GBA Tri-islander Prop Blade Incident
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GBA Tri-islander Prop Blade Incident
Great Barrier flight loses propeller blade - National - NZ Herald News
Nice work by the pilot... no doubt would have been one hell of a vibration!
Nice work by the pilot... no doubt would have been one hell of a vibration!
When the pilot noticed trouble with the engine, he returned to Claris.....
Passengers wouldn't have been too aware before the return that something was amiss.....
Mob at Kingaroy used to have one but was sending the passengers deaf because they had the headset music turned up so loud to cover the engine noise.
Undaunted by technical realities, the design team at Pilatus Britten - Norman has announced plans for the BN2-XL, promising more noise, reduced payload, a lower cruise speed, and increased pilot workload.
We spoke to Mr. Fred Gribble, former British Rail boilermaker, and now Chief Project Engineer. Fred was responsible for developing many original and creative design flaws in the service of his former employer, and will be incorporating these in the new BN2-XL technology under a licensing agreement. Fred reassured BN-2 pilots, however, that all fundamental design flaws of the original model had been retained. Further good news is that the XL version is available as a retrofit.
Among the new measures is that of locking the ailerons in the central position, following airborne and simulator tests which showed that whilst pilots of average strength were able to achieve up to 30 degrees of control wheel deflection, this produced no appreciable variation in the net flight of the aircraft. Thus the removal of costly and unnecessary linkages has been possible, and the rudder has been nominated as the primary directional control. In keeping with this new philosophy, but to retain commonality for crews’ transitioning to the XL, additional resistance to foot pressure has been built in to the rudder pedals to prevent over-controlling in gusty conditions (defined as those in which wind velocity exceeds 3 knots).
An outstanding feature of Islander technology has always been the adaptation of the O-540 engine which, when mounted in any other aircraft in the free world (except the Trislander) is known for its low vibration levels. The Islander adaptations cause it to shake and batter the airframe, gradually crystallise the main spar, desynchronise the accompanying engine, and simulate the sound of fifty skeletons fornicating in an aluminium dustbin. PBN will not disclose the technology they applied in preserving this effect in the XL but Mr. Gribble assures us it will be perpetrated in later models and sees it as a strong selling point. "After all, the Concorde makes a lot of noise" he said, "and look how fast that goes."
However design documents clandestinely recovered from the PBN shredder have solved a question that has puzzled aerodynamicists and pilots for many years, disclosing that it is actually noise which causes the BN2 to fly. The vibration set up by the engines, and amplified by the airframe, in turn causes the air molecules above the wing to oscillate at atomic frequency, reducing their density and creating lift. This can be demonstrated by sudden closure of the throttles, which causes the aircraft to fall from the sky. As a result, lift is proportional to noise, rather than speed, explaining amongst other things the aircraft's remarkable takeoff performance.
In the driver's cab (as Gribble describes it) ergonomic measures will ensure that long-term PBN pilots' deafness does not cause in-flight dozing. Orthopaedic surgeons have designed a cockpit layout and seat to maximise backache, en-route insomnia, chronic irritability, and terminal (post-flight) lethargy. Redesigned "bullworker" elastic aileron cables, now disconnected from the control surfaces, increase pilot workload and fitness. Special noise retention cabin lining is an innovation on the XL, and it is hoped in later models to develop cabin noise to a level which will enable pilots to relate ear-pain directly to engine power, eliminating the need for engine instruments altogether.
We were offered an opportunity to fly the XL at Britten-Norman's development facility, adjacent to the British Rail tearooms at Little Chortling. (The flight was originally to have been conducted at the Pilatus plant but aircraft of BN design are now prohibited from operating in Swiss airspace during avalanche season). For our mission profile, the XL was loaded with coal for a standard 100 N.M. trip with British Rail reserves, carrying one pilot and nine passengers to maximise discomfort. Passenger loading is unchanged, the normal under-wing protrusions inflicting serious lacerations on 71% of boarding passengers, and there was the usual confusion in selecting a door appropriate to the allocated seat. The facility for the clothing of embarking passengers to remove oil slicks from engine cowls during loading has been thoughtfully retained.
Start-up is standard, and taxiing, as in the BN2 is accomplished by brute force. Takeoff calculations called for a 250-decibel power setting, and the rotation force for the (neutral) C of G was calculated at 180 ft/lbs. of backpressure.
Initial warning of an engine failure during takeoff is provided by a reduction in vibration of the flight instrument panel. Complete seizure of one engine is indicated by the momentary illusion that the engines have suddenly and inexplicably become synchronised. Otherwise, identification of the failed engine is achieved by comparing the vibration levels of the windows on either side of the cabin. (Relative passenger pallor has been found to be an unreliable guide on many BN2 routes because of ethnic consideration).
