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Paper checking and AOC's
Found an AOC issued to MQ, the pilot, but not to the advertising web site and the "charterer"
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MickG0105
We appear to have read an entirely different report, I was however mistaken about my assertion about the gear not being retracted. I apologise unreservedly for that.
The last time I read this report was approx 35 years ago, however I used it extensively as a trading aid, as we were operating B200's at that time, and I was C&T on type. Fact a/c took off on 25 Fact a/c impacted 34 rock wall, as best I can recall, approx hdg 130, that turn was accomplished as a largely flat skidding turn as observed by ATC Talk to ATC what they do when an a/c declares a Mayday, it may surprise you to learn that lots of qualified people pick up binoculars and watch intently. What they see, and subsequently give evidence about revealed a lot of what happened to this a/c. ATC observed the aircraft flying on approx reciprocal heading of 34, at a very low level, the pilot was granted approval to use any runway, he chose 34, he flew towards the threshold. The impact damage and trajectory was consistent with a sudden VMC, indications that the pilot pulled up to avoid the 6 metre rock wall. When on an approx parallel downwind heading the pilot chose to fly towards the rock wall, even though the flight path since EFATO had been downhill. I ask you a question MickG0105, "how was he intending to climb to clear the rock wall?" ATSB were absolutely confounded as to how the left engine appeared to have suffered damage at impact consistent with it operating at stabilised idle. The conclusion was that the engine 'auto-ignited' after all water was exhausted by the windmilling engine. The company were complicit in this accident, reduced power T/off's per see are not necessarily a bad thing, but the misunderstanding that in the event of an EFATO all bets are off. The auto feather not being used because of fleet standardisation. The bottom line, this aircraft was capable of climb OEI if flown competently, in spite of high density altitude, and slight over gross. My role as C&T on type was to ensure none of my crew bought the farm, I unashamedly used this report to, 1) highlight about just how well the B200 really climbs OEI, as discussed in excruciating detail in this report. 2) emphasise that EFATO drills in a timely manner will save your life. Cheers Gazumped |
ATSB were absolutely confounded as to how the left engine appeared to have suffered damage at impact consistent with it operating at stabilised idle. The conclusion was that the engine 'auto-ignited' after all water was exhausted by the windmilling engine. |
The auto feather not being used because of fleet standardisation. Moreover, Sod's Law says if an engine failure on take off occurs it will happen to an aircraft that has the Auto feather system available; but switched off:{ |
auto feather not being used because of fleet standardisation... It is indeed no simple task to write and implement SOPs, even more so in a fleet with different types. SOP have to be thought through. Unfortunately, many such [small] aircraft operators have SOPs that make no sense whatsoever and often go against the AFM and, against common sense. Still, this does not excuse the PIC. The AFM/POH always takes precedence over SOPs. Besides, the use of autofeather in King Air is a no brainer, according to the B200 check-list, AFM/POH, it has to be armed before every takeoff and before every landing. Here are some excerpts of The King Air Book by Tom Clements. Every King Air pilot should take the time to read it. [p. 212] A U T O F E A T H E R – W H A T A G R E A T S Y S T E M! ... the Autofeather system has become more prevalent and has proven itself to be trouble free, more and more pilots are realizing that this is a system that virtually cannot be over-used. I understand that a number of pilots are flying with the autofeather switch armed at all times. In my view, that is totally fine. However, my personal preference is to turn autofeather off in cruise when I am at an altitude that gives me plenty of time to analyze and troubleshoot any engine malfunction that may occur. On 90% or more of my flights, I leave the Autofeather switch Armed on the ground, during takeoff and climb, and during descent and landing. But during cruise, I usually turn the switch off for two very flimsy reasons. First, I like having a blank annunciator panel at this time. No big deal, I know, to have two green lights glowing, but I prefer the panel to be dark. Second, I know that I have lots and lots of time, at this high altitude, to think through a suspected loss of engine power and to make my own decision about whether I think immediate feathering is the best course of action. Just in case I decide to allow the propeller to windmill – perhaps to try for a windmilling airstart after I get down in thicker air below FL200 – I now have that option. |
Actually Avionimc, EVERYWHERE I've ever worked, the SOPs over ride the AFM/POH.
