Another Fliteskin ME 109 build thread
01-10-2015, 11:21 PM
#602
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Oh mate that is terrible news.
Yes, step back leave it for a while and fix it when you are good and ready.
I will be back onto my Fokke 109 when I get to Geraldton in a couple of weeks.
Cheers,
Brad
Yes, step back leave it for a while and fix it when you are good and ready.
I will be back onto my Fokke 109 when I get to Geraldton in a couple of weeks.
Cheers,
Brad
01-11-2015, 01:11 AM
#603
Eran,
I'm sorry to hear your maiden didn't go so well, but we all have been there at some point. Luckily, the 109 is very repairable, the nylon wing bolts did their job of releasing energy.
Looking at the picture of the airborne 109 and your description is clear to me what happened: you did not use right rudder and probably was a bit slow for a safe take off.
Not sure you remember a few posts ago you asked me for some tips.
The safest way to take off, specially in the first flights is to use a longer take off run and climb very shallow with plenty of right rudder to correct for yaw. In fact the right aileron will aggravate the situation due to adverse yaw that the ailerons create.
Do not be tempted to yank the airplane off the ground like an aerobatic or 3D airplane. With warbirds, you have to fly the wing.
Also make sure you have full power before the airplane leaves the ground.
Another tip is to use the grass side of the runway as it gives more time to control direction with full power.
Dont get discouraged,
JoseG
I'm sorry to hear your maiden didn't go so well, but we all have been there at some point. Luckily, the 109 is very repairable, the nylon wing bolts did their job of releasing energy.
Looking at the picture of the airborne 109 and your description is clear to me what happened: you did not use right rudder and probably was a bit slow for a safe take off.
Not sure you remember a few posts ago you asked me for some tips.
The safest way to take off, specially in the first flights is to use a longer take off run and climb very shallow with plenty of right rudder to correct for yaw. In fact the right aileron will aggravate the situation due to adverse yaw that the ailerons create.
Do not be tempted to yank the airplane off the ground like an aerobatic or 3D airplane. With warbirds, you have to fly the wing.
Also make sure you have full power before the airplane leaves the ground.
Another tip is to use the grass side of the runway as it gives more time to control direction with full power.
Dont get discouraged,
JoseG
01-11-2015, 02:03 AM
#604
Jose, you are absolutely right ! The real Messerschmitt and the her models in any scale are little difficult in the take off . Always you need to work with the right rudder to correct the running direction. On my model is the same particularly. Especially in the first flight the pilot should consider this !
Here you can see my first fly, in the and of this fly we discovered that the left aileron worked only from mid-bottom , although thе model fly stable.
GOOD LUCK WITH THE NEXT FLIGHT,YOUR MODEL IS RELY GREAT !
https://www.youtube.com/watch?v=Cnb_LGbyq78
Here you can see my first fly, in the and of this fly we discovered that the left aileron worked only from mid-bottom , although thе model fly stable.
GOOD LUCK WITH THE NEXT FLIGHT,YOUR MODEL IS RELY GREAT !
https://www.youtube.com/watch?v=Cnb_LGbyq78
Last edited by fokke; 01-11-2015 at 02:06 AM.
01-11-2015, 04:04 AM
#605
Thread Starter
Jose - Your assumptions on the take off roll are incorrect. Rudder was used throughout and up to the point of disaster the aeroplane was tracking perfectly.
The mention of ailerons was in regards the point of time AFTER the ground roll started.
The aeroplane was on it first 30m out of about 70-80m I was planning on for a long take off, exactly as you advised. What surprised us all was the fact that the behaviour was as if suddenly a brake was applied on the left wheel. The aeroplane swung violently to the left rolling. What you see in the photo is NOT a take off at low speed. This is an aeroplane thrown into the air around the left landing gear by what seems to be a violent stop of rotation of the left wheel.
While admittingly not having much of warbirds experience, I do have 28 years experience flying of very diverse range of aeroplanes, I hold Australian Gold Wing Instructor rating, and am not shy of admitting a "dumb-thumb" when I have one. This was not one of these times.
The reason I was not flying from the grass was that we have some sprinklers there that are currently exposed and can be an obstacle.
