don’t usually tamper with detail in the text except to correct things like grammar and style.
No apologies should be expected for reporting on events that have become topical as a result of recent accidents.
Would anybody care to challenge any of the following facts? All material assertions in the article are supported by documents in my possession.
When a wing or wings, or other major airframe components separate from an airframe in flight, a structural failure has occurred.
All events related to changed Shrike maximum weights occurred before Coastwatch contracts became an issue. The aircraft were imported second-hand by one Jim Wilson and (from memory) his company was called Executive Air Services.
The Shrike Commander 500-S and -U were never certificated in their country of manufacture at any weight higher than 6,750 lb. (I apologise in advance for the use of pounds instead of kilograms but all the documentation is in pounds which were fashionable at the time.)
For 25 years the type has been approved for operation in Australia at MTOWs of 7150 lb IFR and 7400 lb VFR, under an Australian STC issued by the regulator (then the Department of Aviation) in June 1971 when the aircraft were first imported into Australia.
It has been my experience that aircraft approved at a particular MTOW quite frequently take off at that weight.
Manufacture of the Aero Commander 500-S and -U ceased in the early eighties.
The Department of Aviation never made available any flight test data or structural analysis to support the higher STC weights.
The weights were challenged in 1982 when the Government Aircraft Factory’s chief test pilot flew a Shrike against the Australian certification requirement, which as we all know, with the possible exception of the occasional junior lawyer, is that it demonstrate capability to climb with the critical engine inoperative at a one per cent still air gradient in a standard atmosphere, following a takeoff at MTOW.
The test pilot reported that extrapolation of the published data revealed that at 7,150 lb the aircraft failed to meet the requirement by 0.5%. The test flight results showed a worse result. At 6,750 lb the average gradient was 0.85% short of the criteria, and at 7,150 there was a nett deficiency of 1.3%
When told of the performance figures on which the STC was based, Gulfstream American Corporation’s performance engineers didn’t believe the aircraft could be flown to perform 10% better. One of these made two comments:
“We could sure use a test pilot with that kind of talent,” and
“If we’d thought it could have performed to a higher weight, we’d have certified it at that weight, sold a lot more airplanes, and made a lot more money.”
The outcomes of the GAF tests are reflected in the following report by consulting aeronautical engineer Malcolm McLeary: “On the information supplied there appear to be three good reasons why a review is warranted:
The manufacturer has not designed or the State authority of origin has not approved the operation to the higher all up weight figures. The higher weights were unilaterally taken by Australia only.
The flight tests of an Aero Commander carried out by GAF show non-compliance to the certification standards; and
The power loading for the type [weight per available horsepower] is suspiciously high when compared to other aircraft supposedly designed to meet the same requirements.”
And further: “Probably worth noting is the fact that if the power available is just sufficient to meet the minimum performance standards with a TOW max of 6,750 lb, the additional power required to meet the same performance standard at a TOW max of 7,150 lb (Australian Certification) is 14.8%. That is to say, for an approximate 10% increase in TOW, the additional power required is about 15%. Arguing further, if the Aero Commander was able to just satisfy the applicable certification standards at the higher TOW of 7400 lb then at 6750 lb the aircraft would need reserve power of approximately 15%. This would indicate that the flight test aircraft had in fact degraded by over 20%, which is unlikely.
The regulator of the day sought to explain the discrepancy between test flight results as the performance differences between a new and a used (3,090 hour) aeroplane. The Gulfstream American Corporation performance engineer rejected the suggestion that the performance of an aircraft that had flown only a little over 3,000 hours could be degraded by 20%: “Well, maybe if it was run over by a bulldozer,” he quipped.
McLeary further commented: “The D.O.A. exists to safeguard the established standards. I believe that they have no option but to reconsider the performance limits of the Aero Commander if written evidence to support the claim is presented. It is a serious enough deviation from the manufacturer’s limits for you to insist on a performance audit, even if it means by-passing the D.O.A. officers and going direct to the Minister.”
