RTV-A-2 (MX-774) "HIROC"

[bradycros]

Going to have a go at this one.

 

[sandman]

Why did you tape over the dimensions on that drawing??

Any way to get copies of that drawing?

Please.

 

[MarkII]

It doesn't look like anything is taped over. It just appears in the photo that one drawing has been laid on top of another.

Great project idea, Todd!

 

[5x7]

It doesn't look like anything is taped over. It just appears in the photo that one drawing has been laid on top of another.

Great project idea, Todd!

Nose, total length, fin span and cp are taped over.

 

[bradycros]

Any way to get copies of that drawing?

Please.

Done.

 

[bradycros]

A rough upscale of the nose cone and boat tail.

 

[bradycros]

Since the root of the fin is going thru the boat tail, there's no need to draw the curviture of the boat tail on fin template.

 

[rocketguy101]

Why did you tape over the dimensions on that drawing??

Any way to get copies of that drawing?

Please.

It is available from NASM
https://www.nasm.si.edu/research/arch/collections/techdraw/prepsets_list.cfm

 

[bradycros]

The MX-774 Vultee "Hiroc"

Project MX-774 Hiroc was a joint effort between the Army Air Force (AAF) and
Consolidated Vultee to develop an Intercontinental Ballistic Missile
(ICBM). This project later became the Atlas. Due to a lack of funding and
better proposals from other vendors the MX-774 was prematurely terminated.
Even though the project was cut short there were three flights which did
demonstrate innovative design concepts including ballon construction which
made the propellant tanks part of the airframe, gimballed gyroscopic
controlled motors, and a separable warhead.

Dimensions
Length: 31 ft. 7 in. (9.63 m)
Diameter: 30 in. (76 cm)
Finspan: 6ft 10 in (2.08 m)
Empty Weight: 1,205 pounds
Launch Weight: 4100 lb (1800 kg)
Propellant: Liquid (Alcohol/Liquid Oxygen)
Best Altitude: 40 miles (65 km)
First Firing: July 1948

 

[bradycros]

Convair RTV-A-2 Hiroc

Among the various guided missile studies initiated by the U.S. Army Air Force in 1945 was Consolidated-Vultee's project MX-774, which was about supersonic surface-to-surface missiles. After the development contracts for cruise-type winged missiles went to Martin (MX-771, SSM-A-1/TM-61 Matador) and Northrop (MX-775, SSM-A-3/SM-62 Snark), Convair was awarded a contract to develop and test a ballistic research missile under project MX-774. The effort was named Hiroc (High-Altitude Rocket) and the vehicle received the designation RTV-A-2 in 1947. However, the program was formally cancelled in June 1947, but Convair was allowed to complete and fly three test vehicles using available funds.

The RTV-A-2 was powered by a Reaction Motors XLR35-RM-1 four-chamber liquid-fueled rocket motor, and had a cylindrical body with four fixed stabilizing fins. The Hiroc pioneered several new design techniques which would later be used in the SM-65/HGM-16 Atlas. It featured a gimballed rocket nozzle to steer the vehicle by thrust-vectoring instead of weight- and drag-increasing control fins, and had a separable nose cone for the payload. The rocket had no structurally separate fuel tanks, using instead the airframe itself as tank walls. The light weight, pressure stabilized tank structure as later used on the Atlas was considered, but not implemented. The RTV-A-2 used telemetry to transmit flight data to the ground, and the nose cone was designed to be recoverable by parachute.

The first RTV-A-2 flew in July 1948, followed by the other two rockets in September and December that year. All three flights were only partially successful (mainly because of engine failures), but helped a lot to validate the new design concepts.

Specifications
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for RTV-A-2:

Length 9.63 m (31 ft 7 in)
Finspan 2.08 m (6 ft 10 in)
Diameter 76 cm (30 in)
Weight 1860 kg (4100 lb)
Speed 3200 km/h (2000 mph)
Ceiling > 65 km (40 miles)
Propulsion Reaction Motors XLR35-RM-1 liquid-fueled rocket; 35.5 kN (8000 lb)

 

[stardust]

Just about finished with my (MX-774) "HIROC" kit from Advanced Rocketry Group. Nice sport scale model. A good foundation for a super detailed model.

