RAAF 707 Crash East Sale and Nomad Problems
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32 airframes lost out of a production run of 174. I know it's an Australian aircraft but I'm not sure I'd consider it a success, or even be on the fence as to whether it was an unmitigated failure.
18.6% of airframes.
If it were a 737 we'd have lost 1622 of them by now, ramping up to 68 crashing per year in 2015.
I get that it's Australia with very little aircraft design and manufacture knowledge outside of assembling what others have already successfully produced but where was the potential in the Nomad?
18.6% of airframes.
If it were a 737 we'd have lost 1622 of them by now, ramping up to 68 crashing per year in 2015.
I get that it's Australia with very little aircraft design and manufacture knowledge outside of assembling what others have already successfully produced but where was the potential in the Nomad?
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32 airframes lost
I think you need to review the details of each mishap and consider the extent to which the operational difficulties contributed .. not to mention the occasional cavalier operational approach to standards ..
It was a very capable bird in the hands of a sensible pilot and providing the maintenance was kept up to the mark.
I think you need to review the details of each mishap and consider the extent to which the operational difficulties contributed .. not to mention the occasional cavalier operational approach to standards ..
It was a very capable bird in the hands of a sensible pilot and providing the maintenance was kept up to the mark.
B707 Rudder Boost and Vmca
Realising that the B707 element of this thread is now moribund, I hope John and others won't mind me offering a belated comment.
Quote from By George:
"The instructor turned off the rudder boost with two engines out on the same side. This placed the aircraft into a VMCA loss of control at too low an altitude to recover. There was some talk that a warning note in the manual was not transferred from the original Qantas manual when writing the RAAF one."
I don't know what model this RAAF B707 was, but on the B707-320B/C with JT3D-3B turbofans the 3-engine Vmca with rudder boost off is about 180 kt. That obviously allows for an outboard engine failure. (With rudder boost it's somewhere below 120 kt, IIRC.)
With two engines out on the same side, the Vmca is about 147 kt even when the rudder boost is operating...
Quote from Old Fella:
"The Rudder is the only hydraulically assisted primary flight control surface on the B707 and my recollection is that without that assistance available rudder displacement from neutral was approximately halved,"
Yes, it seemed archaic after the VC10, which has 3 separate rudders, each with a PCU and series yaw-damper. Must admit I'm surprised to hear the rudder will only go half-travel manually. I assumed it was simply a question of how hard a typical PF could push (i.e., not enough to get full-travel), and how much trim was applied.
Quote from By George:
"The instructor turned off the rudder boost with two engines out on the same side. This placed the aircraft into a VMCA loss of control at too low an altitude to recover. There was some talk that a warning note in the manual was not transferred from the original Qantas manual when writing the RAAF one."
I don't know what model this RAAF B707 was, but on the B707-320B/C with JT3D-3B turbofans the 3-engine Vmca with rudder boost off is about 180 kt. That obviously allows for an outboard engine failure. (With rudder boost it's somewhere below 120 kt, IIRC.)
With two engines out on the same side, the Vmca is about 147 kt even when the rudder boost is operating...
Quote from Old Fella:
"The Rudder is the only hydraulically assisted primary flight control surface on the B707 and my recollection is that without that assistance available rudder displacement from neutral was approximately halved,"
Yes, it seemed archaic after the VC10, which has 3 separate rudders, each with a PCU and series yaw-damper. Must admit I'm surprised to hear the rudder will only go half-travel manually. I assumed it was simply a question of how hard a typical PF could push (i.e., not enough to get full-travel), and how much trim was applied.
Last edited by Chris Scott; 6th Oct 2015 at 23:29. Reason: Typos.
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Rudder deflection
Chris, it is nearly 35 years since I operated on the B707, and in order to try and clarify the intent of my comment some time back, what I intended to convey was that due to the aerodynamic load on the rudder at the speeds involved it was physically near impossible to get more than about 50% of available rudder deflection without the rudder boost operable. As you alluded to it is dependent on how hard the pilot can push and how much trim has been applied. The comment regarding a warning not being transferred from the Qantas Flight Manual to the RAAF version, I think, is incorrect. My recollection is that there was no published procedure covering double asymmetric engine failure, accompanied by loss of rudder boost, in the QANTAS manuals. In my time on the type double asymmetric was never intentionally attempted in either the aircraft or the simulator. My understanding of the accident sequence was that one engine out Vmca was demonstrated with and without rudder boost. It was following the "without" demonstration that the rudder boost was inadvertently not reinstated and the double asymmetric demonstration was being attempted when the loss of control took place.