A detailed draft of a feature article covering these issues was provided to CASA for comment, and has also been provided to ATSB for its information and assessment. This comment contains its salient points.
CASA, when asked, was unable to cite another single example in which a factory-delivered standard aircraft without aerodynamic or power train modifications, had been certified in this country at a higher MTOW than in its country of certification.
SUMMARY:
Nigel Johnson, a now-retired lifelong GA pilot and senior manager with considerable Shrike Commander experience, comments: “This whole saga is a sad reflection on the competency of government organisations to involve themselves in the more technical aspects of aviation. It has involved three government agencies – an aircraft factory, a bureaucracy set up to guard our coastlines, and the aviation regulator which has changed its name and organisational structure countless times during these events. Almost everything each of these agencies has done during the whole episode, has had the potential to add to aviation’s death toll. No politician of any party has shown any meaningful interest in the complex problems that have been identified, and it seems that even more Shrike Commanders will have to crash before somebody does something about it.
“Although it might mean acknowledging past mistakes, a long-standing CASA aversion, that will need to happen before bureaucratic obstruction and inertia stop killing passengers and pilots.”
Apart from regulatory officials, nobody with whom I have discussed this issue believes that the process by which the STC was issued was a valid one.
Readers are invited to suggest possible conclusions that suggest an alternative explanation other than negligence or deception. I would welcome the opportunity to discuss and if necessary report on any other explanation.
(Edited only to include para breaks. T.W.)
No apologies should be expected for reporting on events that have become topical as a result of recent accidents.
Would anybody care to challenge any of the following facts? All material assertions in the article are supported by documents in my possession.
When a wing or wings, or other major airframe components separate from an airframe in flight, a structural failure has occurred.
All events related to changed Shrike maximum weights occurred before Coastwatch contracts became an issue. The aircraft were imported second-hand by one Jim Wilson and (from memory) his company was called Executive Air Services.
The Shrike Commander 500-S and -U were never certificated in their country of manufacture at any weight higher than 6,750 lb. (I apologise in advance for the use of pounds instead of kilograms but all the documentation is in pounds which were fashionable at the time.)
For 25 years the type has been approved for operation in Australia at MTOWs of 7150 lb IFR and 7400 lb VFR, under an Australian STC issued by the regulator (then the Department of Aviation) in June 1971 when the aircraft were first imported into Australia.
It has been my experience that aircraft approved at a particular MTOW quite frequently take off at that weight.
Manufacture of the Aero Commander 500-S and -U ceased in the early eighties.
The Department of Aviation never made available any flight test data or structural analysis to support the higher STC weights.
The weights were challenged in 1982 when the Government Aircraft Factory’s chief test pilot flew a Shrike against the Australian certification requirement, which as we all know, with the possible exception of the occasional junior lawyer, is that it demonstrate capability to climb with the critical engine inoperative at a one per cent still air gradient in a standard atmosphere, following a takeoff at MTOW.
The test pilot reported that extrapolation of the published data revealed that at 7,150 lb the aircraft failed to meet the requirement by 0.5%. The test flight results showed a worse result. At 6,750 lb the average gradient was 0.85% short of the criteria, and at 7,150 there was a nett deficiency of 1.3%
When told of the performance figures on which the STC was based, Gulfstream American Corporation’s performance engineers didn’t believe the aircraft could be flown to perform 10% better. One of these made two comments:
“We could sure use a test pilot with that kind of talent,” and
“If we’d thought it could have performed to a higher weight, we’d have certified it at that weight, sold a lot more airplanes, and made a lot more money.”
The outcomes of the GAF tests are reflected in the following report by consulting aeronautical engineer Malcolm McLeary: “On the information supplied there appear to be three good reasons why a review is warranted:
The manufacturer has not designed or the State authority of origin has not approved the operation to the higher all up weight figures. The higher weights were unilaterally taken by Australia only.
The flight tests of an Aero Commander carried out by GAF show non-compliance to the certification standards; and
The power loading for the type [weight per available horsepower] is suspiciously high when compared to other aircraft supposedly designed to meet the same requirements.”
