Brand new landing gear for 13 year old P51 Mustang.

[aidan mcatamney]

Hopefully this will solve the problem of numerous noseovers due to landing gear being too straight.   The local engineering works did a great job in breathing new life into the old gear.  I will soon find out soon enough when i take the plane to the club flying field at the next available opportunity.  

[stu knowles]

I couldn't turn up at the field with that model but each to their own  🙂   Not wishing to be a prophet of doom, with the wheels that far forward I think that its likely to be hard to keep straight on Take Off.

 

Hope that it goes well, 

[aidan mcatamney]

30 minutes ago, stu knowles said:

I couldn't turn up at the field with that model but each to their own  🙂   Not wishing to be a prophet of doom, with the wheels that far forward I think that its likely to be hard to keep straight on Take Off.

 

Hope that it goes well, 

Yes each to their own.  Time will tell.  Thanks for your good wishes.  

[Jon H]

IF the gear need that level of rake the model is balanced far too nose heavy. P51's tend to handle well on the ground and have decent size wheels. It should not be necessary to crank them that far forward. 

[aidan mcatamney]

39 minutes ago, Jon H said:

IF the gear need that level of rake the model is balanced far too nose heavy. P51's tend to handle well on the ground and have decent size wheels. It should not be necessary to crank them that far forward. 

Jon, I have that plane 13 years now and it's always been very tail heavy.  So a lot of lead weight needed at the front.  No, this is just an experiment I'm carrying out with the gear raked forward at this acute angle.  If it doesn't work out its just a simple process of raking it back an inch or so.  Thanks for your reply.  

[Frank Day]

I think the tracking will be difficult unless there are some lateral braces, it will also compress and cause a prop strike

[aidan mcatamney]

1 hour ago, Frank Day said:

I think the tracking will be difficult unless there are some lateral braces, it will also compress and cause a prop strike

Will give it a go anyway Frank.  Nothing ventured nothing gained.  I love experimenting and I'm curious to see what the outcome will be whenever I eventually take it to the field.  Thanks for your reply. 

[Frank Day]

On my 1.4m FMS Zero I did the classic washers under the retracts, bent a new pin and Dremmel work as well as changing them to working oleo's with larger wheels as it used to fall over as soon as it saw grass. Slightly more nose up on the ground and dropped the battery down from it weird over the motor position to under the motor to get the weight lower down to reduce the leverage. Lawn driving test successful even on mid rates. Still expecting nose overs but at least it will taxi and i just full beans it to take off so it doesn't have chance to throw itself over.

[aidan mcatamney]

13 minutes ago, Frank Day said:

On my 1.4m FMS Zero I did the classic washers under the retracts, bent a new pin and Dremmel work as well as changing them to working oleo's with larger wheels as it used to fall over as soon as it saw grass. Slightly more nose up on the ground and dropped the battery down from it weird over the motor position to under the motor to get the weight lower down to reduce the leverage. Lawn driving test successful even on mid rates. Still expecting nose overs but at least it will taxi and i just full beans it to take off so it doesn't have chance to throw itself over.

That was good to read Frank, thank you for sending that.  This Hangar 9 P51 of mine was bought 13 years ago and has given me immense pleasure over the years.  I never had any trouble with noseovers and the fixed landing gear held up well until recently when I noticed that that it was starting to noseover upon landing and the reason being that the steel wire had virtually gone straight.  So I took both landing gear wires off , removed the two wheels and took it to the local engineering works where I ask them kindly to put a bend on each wire strut.  Yes, I think I may have ask them to bend it a bit more than required but it's not tye end of the world and when I try out the ground handling at the flying field and its not to my satisfaction,  then its just a case of taking it back out and bending it back a bit more.  I'm excited to see the outcome.  I'm flying 38 years and new experiences always excite me.  Thanks for your reply.  

[Jon H]

7 hours ago, aidan mcatamney said:

Jon, I have that plane 13 years now and it's always been very tail heavy.  So a lot of lead weight needed at the front.  No, this is just an experiment I'm carrying out with the gear raked forward at this acute angle.  If it doesn't work out its just a simple process of raking it back an inch or so.  Thanks for your reply.  