Shortly after takeoff the XL's chief test pilot, Capt. Mike "Muscles" Mulligan demonstrated the extent to which modern aeronautical design has left the BN2 untouched; he simulated pilot incapacitation by slumping forward onto the control column, simultaneously applying full right rudder and bleeding from the ears. The XL, like its predecessor, demonstrated total control rigidity and continued undisturbed. Power was then reduced to 249 decibels for cruise, and we carried out some comparisons of actual flight performance with graph predictions. At 5000 ft and ISA, we achieved a vibration amplitude of 500 CPS and 240 decibels, for a fuel flow of 210 lb/hr, making the BN2-XL the most efficient converter of fuel to noise after the Titan rocket.
Exploring the Constant noise/Variable noise concepts, we found that in a VNE dive, vibration reached its design maximum at 1000 CPS, at which point the limiting factor is the emulsification of human tissue. The catatonic condition of long-term BN2 pilots is attributed to this syndrome, which commences in the cerebral cortex and spreads outwards. We asked Capt. Mulligan what he considered the outstanding features of the XL. He cupped his hand behind his ear and shouted "Whazzat?"
We returned to Britten-Norman convinced that the XL model retains the marque's most memorable features, whilst showing some significant and worthwhile regressions.
PBN are not, however, resting on their laurels. Plans are already advanced for the Trislander XL and noise tunnel testing has commenced. The basis of preliminary design and performance specifications is that lift increases as the square of the noise, and as the principle of acoustic lift is further developed, a later five-engined vertical take-off model is also a possibility."
All in all, a wonderful aeroplane.
We spoke to Mr. Fred Gribble, former British Rail boilermaker, and now Chief Project Engineer. Fred was responsible for developing many original and creative design flaws in the service of his former employer, and will be incorporating these in the new BN2-XL technology under a licensing agreement. Fred reassured BN-2 pilots, however, that all fundamental design flaws of the original model had been retained. Further good news is that the XL version is available as a retrofit.
Among the new measures is that of locking the ailerons in the central position, following airborne and simulator tests which showed that whilst pilots of average strength were able to achieve up to 30 degrees of control wheel deflection, this produced no appreciable variation in the net flight of the aircraft. Thus the removal of costly and unnecessary linkages has been possible, and the rudder has been nominated as the primary directional control. In keeping with this new philosophy, but to retain commonality for crews’ transitioning to the XL, additional resistance to foot pressure has been built in to the rudder pedals to prevent over-controlling in gusty conditions (defined as those in which wind velocity exceeds 3 knots).
An outstanding feature of Islander technology has always been the adaptation of the O-540 engine which, when mounted in any other aircraft in the free world (except the Trislander) is known for its low vibration levels. The Islander adaptations cause it to shake and batter the airframe, gradually crystallise the main spar, desynchronise the accompanying engine, and simulate the sound of fifty skeletons fornicating in an aluminium dustbin. PBN will not disclose the technology they applied in preserving this effect in the XL but Mr. Gribble assures us it will be perpetrated in later models and sees it as a strong selling point. "After all, the Concorde makes a lot of noise" he said, "and look how fast that goes."
However design documents clandestinely recovered from the PBN shredder have solved a question that has puzzled aerodynamicists and pilots for many years, disclosing that it is actually noise which causes the BN2 to fly. The vibration set up by the engines, and amplified by the airframe, in turn causes the air molecules above the wing to oscillate at atomic frequency, reducing their density and creating lift. This can be demonstrated by sudden closure of the throttles, which causes the aircraft to fall from the sky. As a result, lift is proportional to noise, rather than speed, explaining amongst other things the aircraft's remarkable takeoff performance.
In the driver's cab (as Gribble describes it) ergonomic measures will ensure that long-term PBN pilots' deafness does not cause in-flight dozing. Orthopaedic surgeons have designed a cockpit layout and seat to maximise backache, en-route insomnia, chronic irritability, and terminal (post-flight) lethargy. Redesigned "bullworker" elastic aileron cables, now disconnected from the control surfaces, increase pilot workload and fitness. Special noise retention cabin lining is an innovation on the XL, and it is hoped in later models to develop cabin noise to a level which will enable pilots to relate ear-pain directly to engine power, eliminating the need for engine instruments altogether.