B707-320B/C two-engined approach (with rudder boost)
Hi Old Fella,
Yes! 38 years in my case, and only did two-and-a-half years on type (as P2). Your explanation of the rudder-boost failure case now sounds spot-on, in the absence of the FCOM. But I did do an approach in the sim with two engines out at least once - either on conversion with AA at DFW or with my own company, BCAL. But I can't remember if they were out on the same side. Perhaps not...
Unlike simulator sessions on my previous ship, the VC10, the second engine was not failed until cleaned-up and at a safe height. The approach exercise was included in our small Flight Patterns booklet (probably originating from Boeing themselves), which I have on my bookshelf. Curiously, it doesn't mention the Vmca for this or the other asymmetry cases, so I offered those from memory, including the 147 kt for this case on our model of a/c (JT3D-3B engines rated at 17,000 lb at sea-level). It gives the same procedure regardless of which two engines are failed.
Most of the approach is flown with Flaps 14 at Vref + 30, the L/G being extended as the glide slope is intercepted. As usual, the rudder trim is zeroed at 500 ft aal. At 300 ft there is a "Commit Point".
If landing, Flaps 50 is selected and the speed gradually reduced to Vref (plus the usual wind increment) by the threshold, with thrust to suit...
If going-around: "Apply thrust (compatible with directional control)"
, "Flaps up" (zero), Accelerate (downhill, if necessary?) to Vref + 40, "Rotate to go-around attitude", wait for positive climb, "Gear up", and finally "Accelerate to Vref +60 (minimum)".
Yes! 38 years in my case, and only did two-and-a-half years on type (as P2). Your explanation of the rudder-boost failure case now sounds spot-on, in the absence of the FCOM. But I did do an approach in the sim with two engines out at least once - either on conversion with AA at DFW or with my own company, BCAL. But I can't remember if they were out on the same side. Perhaps not...
Unlike simulator sessions on my previous ship, the VC10, the second engine was not failed until cleaned-up and at a safe height. The approach exercise was included in our small Flight Patterns booklet (probably originating from Boeing themselves), which I have on my bookshelf. Curiously, it doesn't mention the Vmca for this or the other asymmetry cases, so I offered those from memory, including the 147 kt for this case on our model of a/c (JT3D-3B engines rated at 17,000 lb at sea-level). It gives the same procedure regardless of which two engines are failed.
Most of the approach is flown with Flaps 14 at Vref + 30, the L/G being extended as the glide slope is intercepted. As usual, the rudder trim is zeroed at 500 ft aal. At 300 ft there is a "Commit Point".
If landing, Flaps 50 is selected and the speed gradually reduced to Vref (plus the usual wind increment) by the threshold, with thrust to suit...
If going-around: "Apply thrust (compatible with directional control)"
, "Flaps up" (zero), Accelerate (downhill, if necessary?) to Vref + 40, "Rotate to go-around attitude", wait for positive climb, "Gear up", and finally "Accelerate to Vref +60 (minimum)".
Last edited by Chris Scott; 7th Oct 2015 at 12:50. Reason: Title clarified.
Hi Chris,
You have stirred up some old memories! When I did my command upgrade on the B707-321F in 1979 we did 2-eng inop. landing (1) + 2-eng inop GA (1) exactly as you described in the aircraft at STN.
From what I recall, if the rudder boost failed and then an engine was lost then the s.o.p. was to fly the approach as a 2-eng SYMMETRICAL approach to avoid the higher Vmca2 issues.
Great fun but scary in retrospect especially the GA.
"You tell the youngsters today and they wouldn't believe you!" said in a yorkshire accent.