The wing bolts worked well taking some energy off. We joked about plastic wing bolts that never snap when you need them to in the pit area just before the test flight. And yes, the aeroplane is repairable. But after 5 years working on it I do not have the motivation to do it at the moment. Maybe when my new shed will be built.
fokke - Thank you for the comments. Your flying field is amazing. I used to fly on full size WW2 bombers base runways many years ago.
Eran
The mention of ailerons was in regards the point of time AFTER the ground roll started.
The aeroplane was on it first 30m out of about 70-80m I was planning on for a long take off, exactly as you advised. What surprised us all was the fact that the behaviour was as if suddenly a brake was applied on the left wheel. The aeroplane swung violently to the left rolling. What you see in the photo is NOT a take off at low speed. This is an aeroplane thrown into the air around the left landing gear by what seems to be a violent stop of rotation of the left wheel.
While admittingly not having much of warbirds experience, I do have 28 years experience flying of very diverse range of aeroplanes, I hold Australian Gold Wing Instructor rating, and am not shy of admitting a "dumb-thumb" when I have one. This was not one of these times.
The reason I was not flying from the grass was that we have some sprinklers there that are currently exposed and can be an obstacle.
The wing bolts worked well taking some energy off. We joked about plastic wing bolts that never snap when you need them to in the pit area just before the test flight. And yes, the aeroplane is repairable. But after 5 years working on it I do not have the motivation to do it at the moment. Maybe when my new shed will be built.
fokke - Thank you for the comments. Your flying field is amazing. I used to fly on full size WW2 bombers base runways many years ago.
Eran
01-11-2015, 08:40 AM
#606
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This may seem far fetch but I had incident upon landing were the left main landing gear strut rotated 180 degrees in the trunion housing. Flying from a dry lake bed the tire did not bite in and the plane gradually veered off to the left. I had no idea what was going on. In your case if this happen during takeoff we see the results.
01-11-2015, 10:33 AM
#607
Erans,
i feel your pain because I've been through the same situation in the past and I made the same mistake.
Otherwise, it is possible that the left wheel locked?
I can't think of another explanation, since you mentioned that the airplane was already tracking perfectly.
JG
i feel your pain because I've been through the same situation in the past and I made the same mistake.
Otherwise, it is possible that the left wheel locked?
I can't think of another explanation, since you mentioned that the airplane was already tracking perfectly.
JG
01-11-2015, 06:28 PM
#608
Thread Starter
flycatch - My retracts (after the ground roll) are intact, and retracted perfectly into the wing (as I took the aeroplane home). It was not a strut rotation issue.
Jose - My theory to the ground loop is as follows:
I was using stronger engine then your prototype and I think that I also swing larger prop (20x8). I may have greater tow-out on my main wheels then your aeroplane (however, this tow-out position of the wheels is the only way that the wheels will fully retract into the wing when the retracts mounted as per the plan, so I can only assume that we have very similar tow-out).
On take-off, the torque from the prop press the left wheel into the ground with greater force then the right wheel (I remember reading somewhere that on the full size ME-109 the tire and shock absorber pressure on the left leg was higher then the right to counteract the torque issue).
As speed increases, I slowly released the back-pressure from the elevator, and as a result the tail was loosing traction.
With the aeroplane now traveling mostly on the main wheels, the left wheel has increased contact with the ground, and the right wheel loosing traction.
Being "tow out", an increase in force to the left result in tire traction "off direction of acceleration" (trying to point further left) and resulting in it the wheel dragging instead of accelerating in rotation, and therefore acting like a break. The right wheel keep accelerating up to the point of loosing contact with the ground.
The left wheel becomes pivot point to the roll throwing the aeroplane around it in the direction of the torque from the prop.
Eran
Jose - My theory to the ground loop is as follows:
I was using stronger engine then your prototype and I think that I also swing larger prop (20x8). I may have greater tow-out on my main wheels then your aeroplane (however, this tow-out position of the wheels is the only way that the wheels will fully retract into the wing when the retracts mounted as per the plan, so I can only assume that we have very similar tow-out).
On take-off, the torque from the prop press the left wheel into the ground with greater force then the right wheel (I remember reading somewhere that on the full size ME-109 the tire and shock absorber pressure on the left leg was higher then the right to counteract the torque issue).