We were offered an opportunity to fly the XL at Britten-Norman's development facility, adjacent to the British Rail tearooms at Little Chortling. (The flight was originally to have been conducted at the Pilatus plant but aircraft of BN design are now prohibited from operating in Swiss airspace during avalanche season). For our mission profile, the XL was loaded with coal for a standard 100 N.M. trip with British Rail reserves, carrying one pilot and nine passengers to maximise discomfort. Passenger loading is unchanged, the normal under-wing protrusions inflicting serious lacerations on 71% of boarding passengers, and there was the usual confusion in selecting a door appropriate to the allocated seat. The facility for the clothing of embarking passengers to remove oil slicks from engine cowls during loading has been thoughtfully retained.
Start-up is standard, and taxiing, as in the BN2 is accomplished by brute force. Takeoff calculations called for a 250-decibel power setting, and the rotation force for the (neutral) C of G was calculated at 180 ft/lbs. of backpressure.
Initial warning of an engine failure during takeoff is provided by a reduction in vibration of the flight instrument panel. Complete seizure of one engine is indicated by the momentary illusion that the engines have suddenly and inexplicably become synchronised. Otherwise, identification of the failed engine is achieved by comparing the vibration levels of the windows on either side of the cabin. (Relative passenger pallor has been found to be an unreliable guide on many BN2 routes because of ethnic consideration).
Shortly after takeoff the XL's chief test pilot, Capt. Mike "Muscles" Mulligan demonstrated the extent to which modern aeronautical design has left the BN2 untouched; he simulated pilot incapacitation by slumping forward onto the control column, simultaneously applying full right rudder and bleeding from the ears. The XL, like its predecessor, demonstrated total control rigidity and continued undisturbed. Power was then reduced to 249 decibels for cruise, and we carried out some comparisons of actual flight performance with graph predictions. At 5000 ft and ISA, we achieved a vibration amplitude of 500 CPS and 240 decibels, for a fuel flow of 210 lb/hr, making the BN2-XL the most efficient converter of fuel to noise after the Titan rocket.
Exploring the Constant noise/Variable noise concepts, we found that in a VNE dive, vibration reached its design maximum at 1000 CPS, at which point the limiting factor is the emulsification of human tissue. The catatonic condition of long-term BN2 pilots is attributed to this syndrome, which commences in the cerebral cortex and spreads outwards. We asked Capt. Mulligan what he considered the outstanding features of the XL. He cupped his hand behind his ear and shouted "Whazzat?"
We returned to Britten-Norman convinced that the XL model retains the marque's most memorable features, whilst showing some significant and worthwhile regressions.
PBN are not, however, resting on their laurels. Plans are already advanced for the Trislander XL and noise tunnel testing has commenced. The basis of preliminary design and performance specifications is that lift increases as the square of the noise, and as the principle of acoustic lift is further developed, a later five-engined vertical take-off model is also a possibility."
All in all, a wonderful aeroplane.
Seasonally Adjusted
Good thing the blade didn't end up in the cabin.
I wonder if this was VH-MRJ, the Trilander that Murchison Relines once operated in WA.
If my memory serves me correctly, with 10 pax on board, all 3 engines need to be producing power.
I wonder if this was VH-MRJ, the Trilander that Murchison Relines once operated in WA.
If my memory serves me correctly, with 10 pax on board, all 3 engines need to be producing power.
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Passengers wouldn't have been too aware before the return that something was amiss
Depending on what runway was in use, when it let go and what the wind strength was it could have been VERY interesting.
Good job getting it down in one peice, That pilot earned his/her $80 for the day.
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Hey ya TQ, thats the old gal. she was the last one in Australia too. none left....... thank Christ/Allah/Budah.....(insert your own deity) . I remember that the old bucket required full noise with eight and bags.........and noise was something it produced without a problem. I think the Ricaro seat was about the best feature in the damn aircraft. I could never get used to the deck angle and height from the ground that the pilot sat when it touched down and lifted off..... was a little eye opening to arrive rather suddenly while still sitting 15 ft off the ground. 
Tri
Sounds real lucky the prop did not go thru the cabin. There is still a whole nest of these things in the Channel Islands doing similar stuff. Great fun watching 15 pax climb thru numberous doors into the beast The Pilots are mostly semi retired grumpy old gits on about 40 000 quid a year who feel no need to move on, its a good gig. But i digress not a prop but just the de icing boot came into the cabin one day and took out one of the Passengers fingers, much to his chargrin. So things can get quite nasty. The airports are the highest part of the Islands which was the key to their success, since a climb segment was optional! The engine out performance was dire and one Pilot just landed on the beach rather than risk a circuit on two. But the local Pax loved them as chock to chock they are faster than a Turboprop on a short sector and they are very cheap efficient transport. Sounds like this Pilot did a great job, long live the mighty tri!
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Actually have a whole 3 hours ICUS on the Tri. Hated the damn thing!
