How badly would a plane like this perform?

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THere is some dispute about the wooden wings, some sources say they were only wood covered. Metal wings are lighter for the same strength and have more volume inside compared to wings with wooden structural memebers. However the same sources say that Hughes chose wood because it wood give a better serface finish than metal. One source claims plywood on wing was covered with ballon cloth and painted with hand rubbed laquer. THe painted (or doped) cloth serface treatment was not uncommon but odes speak to the attempts at drag reduction.

THe Quote from Hughes is supposed to be post war and in 1937 the Army wasn't buying much of anything then that didn't have canteliver monoplane wings (OK, some trainers?) Yes the Army was interested in looking at the Hughes racer but were they interested in the design as a whole or just interested in certain features?
It is claimed the H-1 was the first plane to use flush rivets, the first plane to use butt joints on the sheet metal (vrs lap joints) and the first plane to use wing leading edge air intakes. I don't know if these claims are true but these and other features may have been of interest to the Army even if the design as a whole wasn't.

THe P-35 had a fairly successful career as a race plane itself.

Seversky S-2 air racer

While not in the same league as the H-1 aerodynamicely it should be noted when comparing weights that the P-35 did use the bigger, heavier R-1830 engine, had a bigger, heavier propeller and had a much larger wing in addition to the fat fuselage. I never said the P-35 had a turbo-supercharger. Just pointed out it flew with it's cantelever monoplane wing before the H-1 did. The P-30s had the turbochargers.

As far as raceplanes go try: Wedell Williams No.44 air racer
The Book "Race the Wind" devotes most of a chapter and an appendix to the proposed P-34 Fighter by Wedell with performance comparisons/estimates and weight analysis (a little crude on the weights but it is an estimate after all.) THE Wedell racers were stress for about 5.35 "G"s and were pylon racers. THE Goveremnt was worried about their strength if not beefed up for fighter duties. While Hughes is supposed to have planed to enter the H-1 in the Thompson race he never did. Also considering that the Thopsen could be run using much less fuel than a cross country dash the lower weight results in a lower G loading than the fully loaded plane would have.

Part of the problem is that carrying over the aerodynamics doesn't work so well. In the Wedell case they estimated by the time they loaded down the plane with military gear, raised the cockpit and enlarged the wing to keep the same landing speed as the unecumbered plane the speed advantage dropped to only around 20mph faster than the P-26 using the same engine (500hp 9cyl. wasp) they tried to keep up interest by schemeing a twin wasp Jr (same engine as the Hughes) but the Army figured by the time all the redesign was done the P-35 and P-36 would be Flying (prototypes) and the re-engined Wedell didn't promise anything that the newer all metal planes didn't.

As far as engine size goes I wonder why Hughes didn't stick the R-1830 in the plane to begin with? The R-1830 was the first twin row engine that P&W came out with. The R-1535 was the second so the R-1830 was certainly avialble when he designed his plane. Weights in the 1938 edition of Janes are 1,116 for the Twin Wasp JR. and 1,403-1,433 for the Twin Wasp depnding on Gear ratio. Both engines using single speed/single stage superchargers. Earlier engines may have been lighter?

More later
 

An interesting point, perhaps a mistake on the part of the Hughes team? By the way, Richard Palmer was the designer of the plane, let's not give Hughes 100% credit for it.
 
The P-30s had the turbochargers.

Sorry, I didn't read carefully enough.


I have read that Hughes had received some classified data on the 1535 performance surreptitiously. He may have been more comfortable with that engine than with the 1830. Also, as you have pointed out, the area increase of the 1830 (with only 1000 hp available at the time) would have had to be boosted to 1200 to equal the record breaking speed (my argument was that the rated power was much higher and thus more militarily acceptable), something he may have been more unsure of. He was, of course successful in boosting the 1535 40% (with help from 100 octane gas), if he would have done that with the 1830, he could have had quite a bit more power.
 
An interesting point, perhaps a mistake on the part of the Hughes team? By the way, Richard Palmer was the designer of the plane, let's not give Hughes 100% credit for it.