You have stirred up some old memories! When I did my command upgrade on the B707-321F in 1979 we did 2-eng inop. landing (1) + 2-eng inop GA (1) exactly as you described in the aircraft at STN.
From what I recall, if the rudder boost failed and then an engine was lost then the s.o.p. was to fly the approach as a 2-eng SYMMETRICAL approach to avoid the higher Vmca2 issues.
Great fun but scary in retrospect especially the GA.
"You tell the youngsters today and they wouldn't believe you!" said in a yorkshire accent.
Hello Meikleour,
Surprised and impressed you did a 2-engine G/A on the a/c. I guess it was part of the P1 sylabus, whereas mine was P2.
The situation faced by the RAAF crew at East Sale as Old Fella explains it (failure to reinstate rudder boost before demonstration of two engines at idle on one side) was not, of course, in any SOP. But by discussing the implications of loss of rudder boost in the 3-engine case, and the seriousness of the case of 2-engines out on the same side even with rudder boost available, we may have given some idea of the catastrophic nature of the problem.
Furthermore, this quote from earlier in the thread by IGh suggests the problem of recovering control in the event of simulated failures may be more complex than one might think, although it seems not to have applied in the RAAF case:
"Rudder control system characteristic: in event of shutdown/failure of Auxiliary System pumps rudder system will NOT automatically revert from Powered mode to Manual mode. If rudder boost is lost the Rudder will suddenly center (since tab is Anti-servo); to regain use of rudder pilot must first center the pedals (bring tab into servo range). If unable to achieve Manual Reversion, LoC could result even with speed faster than Vmca. [AIAA Paper #71-793, TGF&HFM, pg 15-6."
Yes, thanks for reminding me that "... if the rudder boost failed and then an engine was lost then the s.o.p. was to fly the approach as a 2-eng SYMMETRICAL approach ..." A visit to my shed reveals a photocopy of the Emergency Check List, which confirms that, and the 3-eng Vmca of 180 kt. Elsewhere, it confirms the 2-eng (asymmetric) Vmca of 147 kt (with rudder boost). It also states that it may not be possible to go-around with #2 and #3 shutdown, due to slow flap retraction and gear-retraction complications.
What a beast! My problem getting it into perspective now, however, is that I never flew the B747 or any other 4-engined jet with widely-spaced engines. I imagine the Galaxy and the early Classics may have shared the 707's lacklustre performance, but at least they would have had some redundancy in their rudder systems.
Surprised and impressed you did a 2-engine G/A on the a/c. I guess it was part of the P1 sylabus, whereas mine was P2.
The situation faced by the RAAF crew at East Sale as Old Fella explains it (failure to reinstate rudder boost before demonstration of two engines at idle on one side) was not, of course, in any SOP. But by discussing the implications of loss of rudder boost in the 3-engine case, and the seriousness of the case of 2-engines out on the same side even with rudder boost available, we may have given some idea of the catastrophic nature of the problem.
Furthermore, this quote from earlier in the thread by IGh suggests the problem of recovering control in the event of simulated failures may be more complex than one might think, although it seems not to have applied in the RAAF case:
"Rudder control system characteristic: in event of shutdown/failure of Auxiliary System pumps rudder system will NOT automatically revert from Powered mode to Manual mode. If rudder boost is lost the Rudder will suddenly center (since tab is Anti-servo); to regain use of rudder pilot must first center the pedals (bring tab into servo range). If unable to achieve Manual Reversion, LoC could result even with speed faster than Vmca. [AIAA Paper #71-793, TGF&HFM, pg 15-6."
Yes, thanks for reminding me that "... if the rudder boost failed and then an engine was lost then the s.o.p. was to fly the approach as a 2-eng SYMMETRICAL approach ..." A visit to my shed reveals a photocopy of the Emergency Check List, which confirms that, and the 3-eng Vmca of 180 kt. Elsewhere, it confirms the 2-eng (asymmetric) Vmca of 147 kt (with rudder boost). It also states that it may not be possible to go-around with #2 and #3 shutdown, due to slow flap retraction and gear-retraction complications.
What a beast! My problem getting it into perspective now, however, is that I never flew the B747 or any other 4-engined jet with widely-spaced engines. I imagine the Galaxy and the early Classics may have shared the 707's lacklustre performance, but at least they would have had some redundancy in their rudder systems.