 

[bradycros]

Just about finished with my (MX-774) "HIROC" kit from Advanced Rocketry Group. Nice sport scale model. A good foundation for a super detailed model.

Speaking for myself, I would like to see as many pictures as you would care to post. Any pointers, gottch ya's or things you would have done differently, now that you know better would be great. Did you do a super detailed build?

 

[stardust]

Speaking for myself, I would like to see as many pictures as you would care to post. Any pointers, gottch ya's or things you would have done differently, now that you know better would be great. Did you do a super detailed build?

I will document the construction an some photos. A few things that I have run into are: Nosecone and tail cone needed considerable sanding to match the diam.of the BTube. And have made the fin profiles prototypical by using the provided balsa sheet. Have the actuators for the fin tabs solid balsa rather than the metal yokes shown on Peter Alway drawings. Also have 2 threaded inserts into the tail cone close to the fins for the motor retainer to be threaded into. Used 3oz. satin weave glass cloth saturated with laminating Areopoxy (Giant Leap) over the fins. Fillets are 3M Micro Baloons mixed with epoxy. Before construction I slathered/saturated the inside of the Btube with superthin superglue for additional strength and water resistance. Glued kevlar (5/8"X 1/16")shock cord 5 times the length of the BT to the motor tube, up through the upper centering ring. Got the nice thin, wide kevlar strap from Missile Works..good stuff... Photos to come, will be in the scale area... LOVE the lines of the rocket...can't wait to fly it!

 

[bradycros]

I will document the construction and some photos. ... Photos to come, will be in the scale area... !

Been checking the Scale section every day for two weeks! Are you still planning to share your build with pictures and commentary?

 

[stardust]

Just do not think I belong on this forum. Have asked to unsubscribe. Sorry for the wait friend...might keep an eye out elsewhere.

Been checking the Scale section every day for two weeks! Are you still planning to share your build with pictures and commentary?

 

[Pem Tech]

Just do not think I belong on this forum. Have asked to unsubscribe. Sorry for the wait friend...might keep an eye out elsewhere.

Did we do something to run you off?

 

[stardust]

Did we do something to run you off?

No Pem Tech, only several others made me disappointed in in some parts of the human kind associated with this forum. Most of you guys are good as gold!

I take exception to responses to my post in which I have had my reasoning and others intellect insulted with shallow, insensitive, and rather less than thinking quotes to the post. The example, in the"techniques" area, with the original post about adhesion promoter. Then a come back by two who obviously did not read the end of my quippet on" hazardous." Then to have the "rules" czar chime in too about spray outside, 2 cents worth etc! Is simply too much stupidity for me. I usually surround myself with winners. And when this type of shallowness occurs, I need to separate myself from these types of entities. It is these types of thinkers that have given us all a world of unnecessary bubble headiness, unnecessary protection, rules and total lack of common sense. It is usually derived from individual self fear. They project on others because they totally lack control over anything at all in their own lives. They are the unfortunates.

I am powerless over others...but can do everything about myself, and my side of the street!


And a Super thanks to all of you good people that have email me in understanding and condolence! Thanks! Dan

 

[sodmeister]

Dear Dan ,it`s called "social engineering" and a scarier thought there is not.It`s kind of a father knows best phenomenon....except father learned through his personal "Darwinistic life experiences" and thought he should pass them along and make them law.

Sorry to hear you are leaving

Paul T

 

[stardust]

Dear Dan ,it`s called "social engineering" and a scarier thought there is not.It`s kind of a father knows best phenomenon....except father learned through his personal "Darwinistic life experiences" and thought he should pass them along and make them law.

Sorry to hear you are leaving

Paul T

Hopefully NO "encounters of the third kinds." And staying out of crossed up hairs I have learned is good too... Hope.

In grade school many decades ago, couddie shots were popular against the afflictions of the types..hee hee, take care Thanks