 

quantify 'tail heavy'. If you are referencing the fact that it needs lead to balance at the marks in the instructions this is not a tail heavy condition and more than likely the model is nose heavy. 

 

Many kits come with extremely conservative c/g recommendations and they can usually be shoved back a good long way before the model becomes unstable. The advantages are obvious with less weight carried and a model which will not spend all day sniffing the dirt. The only thing you need to do to keep the model on an even keel is reduce your elevator travel as you move the c/g back.

 

I have mentioned many times that i balanced my DB Hurricane on the plan c/g and have since removed more than 1lb of lead from the nose. My Sea fury too lost a big chunk after test flights, as have countless other sport and scale models i have in the hangar. 

 

Ultimately, the recommended c/g is a starter for 10 just to get your safely through the maiden flight. After that it will need to be adjusted, often quite significantly. 

[aidan mcatamney]

57 minutes ago, Jon H said:

 

quantify 'tail heavy'. If you are referencing the fact that it needs lead to balance at the marks in the instructions this is not a tail heavy condition and more than likely the model is nose heavy. 

 

Many kits come with extremely conservative c/g recommendations and they can usually be shoved back a good long way before the model becomes unstable. The advantages are obvious with less weight carried and a model which will not spend all day sniffing the dirt. The only thing you need to do to keep the model on an even keel is reduce your elevator travel as you move the c/g back.

 

I have mentioned many times that i balanced my DB Hurricane on the plan c/g and have since removed more than 1lb of lead from the nose. My Sea fury too lost a big chunk after test flights, as have countless other sport and scale models i have in the hangar. 

 

Ultimately, the recommended c/g is a starter for 10 just to get your safely through the maiden flight. After that it will need to be adjusted, often quite significantly. 

Hi J9n and thanks for your reply.  The cg on the Hangar 9 P51 has to be measured back 95mm from the leading edge.  As I've said the plane is very tail heavy and requires the right amount of lead weight inside the cowl , otherwise I would be bringing it home in bits.  Always remember the wise old saying , a nose heavy plane doesn't fly well but a tail heavy plane only flys once.  Other owners of the P51 have reported the same problem.  Lots of weight needed in the nose to balance.  In fact I have two Kyosho Calmato Sports 40 planes and they have the same problem as the P51,  extremely tail heavy and needs a ton of lead in the nose to balance the plane and this is universal.   I have the same engine in both the P51 and my Calmato Sports,  its an OS 55AX.   Just to show you how much weight is required to balance these planes , I've taken a photo of the Calmato as I'm not going to dismantle the cowl on the P51.  But it takes the same amount of weight for all three planes to get the proper cg otherwise they would be a handful to fly safely.  

[aidan mcatamney]

With this amount of weight added to the nose of my P51, the plane is an absolute joy to fly.  

[Jon H]

ok clearly you did understand my post at all. 

 

You cant say a model is tail heavy just because it needs lead to balance it. You can say its tail heavy without ballast, but its not tail heavy per se. 

 

2 hours ago, aidan mcatamney said:

The cg on the Hangar 9 P51 has to be measured back 95mm from the leading edge

 

No, it dosent. This is a starting point to guarantee the model is controllable and to cover off inaccurate balancing. It is not set in stone and you can move it and i would imagine that even 110mm would be fine. Not that you need to measure it, just keep removing weight and making adjustments. As a said before, i took over 1lb out of my large hurricane and about half a pound out of my smaller Hurricane. Both fly better for it despite being 'tail heavy' if measured according to the plans. 

 

2 hours ago, aidan mcatamney said:

Always remember the wise old saying , a nose heavy plane doesn't fly well but a tail heavy plane only flys once

 

This is a half truth at best. There is a perception that cg is a fixed entity perfectly measured at 95mm in your case and that is where it has to be. This is flat out false as any ic model looses several oz of nose weight over a flight as you burn the fuel off. Generally, this has no appreciable effect on the model and its performance. With this fact in mind we can say there is a cg range where the model is controllable, becoming less so at each end of the range. My suggestion is to have the cg as far aft as stability will allow as you end up with a model which is lighter, handles better on the ground and wont sniff the dirt on taxi. 

