Admiral Beez
Major
Why wasn't de Havilland Hornet Griffon powered? It seems an ideal candidate.
Why wasn’t de Havilland Hornet Griffon powered?
- Thread starter Admiral Beez
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Shortround6
Major General
A single stage Griffon was about 400lbs heavier than single stage Merlin and you have around the same weight difference for the 2 stage engines. The Griffon will also need bigger props, a bigger oil system and a few other larger heavier accessories. It may also burn more fuel if you use the extra power.
Upping the empty weight of airplane by 8-9% in the design stage usually means a number of other changes have to be done too.
There may have been proposals for a bigger twin, it would be interesting to see any comments on such a plane. There were proposals for super Mosquito using a pair of Sabre engines but everything was scaled up. There were also proposals for a bigger Mosquito using either Merlin or Griffon engines. The Hornet was sort of scaled down Mosquito using special slim Merlins (accessories relocated to reduce frontal area ) so fitting the larger Griffons would have been counter productive.
DH was also working on the Vampire jet fighter and some of these "based on the Mosquito" designes had to be put aside to work on the Vampire, and let's face it, no matter what kind of piston engines you stuffed into a big twin the Vampire jet was going to beat it for speed and climb.
Upping the empty weight of airplane by 8-9% in the design stage usually means a number of other changes have to be done too.
There may have been proposals for a bigger twin, it would be interesting to see any comments on such a plane. There were proposals for super Mosquito using a pair of Sabre engines but everything was scaled up. There were also proposals for a bigger Mosquito using either Merlin or Griffon engines. The Hornet was sort of scaled down Mosquito using special slim Merlins (accessories relocated to reduce frontal area ) so fitting the larger Griffons would have been counter productive.
DH was also working on the Vampire jet fighter and some of these "based on the Mosquito" designes had to be put aside to work on the Vampire, and let's face it, no matter what kind of piston engines you stuffed into a big twin the Vampire jet was going to beat it for speed and climb.
Glider
Captain
Because the Merlin 130 engine she was equipped with was specially designed for the Hornet. A particular factor being the small frontal area to assist with streamlining and therefore aerodynamics. The merlin was over 2,000 hp, a far cry from the more traditional versions of WW2 and a Griffon would have slowed her down.
ThomasP
Senior Master Sergeant
The additional power of the Griffon 130 would have more than made up for the increased weight and drag. There would (I think) have been a significant increase in speed at higher altitudes, and a significant increase in climb at all altitudes. Range would have been significantly reduced though, without a larger airframe to carry more fuel.
_______Merlin 130____________Griffon 130
Mil VHi______________________ 2050_+25_ 21,000 ft
Mil Hi__1690_+20_18,000 ft
_______1845_+25_14,250 ft____2,250_+25_14,000 ft
Mil Lo _1830_+20__5,500 ft
_______2020_+25__1,500 ft____2420_+25___5,000 ft
TO SL _1645_+20____________ 2350_+25
Also, as Shortround6 points out above, the Venom was in the offing (as well as other jets) by the time a Griffon powered Hornet would have been available.
_______Merlin 130____________Griffon 130
Mil VHi______________________ 2050_+25_ 21,000 ft
Mil Hi__1690_+20_18,000 ft
_______1845_+25_14,250 ft____2,250_+25_14,000 ft
Mil Lo _1830_+20__5,500 ft
_______2020_+25__1,500 ft____2420_+25___5,000 ft
TO SL _1645_+20____________ 2350_+25
Also, as Shortround6 points out above, the Venom was in the offing (as well as other jets) by the time a Griffon powered Hornet would have been available.
swampyankee
Chief Master Sergeant
- 4,020
- Jun 25, 2013
I suspect that the Hornet's design started early enough so that Griffon production was fully committed to Spitfires. Since the Merlin was in production but being supplemented (or supplanted) by the Griffon in Spitfires, deHavilland and the Air Ministry concluded that the Merlin was a better choice. I'm fairly sure that the Griffon's accessories could be relocated, similarly to what was done with the Merlin. A second issue is (as mentioned above) was that the Griffon was significantly heavier (400 lb; thank you Shortround6). This would have increased the aircraft's empty weight on the order of 1600 lb ( 2 lb increase in overall weight for a pound increase in engine weight is a rough rule of thumb). There are some reports that there was an early design decision to include a carrier-based version; those 1600 lb extra weight may have pushed it beyond the size that could fit on available RN carriers.