Ive just read the full report from cover to cover. No mention at all that the engine was at idle or that ATSB was confounded why it "appeared", due the damage, to be at idle. |
EVERYWHERE I've ever worked, the SOPs over ride the AFM/POH
.. now, that would really be an interesting concept to argue in court after the mishap ... I would refer you, inter alia, to the following (a) CAA 1988 S98 (3)(ka) through (kd) (b) CAR 1988 138(1), notwithstanding 139(3) (c) CASR Subpart 42M .. and so it goes on. I presume you meant to say something along the lines of "the SOPs comply with the AFM/POH" ? |
Originally Posted by JT
.. now, that would really be an interesting concept to argue in court after the mishap ...
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Just doing what the ops manual says, yer honour
If CAR 1988 139(3) applies to the aircraft in question .. perhaps. Now, I'm not a legal eagle but I think the earlier poster might be treading on thin ice. |
I presume you meant to say something along the lines of "the SOPs comply with the AFM/POH" ? |
Indeed. Centaurus has a few tales to tell in that vein as well ... Having spent much time in the past teaching pilots about such things, it amazes me how the Industry lets the standard sit where it is.
CASA also has the problem that the average FOI is not an AFM (or, especially, a performance) specialist by any means. Marta would be stretched a bit thin to review the latter stuff for all the frontline FOIs doing the donkey work. I suspect that the pilot would be covered reasonably well for a 139(3) AOC operation but, otherwise, he/she might find him/herself hung out to dry after the prang when everyone is gunning for whatever depth pockets they can find and the pilot did, indeed, have access to the AFM. Now, I'm a rather conservative engineer .. and once the Defence had been lodged, that had me out of the firing line on a couple of occasions in the past .. Really, I despair at some of the comments and throwaway lines we see on PPRuNe from time to time ... obvious tongue in cheek stuff excluded. |
And that's why CASA changed the laws about 20 years ago to "Accepting" rather than "Approving" Ops manuals. They shifted the legal burden away from themselves to the AOC holder and pilots.
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I bow to your wise council John. The Ops Manual in question ordained that pilots were to comply with all instructions issued by the authorities, but then has an SOP of requiring use of dud take off data, where does that leave the poor pilot in the event of an accident caused by the dud data. Not complying with SOP has its own issues if, you want to kick the traces. It's a rhetorical question, because I know what the legal eagles would say.
The conundrum may have applicability on the King Air, where as has been pointed out, on some fits (if using Hartzell props - is in limitations section), arming auto feather is mandatory (a no go item), but folk may not be using it for SOP reasons. The Bangkok QF brought to light the airline was using a procedure as SOP that the manufacturer counselled against. Once again, where does it leave the poor sod in seat 0A. So many masters wanting satisfaction. |
I guess the current morass eventually will be sorted out as the result of judicial findings after the inevitable mishaps.