[aidan mcatamney]

2 minutes ago, Jon H said:

ok clearly you did understand my post at all. 

 

You cant say a model is tail heavy just because it needs lead to balance it. You can say its tail heavy without ballast, but its not tail heavy per se. 

 

 

No, it dosent. This is a starting point to guarantee the model is controllable and to cover off inaccurate balancing. It is not set in stone and you can move it and i would imagine that even 110mm would be fine. Not that you need to measure it, just keep removing weight and making adjustments. As a said before, i took over 1lb out of my large hurricane and about half a pound out of my smaller Hurricane. Both fly better for it despite being 'tail heavy' if measured according to the plans. 

 

 

This is a half truth at best. There is a perception that cg is a fixed entity perfectly measured at 95mm in your case and that is where it has to be. This is flat out false as any ic model looses several oz of nose weight over a flight as you burn the fuel off. Generally, this has no appreciable effect on the model and its performance. With this fact in mind we can say there is a cg range where the model is controllable, becoming less so at each end of the range. My suggestion is to have the cg as far aft as stability will allow as you end up with a model which is lighter, handles better on the ground and wont sniff the dirt on taxi. 

I'm afraid Jon you didn't understand me .  You have your opinion and I have mine.  So I will try again and maybe get through to you this time.   Without any lead being added to either the Kyosho Calmato or to the Hangar 9 P51, both these planes are severely TAIL HEAVY,  and I mean severely TAIL HEAVY.   At 95 mm back from the leading edge you can go either way past that measurement,  but this makes no difference at all, still severely TAIL HEAVY.  The P51 suffers from a des8gn flaw the sane as the Calmato Sports 40.  Go look up on the Forumns in America about the Kyosho Calmato Sports 40 and you will read from the owners themselves about the severity of tail heaviness.  The Mustang has the same problem.  When I first flew it in 2011, I was very very fortunate to get that P51 down in one piece on its maiden flight.  I decided to fly it like you advised without any nose weight and it was a disaster waiting to happen.  So lead had to be added to the cowl and that balanced the plane perfectly and I never had any trouble since that.  I appreciate your views Jon and everyone has their own opinion, but on this matter I am right in what I say even I say it myself, no disrespect to you.  I'm flying almost 40 years Jon and I know a bit about model flying.  In the meantime can we let this rest and I wish you all the best.  Kind regards Aidan.  

[Ron Gray]

On 12/04/2024 at 13:26, aidan mcatamney said:

I will soon find out soon enough when i take the plane to the club flying field at the next available opportunity.  

Despite the awful look (imo) I would be more concerned about landing and the wheels being pushed back through the wing as at those angles there will be very little, or no, give in the legs.

 

Regarding the CG, it’s correct when the model flies well and you’re not fighting it, irrespective of the actual measurement back from the LE.

[toto]

I think there is not going to be a meeting of minds on the subject.

 

In Aidans last post he tries to close the subject down in a reasonable manner but you are simply coming back baiting him Jon. Especially suggesting that he knows nothing after 40 years experience. The remarks are becoming a bit harsh and I think it may be better just left as Aidan has suggested.

 

I can't add anything to the matter in hand but don't like to see things getting out of hand. I think Aidan is prepared to let matters lie. Maybe it's time to back out.

 

Apologies to both if my comments are unappreciated.

 

Toto

[FlyinFlynn]

11 hours ago, Jon H said:

My suggestion is to have the cg as far aft as stability will allow as you end up with a model which is lighter, handles better on the ground and wont sniff the dirt on taxi.

That's ok providing you check 'the stability' at the end of a flight where you have burnt off most if not all of the fuel. It is not a good time to discover you were on the limit of aerodynamic stability when the tank was full. Retracts weight can also come into play if you have them fitted. The most sensitive time for aerodynamic stability is when you are low, slow and dirty - just the same conditions when you are on your finals.