Last edited by Chris Scott; 7th Oct 2015 at 16:25. Reason: Correction in para #2, sentence #1. Correction in para #3, sentence #1.
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Oh boy, you don't know much about Australia and aviation.
So, I'm keen to hear what successful aircraft Australia has made, we seem to differ on what constitutes success.
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Australian designed aircraft.
Anotherday, you really need to do a bit of research. Whilst Australia has largely licence built aircraft with their origins from other lands, we have produced, and still do produce some home grown aircraft which most would consider to be successful. You ask "what successful aircraft Australia has made"?
Without going into chapter and verse I can name a few examples. During WWII, the Wackett trainer was designed and built in Australia, 202 built. These
aircraft served with the RAAF, the Netherlands East Indies (30) and the Indonesian Air force. A number were converted to Crop Dusters post RAAF use.
The Boomerang fighter aircraft, 250 built, saw wartime service with the RAAF.
The CAC Winjeel trainer was designed and built in Australia. 64 built. It was the basic trainer in the RAAF for 20 years (1955-1975) and then a number were used in the FAC role for a further 19 years. Numerous examples
still fly today in civil use. Hardly a failure I would suggest.
Gippsland Aeronautics, now owned by Mahindra, designed and built the GA8 Airvan. Over 200 of these have been built and sold within Australia and also internationally, into the USA.
I don't know what your definition of successful is, however just because an aircraft does not sell in South Africa does not make it a failure.
Without going into chapter and verse I can name a few examples. During WWII, the Wackett trainer was designed and built in Australia, 202 built. These
aircraft served with the RAAF, the Netherlands East Indies (30) and the Indonesian Air force. A number were converted to Crop Dusters post RAAF use.
The Boomerang fighter aircraft, 250 built, saw wartime service with the RAAF.
The CAC Winjeel trainer was designed and built in Australia. 64 built. It was the basic trainer in the RAAF for 20 years (1955-1975) and then a number were used in the FAC role for a further 19 years. Numerous examples
still fly today in civil use. Hardly a failure I would suggest.
Gippsland Aeronautics, now owned by Mahindra, designed and built the GA8 Airvan. Over 200 of these have been built and sold within Australia and also internationally, into the USA.
I don't know what your definition of successful is, however just because an aircraft does not sell in South Africa does not make it a failure.
Last edited by Old Fella; 10th Oct 2015 at 09:21. Reason: Added information.
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.. one could add the Airtourer (learned to fly on that one), AirTruck, Jindivick (thinking of the Pika), other non-pilot machines such as Ikara and Malkara, a number of the smaller end birds ... and there probably are others if we were to ponder it over coffee.
I recall the very recently late and lamented Stan Schaetzel in an undergrad lecture at Sydney in the 60s (he was one of the department's Industry cadre) suggesting that Australia was more than capable of designing and building a Caribou sized aircraft .. the limitation being engineering population.
I recall the very recently late and lamented Stan Schaetzel in an undergrad lecture at Sydney in the 60s (he was one of the department's Industry cadre) suggesting that Australia was more than capable of designing and building a Caribou sized aircraft .. the limitation being engineering population.
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Australia in general needs more emphasis on training Engineers of all sorts.
It has been said that US is a nation of Engineers, and that is how she developed such an advanced and dynamic nation.
It has been said that US is a nation of Engineers, and that is how she developed such an advanced and dynamic nation.
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Dialogue on the Nomad is getting a bit ancient, but I could clarify on a couple of things.
As an ARDU test pilot, I did the first military test flying of the Nomad N2 in 1971. A Preview Assessment was undertaken, which is a complete evaluation of the aircraft in its intended role. On my team were ex-SqnLdr Chris Furse and LtCol Paul Lipscombe ARA. The idea of a Preview is to identify problems at the prototype stage so that rectifications can be incorporated in production aircraft.
Going back a year or so, the original Nomad cockpit design was basically that of a helicopter. Then it became a single-engine transport. Then a swing-tail twin. Then the final fixed tail version. Unusually the aircraft had an all-flying tailplane which - although quite common with power controls - I had not seen with manual controls. This I am sure contributed to many of its longitudinal control problems.
