The Official Newsletter of THE AUSTRALIAN VINTAGE
Transcription
The Official Newsletter of THE AUSTRALIAN VINTAGE
CONTACT The Official Newsletter of THE AUSTRALIAN VINTAGE AVIATION SOCIETY Issue 1 March 2012 www.tavas.com.au W elcome to our first ever newsletter dedicated to the re-creation and preservation of true vintage aircraft - in particular aircraft that flew prior to, or during, WW1. So why the need for this organisation? – Many people consider all pre WW2 aircraft to be ‘vintage aircraft’ and in many respects think all vintage aircraft to be much the same. However there is such a huge difference in aircraft design, construction and handling prior to the end of WW1, that is not so well known about today, that needs to be re-learnt or at least understood in detail to be able to create replicas that are safe and enjoyable to fly. In the decade that followed the Wright Brothers flight in a heavier than air powered aircraft, aeroplane development was characterized by a proliferation of types, conceived by inventors of varying degrees of competence. And for the most part, all of these aircraft were home builts in the truest sense. A few of these aircraft flew moderately well, some poorly, and some not at all. There was little scientific and engineering foundation for aircraft design, and many aircraft built during this period were constructed by nontechnical people as amateur, backyard−type projects. Bleriots crossing of the English channel in 1909 demonstrated to some the true potential of aviation and many of his aircraft were ordered creating the beginnings of a cottage industry aircraft assembly plant. However many people still regarded flying as something of a novelty or a curiosity. That attitude changed shortly after the outbreak of WW1 and the use of aircraft became obvious. As needs and tactics changed, combat aviation developed and the need for better performing, role specific aircraft became apparent and was met. CONTACT – Issue 1 Editor: Andrew Carter Literally hundreds of aircraft prototypes were built and flown over that 4 year period. A multitude of types were tested in combat. The prototype of a fighter aircraft could be designed, constructed, and test flown within a period of a few weeks. Although the designers overcame a huge learning curve in that short time, there was still so much more to learn. So there is no real comparison between the aircraft built from the 1930’s on, to the aircraft built and flown from 1903 – 1920. That was the single biggest learning curve in aviation design, construction and power plants, until the advent of the jet engine some 25 years later. Remember that the DH82 Tigermoth – the aircraft many people would be familiar with and think of when you mention Vintage aviation - came about in 1931 and was Geoffrey Dehavilands 82nd design (and at least the 42nd one of his designs that was built and flown), using all the experience he had learnt since building his first aircraft in 1909 (which he crashed on his first flight!). He knew a hell of a lot more about aerodynamics and structures in 1931, than he (or anyone else) did during World War One. Pre 1920 aircraft are unique in the world of aviation and this organisation aims to help educate and inform anyone with any interest in this period, in particular builders and flyers of replicas, for them to better understand the complexities and quirks and to gain a greater appreciation of the people who both designed and flew these aircraft at a time when aviation was experiencing its initial growing pains. The purpose of this organisation is to bring together all the like minded people who share a common interest and encourage more people to build and fly WW1 replicas and to share information and skills. So in each issue we plan to cover a current build and a current flying project. Over coming issues, we will also look at various power plants available for use and what characteristics they have. www.tavas.com.au Page 1 Pooling skills and information, makes it easier for people building projects or wanting to start one, to succeed in the quickest time with the least frustration - rather than having to spend ages searching out the correct information and people, like Chris Shepherd had to with his unique Albatros D.Va build, which we cover in detail in this issue. IN THIS ISSUE Greeting from the Editor Chris Shepherds Albatros D.Va build Fighter Comparison Albatros vs Nieuport From the cockpit – Sopwith Pup replica Pg 1 Pg 2 Pg 7 Pg 8 Also in this issue we speak to Dave Marshall about flying his Sopwith Pup replica. We have big aims and long term goals for this organisation which you can read about on our website, but it all begins with getting more people building & flying replicas of these incredible aircraft – and that is what we plan to do. Help us keep our members informed of current build projects and flying examples around Australia by sending details to us at