CWH Bolingbroke Update

Sorry to hear about the Bolingbroke, but the decision is understandable.

[Mike]

In addition to the challenges of restoring and maintaining two Mercury engines, a much more critical challenge was the rebuilding of our Bolingbroke wings. The unique process to build the spars is no longer achievable to us.

Have you approached ARCo at Duxford? I know they commissioned a short run of the special steel required when they did theirs.

And whilst on the subject of rare Mercury-engined aircraft, will the Lysander be repaired and flown again?

[JDK]

G'Day bdk - long time no speak! I remembered some stuff in the late Graham Warner's books, that answer your question, so I thought I'd take a look. Though he doesn't quote the tech numbers for the material, I decided to post the full pages here as it tells a great story of the restorations challenges many know, but we should never forget.

While there's nothing significantly different as a design in the Blenheim's wing spars, it's important to remember MOST non-US types of restorations will be dealing with airworthy rebuilds of one, two or less than five of a type, from often few or no airworthy part donor survivors. RELATIVELY speaking, US types are well provided for in spares and survivors, particularly those common-as-muck NAA types.

https://vintageaerowriter.wordpress.com ... par-steel/

Also bonus young John Romain image...

[CWH Museum]

And whilst on the subject of rare Mercury-engined aircraft, will the Lysander be repaired and flown again?

Thanks for asking. We have acquired a replacement landing gear and the engine is at the overhaul shop. The wings are in storage and the fuselage is on display. The timeframe to get the Lysander into restoration hasn't been determined yet but it is definitely our intention to return our Lizzie to the sky once again!

[Fleet16b]

About 10 yrs ago members of the Boly Team approached us at Pratt & Whitney
regarding the installation of PW engines. The Mk 4W had Pratt Wasp Jr's (qty 15 were built)
It seems that the drawings etc for the engine mounts are still controlled by us.
P&W had no desire to release the drawings due to liability fears even though a proposal was made to
provide legal documents absolving them of all liability.
The Bolingbroke operated with Bristols and Pratts though there was one sole example made
with Wrights(MK4C)
So that put an end to alternate engines .

[Zac Yates]

The Mk 4W had Pratt Wasp Jr's (qty 15 were built)

After researching the Wright Hughes H-1 for a model build I knew the engine was rare. I had no idea it was THAT rare!

[rcaf_100]

The Mk 4W had Pratt Wasp Jr's (qty 15 were built)

After researching the Wright Hughes H-1 for a model build I knew the engine was rare. I had no idea it was THAT rare!

Only 15 P&W-powered Bolingbroke Mk IVW's were built, not 15 R-1535's built
Apparently the performance was below the standard Mk IV & IVT and the supply of Bristol Mercurys from England wasn't disrupted, so Fairchild stopped production of the Mk IVW after 15 were completed.

[bdk]

Fascinating James! Thank you so much for remembering the article and looking that up.

One could possibly substitute a similar material accounting for strength differences (titanium spar caps anyone?). You could either find the mechanical property specifications for the old material or do some mechanical properties testing to characterize them from a small piece of the original material. THE UK CAA seems to be more of a stickler for using original materials compared to the US FAA and their Designated Engineering Representative (DER) process.

Assemblies made like this tend to suffer from dissimilar metals corrosion due to their different galvanic properties. The farther apart you are on the galvanic scale the more your assembly acts like a battery, especially in the presence of moisture (the electrolyte).

G'Day bdk - long time no speak! I remembered some stuff in the late Graham Warner's books, that answer your question, so I thought I'd take a look. Though he doesn't quote the tech numbers for the material, I decided to post the full pages here as it tells a great story of the restorations challenges many know, but we should never forget.

While there's nothing significantly different as a design in the Blenheim's wing spars, it's important to remember MOST non-US types of restorations will be dealing with airworthy rebuilds of one, two or less than five of a type, from often few or no airworthy part donor survivors. RELATIVELY speaking, US types are well provided for in spares and survivors, particularly those common-as-muck NAA types.

https://vintageaerowriter.wordpress.com ... par-steel/

Also bonus young John Romain image...

[Zac Yates]

The Mk 4W had Pratt Wasp Jr's (qty 15 were built)

After researching the Wright Hughes H-1 for a model build I knew the engine was rare. I had no idea it was THAT rare!

Only 15 P&W-powered Bolingbroke Mk IVW's were built, not 15 R-1535's built
Apparently the performance was below the standard Mk IV & IVT and the supply of Bristol Mercurys from England wasn't disrupted, so Fairchild stopped production of the Mk IVW after 15 were completed.

I'll go back to my corner - oops!