|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

08-27-2012, 05:02 PM
|
|
|
|
Join Date: Aug 2008
Location: Jacksonville, FL
Posts: 522
|
|
Sam, can you elaborate?
I'm not interested in names or even hints of names. I am interested in the behaviors you were referring to. This could help turn this into a real learning experience for many. It is a very good thread and I appreciate that John started it.
__________________
Wendell VAF#1832
RV-6A 3/4 done...N48JE Reserved 
Build site: www.mykitlog.com/weneng
Donated to VAF in 2020
|

08-27-2012, 05:12 PM
|
|
|
|
Join Date: Dec 2008
Location: na
Posts: 1,457
|
|
Quote:
Originally Posted by RV7Guy
Finally, high speed taxiing has no place in our homebuilt world. As Paul said, flight can occur very quickly.
|
disagree... taxi is a required phase of flight operations and requires careful exploration just like every other. The term "high speed" is up for interpretation however.
Done correctly the risk is easily managed. Just because some loon messes it up doesn't negate the value when done with careful planning and diligence.
What I've witnessed too often is simply improper perspective and a focus on the speed rather than the handling qualities under evaluation. Too many pilots add the power as if they performing a normal take-off thinking they can chop the throttle to keep from exceeding rotation speed (minus a healthy margin). Unless they have experience with make/model/engine/prop combination judging the acceleration and throttle response is gonna be very tricky. Nothing in flight test should be tricky.
This is how I did it (with a well thought out test plan):
Planned Ground Speed DNE (Do Not Exceed) of 45mph,
Wind DNE 5mph,
no flaps,
aft CG,
45psi tire pressure
Test Day Conditions
6000ft paved runway (dry),
DNE 3000ft with power applied.
RPM DNE 1800 (max static of 2150 noted) = ~80% Take-off power
Airworthiness signed off, insurance active, pilot current.
Full aft stick throughout run, trim neutral
Normal throttle application from idle to specified RPM with concurrent brake release.
Run 1: 1000 RPM, noting ground speed per 1000ft marker. At halfway marker throttle to idle, moderate brake application, noting stopping distance. During the run noted any track, yaw, shimmy, vibrations. ~8mph @ 3000ft
Run 2: 1200 RPM ~14mph @3000ft
Run 3: 1400 RPM ~23mph @3000ft
Run 4: 1600 RPM ~ 36mph @3000ft
Run 5: 1675 RPM ~ 43mph @3000ft
No further runs completed as the ground speed DNE would have been exceeded.
It was valuable for several reasons: I was confident the plane would track straight at higher speeds, I was able to give the brakes a good break in, I began to get a feel for the acceleration potential and braking effectiveness prior to first take-off, and noted no adverse handling qualities issues. Airspeed came alive (Dynon Skyview) at ~ 30mph and matched well with GS (no wind). I also gained some foresight into CHT behavior and knew I would have some issues during flight (which I did) and therefore not surprised (surprises are not good in flight test). I also gained a great deal of insight into the pedal workload to maintain centerline with a rocket link installed and was happy for that during the first T/O and Landing.
The only thing dangerous about taxi testing are the pilots who do not give this test the same respect they would give any other phase I task.
Do it or don't, your choice. I found it to be very valuable and the risk easily mitigated through planning and execution.
.02
|

08-27-2012, 06:09 PM
|
|
|
|
Join Date: Dec 2011
Location: Livermore, CA
Posts: 6,797
|
|
Insurance
I see I need to clarify my post. I assumed (my error?) that full, in motion insurance was in force, with all pic requirements met, etc. I wanted to know if the company would attempt to deny coverage solely due to an FAR having been inadvertantly violated.
I am as unhappy as everyone else that my insurance premiums help pay for carelessness or high risk taking; but I also don't want to be with a company that might deny coverage due to a technicality that had nothing to do with the accident.
|

08-27-2012, 06:16 PM
|
 |
|
|
Join Date: Aug 2006
Location: Secluded Lake,Alaska (AK49)
Posts: 359
|
|
Type of thinking
How many time have I put myself at risk with the "Full of my self" or " I can handle it" feeling typical of late teens. Honestly, as an adult?? With or without an airplane? I watched a friend scare himself, me, and his hole family this last week over this type of thinking. Another incident in Denali Park the day after I was there, cost someone their life. I have taken kind of a "saftey stand down" for some calm quite reflection and deliberation of all my past and current behaviors.
We all of could benefit by looking in, and sharing with those close to us our mistakes. When one person brings something to my attention, my thinking is suspect. When two or more people bring the same issue up, then my thinking must be flawed. I have learned to accept that my judgement is bad without understanding why, just trusting that the people who care about me know what they are talking about. Put my inflated ego down long enough to be open to understanding.
Franklin said about pride, and I am para phrasing, that pride is so sneaky that if he were rid of it, he is sure he would be proud of that fact.
|