As speed increases, I slowly released the back-pressure from the elevator, and as a result the tail was loosing traction.
With the aeroplane now traveling mostly on the main wheels, the left wheel has increased contact with the ground, and the right wheel loosing traction.
Being "tow out", an increase in force to the left result in tire traction "off direction of acceleration" (trying to point further left) and resulting in it the wheel dragging instead of accelerating in rotation, and therefore acting like a break. The right wheel keep accelerating up to the point of loosing contact with the ground.
The left wheel becomes pivot point to the roll throwing the aeroplane around it in the direction of the torque from the prop.
Eran
01-12-2015, 12:59 AM
#609
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erans,
sorry for your mishap, 109s are notorious on take-off roll
Just a question, why toe-out? I have toe-in on all my 109's to help keep the retracts locked in the open position.
sorry for your mishap, 109s are notorious on take-off roll
Just a question, why toe-out? I have toe-in on all my 109's to help keep the retracts locked in the open position.
01-12-2015, 01:51 AM
#610
Thread Starter
w1nd6urfa - I didn't design the aeroplane or queried the design. I just build it as per plan. I assume that Jose, when designing the aeroplane, took all the required factors into consideration. His aeroplane, built from the same plans, fly well.
On my aeroplane, to fit the wheels in the wing, the retracted position has tow-out.
I'll wait to Jose's reply to see if I did something wrong on my build in regards to this.
Eran
On my aeroplane, to fit the wheels in the wing, the retracted position has tow-out.
I'll wait to Jose's reply to see if I did something wrong on my build in regards to this.
Eran
01-12-2015, 11:08 AM
#611
flycatch - My retracts (after the ground roll) are intact, and retracted perfectly into the wing (as I took the aeroplane home). It was not a strut rotation issue.
Jose - My theory to the ground loop is as follows:
I was using stronger engine then your prototype and I think that I also swing larger prop (20x8). I may have greater tow-out on my main wheels then your aeroplane (however, this tow-out position of the wheels is the only way that the wheels will fully retract into the wing when the retracts mounted as per the plan, so I can only assume that we have very similar tow-out).
On take-off, the torque from the prop press the left wheel into the ground with greater force then the right wheel (I remember reading somewhere that on the full size ME-109 the tire and shock absorber pressure on the left leg was higher then the right to counteract the torque issue).
As speed increases, I slowly released the back-pressure from the elevator, and as a result the tail was loosing traction.
With the aeroplane now traveling mostly on the main wheels, the left wheel has increased contact with the ground, and the right wheel loosing traction.
Being "tow out", an increase in force to the left result in tire traction "off direction of acceleration" (trying to point further left) and resulting in it the wheel dragging instead of accelerating in rotation, and therefore acting like a break. The right wheel keep accelerating up to the point of loosing contact with the ground.
The left wheel becomes pivot point to the roll throwing the aeroplane around it in the direction of the torque from the prop.
Eran
Jose - My theory to the ground loop is as follows:
I was using stronger engine then your prototype and I think that I also swing larger prop (20x8). I may have greater tow-out on my main wheels then your aeroplane (however, this tow-out position of the wheels is the only way that the wheels will fully retract into the wing when the retracts mounted as per the plan, so I can only assume that we have very similar tow-out).
On take-off, the torque from the prop press the left wheel into the ground with greater force then the right wheel (I remember reading somewhere that on the full size ME-109 the tire and shock absorber pressure on the left leg was higher then the right to counteract the torque issue).
As speed increases, I slowly released the back-pressure from the elevator, and as a result the tail was loosing traction.
With the aeroplane now traveling mostly on the main wheels, the left wheel has increased contact with the ground, and the right wheel loosing traction.
Being "tow out", an increase in force to the left result in tire traction "off direction of acceleration" (trying to point further left) and resulting in it the wheel dragging instead of accelerating in rotation, and therefore acting like a break. The right wheel keep accelerating up to the point of loosing contact with the ground.
The left wheel becomes pivot point to the roll throwing the aeroplane around it in the direction of the torque from the prop.
Eran
Your theory is in part correct about the over size engine. The 109 has a relatively small vertical fin and rudder and you really have to be prepared to use a lot of right rudder on take off and keep it there until air speed has built up. Ailerons at low speed are in-effective. In fact the full size has an air foil on the left side of the fin to help keep it flying straight. Your engine is twice the size of what Jose originally used on his, which I believe was an OS 1.6.