 

I think everyone understands the recommended CofG is only a starting point, designed to get your model flying without re-kitting itself inside the first 10 seconds of airborne flight.

[Ron Gray]

56 minutes ago, FlyinFlynn said:

I think everyone understands the recommended CofG is only a starting point

But do they? I have seen first hand, pilots, from more than one club, who have been flying for years and religiously stick to the instructions for both C of G and control surface throws. Trying to persuade them to try altering these can be hard work and I think that is what Jon is attempting to put across. 

Edited April 14 by Ron Gray

[Frank Day]

Leaving aside the CG discussion until the end. I already commented on the gear, tracking, possible prop strike etc.

 

Does a retract kit exist for this older model from the Hanger 9 stable ie  retro fit, or are there obstacles such as spars, dont have one myself so just pondering.

 

I fly a few "classic" foamies and the instructions regarding CG are interesting stating balance with the battery. I can only assume that batteries from 10 plus years ago must have been substantially heavier. MY 49" Parkzone Mosquito requires the 2200 3S according to the manual and jiggle it about to balance. No chance, I'm running a  3200 3s to balance it, or 4S on my modified one

Edited April 14 by Frank Day
insanity

[aidan mcatamney]

2 hours ago, toto said:

I think there is not going to be a meeting of minds on the subject.

 

In Aidans last post he tries to close the subject down in a reasonable manner but you are simply coming back baiting him Jon. Especially suggesting that he knows nothing after 40 years experience. The remarks are becoming a bit harsh and I think it may be better just left as Aidan has suggested.

 

I can't add anything to the matter in hand but don't like to see things getting out of hand. I think Aidan is prepared to let matters lie. Maybe it's time to back out.

 

Apologies to both if my comments are unappreciated.

 

Toto

Thank you Toto.  A man with some manners.   I'm just back from the flying field after three perfect flights with my Mustang.  The new landing gear didn't change a thing, the plane tracked as straight as an arrow down the runway and it flew as stable as a trainer.  When I bought this plane 13 years ago I had to add 60 grams of weight to the nose as I almost crashed it on its maiden flight due to the extreme tail heaviness of the plane.  13 years later and my Mustang is flying just as good.  I came up the road in the car singing.  Happy as Larry as us proud Irishmen say.  Kind regards Aidan.  

[Frank Day]

N

On 13/04/2024 at 11:42, aidan mcatamney said:

Will give it a go anyway Frank.  Nothing ventured nothing gained.  I love experimenting and I'm curious to see what the outcome will be whenever I eventually take it to the field.  Thanks for your reply. 

Northern?

[aidan mcatamney]

2 hours ago, FlyinFlynn said:

That's ok providing you check 'the stability' at the end of a flight where you have burnt off most if not all of the fuel. It is not a good time to discover you were on the limit of aerodynamic stability when the tank was full. Retracts weight can also come into play if you have them fitted. The most sensitive time for aerodynamic stability is when you are low, slow and dirty - just the same conditions when you are on your finals.

 

I think everyone understands the recommended CofG is only a starting point, designed to get your model flying without re-kitting itself inside the first 10 seconds of airborne flight.

I'm repeating the same to everyone here that I've just returned from the flying field with my P51 after three tremendous flights.  The ground tracking was superb,  as straight as an arrow up tye grass runway.  Into the air and flew as stable as a trainer.  The landing was uneventful,  one of the best I've done in a long t8me and that was for everyone of the three flights  .  The 60g of lead in the n9se has been there for 13 years and is a necessity.   My two Kyosho calmato sports 40 are the same where they ate severely tail heavy and require the same amount of lead up front.  I'm delighted with the new landing gear and the way it tracked on the ground and the landings.  I'm a happy pilot today.  Many thanks and kind regards for your reply.   Aidan. 

[Ron Gray]

Well as long as you’re happy then that is that matters.

[Ron Gray]

42 minutes ago, aidan mcatamney said:

but like a spoilt child

Now you are getting too personal!

[Martin Harris - Moderator]

Let’s all take a step back. There is no place on this forum for personal insults.