08-27-2012, 06:28 PM
|
 |
|
|
Join Date: Jan 2005
Location: Atlanta, GA
Posts: 2,295
|
|
Last year one of our local guys perished in an airplane that he honestly shouldn't have been flying.
The airplane had been sitting for years in the same hangar as my RV and was in a terrible state of disrepair.
Factual
Probable Cause
I saw him three days before the accident and tried to get him to put the plane on a flatbed trailer sitting behind the hangar and drive it to Florida to the man he was selling it to (who was going to re-build it anyway) but he insisted on getting it there by air.
Many probably think that I should feel guilty, but I honestly don't. I spoke my mind and that was it. Nothing short of the airplane not actually making it off the ground was going to prevent him from trying to fly it to Florida.
I speak my mind when people do things I consider to be unsafe. And for God's sake I hope everyone else challenges me in the same way.
__________________
"What kind of man would live where there is no daring? I don't believe in taking foolish chances but nothing can be accomplished without taking any chance at all." - Charles A. Lindbergh
Jamie | RV-7A First Flight: 7/27/2007 (Sold)
Last edited by rv6rick : 08-27-2012 at 08:44 PM.
Reason: removed expletive
|

08-27-2012, 07:31 PM
|
 |
|
|
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
|
|
Quote:
Originally Posted by RV8R999
disagree... taxi is a required phase of flight operations and requires careful exploration just like every other. The term "high speed" is up for interpretation however.
Done correctly the risk is easily managed. Just because some loon messes it up doesn't negate the value when done with careful planning and diligence.
What I've witnessed too often is simply improper perspective and a focus on the speed rather than the handling qualities under evaluation. Too many pilots add the power as if they performing a normal take-off thinking they can chop the throttle to keep from exceeding rotation speed (minus a healthy margin). Unless they have experience with make/model/engine/prop combination judging the acceleration and throttle response is gonna be very tricky. Nothing in flight test should be tricky.
This is how I did it (with a well thought out test plan):
Planned Ground Speed DNE (Do Not Exceed) of 45mph,
Wind DNE 5mph,
no flaps,
aft CG,
45psi tire pressure
Test Day Conditions
6000ft paved runway (dry),
DNE 3000ft with power applied.
RPM DNE 1800 (max static of 2150 noted) = ~80% Take-off power
Airworthiness signed off, insurance active, pilot current.
Full aft stick throughout run, trim neutral
Normal throttle application from idle to specified RPM with concurrent brake release.
Run 1: 1000 RPM, noting ground speed per 1000ft marker. At halfway marker throttle to idle, moderate brake application, noting stopping distance. During the run noted any track, yaw, shimmy, vibrations. ~8mph @ 3000ft
Run 2: 1200 RPM ~14mph @3000ft
Run 3: 1400 RPM ~23mph @3000ft
Run 4: 1600 RPM ~ 36mph @3000ft
Run 5: 1675 RPM ~ 43mph @3000ft
No further runs completed as the ground speed DNE would have been exceeded.
It was valuable for several reasons: I was confident the plane would track straight at higher speeds, I was able to give the brakes a good break in, I began to get a feel for the acceleration potential and braking effectiveness prior to first take-off, and noted no adverse handling qualities issues. Airspeed came alive (Dynon Skyview) at ~ 30mph and matched well with GS (no wind). I also gained some foresight into CHT behavior and knew I would have some issues during flight (which I did) and therefore not surprised (surprises are not good in flight test). I also gained a great deal of insight into the pedal workload to maintain centerline with a rocket link installed and was happy for that during the first T/O and Landing.
The only thing dangerous about taxi testing are the pilots who do not give this test the same respect they would give any other phase I task.
Do it or don't, your choice. I found it to be very valuable and the risk easily mitigated through planning and execution.
.02
|
Gotta agree with everything said here. A detailed proper plan in place prior to starting the engine with good safety margins in place. This is not rocket science, just common sense. People with the "light the fire, let's go" complacent mentality are going to get bitten eventually, especially when test flying. Do it right or get someone else to do it for you.
|