Cheers,
01-12-2015, 09:19 PM
#614
Eran and all,
The theory of the toe out does not really convince me, in my airplane is pretty neutral the effect. Also you mentioned that the airplane was tracking straight and full power was not applied, so why would suddenly turn left?
/ The bigger prop can increase the P factor slightly at full power, my airplane uses a 18-8. All it means is that you increase the airspeed and trim the rudder an extra clic or two.
You call it a ground loop, but in a ground loop the wheels are on the ground, I looked carefully at the picture and I see the airplane completely airborne with full right ailerons and neutral rudder.
All I can say is this exact thing had happened to me in the past with this same airplane and it cost me a bunch of repairs! and the reason: it got airborne too soon and not enough right rudder.
Once I figured that out, I started using the rudder through the WHOLE take off and climb and never had another problem.
The attached pic shows how much rudder it takes to track straight while climbing. The second you let go of the rudder during this phase, the airplane is history. Notice ailerons are neutral.
I hope this helps.
JG
The theory of the toe out does not really convince me, in my airplane is pretty neutral the effect. Also you mentioned that the airplane was tracking straight and full power was not applied, so why would suddenly turn left?
/ The bigger prop can increase the P factor slightly at full power, my airplane uses a 18-8. All it means is that you increase the airspeed and trim the rudder an extra clic or two.
You call it a ground loop, but in a ground loop the wheels are on the ground, I looked carefully at the picture and I see the airplane completely airborne with full right ailerons and neutral rudder.
All I can say is this exact thing had happened to me in the past with this same airplane and it cost me a bunch of repairs! and the reason: it got airborne too soon and not enough right rudder.
Once I figured that out, I started using the rudder through the WHOLE take off and climb and never had another problem.
The attached pic shows how much rudder it takes to track straight while climbing. The second you let go of the rudder during this phase, the airplane is history. Notice ailerons are neutral.
I hope this helps.
JG
01-12-2015, 11:25 PM
#615
Thread Starter
OK, I think it is time to sign off this build thread.
It was a great project, the most complex I tackled to date.
Thank you Jose for the excellent customer support, and thank you everybody who followed and commented.
The aeroplane went into storage and maybe, one day, I will have the energy and time to try and fix it.
All the best,
Eran
It was a great project, the most complex I tackled to date.
Thank you Jose for the excellent customer support, and thank you everybody who followed and commented.
The aeroplane went into storage and maybe, one day, I will have the energy and time to try and fix it.
All the best,
Eran
01-14-2015, 12:28 AM
#616
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On my 109's I use the following trick: I offset the tailwheel slightly to the left when the rudder is centered.
Then on take off roll my thumb is already pushing right rudder to make the tailwheel track straight and when the tail lifts there is no sudden left pull.
erans,
I believe you're experiencing the emotional disappointment that follows a maiden mishap. Just hang in there, in my experience the eagerness to fly her will come back soon and next time you will anticipate that dreaded left pull and tame the beast
Congrats on a great build thread, I enjoyed every step and it helped me a lot in my explorations with Fliteskin (ARF makeovers mostly).
Now you should start a flight thread!
01-27-2015, 12:07 AM
#617
From the photo of the plane before impact I see no rudder input.
From my personal experience with an ESM 109 with a lot of power, AXI 5330-24 on 10S, I had a similar maiden result. Rolling out the tail lifted just fine felt and looked normal. The planed appeared to have good speed and was tracking just fine. I remember not having much rudder input in it at the time because it was tracking nicely. As soon as I began to pull up it began to raise the nose and then immediately rolled left and cart wheeled. I was shocked, I couldnt respond fast enough and I used full right rudder.
This crash looks a lot like what I did so in my opinion its just pilot error unfortunately. More speed and more rudder.
From my personal experience with an ESM 109 with a lot of power, AXI 5330-24 on 10S, I had a similar maiden result. Rolling out the tail lifted just fine felt and looked normal. The planed appeared to have good speed and was tracking just fine. I remember not having much rudder input in it at the time because it was tracking nicely. As soon as I began to pull up it began to raise the nose and then immediately rolled left and cart wheeled. I was shocked, I couldnt respond fast enough and I used full right rudder.
