So you want to own a Taifun?
By
Luc Vermeulen
| Always dreamed of owning your own Taifun. Well, here´s an article by Belgian pilot Luc Vermeulen, who always dreamed of owning one for himself. Last year (2007) he made his dream come true. Luc wrote down his experiences in this story so others can profit. Dreaming
of aircraft In
my case I was looking for a touring motor glider (TMG). However the certification process for TMG’s is far more extensive then for UL’s in addition it allows you access to most of the medium sized aerodromes in Europe. For UL’s this is not the case. The difficulties with International Flight Planning were UL’s often are restricted is a downside in my opinion. Touring Motor Gliders are a hybrid solution, often flown by previous glider pilots who want to expand there horizon but still want to keep the real positive control flying experience as in gliding. The
selection I made was based on the following checklist. So after answering ‘yes’ on the above questions I proceeded with my shopping whish list: •
I love gliding but also touring and sightseeing
All very tempting statements in the end selecting the right type for you is always based on a compromise between your whishes and the capabilities of the aircraft. Preface If you want to live your passion this is all part of it! Thanks to Henk Dumont for all the support and friendship without him this endeavor would surely not have been possible!
Flying is for sure not a one men show! Also many thanks to my gliding Club the VZA and the board members ( Vlaamse Zweefvliegacademie) for letting me store D-KJTN in the club hangar at EBWE. Getting
started After years of evaluating, assessing different types my whish list became more and more demanding. Also the budget for purchasing an RF3 or a Rotax powered Dimona is multiplied by a factor of five or six…In my case the budget was not unlimited. So I started out with a good old Fournier RF3 going up to a RF5 , also an old Dimona was taken into consideration, passing by an AMT 100 Ximango. At the end only two of these were still in the ball game a Dimona and a Ximango. My personal Flying experience although not big in terms of hours covers a wide variety of aircraft and gliders. From ASK-13 to ASW-20 in gliders and from Cessna’s to Pipers a like even a good old WWII Piper L4 60Hp which had to be hand propped. The list of motor gliders I have flown is less extensive, a Grob G109 and a Super Dimona on which I trained for my JAR TMG class rating. After careful consideration the Dimona fell out of the list due to the lack of speed in cruise. The Ximango was the only contender left, however due to the unavailability in Europe of the type and also the price tag of the Rotax equipped Ximango’s which soared up to 100K euro this became a No-Go. Although I almost went to Brasil to look for a reasonable priced AMT 100 (the problems and cost of getting the aircraft to Europe made me decide to abandon this project). The AMT100 was in fact the RF10 (Fournier) build in Brasil. The later versions had Rotax water cooled engines. I discussed with several AMT owners who praised the type, others were less enthusiast, mainly about the comfort and difficulty of restarting the Rotax engine in flight. Which I believe is the main advantage of the AMT being a good soarer.. So at the time I was making all this considerations I found out that there was a website called www.powerglidertaifun.de the website is hosted by Henk Dumont a Taifun 17EII owner who loves the type and wants to share this with others. I send Henk a small email were I expressed my interest in the type. Not so long after that a reply came. As we speak the same language a first telephone was made. We say in Dutch from one thing comes another…and so our friendship started! Henk
came up with a generous offer to fly over to Weelde in Belgium to
demonstrate the aircraft to me. So on a special VFR morning in April
Henk flew from ETNG (Geilenkirchen) to EBWE. Of course I was very
impressed by the wonderful and very sharp looking Taifun II Henk owns.