I was supposed to get endorsed on them eventually but the company went bagarup before it happened.
Most of the blokes in the company that flew then did'nt mind them though, so I suppse that I would have become used to it. Sad it did'nt happen then, I guess.
I was supposed to get endorsed on them eventually but the company went bagarup before it happened.
Most of the blokes in the company that flew then did'nt mind them though, so I suppse that I would have become used to it. Sad it did'nt happen then, I guess.
I've got about 250 hours on the trislanders and maybe 600 on Islanders and I found the trislanders much more pleasant (if you can call it that) to fly. More stable, a touch faster and if possible quieter up front if no where else!
I reckon they are not a bad machine - just fill her to the brim and away you go. Admittedly I have no experience on Otters or Caravans to compare it to, just the Nomad, and for what we used it for the Trislander was much better than the Nomad.
I reckon they are not a bad machine - just fill her to the brim and away you go. Admittedly I have no experience on Otters or Caravans to compare it to, just the Nomad, and for what we used it for the Trislander was much better than the Nomad.
"...she was the last one in Australia too."
Both Trislanders were ex Aerial Tours/Douglas Airways in Port Moresby, then Cape York Air in Cairns. I have a feeling Dennis Douglas may have originally purchased them from Bush Pilots in Cairns?
I thought both Trislanders had very few cycles or hours left on the wing - or did someone turn the clock back?
The Trislanders in the Channel Islands are a little different - they are the long nose variant, a better balanced machine. There was also a very unique long nose Islander in Australia.
There is or was also 8 to 10 new Trislander airframes somewhere in Australia, bought from Britten Norman many years ago with the intention of installing two V8 engine conversions, rather than three Lycoming 540s.
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Always brought on a cold sweat when you picked up the roster and saw that you were sentenced to a Gulf run in a BN-3. Out of POM with 18 pob meant not reaching 4,000 until 28DME. Damn thing only ever got airborne because the earth is round
. Made the BN-2 look like a sports car on steroids.
Had an upside though. Remember a certain senior pilot who couldn't start No 2. Threw the pax off, took off on 2 engines, did an air start on No 2, landed, left it running, picked up the pax and departed. Ol' Biscuit gave him a few extra Kina that week; mind you given where he was a overnight would have been shi**y to say the least.
Fondest memory of the BN-3 was hearing those two words wispered that made you want to wet yourself with pleasure; sorry mate, she's tech!!
. Made the BN-2 look like a sports car on steroids.Had an upside though. Remember a certain senior pilot who couldn't start No 2. Threw the pax off, took off on 2 engines, did an air start on No 2, landed, left it running, picked up the pax and departed. Ol' Biscuit gave him a few extra Kina that week; mind you given where he was a overnight would have been shi**y to say the least.
Fondest memory of the BN-3 was hearing those two words wispered that made you want to wet yourself with pleasure; sorry mate, she's tech!!
Tri trivia
Yeah Torres the Pom ones had the long nose, took quite a few bags there too. And it was mostly cold and there were 15-30 min sectors for the most part, so a good machine for the job. Biccie used to sentence miscreant pilots to the Gulf run in them
( as you would). Then he realised they found it a much easier and less terrifying way of logging hours than flogging an Islander round in the mountains and gave up. May have been the same senior Pilot legend has it leapt up on the back of the Fuse to swing start nu 2. If so he must have really really not wanted to overnight that would be dodgy.
( as you would). Then he realised they found it a much easier and less terrifying way of logging hours than flogging an Islander round in the mountains and gave up. May have been the same senior Pilot legend has it leapt up on the back of the Fuse to swing start nu 2. If so he must have really really not wanted to overnight that would be dodgy.
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Seems like everyone is testing the memory here so I will have a go with my version of them. I believe the name was BN-2A Mk III Trislander, and there three different variants, long and short nose and then the FAA certified variety with auto-feather.
The CAA certified machines used the same 25 hundred rpm box to activate the rear engine failure warning light, when armed. I think all memories will concur it was a crude and debatablly effective method of alerting the pilot. From memory the mirror was of more use during start.
I believe about 78 were produced and I have been involved in one way or another with many of them. Did some hours flying them and was involved in maintenance in a few countries, including the Guernsey based machines.
The Trislander is one of those machines that performed well in the right conditions, and yes the Channel Islands seemed ideal for them. Even the long nose could be effectively utilised carrying flowers.
Of course hot and high in places like Lake Kariba were not so ideal.
I can recall a saying of that era..... If you can make money operating an Islander then you will be creaming it with a Trislander. Very little extra operating cost for an extra 6 to 8 seats, the cargo hold could seat two kiddies.