The cockpit design was a shambles and any relation to ergonomics was coincidental. Surprisingly for a firm designing and building a new aircraft type, GAF did not employ a test pilot until Stuart Pearce was hired just in time for the flight test programme. In 1970 ARDU offered to give GAF some gratis advice on the cockpit design and I and a couple of other ARDU tp's spent a few weeks putting together a cockpit mock-up at GAF which was more or less built into the first prototype (VH-SUP).
Probably the major and continuing problem was that to get funding GAF had to produce a prototype for military evaluation. But GAF was very firmly targeting the civilian market. Thus whenever we wanted a change, GAF would consider its effect on the civilian aircraft, ie whether to include the mod at extra cost, or to have two build standards - also at extra cost. Or to try and reject the mod. As a result many of our desired mods were not incorporated.
I am now based in India and don't have my test report here. But from memory basically I thought the aircraft had a lot of potential but had a large number of problems, all of which were fixable with time and effort. Unfortunately this was not applied.
STOL performance was very important to the Army and the Nomad was quite good. I described it as like landing into a bowl of soggy pudding mix - ground roll I recall at about 400-ft. Except that the early brake pedals were designed to blow the tyres on landing - which I did, both of 'em once.
The two crashes - Mansfield and Avalon - were not really aircraft faults, but human errors.
The one at Mansfield was caused by a twin engine failure as a result of intake icing. There was nothing wrong with the de-icing system - it just was not fitted and the aircraft was not cleared for flight in forecast icing conditions. Nevertheless the aircraft was being flown in icing conditions and guess what? Even then, the aircraft could have force-landed with just minor damage in a large open field straight ahead at cloud break. Instead, Stuart tried to land on a narrow road bordered by tress and overshot his touchdown and had to try and negotiate a dogleg through a railway level crossing. Score - level crossing 1, Nomad 0. Very luckily no one was injured although some patrons at a pub were somewhat surprised as he went past the front door. You could talk to Peter Reddel (ex-Cathay) who was RHS and had a full head of hair prior.
The N24 tailplane tests were pretty cavalier. Try one thing and if it doesn't work try another. I am not sure who was more to blame, the design or flight test depts. The fatal flight took off on the short cross runway at Avalon and encountered unmistakable flutter at about 800-ft. Some may not understand the significance of flutter. It is not just a vibration in a part of the airframe. Flutter is a structural instability that within seconds will likely cause a major airframe failure - e.g. loss of wing, empennage, fuselage break-up. Answer was to reduce speed and put the aircraft on the ground ASAP - any ground. Pat Larcey - the FTE and only survivor - immediately grabbed a parachute and was halfway to the door when Stuart said it was OK he'd got it. Pat had just enough height to jump out, but returned to his seat and strapped in. Stuart, instead of landing straight ahead in an open field, tried to complete a circuit back to the takeoff runway but only got halfway there before complete control was lost and he crashed beside the main runway. Stuart died instantly from a ruptured aorta but David Hooper (design) was ejected through the front windscreen still strapped in his seat and died sometime later. As I recall there was something wrong with the seat. Pat's station in the cabin was at the CG and, as they hit, he suffered a severe vertical deceleration causing paraplegia.
Sure the N24 had some stability problems but they did not cause the accident. Nor did flutter problems - which were introduced by the players. Once flutter occurred, the severity of the situation was exacerbated by poor handling by the pilot.
So, the main causal factor in both these accidents was human error rather than aircraft design deficiency.
In summary. my experience with the Nomad was that it was a potentially good aircraft, both for the military and civilian market, but development of which was screwed by a dysfunctional management system.
As an ARDU test pilot, I did the first military test flying of the Nomad N2 in 1971. A Preview Assessment was undertaken, which is a complete evaluation of the aircraft in its intended role. On my team were ex-SqnLdr Chris Furse and LtCol Paul Lipscombe ARA. The idea of a Preview is to identify problems at the prototype stage so that rectifications can be incorporated in production aircraft.