It has a beautiful paint scheme together with an almost perfect gelcoat
condition. I was immediately impressed by the looks and its virtual
IFR equipment. The
different Taifun types Today the type design certificate is owned by Korff a German aircraft company who further develops improvements for the type e.g. installations of stronger water cooled engines. The Taifun had during its production a lot of competitors, Grob and Dimona were the most close ones, maybe the design was too advanced for its time. With a complex retractable gear, carbon spar, flaperons. All this features of course led to increased production costs. The Taifun was seen as the Mercedes class of its kind. The main difference between the first and the last version is that on the first the wings can be folded backward and remain attached to the aircraft and the undercarriage is retracted manually by turning a lever. The Taifun II has an electric hydraulic motor/pump to retract the gear however the wings can be disconnected but not folded. Also the type went trough some serious improvements since its development. The early Taifun’s were seriously under powered with only 80 HP. In the early nineties most were modified with more powerful 90 HP Limbach and Sauer engines also on a lot on them the new innovative electric Constant Speed propeller from Muhlbauer was retro fitted. Getting
a first grip on the bird
The pitch control is light and responsive as you can find in most gliders. Roll rate is impressive and can be compared to lets say a Janus glider. In fact the Taifun inherited the same profile as the Janus (Worthmann FX….). The approach can be flown power on or power off by selecting the appropriate flap setting and glide slope is controlled by very effective ‘Schemp Hirth’ speed brakes. In cruise after gear retraction and setting negative flaps you really feel the increase in speed. For those who have flown performance gliders with negative flap settings know what I mean. A build-up of momentum and airspeed. After that flight it was clear to me, this is the bird I wanted to have…..Now the challenge was, were to find a Taifun like that in good condition with the right equipment and still within budget…Not an easy challenge! A
restless potential buyer
The weeks passed by and on an evening I received a phone call from Henk that he knew maybe a Taifun for sale somewhere in Germany. It had very low airframe and engine hours and propably was equipped with CS prop…..Wow this was very good news. He didn’t have more details but was going to find out more…..Of course this was a very friendly offer from him because we only met once but he told me I was OK for a Belgian (Flemish) bloke and we live an hour drive from each other… Surprisingly the next evening Henk called me he had seen the Taifun and it looked in a very good shape….This was a Sunday evening. Over excited with all this good news Henk offered to take a look at the bird the next day. Monday I had to go to work but in stead of driving to eurocontrol in Brussels I took a day off and drove to the NATO airbase of Geilenkirchen, Henk’s homebase.
Can
all this be through…..Henk was already grumping … you…lucky….grpmppp.
The
inspection flight and purchase agreement Preparation
for the move The
ferry flight
Still we decided to make the 400 km drive and pick up Henk on the way. Early in the morning the weather in Belgium was still pretty good however the more we drove into Germany the weather started to deteriorate with low clouds and patches of fog…Siegerland is situated in more or less hilly region were winds can blow strong and low cloud can make departures impossible. The elevation of Siegerland is about 600m.
Immediately after arriving at Siegerland I prepared the aircraft for departure. The procedure requires the Motor Glider to be pulled out the hangar by the fire brigade to avoid damage to other parked aircraft. I installed myself in the Taifun and went trough a quick start-up checklist for taxi to the fuel station. Beacon on, master switch on, fuel pump on, ignition on engage starter…a couple of rotations nothing….mhhhhhmmm…of course pull choke. Another attempt …chok chok..etc…nothing….not even a sound of ignition…I was getting more and more nervous as it became clear there was something wrong….We pulled the aircraft to the fuel station in order to start it with external power as the battery was dead by now after several unsuccessful attempts. Even with the help from the fire brigade which had a battery cart for starting the engine wouldn’t start… This was not going as planned, on top of that the weather deteriorated significantly and it started to rain….I decided to look for a mechanic on the virtually empty airfield. After a while I found a mechanic however he claimed not to have to much experience on piston aircraft as he was mainly a Turbine guy! When arriving at the fuel station with the mechanic, Henk at opened the fuel line to the engine to check if any fuel was running. When switching the electric fuel pump on. So we tried again and suddenly the engine kicked in, wow what a relief… We
closed the cowling, I fired the engine and let it run for about 10
minutes to charge the battery. Meanwhile it started to rain harder
and also some patches of clouds were rolling already over the end
of the runway. Henk was getting very nervous and wanted to leave immediately.