They shifted the legal burden away from themselves to the AOC holder and pilots. I suspect that present and recent protocols would tie CASA into a judicial action regardless of what they may choose to call the process ? However, (a) The Ops Manual in question For what it may be worth CAAP 215-1(2) imposes the following - (i) at 2A1.4 Note the requirement to operate company aircraft in accordance with the up-to-date Aircraft Flight Manual (AFM) or other equivalent document (e.g. the company Operations Manual Vol. 2A). (See CAR 54, 138 and 139). The reference to "other equivalent" can only refer to a 139(3) situation, I suggest. (ii) at 2AA.1.7 In respect of takeoff and landing data - The manual must contain information on the method of derivation of the data presented, in agreement with the data presented in the flight manual. Dud data directions probably get sheeted home to the AOC holder and, perhaps, CASA. (b) arming auto feather is mandatory (a no go item), but folk may not be using it for SOP reasons As a certification chap, but not legally competent, I see that as being culpable. No philosophical difference to requiring the pilot to fly outside any other certification (AFM) limitation. (c) The Bangkok QF brought to light I don't have sufficient information to comment specifically. However, the usual airline practice is to seek an NTO for any variation to AFM procedure. I would be surprised if QF had not done this ? One of the points which tends to confuse folks is that parts of the AFM are approved and required per certification standards while other parts are advisory and may be up for discussion. As to who gets hung out to dry after the wreckage has been cleared away, I guess that is up to the presiding Judge. It was much simpler when Megan and I were involved in the coalface activities .. an AOC setup involved a straightforward Statement of Compliance analysis of the documentation and procedure set which could then be ticked off by the Regulatory representative. Now, with the likes of some of the CAAPs, one wonders just who is responsible for keeping track of the tie up between the rule book (regs, etc) and the process book (CAAPs and similar CASA documents). It seems to me that a (basically) simple and straightforward bit of work has become a convoluted nightmare by comparison. Probably we both are better off thinking more about grey nomad things and pleasant places along the GRR and like goat tracks ? |
Just for info John.
In attachment H, the conclusion is drawn that the informal risk assessment process used by the company in evaluating the flaps 25 and idle reverse proposals contained several weaknesses. These included: • There is no evidence that Qantas had sought Boeing’s opinion regarding the safety impact of the new procedures and their potential effect on carbon brake wear. Management personnel agreed that Boeing’s opinion on such issues would be useful, and that they would normally consider the manufacturer’s opinion before changing procedures. Boeing has since stated that it does not support the use of idle reverse thrust as a normal procedure as it increases landing distance. It has also stated that modified braking techniques alone would produce almost as much reduction in brake wear as the combined effect of the flaps 25/idle reverse procedures. • Qantas examined the flaps 25/idle reverse procedures of two other operators as part of the project development process. This examination was incomplete and did not identify that the procedures used by these operators were more conservative than the proposed Qantas procedures, and had additional safeguards in place for operating on water-affected runways (see airlines D and E in attachment I). • The performance differences between idle and full reverse thrust, and between flaps 25 and flaps 30, were not fully examined. Such an examination would probably have highlighted the significant differences in landing distance on wet or contaminated runways using these various configurations. • There is no evidence that a systematic attempt was made to identify all the situations for which flaps 30 and/or full reverse thrust would be more appropriate. • The term ‘contaminated’ was used in the flaps 25 procedure but was not defined. • There appears to have been no review of the human factors implications of the new procedures. For example, there appears to have been no consideration of the extent to which the use of flaps 25/idle reverse could become a skill-based habit (i.e. ‘ the norm’), and therefore might be used by crews when a more conservative configuration was required. |
Originally Posted by megan
The Bangkok QF brought to light the airline was using a procedure as SOP that the manufacturer counselled against. Once again, where does it leave the poor sod in seat 0A.