info@tavas.com.au Chris Shepherds beautiful Albatros D.Va build in its new home – read article below for full details. Andrew Carter Founding Director TAVAS CHRIS SHEPHERDS ALBATROS D.VA BUILD First, a brief history of Albatros aircraft The Albatros Werke began to build airplanes in 1910. In 1916, they began building an incredibly advanced fighter design, the D.I. Small improvements to that design to improve visibility for the pilot ended up as the D.II, powered by the Mercedes water cooled 160 hp engine. With further refinements, the D.III was introduced in 1917. The D.IV was produced with a more rounded fuselage (the earlier models had all been flat sided) and was fitted with an experimental geared version of the Mercedes which proved to be problem ridden and so no production run of that aircraft was ever ordered. The D.V was released shortly after, with the rounded fuselage of the D.IV, but with wings very similar to the D.III. It was originally fitted with the 160 hp engine, but this was soon replaced with a Mercedes 180 hp. This aircraft suffered a spate of upper wing spar failures, usually during high speed dives. This was CONTACT – Issue 1 due to the single spar being located well behind the quarter−chord point (the approximate location of the aerodynamic center in the chordwise direction). This spar location caused aeroelastic divergence, a phenomenon apparently not understood at the time the Albatros fighters were developed. An increase in torsional stiffness or a relocation of the wing elastic axis, or combining both, would have cured that. www.tavas.com.au Page 2 They attempted to fix the problem, by strengthening the ribs and spars and reinforcing the fuselage. This resulted in the aircraft re-designation, D.Va. These remained in production until April 1918, but were flown in combat right up till the end of the war. Many of the highest-scoring German aces achieved the majority of their victories while flying Albatros fighters. Although the Red Baron, Manfred von Richthofen, is most often associated with the Fokker Triplane, he actually won three-quarters of his 80 combat victories in Albatros aircraft. Approximately 4,800 Albatros fighters of all types were built during World War One, with 1,612 of those being the D.Va. Yet despite such high numbers having been produced, only 2 original Albatros D.Va exist today. One at the Smithsonian National Air and Space Museum in Washington D.C. and the other at our very own Australian War Memorial (AWM) in Canberra. official hours gliding in the Air Training Corp and a few dozen hours with the Sydney Aerobatic School. His father Lloyd was, until recently, a pilot with Qantas and had flown a Sopwith Pup replica on occasions. He had also built an Acro Sport II and rebuilt 2 Piper Pacers over the years. So with that background, some solid family support and a strong interest in World War One aircraft, it was no surprise that Chris decided to build his own WW1 fighter. What was a surprise is the subject matter he chose was possibly the most difficult he could have selected – especially given this is the first aircraft he has ever built. The idea came to him after a visit to the Australian War Memorial (AWM) in Canberra more than 30 years ago, where he first saw the Albatros. Chris (like most of us) decided he wanted one and (unlike most of us) decided 20 years later to build one for himself. Thus began a long time research project, obtaining all drawings and information he could find on the subject. Some of it, like the National Air and Space museums book on restoring their D.Va, was very good, but the majority of it was not. He made many parts based on flawed drawings only to find later that they weren’t accurate and most of those parts subsequently had to be thrown away. This included an entire set of lower wing ribs and almost all of the original fourteen fuselage bulkheads. One of only 2 surviving D.Va’s. This one resides in the Smithsonian Air and Space Museum in Washington. The Vintage Aviator Limited (N.Z.) has produced 2 extremely accurate reproductions and Col Palen’s Old Rhinebeck (U.S.A) has a Ranger engine powered example, but very few others exist due to the complex elliptical cross-sectioned, semi-monocoque fuselage construction and lack of suitable engines. Despite those difficulties, one man on the NSW Central Coast, is in the process of creating his own flying replica Albatros D.Va. In 2006, the D.Va was removed from general exhibition at the AWM for restoration. Through the very helpful John White, Chris was granted access to the actual aircraft during that time. Using measurements and photos he took during those visits and combining that information with the very accurate Bob Waugh drawings, Chris was finally on his way to creating his dream as accurate to the original as he could. Chris Shepherd – is a 40 year old, school teacher whose interest, patience and perseverance has seen him ride