The Skyshark in RAN FAA service

[rickshaw]

The Skyshark in RAN FAA service

On 25 June 1945, the Bureau of Aeronautics (BuAer) asked Douglas Aircraft for a turbine-powered, propeller-driven aircraft.  Three proposals were put forth in the next year and a half: the D-557A, to use two General Electric TG-100s (T31s) in wing nacelles; the D-557B, the same engine, with counter-rotating propellers; and the D-557C, to use the Westinghouse 25D. These were cancelled, due to engine development difficulties, but BuAer continued to seek an answer to thirsty jets.

On 11 June 1947, Douglas got the Navy's letter of intent for a carrier-based turboprop. The need to operate from Casablanca-class escort carriers dictated the use of a turboprop instead of jet power. The advantages of turboprop engines over pistons was in power-to-weight ratio and the maximum power that could be generated practically. The advantage over jets was that a turboprop ran at near full RPM all the time, and thrust could be quickly generated by simply changing the propeller pitch.

While it resembled the AD Skyraider, the A2D was different in a number of unseen ways. The Allison XT-40-A2 at 5,100 hp (3,800 kW) had more than double the horsepower of the Skyraider's R-3350. The XT40 installation on the Skyshark used contra-rotating propellers to harness all the available power. Wing root thickness decreased, from 17% to 12%, while both the height of the tail and its area grew.

Engine development problems delayed the first flight until 26 May 1950, made at Edwards Air Force Base by George Jansen.

Navy test pilot Cdr. Hugh Wood was killed attempting to land the first prototype XA2D-1, BuNo 122988, on 19 December 1950, on its 15th flight. He was unable to check the rate of descent, resulting in a high-impact crash on the runway. Investigation found the starboard power section of the coupled Allison XT40A turboprop engine had failed and did not de-clutch, allowing the Skyshark to fly on the power of the opposite section, nor did the propellers feather. As the wings' lift disappeared, a fatal sink rate was induced. Additional instrumentation and an automatic de-coupler was added to the second prototype, but by the time it was ready to fly on 3 April 1952, sixteen months had passed, and with all-jet designs being developed, the A2D program was essentially dead. Total flight time on the lost airframe was barely 20 hours.

In December 1952, Allison was forced to call for help from the rest of the aircraft industry because of it's troubles with the engine and gearbox of the Skyshark.  Armstrong-Siddeley, in the UK answered their call and suggested that they substitute the Double Mamba engine and it's combining gearbox from the Gannet ASW aircraft.   "Why not?"  Agreed Allison and so they took the Mamba and "Americanised" the design.   The result was a much better engine than the languishing T40.  Mean time between failures soared and the reliability of the engine improved phenomenally.   The aircraft's maximum take off load fell though, due to the substantially decreased horsepower which was available because of the lower thrust engine. Whereas the T40 developed (on a good day) 5,100 hp, the Double-Mamba only developed in it's early versions approximate 3,100hp.  The result was a loss in warload and speed, which was felt was justified in exchange for the massive increase in reliability.   The Skyshark entered service with the US Navy in 1955.

Two hundred Skysharks were built, two prototypes and ten preproduction aircraft included. However, it's time was rapidly passing as the US Navy adopted the A-4 Skyhawk to replace it with a jet powered aircraft.  Due to the decision to retire the US Navy's escort carriers, the need for the Skyshark reduced.

The Royal Australian Navy, on the look out for an aircraft to equip it's nearly acquired modernised Essex carrier, adopted the Skyshark with alacrity though, in 1958.  Able to carry twice it's predecessor's war load, the Skyshark proved an able performer in the naval strike role in Australian service.   It's range was also nearly twice as far as the Fairey Firefly.   Until 1968 when replaced in RAN service by the A-4 Skyhawk, the Skyshark gave stirling service off of HMAS ADELAIDE.






The Model

The model is the abysmal Mach 2 kit of the Skyshark.   This is not a kit I would recommend to beginners.   It was my first Mach 2 kit and it will remain my only one for some time to come.  It has taken about 3 years to complete after I first opened the box and looked at it's contents.  I'd recommend the Anigrand one simply because it more than likely actually fits better, being a resin kit.  Painted with a hairy stick, the decals came from the spares box.

[Leading Observer]

Excellent work & back-story

[PR19_Kit]

THREE years? 

I hope that's not a portent for my current Mach 2 build. Well done for sticking with it Brian, and it looks great too. 

If it had longer wings you could have more pylons though. 

[zenrat]

Well done for persevering.

[rickshaw]

THREE years? 

I hope that's not a portent for my current Mach 2 build. Well done for sticking with it Brian, and it looks great too. 

If it had longer wings you could have more pylons though. 

Three years.  It was your Mach 2 build which prompted me to finish this one.  I took it out of it's box and thought, "If Kit can do it, I can do it," and so I did it.   Like your experience it wasn't a happy one.   

[Dizzyfugu]

OMG, is this thing ugly... (not referring to the kit as such, but the massive aircraft - the light grey glorioussly underlines the sheer bulk of the thing!)

[NARSES2]

It's an interesting aircraft and coincidentally I did mine as RAN FAA a few years ago. Mind you I built the Anigrand kit which went together very well.

I do have to admire your perseverance mate  I didn't even know Mach 2 did a kit of it, mind you they are not a manufacturer I tend to look at that much.

[PR19_Kit]

THREE years? 

I hope that's not a portent for my current Mach 2 build. Well done for sticking with it Brian, and it looks great too. 

If it had longer wings you could have more pylons though. 

Three years.  It was your Mach 2 build which prompted me to finish this one.  I took it out of it's box and thought, "If Kit can do it, I can do it," and so I did it.   Like your experience it wasn't a happy one.   

Is any Mach 2 build a happy one? I've yet to hear of one, but I live in hope. 

[Old Wombat]

OMG, is this thing ugly...

Oh, yeah! Even more-so than the Gannet!

[TheChronicOne]

Hell of a deal! This is awesome... I've never seen such a thing! And, yeah, it's a goofy looking contraption, I have to agree with the rest on that but on the flip side it is really cool looking! I do adore the stranger and more obscure aircraft.

I think it looks great... and... man, doesn't it feel good to get them stalled projects finished?! 

[Weaver]

Nice one - you got there in the end! 

I had a long look at Mach 2's Ryan XF2R Dark Shark at a show (last year?), but the sucking of air through teeth from the rest of the What If crew persuaded me put it down again carefully and step away from it...

[sandiego89]

Having been under and all around the sole survivor Skyshark in California "ugly" is not quite the word I would use.  While ugly is very subjective, and it is certainly not pretty, perhaps "mean", "beast" "brutish" or "rugged" best describes it.  It towers above you and really needs to be seen in person.  Thinking of it as an slightly enlarged SkyRaider does not do it justice.  Very impressive.  I can not imagine being near a squadrons of these aircraft up and running.

I save "ugly" for some of those 1950's Russian jets or the X-32....

[Glenn Gilbertson]

All that effort has paid off - an impressive model.

[NARSES2]

Having been under and all around the sole survivor Skyshark in California "ugly" is not quite the word I would use. 

Didn't realise there was one.

Must admit ugly is not a word I would use for it either. Brutish is a very good choice of word with perhaps thugish coming in second