Regarding flaps 25 vice flaps 30, Boeing said; Regarding the 747-400, Boeing recommends Flaps 30 be used to minimise landing distance and landing speed. Flaps 25 will provide better noise abatement and reduce flap wear. Therefore, flaps 25 is an acceptable flaps setting as long as the crew is satisfied that there is ample runway available for the given conditions. PREFERRED LANDING FLAP IS 25. This will normally be used. The wear characteristics of the B747-400 carbon brakes are such that maximum life is obtained by maximising energy absorption and minimising the number of applications. This leads to the choice of Flap 25 with its higher landing speeds as the preferred landing flap setting. Use of Flap 25 also reduces fuel, time, and noise. Flaps 30 gives lower landing speeds and hence the shortest landing distances. This setting should be used when: • landing field length requirements are critical (for e.g. when you land too long, too fast, and too gently on a wet/patches runway and one engine at TOGA); • landing at HGK [Hong Kong] R/W [runway] 13; • landing on a contaminated runway; and • landing in LOW VIS [visibility] conditions. Boeing does not consider the standard practice of going to reverse idle (idle detent) only to be patently unsafe, but does think that it reduces the existing performance margins. It is acceptable pilot technique to do this (using good judgement) as an exception to the normal procedures when landing on a long, dry runway. We perceive, however, that there is a human factors issue of developing a habit pattern of not using reverse thrust beyond the idle detent. The pilot may then fail to respond quickly when such reverse thrust is needed during an RTO [rejected takeoff] or landing in some type of performance-critical situation. We therefore do not provide a “No Technical Objection” for this as the standard operating policy. At times and locations as specified in Company manuals, reverse thrust may be left at the reverse thrust idle position after touchdown. Sufficient runway must be available to provide the required Performance Manual landing field length increment. The Pilot-In-Command shall also consider runway surface conditions and be satisfied that a safe operation is assured. IDLE REVERSE THRUST Idle Reverse Thrust should normally be used for all landings provided at least 300 metres of surplus runway is available. Use of idle reverse maximises carbon brake life by putting more energy into the brakes, reduces noise and reduces reverser maintenance costs. This does not preclude the use of full reverse thrust should abnormal conditions exist. the autobrake system on the B747-400 aircraft sets a particular deceleration rate and modulates the brake pressure to provide that programmed rate. If the thrust reverser is achieving a higher deceleration rate than required by the autobrake setting, the autobrake system will then reduce the pressure to the brakes. Therefore, to maintain a relatively high brake pressure, a comparatively lower r everse thrust setting is now desirable. Initiation of idle reverse thrust after main gear touchdown will nullify all forward thrust from the engines, and permit the carbon brakes to operate at their peak efficiency. In cases where landing field length is limited, or if any other operational considerations are likely to affect the landing roll or procedures, the Captain should elect to use full reverse thrust during the landing roll. |
Now, I'm speculating that QF used the 139(3) exemption - I can't imagine that they wouldn't. [Some may recall that, when the ANRs were in vogue, this reg was 113(3), as I recall .. same, same .. just in case the reg number call out is causing any confusion].
If that be the case, the pilot does not have access to the AFM as it lives in the ops eng tech library or some similar place. The pilot only has the information in the ops manual so the operator must, necessarily, carry the can for providing the information upon which the pilot is directed to rely. I would speculate further that the procedure hadn't gone through Tech Services and was a Flight Ops matter ? Ignoring the absence of an NTO concurrence would have produced much navel gazing in the engineering empire. I preferred the AN approach .. the pilot exercised considerable autonomy in such decisions on the line .. just don't embarrass the boss by doing something stupid. Curiously, I recall the complementary problem with another operator in the past. An optional mod to the fleet was assessed by maintenance only. The decision was that it was not worth the cost. Had it gone through operations, the Chief Pilot would, most definitely, have required its embodiment. You guessed it, some time later its absence caused damage in the lots and lots of dollars region ... Needless to say, the internal processes were changed very rapidly so that all relevant stakeholders had a say in such matters thereafter. |