Take
off in difficult circumstances The engine revved fine slowly we started to roll. At 85 km/hr I started to feel the aircraft wanted to fly , I slightly rotated the nose and felt the aircraft lifting off in ground effect. The nose aligned into the wind to stay on the centerline. Build up of speed was very slow and we were consuming RWY like crazy. In the climb I tried to pitch up the nose a bit to gain some altitude. This was immediately countered by the stall horn. I need to retract the gear immediately to clean up the aircraft was my thought…After doing that the situation improved significantly. The distance with the threes below us improved also….Most of the rain was also from the wing and with a clean airframe we continued our climb with a bank to the right as otherwise we would hit cloud about 250 ft on the RWY centerline…We had to avoid some severe CB’s and rain showers. After about 30 minutes flying we were leaving the hills below us and noticed a weather improvement along the Dutch Belgian border. We decide to fly more northly as the weather was better. The only setback was we had to fly through Maastricht controlled airspace. So after 1hr20 minutes I called for finals 25 Weelde. During finals the gear was not coming out immediately so Henk tried to extend the gear which worked fine the second attempt. With a big relief we landed and taxied to the Club house for a good Belgian Beer. Two hours later Frank arrived………Oeeeeeeeeeps I forgot to give him a call that we arrived safely as promised…He was in fact worried like crazy, driving back to Belgium he several times was driving through heavy rain and thunderstorms, he thought we had to deviate and did not make it, or even wors we were hanging in the trees somewhere…. After
the heavy rain we folded the wings and parked the Taifun in his new
home.
How lucky or stupid can one be? The weeks after that the weather was lousy so not much flying was happening. So it was already July when I could take her out and go for a flight. On a nice Sunday I decided to go for a local training flight doing some touch and go’s. The engine didn’t start immediately only after the third attempt the engine kicked in. Everyhting seemed OK I did an extensive ground run to be sure everything was fine. I performed an hour of touch and goes after I was pleased with myself and ready to take my friend Frank for local VFR flight.
Same procedure as before. This time the engine started after the second attempt and everything seemed fine again…I rolled onto the RWY and throttled up the engine. We took off and started to climb. I immediately retracted the gear for improved climb. Then it happened, three loud bang’s from the engine. Instinctively I lowered the nose and started to initiate a turn backward to the airfield. My passenger went silent and pale in the face…( I think). When I was established on the back course I wanted to lower the gear, however suddenly realizing there was no time for this. I’d better focus on landing safely gear up then messing up the landing with a gear not totally extended. This happened in seconds during the turn the engine started to run normally again. Being very low I decided to climb above the airfield and assess the problem at a safer altitude. I looked at the engine instruments but all parameters seemed OK. Although the engine misfiring caused a temporary strange smell in the cockpit, which I attributed to the misfiring. I flipped through all cylinder head temperatures and everything seemed OK. I
made there a very bad decision (which I boldly admit); however it
was based on lack of experience with this engine not realizing something
severe had happened. I decided to fly to a neighboring airfield and
try to find out what is wrong during the flight. Not that all confident
I decided to stay in gliding reach of the airfields. After a while
we turned back and as it was perfect gliding day I wanted to climb
in a thermal to see how well it climbed also when the engine quits
we would have time to prepare for an emergency landing. During the
spiraling and idling the engine I noticed an increase in vibration……which
made me worry seriously I didn’t tell my passenger not to upset
him more... Being at 2500 Ft I told my passenger I am going to reduce
airspeed and start the lowering of the gear so we don’t have
to deal with this issue later on……. The
ground informed to stand by as the grass rwy was going to be cleared
so I had a clear landing area….During this 10 minutes I tried
maybe 40 times to unlatch the mechanism. My hand was bleeding but
I didn’t notice it too much as the adrenaline was pumping like
crazy through my vanes. Frank said to me give it up its stuck, concentrate
on the landing….Being stubborn I only give up when I will run
out of fuel…..and then surprisingly the handle released (what
a relief) I lowered the gear. I told the ground I would like to make
a low pass to check if the gear was out properly. The second mistake
I made that day was going around with an engine not running properly
I should have continued to landing after a positive check from the
ground! As it was already very late and everybody was very tired the troubleshooting was left for the next week……….ooooooooooh boy what a day again!!! A
chain of unbelievable events
Then I inspected the top of the engine and suddenly my eyes noted a disconnected tube (see fig). In fact it’s a compensation tube used for synchronizing the two carburetors. The tube was disconnected and thus static air leaked in, causing starting trouble, this process must have been a slow process aggravating in time until it totally became loose the moment I landed….Remember that the aircraft underwent a JNP just a couple of weeks before. To see that the rubber tube was not fastned was easely to overseen. The next weeks I was on summer holiday in Hungary and not able to further investigate as family comes first…. Solving
the gear and valve problem
Also
on Henks website a US solution is described, but this tool is to my
understanding over-engineered and complex to build for correct alignment.
