9 or 9A question

[RVbySDI]

Originally Posted by flyboy1963

I'd lean towards a constant speed prop so you can get full takeoff power from a 180 hp to get OUT of those soft, short strips that you so easily go IN to!

I am going to politely disagree with this idea. Constant speed ads a considerable amount of weight on the nose gear. Landing on soft fields with a nose gear RV is NOT going to be the same as landing on soft fields with a nose gear Piper/Cessna. That extra weight the constant speed prop brings ads considerable risk that, in my opinion, is detrimental to repeatable successful soft field landings.

On another note about

full takeoff power from a 180 hp to get OUT of those soft, short strips

Again one does not fly these RV's as one does a Piper/Cessna. That includes the notion that being under powered for takeoff is a similar issue to address. The power to weight ratio of RV's is much better with the RV. If one has a 180 hp RV with a fixed pitched prop appropriately configured for such an engine and airframe combination I will opine there will be no issues with getting OUT of a soft, short strip. To use my 9A as an example. I have a 180 hp engine with a fixed pitched Catto prop. Just this past Saturday on a 92 deg 80-90% humidity day and DA at 3500', I was able to take off and climb at 1400 fpm on initial climb out.

Constant speed props are very nice to have but there most definitely are some drawbacks to operating them. Weight on the nose is one of those drawbacks that must be considered when evaluating continued use of the airplane on soft, short field runways.

My .02.
Live Long and Prosper!

[tjo]

As a reference, I did a poll a couple of years ago and asked:
Did you build an A-model or Tailwheel?
Would you do it again?
Do you want to change it?
Did you change it?

1) The bottom line was that 50% are built as A-models, 50% as TW
2) 10% that were A-models either wish they had a TW or actually changed to a TW
3) Only one TW owner wanted to change to an A-model and did.

So, they are 50/50 as built, and 60/40 TW to A-model if all owners had what they wanted. The total response population was 132.

This is not a commentary on what is better, or for sure it is not a commentary on what you should do, but is just info about what is out there today along with owner's preferences.

HTH

Tim

[agirard7a]

I'm building a 9 that I converted from a 9a. Having flown
A tail dragger 3 for 250 hrs, personal preference to the tail wheel.

With the right technique keeping the nose wheel off the ground as much as possible, you'll be fine, however, I do like the look of the tail dragger. You don't want to come in hot and 3 point a nose wheel!! Hold the plane 6" off the runway, nose high, disapate energy and touch down on the mains only, all the time!

[PerfTech]

... I see some things here that are not exactly correct, so I will input my opinion. Firstly, I have had many many props on our RV-9A starting with the F/P Sencinitch at 45.3 lb. with spacer and spinner. We now have the Whirlwind 200 RV 40.2 lb. with spinner. That is a 5.1 lb. reduction in weight, with tremendous performance increases. We plan just over 200 mph for cross country, and usually are 207 mph. With full fuel and pilot our initial climb rate is 2,700 fpm and have 1,300 fpm at 10,000 ft. We routinely operate out of a 500 ft long runway and only require 50% of that for take off. These numbers are virtually unachievable with a F/P propeller. Catto is a very good friend of mine and we worked together playing musical propellers on our RV-9A as well as some others, to get the best combo of climb and speed. His prop was actually faster, but didn't have the climb performance and required a higher rpm to achieve the speed. As for 9A or 9, The A model is more forgiving on landings and that is very nice when trying to get in on very short fields. I compete in a lot of spot and short landing contests with our 9-A and find it a joy to win with (personal best, shortest landing 197 ft). To us, the A models with a few little mods offer a safer more versatile little airplane. This from a guy with over 3K tail wheel hrs. Thanks, Allan..

[PaulR]

Allan,
You cruise at 200 MPH with an O-320? What kind of fuel burn? That's pretty fast for 160 HP. I assume you mean TAS?

[PerfTech]

Originally Posted by PaulR

Allan,
You cruise at 200 MPH with an O-320? What kind of fuel burn? That's pretty fast for 160 HP. I assume you mean TAS?

...Hello Paul
Yes that is TAS! We usually are high 10,500 to 14,500 but the interesting thing is the airspeed is always the same and the fuel burn goes lower with altitude. At 9,000 about 8 gph and at 14,500 about 7.1 average. My plane is very clean and we changed the rigging around a bit. It weighs 1,002 lbs, and I always try to run with as much aft c/g as possible. Regards, Allan..

[grubbat]

Now Allan,
You know that the -9 is the weaker vessel of the Van fleet and we shouldn't be sharing those speeds with the general population. We don't want them to get any ideas that the -9 is the hidden jewel of all the Van's designs.

Seriously, thanks for sharing the numbers Allan. Hope I am able to get some respectful speeds after I retrofit tundra tires on my -9 build......

Originally Posted by PerfTech

... We plan just over 200 mph for cross country, and usually are 207 mph. ..

[bret]

Originally Posted by PerfTech

...Hello Paul
Yes that is TAS! We usually are high 10,500 to 14,500 but the interesting thing is the airspeed is always the same and the fuel burn goes lower with altitude. At 9,000 about 8 gph and at 14,500 about 7.1 average. My plane is very clean and we changed the rigging around a bit. It weighs 1,002 lbs, and I always try to run with as much aft c/g as possible. Regards, Allan..

Care to share your changes, engine offset angle? HS incidence?

[PerfTech]

Originally Posted by bret

Care to share your changes, engine offset angle? HS incidence?

...The most effective changes we did wouldn't work for the RV-7..

[diamond]

Originally Posted by flyboy1963

?..Why not build the 9A, with 10 gear? Quite a few folks have put larger main tires ( 6.00x6") and the -10 nose yoke with a 5.00x5" tire/wheel?.

Could you please elaborate on this. I didn't think putting -10 nose gear on a 9A could or had been done.