In QF1's case, if there had been fatalities, the sod in seat 0A would have been legally required to carry the can, CAR 224 notwithstanding. Significant latent failures Significant latent failures associated with Qantas Flight Operations Branch activities were: • Company-published information, procedures, and flight crew training for landing on water-affected runways were deficient. • Flight crew training in evaluating the procedural and configuration options for approach and landing was deficient. • Procedures and training for flight crew in evaluating whether or not to conduct an emergency evacuation were deficient. • Procedures and training for cabin crew in identifying and communicating relevant information during an emergency were deficient. • The processes for identifying hazards were primarily reactive and informal, rather than proactive and systematic. • The processes to assess the risks associated with identified hazards were deficient. • The processes to manage the development, introduction and evaluation of changes to operations were deficient. • The design of operational procedures and training were over-reliant on the decision-making ability of company flight crew and cabin crew and did not place adequate emphasis on structured processes. • Management culture was over-reliant on personal experience and did not place adequate emphasis on structured processes, available expertise, management training, and research and development when making strategic decisions. Responses to the pilot survey, along with information obtained during interviews, indicated that the Qantas One flight crew were not atypical of most other company B747-400 pilots. There was, therefore, an unquestionable link between the performance of the crew and the company flight operations system in which they trained and operated The flight crew did not use an adequate risk management strategy for the approach and landing. Given the minimal level of procedures and training provided to the crew regarding landing on water-affected runways, they were not equipped to appropriately handle the situation they faced. It is, therefore, unreasonable to expect the crew to have developed an adequate risk management strategy for the approach and landingBoeing's opinion was not sort until after the event. Boeing - we do not advocate intentionally increasing brake temperatures as a means to increase carbon brake life. We have concerns that such techniques could result in increased occurrences of fuse plug melting and dispatch delays for brake cooling. Additionally, some of the techniques we have heard discussed, such as reduced landing flap settings and the use of idle reverse thrust, have a negative impact on airplane stopping performance. Therefore, these techniques are not recommended as standard practice… Boeing did not support the use of idle reverse thrust as a standard practice for normal landings or for increasing brake temperatures of carbon brakes. Further, they were concerned with the human factors implications of having idle reverse thrust as the standard practice There is no evidence that Qantas had sought Boeing’s opinion regarding the safety impact of the new procedures and their potential effect on carbon brake wear. Management personnel agreed that Boeing’s opinion on such issues would be useful, and that they would normally consider the manufacturer’s opinion before changing procedures. Boeing has since stated that it does not support the use of idle reverse thrust as a normal procedure as it increases landing distance. It has also stated that modified braking techniques alone would produce almost as much reduction in brake wear as the combined effect of the flaps 25/idle reverse procedures. • The performance differences between idle and full reverse thrust, and between flaps 25 and flaps 30, were not fully examined. Such an examination would probably have highlighted the significant differences in landing distance on wet or contaminated runways using these various configurations. • There is no evidence that a systematic attempt was made to identify all the situations for which flaps 30 and/or full reverse thrust would be more appropriate. • The term ‘contaminated’ was used in the flaps 25 procedure but was not defined. • There appears to have been no review of the human factors implications of the new procedures. For example, there appears to have been no consideration of the extent to which the use of flaps 25/idle reverse could become a skill-based habit (i.e. ‘ the norm’), and therefore might be used by crews when a more conservative configuration was required. The post-implementation review of the effects of the changes was shallow, informal, and undocumented. Flight crew were asked in newsletters to provide feedback. Fleet management received limited written and verbal feedback. Although mainly critical in nature, this feedback appeared to be disregarded as the number of sources was relatively small, and many of the sources were perceived to be resistant to change. There was no method of actively obtaining information from flight crew or check-and-training personnel. It is reasonable to conclude that a more detailed and positive feedback program would have identified the strong views of many line pilots about the operational benefits of flaps 30 over flaps 25 (see section 1.7). Such a process should also have identified the lack of flight crew understanding of aspects of the procedures, such as the meaning of the term ‘contaminated runway’. The comment that it may become the "norm" seems prescient in hindsight. |
The lack of training about the implications of rejected landings and especially the changes to the auto spoilers, auto brakes and autothrottle responses and indications is very significant. Given that we almost never saw these situations on line, an exercise during the triennial cyclic matrix would have been valuable.
A massive human factors fail was the fact that nobody knew who was flying after the attempted G/A. Had even idle reverse been selected the outcome would almost certainly have been OK, a bit scary maybe, because the auto spoiler would have extended the spoilers and enhanced the braking enough to stop her. |
Originally Posted by megan
As much as some people hate the Reason model, when holes line up is it reasonable to place the entire blame (hate the word) on 0A.
