Frequently Asked Questions

Q: Who can answer all the complicated questions about these airplanes? 

A: Fortunately, by virtue of my superior intelligence, I can answer any question..... ;-)  Uh, well, maybe or maybe not.  Please remember my answers are worth what you're paying for them.... nothing.  Use this info at your own risk.  It is not intended to offend anyone or promote any particular product.   The info below is what I have gathered from my limited exposure to the parties involved.

Q: Why do all you Rocket guys do those vertical climb outs?

A: Because we can!  (No, I never get tired of saying it)

Q: Are the RVs and Rockets really as good as everyone says?

A: YES!!!! I have firsthand knowledge obtained from building and flying an RV-4, an RV-6, and now an RV-8A.  The RV series fly flawlessly and they are pussycats on the ground.  The controls are smooth and light, yet not twitchy.   The RVs will easily hit 200 mph.  I was lucky enough to get a ride in Tom Martin's Rocket.  The Rocket is even better , IMHO.  Compared to my RV-4, I thought that the longer tail and slightly higher wing loading of the Rocket made it more stable and comfortable in turbulence.  However, the shorter wing didn't give up any of the wonderful responsiveness that I loved in the RV-4. 

(1-5-06: Now that I have 80 hours on my own Rocket I can verify that the Rockets are AWESOME!!! They perform exactly as advertised. Vince)

Q: Why not just build an RV-8?  It seems similar.

A: I'll let a couple builders answer this question, after stating my opinion.  "The RV-8, while similar, is outclassed in all aspects by the Rockets."

Bob Japundza says:

Being an RV-6 builder/driver and F1 builder, having flown both an RV-8 and a HR2, I can tell you that as soon as I rode in the Rocket I fell in love. It is night and day different when comparing them to RV's.  There is NO COMPARISON. Consider the following:

1. Burns less gas when flying at the same speed as RV's.
2. More power. More room in the front cockpit, back seat has more legroom.
3. Insurance isn't out of line if you consider that your hull coverage is twice what it is with an RV. I was quoted $2800/yr. To me it's the price of admission.
4. More comfortable cockpit. In the RV-8, I found that I didn't particularly care for rudder pedals being so close together, or the gear towers. The panel is closer and lower. In a roll I had the stick well into my thigh. Roll rate is better in the Rocket. Vertical performance is also much better. I'm not knocking the -8, I just didn't "feel at home" in it. I do in a RV-4, more than I do than in my -6.
5. Engines are cheaper (that will change.) I paid 7K for my 540, zero-time but overhauled 20 years ago and never installed. Bought a prop for $1800, 300 smoh. Add it all up and I will about the same $$ as building a 200hp-C/S QB RV. Maybe even less.
6. Most Rocket guys cruise at very low power settings, thus improving the life of the engine and burn less gas than an IO-360-powered RV. 10 to11 gph is typical for cruise. Depends on who's buying the gas.
6. Chicks dig cool planes.
7. Not everyone has one.
8. Tandem seating is the way to go. Tons more room, you aren't rubbing elbows, etc.
9. I'd rather fly than bang rivets every evening and having built a prehistoric era RV-6, QB is the only way to go.
10. Yes it costs more, but I drive a beat-up jeep and would rather invest my money in airplanes than waste it on a car payment.

ok??   Bob Japundza

John Starn says: 

One plane at a time...

RV-4: Have flown in -4 several times. Kinda tight at the shoulders and without the heel cups tough to fit in the back seat for a long time. I'm 6-0 240# and my legs get in the way of the canopy cross member. -4 is "U-drill" the holes and is much more of a challenge than the later -7, -8 and -9 RV's with the pre-punch. Not just of the drilling holes but the jigs and alignment problems that don't exist with pre-punch. Have observed construction of -4, -6, -7, -8, -9 (& A's) and of course the HRII in our hangar.

RV-8: More room than the -4 because of the cowl being widened to cover the engine (no cowl cheeks) and that width carried back which widens both the front and rear cockpits. HRII has more leg, hip and shoulder room in both front and rear seats. The pre-punch is a huge advantage over the early RV's and the HRII in construction. The foot room in front of a -8 vs HRII makes the HRII a winner. 561FS has the battery between the rudder foot wells and still has lots of area for in-flight foot movement.

HRII: Much the hardest to build. You take some -4 parts from supplier "V", mix and fit with other parts from supplier "HR", nothing is pre-drilled, pre-aligned or done for you (QB types). HRII has more room everywhere (wider, longer, taller) except between the firewall and engine. Have flown with -4 and -6 (and other makes) along side the HRII in search of a hamburger. They all fly out about the same amount of fuel when the HRII power is pulled way back and set to fly with a -4 or -6 but with a lot in reserve. We normally take off last as we have no problem catching up with anyone.