The first week after the summer holidays I decided to change the spark plugs and do an engine servicing and see how things evolve. Henk passed by that weekend to help out with jacking up the aircraft. He was impressed by the construction and so we jacked up the aircraft to swing the gear.
Again I was unable to extend the gear the handle was locked. We found out that the pushbutton release mechanism was stuck probably caused by hardened grease over time. After injecting the mechanism wih kreep oil the unlatching improved significantly. I also called Sauer to send me new longer rubber hoses for the compensation tube so after the oil change, sparkplug replacement (one had a melted contact point which I found very strange) I started the engine and it fired immediately however in the lower RPM’s it had serious vibrations. I cut the engine and some engine experts from the neigbouring club were called in Jan and Gerrit for assistance. I already had a feeling it was running on three legs’s. The compression test revealed zero compression on cylinder three. This was very bad news! After dismantling the cylinder head we discovered a broken exhaust valve. Luckily the cylinder was not damaged! I had not option to also remove the other cylinder head to check for any damage incurred by the disconnected tube!....A new valve was ordered from Sauer the cylinder heads were inspected and then the whole assembly went to specialized engine shop for repair….Disassembly of the cylinder heads is not rocket science however a good preparation is half the work. During that period my learning curve on VW based aircraft engines was very steep.
Gerrit assisted a lot in finding the right spare parts and Jan had the knowledge on the Sauer engine. Without there support and my friend Ronald who came along on some evening mechanic workshops, the whole situation would have been a lot more frustrating. After several evenings’ assembly and disassembly of engine parts we finally were able to have back a one piece engine. The most difficult part is mounting the cylinders on the engine casing which requires a special tool to compress the piston rings. Also the cylinder head assembly requires more then one hand as the tubes for the valve pushrods tend to fall out when not kept in place by several hands. Correct alignment of these push rods is very important and not so easy to achieve. What stayed a problem was the valve adjustment. The Sauer engine has hydraulic lifters which don’t need maintenance however the initial adjustment has to be done correctly. When performing the adjustment according the book (2 full turns on the valve adjustment screw) the compression was lost on that cylinder. After several phone calls and emails to Sauer and plenty of reading on the internet I found out that one needs to wait two hours after the initial valve setting as it takes about that time for the lifters to set correctly. So finally we were according the book with good compression rates and an engine which started on the fly. What a relief after months of troubles!
To
hear the sound of the prop and hear the engine spin like a cat made
my heart jump of joy! Then on a cold clear November morning I was
aligned with the runway 25 and I pushed the trotthle forward rolled
down the runway finally testing the aircraft in its full glory. What
a moment, what a joy to finally fly the aircraft in its full glory………
Conclusion Some
Tips for potential Taifun buyers! Check the paperwork, if all the AD’s are implemented and check if there is any indication for a serious problem. In my case the aircraft had very limited hours over the years which had an adverse effect on the engine reliability immediately after the purchase! Understand that after the purchase you will always have to deal with things that were not detected during the inspection. Try to avoid major issues popping up. A Taifun is a complex aircraft and I strongly believe that this type is not a club aircraft. You can look at it like Stradivarius when tuned correctly the sound is fantastic when not maintained it sounds awfull…. It’s an incredible aircraft which was designed years ahead of its time. It has a very good performance and fantastic flying characteristics. To
fly this aircraft safely the pilot should have experience on: All this makes this aircraft not suited for a novice PPL Pilot to my understanding. Anyway if you still want to go for it! Keep in mind it can get very addicting!
Luc Vermeulen |