This crash looks a lot like what I did so in my opinion its just pilot error unfortunately. More speed and more rudder.
05-07-2015, 02:32 AM
#618
Thread Starter
My friend David cleaned his shed and invited me to bring the ME-109 for inspection.
Since I lost my job last week and have time on my hands, I took on his offer (order?) to assist.
So, over the last three days we re-attached the broken landing gear mounts, and worked out (by trial and error) a new alignment for the landing gear which is not towed out, but rather perfect strait. This was achieved while still being able to retract the landing gear into the wing with minor modifications to the wheel bays walls.
Achieving this was pre-requisite to an effort to fix the rest of the aeroplane for another test flight.
Over the next few weeks we will work on the rest of the damaged areas. We started by fabricating a new short spar for the wing tip and got it glued back in place.
David took on himself to re-build the rudder for me, and may do some work on the ignition and fuel tank trays.
On inspection into the vertical fin, the horizontal stabilizer glue cracked at the top joints, but is intact on the bottom joint. This should be a reasonably easy fix.
We will also need to attend damage to the cockpit area (which I am yet to investigate in full), the engine cowling, and multiple areas in the fuselage fibreglass (which do not look structural, so we may ignore them for now).
If David will keep cracking the whip on me, I expect rapid progress...
Cheers,
Eran
Since I lost my job last week and have time on my hands, I took on his offer (order?) to assist.
So, over the last three days we re-attached the broken landing gear mounts, and worked out (by trial and error) a new alignment for the landing gear which is not towed out, but rather perfect strait. This was achieved while still being able to retract the landing gear into the wing with minor modifications to the wheel bays walls.
Achieving this was pre-requisite to an effort to fix the rest of the aeroplane for another test flight.
Over the next few weeks we will work on the rest of the damaged areas. We started by fabricating a new short spar for the wing tip and got it glued back in place.
David took on himself to re-build the rudder for me, and may do some work on the ignition and fuel tank trays.
On inspection into the vertical fin, the horizontal stabilizer glue cracked at the top joints, but is intact on the bottom joint. This should be a reasonably easy fix.
We will also need to attend damage to the cockpit area (which I am yet to investigate in full), the engine cowling, and multiple areas in the fuselage fibreglass (which do not look structural, so we may ignore them for now).
If David will keep cracking the whip on me, I expect rapid progress...
Cheers,
Eran
05-07-2015, 03:16 PM
#619
Eran,
great news you are back to the 109!! look forward to see this bird airborne. When you glue the stab, use a few threads of glassfibre (tow) to strengthen the joint line. If you have cracks on the fuse, sand really well and epoxy a small patch of glassfibre on the inside. Should make even stronger than before.
Regards,
joseG
great news you are back to the 109!! look forward to see this bird airborne. When you glue the stab, use a few threads of glassfibre (tow) to strengthen the joint line. If you have cracks on the fuse, sand really well and epoxy a small patch of glassfibre on the inside. Should make even stronger than before.
Regards,
joseG
05-12-2015, 02:17 AM
#622
Thread Starter
Most of the fibreglass work is now completed, with the horizontal stabiliser still waiting to be done (inside the vertical fin). Due to the location of many of these patches (deep inside the fuselage), I could not take photos, and in the photos I did took (below), the fibreglass patches are not as obvious sometimes.
Also, David refurbished the fuel tank tray and is in the process of fixing its mounts.
Eran
Also, David refurbished the fuel tank tray and is in the process of fixing its mounts.
Eran
05-12-2015, 05:00 AM
#623
Thread Starter
I forgot to mention that David completed the rudder fix, and now, back at home, with the wing of my next project ready to come off the plans, it is time to cover the rudder.
Eran
Eran
05-14-2015, 01:53 AM
#625
Thread Starter
The ignition is back on its tray, the refurbished fuel tank tray is now screwed into place.
The main task for today was however to fibreglass the horizontal stabiliser, which is now drying. Hopefully it will prove to be satisfactory strong.
Eran
The main task for today was however to fibreglass the horizontal stabiliser, which is now drying. Hopefully it will prove to be satisfactory strong.
Eran