Going back a year or so, the original Nomad cockpit design was basically that of a helicopter. Then it became a single-engine transport. Then a swing-tail twin. Then the final fixed tail version. Unusually the aircraft had an all-flying tailplane which - although quite common with power controls - I had not seen with manual controls. This I am sure contributed to many of its longitudinal control problems.
The cockpit design was a shambles and any relation to ergonomics was coincidental. Surprisingly for a firm designing and building a new aircraft type, GAF did not employ a test pilot until Stuart Pearce was hired just in time for the flight test programme. In 1970 ARDU offered to give GAF some gratis advice on the cockpit design and I and a couple of other ARDU tp's spent a few weeks putting together a cockpit mock-up at GAF which was more or less built into the first prototype (VH-SUP).
Probably the major and continuing problem was that to get funding GAF had to produce a prototype for military evaluation. But GAF was very firmly targeting the civilian market. Thus whenever we wanted a change, GAF would consider its effect on the civilian aircraft, ie whether to include the mod at extra cost, or to have two build standards - also at extra cost. Or to try and reject the mod. As a result many of our desired mods were not incorporated.
I am now based in India and don't have my test report here. But from memory basically I thought the aircraft had a lot of potential but had a large number of problems, all of which were fixable with time and effort. Unfortunately this was not applied.
STOL performance was very important to the Army and the Nomad was quite good. I described it as like landing into a bowl of soggy pudding mix - ground roll I recall at about 400-ft. Except that the early brake pedals were designed to blow the tyres on landing - which I did, both of 'em once.
The two crashes - Mansfield and Avalon - were not really aircraft faults, but human errors.
The one at Mansfield was caused by a twin engine failure as a result of intake icing. There was nothing wrong with the de-icing system - it just was not fitted and the aircraft was not cleared for flight in forecast icing conditions. Nevertheless the aircraft was being flown in icing conditions and guess what? Even then, the aircraft could have force-landed with just minor damage in a large open field straight ahead at cloud break. Instead, Stuart tried to land on a narrow road bordered by tress and overshot his touchdown and had to try and negotiate a dogleg through a railway level crossing. Score - level crossing 1, Nomad 0. Very luckily no one was injured although some patrons at a pub were somewhat surprised as he went past the front door. You could talk to Peter Reddel (ex-Cathay) who was RHS and had a full head of hair prior.
The N24 tailplane tests were pretty cavalier. Try one thing and if it doesn't work try another. I am not sure who was more to blame, the design or flight test depts. The fatal flight took off on the short cross runway at Avalon and encountered unmistakable flutter at about 800-ft. Some may not understand the significance of flutter. It is not just a vibration in a part of the airframe. Flutter is a structural instability that within seconds will likely cause a major airframe failure - e.g. loss of wing, empennage, fuselage break-up. Answer was to reduce speed and put the aircraft on the ground ASAP - any ground. Pat Larcey - the FTE and only survivor - immediately grabbed a parachute and was halfway to the door when Stuart said it was OK he'd got it. Pat had just enough height to jump out, but returned to his seat and strapped in. Stuart, instead of landing straight ahead in an open field, tried to complete a circuit back to the takeoff runway but only got halfway there before complete control was lost and he crashed beside the main runway. Stuart died instantly from a ruptured aorta but David Hooper (design) was ejected through the front windscreen still strapped in his seat and died sometime later. As I recall there was something wrong with the seat. Pat's station in the cabin was at the CG and, as they hit, he suffered a severe vertical deceleration causing paraplegia.
Sure the N24 had some stability problems but they did not cause the accident. Nor did flutter problems - which were introduced by the players. Once flutter occurred, the severity of the situation was exacerbated by poor handling by the pilot.
So, the main causal factor in both these accidents was human error rather than aircraft design deficiency.
In summary. my experience with the Nomad was that it was a potentially good aircraft, both for the military and civilian market, but development of which was screwed by a dysfunctional management system.
The same book had a rather interesting first-hand description of an aborted go-around that gives the impression it pretty much destroyed the aircraft, but if it was this one (see- below, the only other RAAF incident that I can find any info about) it obviously flew again - does anyone know anything about that one?