a steep learning curve and produce a magnificent looking build of one of the most unique looking aircraft of WW1. He has been around aircraft for most of his life but with little active involvement other than a few CONTACT – Issue 1 The only other original surviving D.Va. This one at the Australian War Memorial where it was undergoing restoration and Chris had access to it at that time. www.tavas.com.au Page 3 Fuselage construction. The fuselage has been built in a 2 car garage, so not a lot of room for elaborate jigs and molds. Chris was able to make a small jig using a series of wooden sawhorses and a long rectangular frame like a ladder. This was leveled and then nailed to the floor with cross bracing to help counter any twisting at a later date. With the centreline longerons cut into the bulkheads and using a long line on the floor it wasn’t hard to drop a plumb bob at each frame. Once happy with the positioning, Chris used a nail gun to drive blocks either side of the longeron where it crosses the ladder cross members. Where needed, he used small packers tucked under the longerons to ensure they were level. The main reason he constructed the fuse this way is that he could then still lift the fuselage up (and with some helpers) remove the cross members and re-jig the fuselage upside down to skin the lower side. The cross members then support the longerons in the same way. in temperature and humidity resulted in the wood skins swelling and distorting in the rearmost, and unfixable, bottom corner panel where they had been glued to the formers. The following day, Chris had to take to it with a hammer and chisel and remove the skin from that side and start again. Lesson Learnt – don’t change what works the first time. During the war, Germans skinned the D.Va mainly with 2mm and 1.5mm ply. Chris has used 3mm ply from the engine bay to aft of the cockpit and then 2mm ply from there back to the tail where it becomes 1.5mm. This was done for longevity and as a safety measure given the many images Chris had seen of DVa’s with broken backs after a hard landing Also the type of wood used in the build differs slightly, while the Germans used Birch and Adler pine, Chris has used Douglas Fir and Hoop Pine. The types of glues differ too, with some interesting consequences. The German glues required that small nails were used every 25mm on average, to hold the skins together and to the bulkheads. Modern day epoxy is much stronger or at least better bonding and as a result, the nails aren’t needed. But as Chris says, “It just doesn’t look like an Albatross without the nails”, so he has put them in – all 2000+ of them! Fuselage on the move The simplified jig Chris created to mount the bulkheads and begin his build. What makes this story even more interesting is that late last year Chris moved house, which meant having to move a nearly completed fuselage as well, from the deck of his shed - 20 meters above the road, surrounded by trees and power lines! Sounds simple in theory, but like all these things, provides challenges in practice. The wood skins don’t actually join on the bulkheads, but behind them. Chris started planking one side from the rear of the fuselage forward, gluing it with epoxy. This proved quite successful, but Chris decided to see if he could create one complete skin and sheet the other side in one go. He spent considerable time measuring and cutting each panel and trial fitting it, before gluing it all together over an 8 day period, to form one large correctly curved skin. On the day he fitted that skin, the weather went from cool and mild, to hot and humid, before resulting in a thunderstorm. The rise CONTACT – Issue 1 The man in his machine – Chris Shepherd and his D.Va in the work shed 20 meters above the road. www.tavas.com.au Page 4 He wrapped the entire fuselage in plastic in case it rained and mounted it on wooden wheels and pushed it out onto the deck. Waters Cranes tuned up on a day when unfortunately the winds were blowing up to 40km an hour. The slings were attached to the undercarriage and tail, then the lift began. Despite the strong winds and multiple obstacles, the crane operator lowered the aircraft onto the road not only without a scratch, but without even disturbing a gum leaf on the way down. Chris and his wife were so impressed with the skilled operation they both gave a standing ovation followed by a ‘Wayne’s World – we’re not worthy’ bow. The entire operation from the time the crane arrived to the time it left was only 45 minutes. The fuselage was then trailered to Chris’s fathers’ hangar at Wedderburn airfield (a careful 2 hour drive south). Once Chris and his family moved into their new house and settled, Chris had to trailer the aircraft to its new location where he will complete it. He says it was a most interesting journey avoiding wandering semi trailer drivers trying to take photos out of their left window on mobile