F-1: Have seen several but not flown nor helped to build an F-1. Have used several of Marks Rocket products on 561FS and find them all to be great. F-1 is only available in Quickbuild mode so the cost up front is a lot more than the HRII and because 49% (yea, right) has been done for you it builds quicker. The F-1's I've seen were built by "others" which is OK if you have lots of money.

Bottom line (from my point of view): I enjoyed the building of 561FS, BUT it did take 5 years of blood, sweat and tears. I know every rivet, some 16,000+, up close and personal. Tom, Wendell and I did not assemble somebody else's pre-made sections, we made and assembled a bunch of aluminum sheets, angle and "stuff" into a flying Rocket. Took apart and under the direction of an AI assembled everything including the IO-540. Would I do it again ? Yes. Would I build another HRII rather than a -7, -8, -9 ? Yes (but I sure wish HRII came in an "a" model.) Would I buy a QB of any type ? No. Would I change anything the next time ? Yes. Four seats and pre-punched, come on RV-10, our next project. 561FS is not the fastest Rocket, the best looking and was financed and owned by Gummibear but somewhere in there it's still, in some small part, "MY ROCKET". Would I trade it for the RV-10 ? NO. I would want both. Would I trade it for anything else, maybe a T-28D or and F-86H. (Tom would choose an F-4E) MAYBE....... KABONG

Stu McCurdy , an RV-8 builder said this: I went through the same decision about two years ago. Here's my thought process and why I decided on the RV-8, recognizing I live very close to my friend Mark Frederick and his Rocket facility. 


1. Spring steel gear rather than the rod gear with its wheel dance.   (Wheel dance.... what wheel dance?)
2. Front and rear baggage for cross loading rather than stuffing it all behind the rear seat, creating a more aft CG.  (Huh? I have FOUR forward baggage areas inside my Rocket. Each is approximately one cubic foot in size. Certainly big enough for oil, tools, etc. Vince)
3. Insurance costs lower and easier to obtain for RV-8.
4. IO-360 vs IO-540. I spend 90% of my flying in formation, mostly with other RVs, but also with various other experimental and general aviation aircraft like Bonanzas, Grummans. I would rather spend that time at more normal power settings rather than low power settings.
5. The looks of the RV-8 slick lower cowl rather than the airscoop.  (I like the P-51 scoop on my F-1)
6. Inflight adjustable rudder pedals.  (Shouldn't you do that on the ground before takeoff?  The Rocket can be adjusted also... just needs a wrench. Vince)
7. More room between rear of engine and firewall for maintenance on the mag, oil filter, prop gov, fuel pump, pneumatic pump.  (You're still putting 20# of stuff in a 10# bag with either plane!  Vince)
8. RV-8 less expensive to achieve a responsive formation platform.  (Debatable.  I'll have approximately $45K, all documented, in my Rocket with a brand new Hartzell, O SMOH engine, and NICE VFR panel.  Vince)
9. Van's Aircraft has a 25 year history of excellent product support.

Rocket: Great looking airplane with lots of power and performance. Mark is a great, hard working, knowledgeable, trustworthy guy. If it was not for my formation flying interests, I might have chosen the Rocket. But, for the above reasons, I chose the RV-8.  Stu McCurdy

Jerry Springer said this:

I will give you some really cheap advice, build what you like and don't  base your choice on what someone else likes. In the end you well be the only one that has to be satisfied. Rockets are great airplanes but not all of you "jet jock wannabees" are up to building OR flying one.  (Debatable.  No harder to build or fly than any other RV.  Vince)

I have ridden with John Harmon in his Rocket and absolutely loved it but in the end would I be happier if I had one? I doubt it, because to go faster you will burn more fuel and if you are going to just cruise around with your RV buddies at their speed then why do you need a Rocket.  Yes it is great to climb at 3500fpm and go sailing by your buddies in their slow RVs but how many times are you going to do that? 

Q: Isn't  the Rocket just a souped up RV-4?

A: Yes and No.  The HRII is derived from an RV-4.   The F-1 is a descendent of the HRII.  Both use a 6 cylinder IO540 engine.   The RVs all use 4 cylinder engines.

Q: Huh?  You mean there are two different Rockets?

A: Yes.  There is the Harmon Rocket II which is supported by John Harmon of D&J Harmon, Inc. and there is the F-1 Rocket which is supported by Mark Frederick of Team Rocket, Inc.  There are also a few hot rod 6 cylinder RVs, which are often referred to as having been "Rocketized", but I'm not going to address them here.

Q: What's the difference between the HRII and the F-1?

