Rate of climb data required!

[Pilottonny]

Hello everybody,

Since I did not get an answer on my question in my last thread, I started a new one, with a new title.

I hope someone can help me with the following numbers, that I require to supply to the Silencer Manufacturer "Liese" in Germany, so he can calculate whether he can supply me some mufflers to satisfy the very stringent European noise regulations.

Can anybody give me the "Max Rate of Climb @ what airspeed" for an RV9A equipped with an IO-320 with CS-Prop (at solo weight and MTOW, if possible).

Also I need to know the take-off over 50 ft obstacle (at solo and MTOW, if possible). If you do not know that, just give me the ground roll and I will calculate it with the max rate of climb and the airspeed. That should then be close enough.

Thanks in advance for your help.

Regards, PilotTonny.

 

[gmcjetpilot]

There is Van's data?

Have you tried Van's web site for the "spec" performance. Most RV's make spec if built per plans.

http://www.vansaircraft.com/public/rv-9per.htm

RV-9A, 160HP, Fixed prop

Takeoff roll solo...= 300 ft
Takeoff roll gross = 475 ft
---------------------------------------
ROC solo (initial/max/SL/std)#.. = 1,900 fpm
ROC gross (initial/max/SL/std)# = 1,400 fpm

# Van does not specify specific conditions, my assumption, sea level standard day max rate of climb.



There is no 50 ft obstical clearance data from Van's aircraft, but you could
assume approx Vx speed of 80-90 mph to be conservative. To climb to 50
feet:

90 mph * 5280 ft/mile * hour / 60 min * 50 ft/ (.90sf * 1,400) ft/min = 283 feet (distance from lift-off to 50 feet height)

Total from take-off the 50 ft (gross) >> [475 * 2sf] + 283/0.90sf = 1264 ft

(Note: sf = Safety factor, double takeoff roll (surface, winds) and reduce climb by 10%)

Total take off to 50 ft (solo) >> [ 300 *2sf ] + 208/0.90sf = approx 830 ft

If you want to remove the "fudge factors" or safety factors the total distance to 50 feet would be about 800 feet (gross) and 550 feet (solo). That is pretty short.



Good luck. In above I double the takeoff roll and reduced climb by 10%. This should give you flight profile for your noise calculation. Constant speed prop should improve it a little, but be conservative to make sure you can climb high enough, fast enough to cheat the noise meter.

 

[Steve Sampson]

Climb results

Tonny - I had all that data but cant find it now. The only bit that may be of help to you is this. It is offered since you have had so little response.

G-IINI (-9A) was 1044lbs - this test done at about 1650 lbs gross.
MT electric c/s prop
O-320 -E2D - 150hp
2 May '05

Full power @ 2700rpm climb from 1-2000' @1013 = 37 secs or 1620fpm at 90mph. (No fairings.)

We started each climb at 500' so as to be stable in the climb by 1000'. (This rather bothered my data recorder since the ground is nearly up to 500' around there!)

The temp data I can not find but about 6oF.

This was averaged over 3 climbs but they were all very similar.

The major thing I learned was doing these tests is very hard. I also formed the opinion subsequently that 100mph would give a slightly better result.

I hope that is of some help.

What was clear was that 150hp was plenty of power for a -9A.

Cheers!

PS Tonny - you say European noise regs. Surely at the moment they are German? So far they dont apply here. My -4 with a 4 pipe is going to be lots of fun in Germany! Perhaps the UK is not a part of Europe yet?

It reminds me of the 1930 headline in the Times. Something like this: "Thick fog in the channel. Europe cut off."

 

[Pilottonny]

Thanks George and Steve, I guess this should be accurate enough to get Mr Liese calculating.

Steve, there are certainly still a lot of differences between the UK and the rest of Europe (regulations). If you are going to fly your RV4 with straight pipes to Germany, you are going to find that you may be grounded at some airfields, between certain hours, due to noise abatement regulations! Also you will end up paying up to 5 times more landing fees than an aircraft equipped with silencers (that is complying to the German ?Erh?hter L?rmschutz?).

Regards, PilotTonny