phones! A short stop was made about 10 minutes from home to prepare mentally for the 1km long bush track driveway, whereupon the aircraft attracted the attention of a mini-bus load of young women who stopped to have their photo taken in front of the Maltese cross painted “Spitfire”…... yes folks, they called it a “Spitfire”. Wing construction The deck outside the shed, The crane in place & ready 20 meters above the road. for the delicate operation. The plastic covered fuse being lifted off the decking. On the trailer just before being driven to Wedderburn CONTACT – Issue 1 Lower wing construction is coming along (see picture next page). Ribs are made for the other lower wing and top wing which he hopes to have finished by the end of the year. With a wingspan of 9.05 metres (29.75 feet), this will certainly take up a considerable amount of space in Chris’ shed. The wing structure is based around a single main spar and two auxiliary spars. The ribs are ply rather than the original planks of solid linden wood, with ash cap strips. Generally the structure is very lightly built and with a single spar it is somewhat flexible. The leading edge is sheeted in 1.5mm ply which ties the very complicated (cambered and washed out) wingtip bow, to the wing itself. A single bolt and housed pin secure the spar to the fuselage although Chris will also use a 1917 variation that provides for a second bolt to secure the leading edge. The original aircraft was reported to suffer from lower wing failures and modern structural www.tavas.com.au Page 5 analysis reports flutter to be a significant risk, even within the upper operational speed of the aircraft. Chris is planning to add additional mass to the inside of the leading edge to preclude flutter from occurring at such speeds. as they don’t look like the original, he will most likely swap or sell them and get one that is more accurate. He just needs to cover the seat cushion and then it and the finished controls can all be installed, while waiting for the aluminium and phenolic pulley sheaves to be manufactured. The fuel tank has been built and requires welding before being installed with all of the plumbing. The tank is built from aluminium rather than soldered brass sheet, not because of cost but rather serviceability and sturdiness. Engine Original Mercedes D.III engines aren’t easy to come by and many of the aero engines available for this type of aircraft either don’t have enough power or enough torque to turn an accurate propeller and provide the critical performance equivalent to the original D.Va. So after a lot of research, Chris settled on a converted auto engine, the Chevrolet 292. The interior of the D.Va at this stage. It’s a 4.8 litre, straight 6 which will be fitted with an internal inline spur gearbox with a 2.17 to 1 reduction. Dyno tests performed in the USA, showed the engine produces 184 hp at 3146 rpm (1450 at the prop) and gives around 560 foot pounds torque, which will swing a full size 2800mm prop and give climb and speed performance equivalent to the D.Va’s of 1917, albeit with reverse prop rotation. To keep the look of the original Mercedes, Chris will manufacture an engine cover that will look like the exposed top of the original engine. Instruments Making the exterior look original is one thing, but many replicas fall down in authenticity with modern instruments and interiors. Chris however, is putting as much time and effort into the inside as he has with the exterior. He has obtained some original instrument cases (one believed to be from a crashed Albatros) and will either restore them or use them to create faithful replicas. He has a fuel gauge, an Airspeed meter, a brass faced altimeter and a couple of compasses, but CONTACT – Issue 1 The one question Chris is asked most is “What colour scheme will you finish it in?” The simple answer is you’ll know when you see it, because Chris hasn’t settled on a scheme yet and figures he still has plenty of time to do so, so is not rushing into it. He has expressed that he has no intention of using a well known “Aces” scheme but will use something that includes a few splashes of colour to make the green and lilac camouflage a little more visible in the circuit. Many builders are also curious to know - what does his wife think of his decade long project? She has supported him throughout (Chris reckons this is because she has blocked out how much it all costs), knowing it’s what makes him happy and that it “keeps him off the streets at night”. Congratulations Chris. This is a very impressive project, even more so as it is your first build. We will be following the completion of this project with great interest and will keep our members updated with his progress. www.tavas.com.au Page 6 FIGHTER COMPARISON Albatros Vs Both aircraft underwent many improvements and variants during the war. As a basic comparison we look here at the Albatros D.III (whose wings were