A: Hay Carumba!  This is a tough one and requires a bit of history.  Let's go way back....  Ray Stits built a small homebuilt known as a Playboy.  Dick Van Grunsven, of Van's Aircraft, built one and then improved it.   Eventually it developed into the RV-3.  The RV-3 grew into an RV-4.  John Harmon built souped up versions of both the RV-3 and RV-4.  These hot rods were known as Rockets.  John developed a conversion kit (more about that later) to modify an RV-4 kit into the HRII.  Mark Frederick then developed the F-1, which did not require a builder to purchase anything from Van's.

Q: OK that's a little history.  So what's the difference? 

A: To the untrained eye, not much, but then again an untrained eye can't tell the difference between a Cessna 172 and  the Space Shuttle.

The HRII requires that you buy the tail, fuselage, and wings from Van's.  Unnecessary parts can be deleted from Van's kits to save money.  Then you buy the conversion kit from John Harmon.  The HRII is a slowbuild kit. The parts I bought in 1999 cost about $16,000.  That amount includes Van's kits and John's kits as well as a canopy, wheels, brakes, and tail kit. 

The F-1 kit is pretty much one-stop shopping.    The F-1 kit is available as a quickbuild, which sells for about $35,000.  You'll need a tail kit, not included, for another $1200 or so.  Of course, you get what you pay for, meaning that Mark's kit has more work done than John's kit. 

Don't misinterpret me, both are good kits.  It depends on whether you have more time or more money.   More about that later.

The differences between the finished planes are subtle.   The HRII has 42 gallons of fuel, the F-1 has 52 gallons.  The HRII typically has a flop over canopy, the F-1 has a slider.  The F-1 forward fuselage has a slightly different shape. 

The F-1 was designed for efficient production, so the parts fit better (They are really nice!).    The HRII parts are much like other kits.... just make 'em fit and keep building.

I could go on and on but many of the differences become evident by reading the other questions and doing a little simple research.

Q:  Can I convert an RV-3,6,8,or 9 (or a Cessna 152, or a Fieseler Storch) to a Rocket?

A: You can convert anything to a Rocket if you try hard enough.  It's easier to follow the path blazed by others though.  John Harmon's kit is designed to convert an RV-4 into a Rocket.  Mark Frederick's kit requires no conversion... it is what it is.

Q: Well, can you tell me more about the F-1 kit?

A: Sure.  Mark produces an outstanding kit.   The F-1 is as complete as any kit on the market.   As I said earlier, a slowbuild kit is available, but many opt for the quickbuild kit.   This means that the airframe is almost completely assembled.  You will have to make a few airframe parts to satisfy the FAA's 51% rule, but much of the grunt work is already done.  Of course, you still have a considerable amount of work to do to install the engine, instruments, wiring, plumbing, interior, and to do the painting.

As I mentioned, the QB kit costs around $35,000+.   The higher initial cost of Mark's product gives you a refined, QB kit, with some options that don't come with the HRII conversion kit.  There are about 50 F-1s flying.

Q: OK, can you tell me more about the HRII kit?

A: The HRII kit will work just fine.  As I mentioned before, the HRII requires that you buy the tail, fuselage, and wings from Van's.   Unnecessary parts can be deleted from those kits.  Then you buy the conversion kit from John Harmon.  This will cost around $16,000 (in 1999 dollars) for both the RV and Harmon parts combined.  The kit is assembled by comparing Van's RV-4 plans to the conversion plans that John provides.  This requires that the builder be prepared to do a lot more thinking and planning to get everything together.   You get to build every piece.  Is it doable?  Of course! There are 100 or more flying HRIIs out there.   All were built by mere mortals... including several built by Mark Frederick of F-1 fame.

Jim Cash had the first flying F-1.  Now there are at least 30 flying.  Here's Jim's first flight report:  "Jimmy Cash (Montana) has made the first hop in his F1 "Blackjack"! The initial flight went smoothly, with speeds limited to 210 MPH indicated (20"/2300 RPM).  Jim says he estimated the EW at 1220 lbs with 62 lbs on the tailwheel. Pretty good! We had hoped for 60 lbs minimum on the TW (to minimize the tendency of a nose-over with braking), and it looks like we hit the target.

Jim is running an AeroSport Power (Bart Lalonde) engine and a 3 blade Hartzell. He says the combination is very smooth, and produces plenty of power. I recall Jim saying the engine tested at close to 300 HP on the dyno.  I suspect Jim was a bit excited by all this, as I didn't really get any further flight data. He will be making further hops as weather permits, and we'll be getting updates as he expands the flight envelope."    Check out the Team Rocket website for more info.

Q: Van's, John Harmon, and Mark Frederick seem to be in direct competition.   How do they get along?