I seem to recall Aurigney operating Single Pilot IFR with 17 pax in them, - perhaps someone may have some comments there also.
As others have noted, they fly completely differently than the Islander, but then again they are for a different operation...... generally. The Islander will get in and out of almost any strip, - you had to be a little more selective when operating the Trislander.
Where are the ones rumoured to be be in Aussie, - weren't they basically new airframes ?
The CAA certified machines used the same 25 hundred rpm box to activate the rear engine failure warning light, when armed. I think all memories will concur it was a crude and debatablly effective method of alerting the pilot. From memory the mirror was of more use during start.
I believe about 78 were produced and I have been involved in one way or another with many of them. Did some hours flying them and was involved in maintenance in a few countries, including the Guernsey based machines.
The Trislander is one of those machines that performed well in the right conditions, and yes the Channel Islands seemed ideal for them. Even the long nose could be effectively utilised carrying flowers.
Of course hot and high in places like Lake Kariba were not so ideal.
I can recall a saying of that era..... If you can make money operating an Islander then you will be creaming it with a Trislander. Very little extra operating cost for an extra 6 to 8 seats, the cargo hold could seat two kiddies.
I seem to recall Aurigney operating Single Pilot IFR with 17 pax in them, - perhaps someone may have some comments there also.
As others have noted, they fly completely differently than the Islander, but then again they are for a different operation...... generally. The Islander will get in and out of almost any strip, - you had to be a little more selective when operating the Trislander.
Where are the ones rumoured to be be in Aussie, - weren't they basically new airframes ?
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torres, I don't know what happened to the sister ship. It was rumored to have gone into a box and shipped off to Unzud as well. I do know that Juliet was the last of them though, as there was a bit of a fanfare about her being the last of her kind in country. I still have photos of her just before the departure. I also have bad memories of rowdy crowds of reline crews playing ball in the back... the pitch changes were eye opening to say the least.
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Torres...I also remembered the all white Trislander based out of YMMB some 10ish years ago doing freight runs to Tassie and Bass Straight Islands. Trying to remember the guy who owned/operatored it????
Wiz.
Perchance ... were you the pilot with Murchison when they bought that aircraft? Did you pick it up from Alice Springs or Urulu by any chance......?
Baron.
Surprisingly, at one time the BN2 Islander and BN2A Mk III Trislander were a common pilot type endorsement in Australia.
I'm guessing here but I think Cape York Air sold both aircraft around 1996 or 1997. They were auctioned off and sold for around $325,000 each. Both aircraft had very limited life, either cycles or hours, I don't remember.
Rumour had it that the crated new air frames were on the NSW north coast, but that would be at least 15 years ago.
Bikkies had a third aircraft which sat derelict at Port Moresby for many years. Last I heard (over a decade ago) it had been restored and was heading to Australia but I guess never made it.
The only reason I keep track of those aircraft is to ensure I never again get any where near the things......
Perchance ... were you the pilot with Murchison when they bought that aircraft? Did you pick it up from Alice Springs or Urulu by any chance......?
Baron.
Surprisingly, at one time the BN2 Islander and BN2A Mk III Trislander were a common pilot type endorsement in Australia.
I'm guessing here but I think Cape York Air sold both aircraft around 1996 or 1997. They were auctioned off and sold for around $325,000 each. Both aircraft had very limited life, either cycles or hours, I don't remember.
Rumour had it that the crated new air frames were on the NSW north coast, but that would be at least 15 years ago.
Bikkies had a third aircraft which sat derelict at Port Moresby for many years. Last I heard (over a decade ago) it had been restored and was heading to Australia but I guess never made it.
The only reason I keep track of those aircraft is to ensure I never again get any where near the things......
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Passengers wouldn't have been too aware before the return that something was amiss," Mr Rea said. "They're quite a noisy aeroplane anyway - it's like a bus to the Great Barrier."
"It was like an explosion going off inside the plane," one told the Herald yesterday.
"The propeller came off and hit the side of the plane ...
"Both propeller blades came off - the whole thing just destroyed itself. It just completely self-destructed.
"A door got ripped off and the side of the plane got smashed in - we all got covered in glass.
"There was a huge amount of debris that we were just covered in. There were chunks the size of golfballs that came back and hit you."
"The propeller came off and hit the side of the plane ...
"Both propeller blades came off - the whole thing just destroyed itself. It just completely self-destructed.
"A door got ripped off and the side of the plane got smashed in - we all got covered in glass.
"There was a huge amount of debris that we were just covered in. There were chunks the size of golfballs that came back and hit you."
Not too sure about the "bus" comment either
Maybe he should enrol in Marketing 101 at the open polytech