interchangeable with the D.Va) and the Nieuport 17. ALBATROS D.VIII 7.33 m (24 ft 0 in) 955 kg (2,105 lb) 23.6 m² (254 ft²) 37.5 kg/m² (7.67 lb/ft²) 0.13 kW/kg (0.081 hp/lb) 94 knots NIEUPORT 17 Length: MTOW: Wing area: Wing loading: Power/weight: Max speed: One advantage was its two fixed, forward−facing 7.62mm Spandau machine guns, synchronized to fire between the revolving blades of the propeller. The Albatros fighters were among the first biplanes to be armed in this way and may be thought of as setting a trend in fighter design which was to last for the next two decades. BASIC DATA – Length: MTOW: Wing area: Wing loading: Power/weight: Max speed: Nieuport 5.80 m (19 ft 0 in) 560 kg (1,232 lb) 14.75 m² (158.8 ft²) 37.9 kg/m² (7.77 lb/ft²) 0.15 kW/kg (0.09 hp/lb) 96 knots The Albatros was a larger and heavier aircraft and not as maneuverable as the Nieuports. Its wingspan was almost 3 feet longer than the French fighter. Although the D.III was heavier, had more wing area and a more powerful engine than the Nieuport, the values of the wing loading and the power loading for the two aircraft are not greatly different. Also, the values of the zero−lift drag coefficient and the maximum lift-drag ratio are about the same. These two aircraft can therefore be considered to have about equal aerodynamic efficiency and accordingly, to exhibit about the same performance characteristics. In fact, the maximum speeds are about the same although the altitudes at which the max speeds were obtained are somewhat different. Since, for small altitude variations, the decrease in drag that accompanies the reduction in air density is about offset by the reduction in power with altitude, the speed comparison of the two aircraft is valid. The Albatross had more power than the Nieuport (160hp compared to 110), but this was not enough to offset its extra weight and so the Nieuport had a slightly better power to weight ratio. Values of the time required to climb to various altitudes are also about the same for the two aircraft at lower altitudes, however the climbing capability of the Albatros is superior to that of the Nieuport above 10 000 feet. The Albatros was a great fighter for its time, with its greatest limitation being the wing spar failure, but combat pilots learn to operate within the confines of an aircrafts weakness and play to its strengths. That, plus the heavier armament of the Albatros is no doubt responsible for the generally accepted opinion that it was a more effective fighter than a Nieuport. CONTACT – Issue 1 www.tavas.com.au Page 7 FROM THE COCKPIT SOPWITH PUP Entering service in mid 1916, the Sopwith Pup was initially a huge success and much admired by those who flew it. The Pup's light weight and generous wing area gave it a good rate of climb. Agility was enhanced by aileron surfaces being fitted on both upper and lower wings. The Pup had half the horsepower and armament of the Albatross D.III, but was much more maneuverable, especially above 15,000 ft due to its low wing loading. British Fighter Ace, James McCudden, stated that "When it came to maneuvering, the Sopwith [Pup] would turn twice to an Albatros' once ... it was a remarkably fine machine for general all-round flying. It was so extremely light and well surfaced that after a little practice one could almost land it on a tennis court.” It was this quality that made it so well suited to beginning ship borne operations of the day. The leading Australian ace of World War I, Captain Robert Little DSO, DSC, achieved nine of his 47 kills while flying the Pup with the Royal Naval Air Service. On December 1917, a Sopwith Pup pioneered Australian Naval aviation when it was successfully launched from the light cruiser HMAS Sydney. Shortly after the Wars end, eleven Pups were supplied to the Australian Flying Corps as part of the Imperial Gift. In 1921, with the formation of the RAAF, the aircraft were allotted to No 1 Flying Training School at Point Cook for use as an intermediate fighter trainer until 1930. Dave Marshalls Replica Pup. First ever aircraft landing on a moving ship Sqn Cdr E. H. Dunning landing on HMS Furious in a Sopwith Pup on the 2nd August 1917. The Sopwith Pup is significant to Australian aviation for many reasons. During WW1, it was flown by Australian Pilots in No. 5, 6 and 8 Training Squadrons of the Australian Flying Corp and in combat with Australian pilots serving in British squadrons. The first combat victory by a pilot flying the Pup was achieved by Australian Sub-Lieutenant Stanley Goble while serving with the Royal Naval Air Service on September 24, 1916. (He went on to become an Air Vice-Marshal and three-time Chief of Air Staff). CONTACT – Issue 1 In 1979 the Transavia company started construction on 2 replica Sopwith Pups. They were both built to very accurate drawings of the original, but the fuselage was contructed of welded tube instead of wood and they were both powered