A: Another tough one.  They don't directly support one another, which is understandable from a business and liability standpoint.  Van's doesn't want to sell parts that will be converted to an HRII.  Obviously, he'd prefer that you buy an RV-3,4,7,8 or 9.  John and Mark don't directly support each other either, though they seem much more supportive of each other than Van's.

Q: So what do you do to get the parts you need?

A: Respect what each company is trying to do.  That and some cash will allow you to buy parts from anyone.  However, don't say the "R" word (ROCKET) when you're talking to Van's.  Van just isn't too wild about builders hot rodding his babies.  I can respect that.

Q: Will Van's sell me an RV-4 kit?

A: Do you have money?  :-) They sold me one.  I sent Van's an order with the unnecessary parts deleted.  They sent me a "non-conforming kit" contract which I had to sign.  I suppose that the contract releases them from liability.   Who knows?  Who cares?  Anyway, I soon had the parts I wanted.  I never said the "R" word and they never asked.  And they have been very supportive of me since the sale.  I have bought many items from them.... I just remember to say that it's for my RV-4.

Q: Why did you chose the version are you building?

A: I am building the HRII for several reasons.  I enjoy the challenge of building.  I have built other planes before.  I am in no huge hurry to finish.  And, most importantly, my wife says I can't spend the money for the QB unless I want to give up something the IO-540 engine, my love life, my house, and my kids!

Having said that, if I were pressed for time, or inexperienced at building, AND had the money available I would certainly build the F-1 QB.

Update 12-2001:  I bought the F-1 parts to modify my HRII from the main spar forward to the spinner.  I suppose that this change will make my HRII into an F-1H.  The reasons I switched some of the parts are addressed elsewhere on this site.  Go to the "Fuselage Construction" page.

Q: Which plane is better?

A: That's like saying "Who is more gorgeous: Cindy Crawford or Claudia Schiffer?"  Both the F-1 and the HRII are fabulous airplanes.   You can't go wrong with either. 

Q: I've noticed that many of the Rockets have different vertical and horizontal stabilizers.  Why?

A: Originally the RV-4 tail was standard.  Lately, several builders have opted for the RV-8 empennage since it has a balanced rudder, which supposedly would be more flutter resistant.  The RV-8 tail is also pre-punched and somewhat easier to assemble, though Mark Frederick informs me that the HS and elevators are a bit small for a Rocket.  RV-6 horizontal tails are also used as they are slightly bigger and have protected mass balance arms.  Who can say which is better?   They all seem to work fine.  I'm going to use the RV-4 tail unless some valid reasons not to do so appear. 

Of course, the F-1 guys get there own tail!

Q: Flutter?

A: Don't panic.  I've never heard of anyone experiencing flutter on the Rockets.  Even though I have heard of some builders who have 340+ horsepower and top out at 275mph+. 

Q: What's the status of your project?

A: As of 1-5-2006, I have 80 hours on the plane.  It is GREAT!  The first flight was October 2004.

As of 9-10-04: I am virtually done and plan to take the plane to the airport on 9-18-04.  WOO HOOO!!

As of 6/16/2003, I have the airframe complete and hope to do the finish painting this summer.  I plan to spend this cold months this winter installing the engine, instruments, and all the other stuff.  I hope to finish it all by summer 2004.

As of 6/10/2002, I had the tail feathers and F404 bulkhead, both wings, and tanks are completed.  The fuselage jig is glued to the floor and leveled.  I have the fuselage skinned and am busy putting the cockpit floor and baggage compartment in.   I have had the canopy temporarily installed and actually sat under it to check the headroom.

All the other parts, including the engine and cowling, are scattered about the shop.  I've finished priming (I hate that job) all the 6061 and steel parts with Poly-fiber (formerly Stits) epoxy primer.   I've done some of the prep work on various small parts so they'll be ready when needed. 

Last question:

Q: How'd you get so smart?

A: By hanging around other smart people who build RVs and Rockets.  NOW PICK ONE AND GET TO WORK!!

Alternate last question:

Q: I think you're a blithering idiot.  Where else can I find information?

A: Sign up on the Rocket List, a daily e-mail forum where you can get your questions answered by other Rocket builders.  Go to and click on the e-mail lists at the bottom of the main page and sign yourself up.  You'll get more info than any human can possibly digest... and some of it is invaluable.  There are also many related links on my homepage.

If you purchase an F-1 from Mark, there is a private F-1 email list just for F-1 builders.

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And after that they durst not ask him any question at all.
Luke 20:40

Last updated on: 09/01/2006

CAUTION:  This web site is not a publication of, nor approved by, Harmon LLC, Team Rocket, Van's Aircraft or  any other person or entity listed herein, except me.  Be advised that I am a blithering idiot with neither brains nor money and my advice is not to be trusted.  So there.  You have been warned!  Vince