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  #1  
Old 02-26-2015, 09:09 AM
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Bill_H Bill_H is offline
 
Join Date: Aug 2010
Location: Peel, AR
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Default Highest Flight in an RV-12: 16,214 Ft

A friend has made and documented what may be the highest flight in an RV12! Here is a summary, and there are more details and pictures at the link.

A private pilot with medical can fly the RV12 to 17999 ft. (I guess if you are instrument rated and the RV12 is equipped for IFR, you could legally go higher.) If you are exercising Sport Pilot privileges (such as being a PP with lapsed "driver's license" medical) then you are limited to 10000 feet or (the KEY) 2000 ft AGL, whichever is higher. So for maximum altitude in that case, fly over a mountain - like Mt. Rainier, at 14410 MSL, 14800 on the chart! So that would allow for a 16,800 ft attempt.

He waited for good weather, took oxygen and a saturation meter, and made the flight with ATC flight following.

He achieved 16214 feet (density altitude) and was still climbing. He was at less than gross weight, about 1070 pounds.

He has flight logs form the Skyview and all the Density altitude/true altitude calculations.

Climb rates were:
Sea Level to 10,000 ft was 14 minutes. = 714 fpm
10 - 12 thousand was 5 min. = 400 fpm
12-16 thousand was 24 minutes. = 167 fpm
15 to 16 thousand was 8 minutes. = 125 fpm

The RV12 POH lists the service ceiling as "Estimated 12,000 feet." Service Ceiling is defined as the maximum altitude using max continuous or climb power when the ROC (Rate of Climb) falls to 100 fpm while flying at Vy (Best Rate of Climb Speed ) (75 kts for the RV-12) at an ISA Standard Day, which defines a "normal" temperature for different altitudes.

Bob Bogash says "I could have held on for 17,500, but that would have probably taken another 10- 20 minutes - and at less than Vy.

That would likely be the Absolute Ceiling - the Maximum Altitude the airplane can achieve at any speed when the Rate of Climb goes to Zero.

I didn't want to get into that part of the flight envelope - my goal was the Service Ceiling."

"I figure I determined the Service Ceiling with some degree of accuracy - it's about 16,500 feet at ISA at a "typical" solo operational weight of 1050 lbs.
The Service Ceiling is no longer "estimated."

Much more detail and pictures of the flight are here:
http://www.rbogash.com/RV-12/Service...e-Ceiling.html

Has anyone gone higher?
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  #2  
Old 02-26-2015, 09:41 AM
redbaron redbaron is offline
 
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Location: Lucerne,Ca
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Default Great light

Thanks Bob A great write up. After my first read thru I plan to reread in more detail.
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  #3  
Old 02-26-2015, 10:46 AM
PilotBrent PilotBrent is offline
 
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Location: Hackettstown, NJ
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Default Service ceiling

Excellent summary & website story. Remarkable how capable a 912 powered RV-12 can perform - one almost thinks Van's low balled the service ceiling in the POH. (wonder if it will be revised in next version?)
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  #4  
Old 02-26-2015, 11:40 AM
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pierre smith pierre smith is offline
 
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Default Amazing

Great story and pictures...thanks much,

Best,
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  #5  
Old 02-26-2015, 12:45 PM
rv9builder rv9builder is offline
 
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Default

Quote:
Originally Posted by PilotBrent View Post
One almost thinks Van's low balled the service ceiling in the POH.
Is the figure in the POH at gross weight? That might explain the difference.
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  #6  
Old 02-26-2015, 12:59 PM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by rv9builder View Post
Is the figure in the POH at gross weight? That might explain the difference.
I am pretty sure all of the values in the POH and the sales literature are at gross weight unless specifically stated otherwise.
That is at least partially why the service ceiling was an estimated value... it is not possible to reach max service ceiling at maximum gross weight, without having taken off higher than the approved gross weight.
Another reason it would be quoted as an estimate, is with a ground adjustable propeller there are no performance absolutes. Climb performance (and service ceiling) is to some degree dependent on propeller pitch. Completion of the PAP tests confirms that the airplane performs to a minimum (to match data published in the POH), but there is some tolerance. That, coupled with the fact that Bob was well below gross weight probably accounts for the majority of the difference.
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Last edited by rvbuilder2002 : 02-26-2015 at 01:07 PM.
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  #7  
Old 02-26-2015, 01:02 PM
rv9builder rv9builder is offline
 
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Quote:
Originally Posted by rvbuilder2002 View Post
it is not possible to reach max service ceiling at maximum gross weight, without having taken off higher than the approved gross weight.
Good point, Scott! Thanks!
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  #8  
Old 02-26-2015, 05:47 PM
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MartySantic MartySantic is offline
 
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Bob.... a fantastic and complete blogpost. Thanks!
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  #9  
Old 02-26-2015, 06:13 PM
rgmwa rgmwa is offline
 
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Great writeup, Bob! Van's obviously designed a good one. You might be interested to know that you've just flown well over twice the height of Australia's highest peak, Mt Kosciuszko (7,310').
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  #10  
Old 02-27-2015, 08:28 AM
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WingedFrog WingedFrog is offline
 
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Default

Quote:
Originally Posted by rvbuilder2002 View Post
Climb performance (and service ceiling) is to some degree dependent on propeller pitch..
This also begs for the question: What kind of pitch (/static rpm) did Bob have for the flight?

Great contribution Bob, the whole flying community will benefit!
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