by Armstrong Siddeley Genet Major radial engines of 145 hp instead of the 80 hp Le Rhone radial. One of these aircraft ultimately ended up being owned by the RAAF museum at Point Cook. The other was purchased partially built by Ron Jackson in 1982. Ron started work part time on the aircraft in 1983 and finished it on October 13th 1992. The aircraft was covered with Ceconite and painted in the traditional colours of the AFC. www.tavas.com.au Page 8 Although this pilot had plenty of time on Stearmans, the much slower landing speed and desire to float on landing, meant that the Pup landed long, in the long grass and caught a hidden fence and flipped on its back, resulting in more serious damage to much of the aircraft. Despite these setbacks, Dave is very keen to get the aircraft airborne again as he states that this is an incredibly enjoyable aircraft to fly, free of vices. The Sopwith Pup at Riddell airfield At the start of Easter in 1993, Ron decided to fly the Pup to the Mangalore Airshow, however he didn’t make it. A design fault with both Pup replicas was that the fuel tank was not properly pressurised resulting in the engine ‘hiccupping’ on occasion at full power. Due to the Pup having a tail skid and no brakes, Dave says that ground handling is an issue, as it can be difficult to turn on the ground at times. Having a wing walker whilst taxing is beneficial. Taxing in any sort of cross wind is not recommended as it can be easy to ground strike a wing tip in a turn. And that’s exactly what happened that day, at that crucial moment after takeoff - and Ron went into the trees at the far end of the strip. This resulted in considerable damage to the lower wing, engine mount, undercarriage and prop. Barry Bishton repaired the aircraft and a forward facing vent was installed in the fuel tank to provide pressurisation, which fixed the engine problem. Takeoffs are relatively simple, with the aircraft easily tracking straight on the ground and there is plenty of power to get it airborne in a short distance. In fact Dave says that it does have too much power and that most flying is done at half throttle, but even then it requires some forward stick pressure to maintain straight and level as there is no elevator trim on this aircraft. With 4 ailerons, the roll rate is quick, but not twitchy. There is no adverse yaw tendency and it is light in pitch. All the controls are light and well balanced. This is a light aircraft. Even though the replica has an empty weight 100kgs heavier than the original, the MTOW is the same at 558kgs. With a wing area of 254 sq ft, this gives a very low wing loading, more in line with some ultralight aircraft. This can potentially catch people out as Dave found when he lent the Pup to a mate to fly on the 4th of Feb 2009. CONTACT – Issue 1 The pilot sits quite high in this Pup, which gives him good visibility, but more exposure to the airflow. However Dave claims you are a lot less buffeted in the cockpit of the Pup than you are in the rear seat of a Tigermoth or Stearman. The overall performance of the aircraft, as already mentioned, is more in keeping with an ultralight aircraft with slow climb, cruise and landing speeds, very similar to the original, but the RoC is higher. www.tavas.com.au Page 9 The incredible looking and great handling Sopwith Pup lined up and ready for take off at Riddells Creek Airfield All things considered, this is a very accurate looking and flying replica and is a credit to the men who built and finished it. Sadly, Ron Jackson passed away in 2009, and so the Pup has a lot of sentimental value to Dave, who will keep it flying in Rons memory. If you are interested in building your own Sopwith Pup with the least hassle and expense, you might want to consider Rob Baslees Airdrome kits, with the Sopwith Pup deluxe kit costing only US$12,495 – www.airdromeaeroplanes.com/sopwithpup.html There is a short video on youtube of Ron Jackson flying the Pup in a low, slow flyby. Click on the link to see it – www.youtube.com/watch?v=nn8Pzsjjjhc Dave Marshall is also in the process of building an accurate Fokker DR1 reproduction, with an original Le Rhone 110hp Rotary up front. The reconstruction of that engine will be an article in a future issue of Contact, as will the DR1 when Dave finally gets time to continue work on it. Rob Baslee kit built Sopwith Pup (Rotec powered) That’s all, for this our first issue. The next newsletter is due mid 2012. We are looking for contributions for future newsletters. If you would like to submit an article on any facet of WW1 aviation in Australia, please contact us with your suggestion. If you have any news, photos or information of vintage aviation in Australia, or would just like to give us feedback about the website or the newsletter, please share it with us by emailing us at info@tavas.com.au Until then, Build light and strong - and fly safe. CONTACT – Issue 1 www.tavas.com.au Page 10