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So, can I ask the experts on policy, policy implementation, the Flight Manual etc:
Where does the fact where the person in 0A, directs the F/o to go-around, then takes over from him, then elects to discontinue the go-around, the aircraft makes contact with the runway, that disarms the auto spoiler and the autobrake, then touches down on a runway with standing water which is unreported, tries to stop without auto brakes and no speedbrakes up, neglects to select ANY reverse ( let alone idle), no one realises the spoilers haven't deployed so they are faired until the end of the landing roll, and one engine is in forward thrust which is undetected or unreported by any of the pilots. Who in the hell discontinues a go around anyway? I haven't ever seen any landing data that gives a runway distance required for a discontinued go around, let alone on a contaminated runway. The only cheese that suits what happened is not Swiss, it's a smelly blue cheese, one that is the product of something well out of the ordinary. A few minutes earlier the 0A seated person on another aircraft on the other parellel runway carried out a go around which was not discontinued. They landed after a second approach and were in the hotel whilst the other one was checking out the golf course. |
Wombat watcher, I think that is an oversimplification of what occurred. I will admit that it is a very long time since I read the report on QF1, but, I think it was the FO as PF who initiated the go-around (2nd one), that decision disabled the auto-spoilers and auto-brakes, not the contact with the runway, the Capt. then sights the runway and takes over and lands the aircraft, albeit well down the runway. By now it was confusion aplenty in the cockpit and no-one knows what the responsibilities are or what they should be looking for.
Yes there were shortcoming all round but it did highlight something which I think still rings true today, that the most dangerous thing in aviation is the accountant mentality. |
"When the aircraft was approximately 10 ft above the runway, the captain instructed the first officer to go around. As the first officer advanced the engine thrust levers, the aircraft’s mainwheels touched down (1,002 m along the 3,150 m runway, 636 m beyond the ideal touchdown point). The captain immediately cancelled the go-around by retarding the thrust levers, without announcing his actions. Those events resulted in confusion amongst the other pilots, and contributed to the crew not selecting (or noticing the absence of) reverse thrust during the landing roll. Due to a variety of factors associated with the cancellation of the go-around, the aircraft’s speed did not decrease below the touchdown speed (154 kts) until the aircraft was 1,625 m or halfway down the runway."
Lovett, here it is for you to read and modify your opinion. |
PLovett, not quite. The FO was PF, and was looking good till very short final, although a little fast. Entering IMC he then slipped high on slope. The Captain called the go around approaching the flare, at which point the FO advanced the throttles. Suddenly in reasonable vis though, the Captain then decided to cancel the go around (without informing anyone) and retarded three of the four throttles, but missed one which consequently remained set at TOGA. This is what disarmed the auto-brakes. By this stage, thanks to being high and fast on final, attempting to initiate a missed approach and then extending the flare/AoA/nose high attitude into a gentle touch, and having one engine at TOGA, they were a considerable distance from the threshold by the time they started applying manual brakes. The gentle touch assisted the dynamic aquaplaning that then occured, and reverse thrust was not employed.
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wtf has QF1 got to do with the King Air crash?
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About as much as your post has to do with it!
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Was thinking the same, maybe some people just want to show off rather than discuss the KingAir autofeather issue
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EVERYWHERE I've ever worked, the SOPs over ride the AFM/POH This was to cover a couple situations where a third party not familiar with the AFM/POH published conflicting information in the OM or the AFM/POH was amended that put the OM in conflict with the AFM/POH. The only SOP that I know off that was against the AFM was in one company who flew a mixed fleet of fixed gear and retractable gear aircraft where the undercarriage up and down calls were standard across the fleet. And that's why CASA changed the laws about 20 years ago to "Accepting" rather than "Approving" Ops manuals. They shifted the legal burden away from themselves to the AOC holder and pilots. One crucial bit of the approach in QF1 that the ATSB missed and did not comment on, which would have prevented the accident, was during the approach where one of the crew stated, during the investigation, that the runway was only visible to the crew directly behind the sweep of windscreen wipers. I believe that it is a requirement for the runway to be continuously visible to the crew when continuing the approach below the DA. If they had conducted a missed approach when the continuous visibility requirement was lost, we would not be talking about this today. Anyway this is completely of topic. Back to the B200. Auto-feather is there for a reason, especially with Raisbeck 4 bladed props. Use it. End of story. |
Originally Posted by megan
(Post 9703785)
Ask away, what is it you want to know about auto feather?