And further: “Probably worth noting is the fact that if the power available is just sufficient to meet the minimum performance standards with a TOW max of 6,750 lb, the additional power required to meet the same performance standard at a TOW max of 7,150 lb (Australian Certification) is 14.8%. That is to say, for an approximate 10% increase in TOW, the additional power required is about 15%. Arguing further, if the Aero Commander was able to just satisfy the applicable certification standards at the higher TOW of 7400 lb then at 6750 lb the aircraft would need reserve power of approximately 15%. This would indicate that the flight test aircraft had in fact degraded by over 20%, which is unlikely.
The regulator of the day sought to explain the discrepancy between test flight results as the performance differences between a new and a used (3,090 hour) aeroplane. The Gulfstream American Corporation performance engineer rejected the suggestion that the performance of an aircraft that had flown only a little over 3,000 hours could be degraded by 20%: “Well, maybe if it was run over by a bulldozer,” he quipped.
McLeary further commented: “The D.O.A. exists to safeguard the established standards. I believe that they have no option but to reconsider the performance limits of the Aero Commander if written evidence to support the claim is presented. It is a serious enough deviation from the manufacturer’s limits for you to insist on a performance audit, even if it means by-passing the D.O.A. officers and going direct to the Minister.”
A detailed draft of a feature article covering these issues was provided to CASA for comment, and has also been provided to ATSB for its information and assessment. This comment contains its salient points.
CASA, when asked, was unable to cite another single example in which a factory-delivered standard aircraft without aerodynamic or power train modifications, had been certified in this country at a higher MTOW than in its country of certification.
SUMMARY:
Nigel Johnson, a now-retired lifelong GA pilot and senior manager with considerable Shrike Commander experience, comments: “This whole saga is a sad reflection on the competency of government organisations to involve themselves in the more technical aspects of aviation. It has involved three government agencies – an aircraft factory, a bureaucracy set up to guard our coastlines, and the aviation regulator which has changed its name and organisational structure countless times during these events. Almost everything each of these agencies has done during the whole episode, has had the potential to add to aviation’s death toll. No politician of any party has shown any meaningful interest in the complex problems that have been identified, and it seems that even more Shrike Commanders will have to crash before somebody does something about it.
“Although it might mean acknowledging past mistakes, a long-standing CASA aversion, that will need to happen before bureaucratic obstruction and inertia stop killing passengers and pilots.”
Apart from regulatory officials, nobody with whom I have discussed this issue believes that the process by which the STC was issued was a valid one.
Readers are invited to suggest possible conclusions that suggest an alternative explanation other than negligence or deception. I would welcome the opportunity to discuss and if necessary report on any other explanation.
(Edited only to include para breaks. T.W.)
Last edited by tail wheel; 16th Aug 2007 at 00:59.
Paul,
Whilst not disputing the facts you present, there is a logic dis-connect between the evidence you produce and the conclusions reached or at least implied in your article.
You argue, persuasively, that the STC to increase the MTOW on the Shrike was not justified on a PERFORMANCE basis.
The accidents in question were due to in-flight failures. Whilst you draw the simple conclusion that more weight= more stress, you do not present any evidence, or even opinion from the manufacturer, that the increased MTOW was in any way related to the in-flight failures.
What evidence do you have that the aircraft, even if they had spent their lives operating at the original MTOW, would not have broken up under the stresses present in these accidents?
Whilst not disputing the facts you present, there is a logic dis-connect between the evidence you produce and the conclusions reached or at least implied in your article.
You argue, persuasively, that the STC to increase the MTOW on the Shrike was not justified on a PERFORMANCE basis.
The accidents in question were due to in-flight failures. Whilst you draw the simple conclusion that more weight= more stress, you do not present any evidence, or even opinion from the manufacturer, that the increased MTOW was in any way related to the in-flight failures.
What evidence do you have that the aircraft, even if they had spent their lives operating at the original MTOW, would not have broken up under the stresses present in these accidents?