P-51 Mustang IV

This is an aircraft that I modelled many many years ago and I always wanted to make another to F4B (Control line Scale) standard.

I have the plans for the Brian Taylor 60" Mustang. I spoke to Brian about the accuracy of those plans, he said 'I shouldn't build it as his 69" Mustang plan was more accurate'.

That's all well and good but the fuselage length of the P-51 is almost as long as the span is wide !

   I have read of much larger (80" span) C/L scale models being flown but of those I have seen flying none of them had the sort of performance that I desire from my control line scale models.

What finally got me started building the 69" Mustang was seeing a radio version of it at the British National Championships - it looked big and weighed 12 lbs but as all radio fliers seem to have little control over the weight of their models I decided that I would start building regardless.

Careful wood selection and monitoring of all the component's weights should make my model around 7  lb.

Latest news  2017 ~ British National Championships - 1st place !

Yes, it is very long !

Glass fibre cowl - from Brian Taylor.

The retracting tail wheel mechanism is hand made from ply wood and brass tube, with litho plate doors.

 

Ample room in there for a bellcrank. The servo is for the retracting tail wheel.

 

The wing with the flaps loosely placed in position.

 

Servos work the Undercarriage mechanism (4" dia' wheels), Wheel Well Doors, Flaps and Drop Tanks. Two further servos operate the Throttle and retracting Tail Wheel.

A sixth servo has now been fitted which controls the U/C doors, in addition, an electronic Servo Sequencer was used to ensure the undercarriage deployed correctly, but, although I could get it to work ok on my workbench, in flight, centrifugal forces delayed the retraction of the undercarriage legs causing a collision with the wheel well doors.The wheel well doors and undercarriage are now controlled separately and manually.

Undercarriage sequence : Doors open, U/C down, doors close. Doors open, U/C retracts, doors close.

The Wheel Well doors are made from Litho plate and balsa.

 

The U/C legs are bent to shape from 8 gauge Piano wire then covered with balsa.

The drop tank release mechanism is constructed as per the plan, with my own design 'fittings' within the drop tanks..

 

Loose assembly.

 

Moving towards completion.

 

Preparation coats of silver.

 

The colour scheme is from RAF 112 squadron.

 

The airbrushing continues.

 

The cockpit.

 

Test flown - engine and undercarriage problems finally overcome.

 

It's been a long road but the end results were worth the trouble.

 

The following photographs were taken at the 2017 British National Championships.

Take-off !

 

In flight - with all systems working.

 

Low fly-past.

 

Drop tanks gone.