Reluctant Poster
Tech Sergeant
- 1,637
- Dec 6, 2006
The Griffon 130 has a major advantage in its 3 speed supercharger drive. A 3 speed drive was planned for the Merlin which would erode much of this advantage.
- Thread starter
- #8
Admiral Beez
Major
Perhaps that's the same reason the Avro Lincoln was Merlin powered.
I didn't know these were areas in need of improvement. The Griffon, if added would be to add speed and perhaps rate of climb.
Rate of roll is obviously made worse with heavier engines and the increased all up weight for all reasons not just the engines would make it more problematic to land.
Glider
Captain
I must disagree with the idea that the Griffon would have been an advantage over the Merlin in the Hornet.
I tend to look at things from a common sense perspective. This tells me that we can assume that both Rolls Royce and De Haviland were more than aware of the characteristics of both the Merlin and the Griffon and if the Griffon was better suited, then they would have used it.
People tend to gloss over the aerodynamics but when you look at tests done for instance of the benefits of flush riveting compared to 'normal' rivets, or the impact of minor blandishments on the efficiency of a wing, or how the installing of a rear view mirror on a cockpit impacts drag and speed. Sticking a couple of heavier drag inducing engines would have had a significant impact, let alone to the COG considerations, increased wing loading and every other area of performance.
If anyone believes that the extra power will more than compensate then I strongly suggest they have a good long look at the sorry saga of the Spey equipped F4.
In high performance aerodynamic aircraft, drag is very important.
I tend to look at things from a common sense perspective. This tells me that we can assume that both Rolls Royce and De Haviland were more than aware of the characteristics of both the Merlin and the Griffon and if the Griffon was better suited, then they would have used it.
People tend to gloss over the aerodynamics but when you look at tests done for instance of the benefits of flush riveting compared to 'normal' rivets, or the impact of minor blandishments on the efficiency of a wing, or how the installing of a rear view mirror on a cockpit impacts drag and speed. Sticking a couple of heavier drag inducing engines would have had a significant impact, let alone to the COG considerations, increased wing loading and every other area of performance.
If anyone believes that the extra power will more than compensate then I strongly suggest they have a good long look at the sorry saga of the Spey equipped F4.
In high performance aerodynamic aircraft, drag is very important.
Wow! V-1710 can't even get out of 1st gear.
I think use of the name "Hornet" should be used loosely in this thread.
The "Hornet" that we know and love would have been a different "Hornet" designed with/for Griffons.
Perhaps I am interpreting the OP wrong, but I didn't assume it meant sticking Griffons on an existing Hornet.
IMO - the ideal candidate for the 2-stage Griffon were, out of the British aircraft, the Fury (post-war, as the Hornet was) and MB-5, and then the Tempest. Granted, the prop-driven fighters of 1944-46 were hitting the combined wall of compressibility & low prop efficiency at 450-490 mph (depending on the A/C and engine used) at altitude, so Griffons don't add much on a twin that already does 460-475 mph on Merlins.
It would have been bigger and heavier, maybe marginally better in speed and ROC whether that was overall better is something I doubt.
Not sure if this analogy is completely accurate, but think of B-25 (R-2600 powered) to B-26 (R-2800 powered)
Of course, the air frames are apples to oranges.
If there were no B-26, some today might be saying that a R-2800 powered Medium wouldn't have been worthwhile.
Shortround6
Major General
They tried a B-25 with R-2800 engines. They broke the wings pulling up from a high speed low altitude pass and the test crew died.
Nobody accuses the B-25 of being a weak aircraft.
Nobody accuses the B-25 of being a weak aircraft.
Bingo! The same reason why Peregrines were installed into the Westland Whirlwind. Extensive redesign would have been necessary if retrofitted - although Petter offered the Whirlwind Mk.II to be powered by Merlins after the Peregrine was canned. The Hornet was the result of careful design in terms of aerodynamics, weight, range all that stuff - as SR alluded to.
yulzari
Staff Sergeant
A Hornet with twin RR Crecys would be amusing........
