P-51 with contra-props (1 Viewer)

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wuzak

Captain
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Jun 5, 2011
Hobart Tasmania
Was any consideration given to fitting a P-51 with contra-rotating props?

Rolls-Royce and Supermarine tested Spitfires with contra-props from 1944, IIRC, both with Merlins (Mk.VIII) and with Griffons (Mk. XIV). These were Rotol props, I believe.

Were any similar systems being tested at the same time in the US that may have been fitted to a P-51?

What are the advantages and disadvantages of doing this?

Could a contra-prop P-51 made the war?
 
Loads of info on this Secret Projects Forum thread
 
Why?

Spitfires got contra-rotating props because they were small aircraft, sitting close to the ground, with engines putting out well over 2000HP. Did the Americans even try five blade props?

The contra-rotating props on various British aircraft were due to version of the Rolls Royce Griffon having two conta-rotating output shafts were they not? Mustangs that (fairly) recently have received contra-rotating props are powered by Griffon_57s.
 
The Spitfire sat no lower than the P-51.

Did the Americans even try five blade props?

Yes.

XP-51G.jpg
 
IIRC, no but there were experiments with contra-rotating props, The XB-35, XB-42, XP-56, XFY-1 and the XFV-1 to name a few.

Between the complexity of the design ad extra weight, I see no real advantage on a single engine fighter.

Today the Latest model of the C-130 uses 6 bladed propellers
Also the XF4U-4. There is a photo of it in Barrett's B Barrett book, "Corsair The F4U in World War ll and Korea". Two photos on Reddit

 
The Spitfire sat no lower than the P-51.



Yes.

View attachment 684123
As I understand it how it sits isnt so important. When taking off and landing the Spitfires wheels are further back so it needs fewer degrees of rotation forward for the prop to touch the ground, later Spitfires had legs that telescoped out to increase clearance from WIKI
The Griffon engine drove an 11 ft (3.4 m)-diameter five-bladed propeller, some 7 in (18 cm) larger than that fitted to the Mk XIV. To ensure sufficient ground clearance for the new propeller, the undercarriage legs were lengthened by 4.5 in (11 cm). The undercarriage legs also had a 7.75 in (19.7 cm) wider track to help improve ground handling. The designers used a system of levers to shorten the undercarriage legs by about 8 in (20 cm) as they retracted, because the longer legs did not have enough space in which to retract; the levers extended the legs as they came down. The larger diameter four-spoke main wheels were strengthened to cope with the greater weights; post-war these were replaced by wider, reinforced three spoke wheels to allow Spitfires to operate from hard concrete or asphalt runways. When retracted the wheels were fully enclosed by triangular doors which were hinged to the outer edge of the wheel wells.[41]
 
Why?

Spitfires got contra-rotating props because they were small aircraft, sitting close to the ground, with engines putting out well over 2000HP.

Spitfires got contra-rotating props to cancel out torque reaction.

It may not have been as big an issue with the P-51, but still may have been a problem.


The contra-rotating props on various British aircraft were due to version of the Rolls Royce Griffon having two conta-rotating output shafts were they not?

Spitfires were tested with Merlins and Griffons fitted with contra-props in WW2.

The Short Sturgeon was one WW2 era aircraft that was fitted with contra-prop Merlins

Short_Sturgeon_S.A.1_T_Mk.1_prototype.jpg

 
Correct, the higher powered Griffon engined versions had vicious torque issues - a small light airframe with too much power.
Took an age to get into service - and was already far eclipsed by jets - and quickly exited stage left
Do you just make stuff up? The first production Griffon Spitfire appeared in Oct 1942 have first flight in Nov 1941, this is before any jets were in service however there was a war on. When discussing the vicious characteristics of a Griffon Spitfire please compare to a P-80 from Wiki
The Shooting Star began to enter service in late 1944 with 12 pre-production YP-80As, one of which was destroyed in the accident in which Burcham was killed. A 13th YP-80A was modified to the sole F-14 photo reconnaissance model and lost in a December crash.

Four were sent to Europe for operational testing (demonstration, familiarization, and possible interception roles), two to England and two to the 1st Fighter Group at Lesina Airfield, Italy, but when test pilot Major Frederic Borsodi was killed in a crash caused by an engine fire while demonstrating a YP-80A (44-83026) at RAF Burtonwood, Lancashire, England, on 28 January 1945, the YP-80A was temporarily grounded.[14][15]
 
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Spitfires got contra-rotating props to cancel out torque reaction.

It may not have been as big an issue with the P-51, but still may have been a problem.




Spitfires were tested with Merlins and Griffons fitted with contra-props in WW2.

The Short Sturgeon was one WW2 era aircraft that was fitted with contra-prop Merlins

View attachment 684183
You missed the Avro Shackleton! Now that it is retired, its Griffon 57s with single stage superchargers and twin output shafts are being installed in Mustangs, and in a Seafire_47 apparently.
 
Correct, the higher powered Griffon engined versions had vicious torque issues - a small light airframe with too much power.
Took an age to get into service - and was already far eclipsed by jets - and quickly exited stage left
Spitfire Mk XII Performance Testing were in service in 1942, didn't exited stage left until the war was over, did you research the Griffon Spits at all before posting?.
 
Took an age to get into service - and was already far eclipsed by jets - and quickly exited stage left

With the other posters here, you don't know as much as you like to think you do.

The first Griffon powered Spitfire, Mk.IV DP845 first flew in November 1941. First production Mk.XII, the first production Griffon engined Spitfire rolled off the production line in October 1942 and entered RAF service in February 1943. From prototype to production to service in 15 months isn't "an age" in wartime.

"Already far eclipsed" by jets in 1943? How many jets in service in February 1943? None! the Messerschmitt Me 262, the first operational jet fighter first entered service more than a year later, nearly the same time it took the Griffon-engined Spitfire to go from prototype to service, actually.

The last flights of RAF Spitfires took place in 1957. The last operational sorties in 1954, by fighter recon aircraft for Operation Firedog in the Malayan Emergency. Griffon-engined Spitfire FR.18s and PR.19s.

None of that matters, right? Spitfire bad.
 
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