We are often giving credit to the famous and the many significant contributors go unnamed. The aircraft is a beautiful example of excellent aerodynamics.
 
We are often giving credit to the famous and the many significant contributors go unnamed. The aircraft is a beautiful example of excellent aerodynamics.
Palmer later went to work for Vultee and designed their arguably most successful plane, the BT-13 Valiant.
 


I believe the story went that on visit to the P&W factory he was left alone with the data in an office after the employee who wasn't "supposed" to show him the data was "called down the hall" for an extended period of time. Given that "lack" of co-operaton I doubt that Hughes couldn't have gotten similar information on the R-1830 if he wanted it.

I believe Jimmy Dolittle was supposed to have gotten an R-1340 up to 900hp on 100 octane fuel in testing in the very early 30s.
THese early HP ratings just showed the potential of the 100 octane fuel however. Getting the engines to hold together at these power levels for more than a few moments ( or to be able to hold cylinder temperature limts in any but optimium conditions) took a bit more work.

Streamlineing wasn't as well understood in the early-mid thirties as it was even in 1940. A lack of large scale, high speed wind tunnels ment that it was hard to test therorys. A number of racing planes were built to take both Wasp JR and Wasp engines interchangably to suit the costomers ideas on frontal area vrs power. ANd perhaps fuel consumption on long flights?

Hughe's record cross country flight was probably planned to use a an approximatly 20,000 ft cruising altitude. Benny Howard had won the Bendix race the year before cruising at 22,000ft, while on oxogen. Hughes plane was equiped with oxogen but a malfuction in the equipment almost caused him to black-out.
Actual cruising altitude may be unkown. Hughes had made 12 trips west to east as a co-pilot in DC-3s and had flown Jackie Cochran's Northrop Gamma to a west-east record the year before.

Since I don't know what certificate the Hughes racer flew under (experimental? group 2?) we don't really know what it was stressed for. SOme of these cross country planes took off heavily loaded with fuel ( a bit like a ferry flight and so thier "gross" weight might relate more to a fighter with carring full over load ferry tanks. For instance, The Mustang was rated at 8 "G"s but that was at 8,000lbs. To get the Mustangs "G" rating at other weights divide the weight into 64,000. ("8"s x 8,000lbs). For a tak-off weight of 12,400lbs the Mustang would have a "G" rating of 5.16 not figuring for local load limits on the attachment points or center of gravity issues.
Going back to the Hughes Racer if it's max gross weight was 5,492lb on the cross country flight we have no idea if the plane was stressed for any but the most gentle manuevers at such a loading. We do that bombers are desinged to a lower "g" loading than fighters and we know that currently the load factor for commercial light planes is 3.8 in the normal and commuter catigories, 4.4 for utility and 6 for acrobatic. Going back to the 1930s the regulations may have been a bit more lax, especially for a one-off special purpose airplane. On the other hand with high speed flight and the resultant stesses in it's infancy the engineers just might have erred on the side of caution and built the plane just a bit heavier than need be.

I did use the Brewster Buffalo as weight comparison becasue it is the only plane that is close to the weight of the hughes that I have a good weight break down for.

More later.
 
Actually I don't know

What I do know is that in Joseph Juptner's series on U.S. Civil aircraft (of Approved type Certificates) in volume #9 There is a chapter on planes that had "Group two approval" instead of a full Approved type Certificate. As described in the introduction to this chapter.

"....(Group 2) was usually awarded to an airplane that be built either in one or two examples only, a limited quantity for test and evaluation, or for some predetermined number of airplanes; this approval was also awarded for certain modifications (such as a different engine, increased, decreased, or rearrenged seating, major interior changes, increased fuel capacity, etc.) of a standard type airplane already in approved (ATC) production."

It does not say what the differences are. I will note that while a few long distance record setting planes are in this chapter there don't appear to be any of the Thompson trophy racers.
 
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As a side note
There was a racer based fighter in service 1939-40, namely Caudron C.714, but it wasn't a success. Rather fast if compared to M.S. 406 but underpowered, so lousy climber and rather unmanoeuvrable. So a failure as a fighter.

Juha
 

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