PS: threads often side track in the course towards a destination. Think of it as off track sight seeing. We get there in the end. ;) |
Eddie, a lot depends on what the failure was and whether or not the core is still rotating.
With an engine that is shut down and the plane flying along you still get airflow through the engine and you'll see it on the Ng. Now, since the Ng doesn't stop completely (unless say a bearing fails) the oil pump is still driven and sending oil to the primary governor, which boosts the pressure and the prop keeps spinning. On the ground if you shut a PT6 down and don't feather it, they'll spin for a long time, stop, and as the Ng has also stopped the blades will feather themselves. The need for the "separate system" you mention (the auto feather) is not because you cannot feather the prop (there's a lever for that), but if you go back several posts it is due specifically for Vmca certification criteria on specific King Airs. In short the 4-bladers require autofeather because if they windmill they are VERY draggy. The auto feather system will feather it quicker than relying on the pilot to do it. But, you can still manually feather if the auto system fails (which I've never heard about, it's fairly simple and quite robust). |
is there a ' negative torque switch' like there was in Electra ham standard props?
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No Sunny, no negative torque switches.
A very basic rundown for you if your interested: There's a main autofeather system switch, arm test off. Let's say it's switched to arm. There is a micro switch on each power lever. Their position corresponds to roughly a position that commands 90% N1. With these switches made, the system knows you are commanding high power (pull one or both back and it will disarm the AFX system). In the AFX system, on each side, there are two torque switches; one set to open at 200 ft/lbs and the other set to open at 400 ft/lbs, as the power is increased. Now, high power is set and the torque switches are open. You then suffer an engine failure. Tq on that engine drops below 400 and closes the first switch- this disarms the autofeather on the opposite side (you cannot have a double-auto-feather event). Then when the failed engine drops below 200 ft/lbs this will close the second switch- this then commands the dump valve to open and feather the failed prop. |
Originally Posted by Sunfish
(Post 9712203)
is there a ' negative torque switch' like there was in Electra ham standard props?
The PT6A is a free-turbine engine, the compressor turbine and compressor are on a different shaft than the power turbine. The latter driving the reduction gearbox and the the propeller. These two shafts are not connected. On the other hand, Negative Torque Sensing or NTS system is installed on a single [spline] shaft like the TPE331 engine. Where all engine components (compressor, power turbinne, gearbox & propeller, accessories, etc.) are geared to that one shaft. |
ATSB Report due today
ATSB report due out today.
Maybe we will find out what happened. |
Only the preliminary factual details Eddie, not the final report.
I doubt we will find out exactly what happened today. |
Just released.
Investigation: AO-2017-024 - Collision with terrain involving B200 King Air VH-ZCR at Essendon Airport, Victoria on 21 February 2017 Have begun reading, somewhat interesting so far. Lack of CVR recording is going to make it more difficult. |
Bugger, raises more questions than it answers.
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Basically says that both engines were running at the time of the crash.
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Originally Posted by Obba
(Post 9722385)
Basically says that both engines were running at the time of the crash.
If your vital actions after OEI called are Pitch, Power, Cleanup, I would expect the gear to have been raised, or at least raising as the aircraft went over the perimeter fence. Strange about the CVR. How many flights would have been operated in the seven weeks between 3 January and 21 February? |
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