08-27-2012, 08:03 PM
|
 |
|
|
Join Date: Jan 2005
Location: Chandler, AZ
Posts: 2,904
|
|
Quote:
Originally Posted by RV8R999
disagree... taxi is a required phase of flight operations and requires careful exploration just like every other. The term "high speed" is up for interpretation however.
Done correctly the risk is easily managed. Just because some loon messes it up doesn't negate the value when done with careful planning and diligence.
What I've witnessed too often is simply improper perspective and a focus on the speed rather than the handling qualities under evaluation. Too many pilots add the power as if they performing a normal take-off thinking they can chop the throttle to keep from exceeding rotation speed (minus a healthy margin). Unless they have experience with make/model/engine/prop combination judging the acceleration and throttle response is gonna be very tricky. Nothing in flight test should be tricky.
This is how I did it (with a well thought out test plan):
Planned Ground Speed DNE (Do Not Exceed) of 45mph,
Wind DNE 5mph,
no flaps,
aft CG,
45psi tire pressure
Test Day Conditions
6000ft paved runway (dry),
DNE 3000ft with power applied.
RPM DNE 1800 (max static of 2150 noted) = ~80% Take-off power
Airworthiness signed off, insurance active, pilot current.
Full aft stick throughout run, trim neutral
Normal throttle application from idle to specified RPM with concurrent brake release.
Run 1: 1000 RPM, noting ground speed per 1000ft marker. At halfway marker throttle to idle, moderate brake application, noting stopping distance. During the run noted any track, yaw, shimmy, vibrations. ~8mph @ 3000ft
Run 2: 1200 RPM ~14mph @3000ft
Run 3: 1400 RPM ~23mph @3000ft
Run 4: 1600 RPM ~ 36mph @3000ft
Run 5: 1675 RPM ~ 43mph @3000ft
No further runs completed as the ground speed DNE would have been exceeded.
It was valuable for several reasons: I was confident the plane would track straight at higher speeds, I was able to give the brakes a good break in, I began to get a feel for the acceleration potential and braking effectiveness prior to first take-off, and noted no adverse handling qualities issues. Airspeed came alive (Dynon Skyview) at ~ 30mph and matched well with GS (no wind). I also gained some foresight into CHT behavior and knew I would have some issues during flight (which I did) and therefore not surprised (surprises are not good in flight test). I also gained a great deal of insight into the pedal workload to maintain centerline with a rocket link installed and was happy for that during the first T/O and Landing.
The only thing dangerous about taxi testing are the pilots who do not give this test the same respect they would give any other phase I task.
Do it or don't, your choice. I found it to be very valuable and the risk easily mitigated through planning and execution.
.02
|
Your plan was fine and I don't consider this "high speed." I'm talking about speeds where flight could occur. I still stand that virtually everything you need to know before flight can be done at lower speeds.
"if it predictable, it is preventable." The odds of an incident rise with speed. Speed that in most cases is uneccessary. Too many events support, "don't do it."
As you said, "it is your choice."
__________________
Darwin N. Barrie
Chandler AZ
www.JDair.com
RV-7 N717EE-Flying (Sold)
RV-7 N717AZ Flying, in paint
EMS Bell 407,
Eurocopter 350 A-Star Driver
|

08-27-2012, 10:24 PM
|
 |
|
|
Join Date: Jul 2007
Location: Delta, CO/Atlin, BC
Posts: 2,391
|
|
Andrew - well said, thank you.
Greg
__________________
Greg Arehart
RV-9B (Big tires) Tipup @AJZ or CYSQ
N 7965A
|

08-28-2012, 04:35 AM
|
 |
|
|
Join Date: Jan 2005
Location: Louisville, Ga
Posts: 7,840
|
|
Quote:
Originally Posted by 868RM
Pierre, Was the 9a fitted with the leg brace ? Just curious. Thanks Ron
|
No Ron, it was not and I don't believe that the owner was even aware of its existence. I will point it out to him during the rebuild.
Best,
__________________
Pierre Smith
RV-10, 510 TT
RV6A (Sojourner) 180 HP, Catto 3 Bl (502Hrs), gone...and already missed
Air Tractor AT 502B PT 6-15 Sold
Air Tractor 402 PT-6-20 Sold
EAA Flight Advisor/CFI/Tech Counselor
Louisville, Ga
It's never skill or craftsmanship that completes airplanes, it's the will to do so,
Patrick Kenny, EAA 275132
Dues gladly paid!
|

08-28-2012, 07:08 AM
|
|
|
|
Join Date: Feb 2008
Location: Taylorsville, GA
Posts: 748
|
|
Insurance...
Quote:
Originally Posted by BobTurner
I see I need to clarify my post. I assumed (my error?) that full, in motion insurance was in force, with all pic requirements met, etc. I wanted to know if the company would attempt to deny coverage solely due to an FAR having been inadvertantly violated.
I am as unhappy as everyone else that my insurance premiums help pay for carelessness or high risk taking; but I also don't want to be with a company that might deny coverage due to a technicality that had nothing to do with the accident.
|
Sam - To clarify, there are two types of "ground" coverage. One is GNIM - Ground Not In Motion. The other is GNIF - ...Not In Flight.
Most of the time the coverage you get for non-flying aircraft (or to self inusure in flight losses) is GNIM. The policy clearly defines what Not In Motion means - (READ THE DEFINITIONS OF YOUR POLICY) - for airplanes, it means "moving under its own power or the resulting momentum thereof." Stationary engines runs ARE covered under GNIM. Taxing over to the hangar next door or to the fuel pumps is not. Towing the airplane 14 miles to the other side of the airport IS covered under GNIM, turning around on the ramp under power is not. Jumping the chocks during an engine run that was supposed to be stationary IS NOT COVERED by GNIM. The best choice is to go ahead and buy full coverage (IN FLIGHT) before running the engine.
Bob - It is a common myth that insurance companies deny claims due to FAR violations. Your car insurance doesn't deny claims because you were speeding when you got into an accident, or because you didn't notice the stop sign. Same's true with aviation policies. Even dumb things are covered.
But, he may have problems from flying without a CofA. Holding a current and valid CofA is a specific policy condition.
__________________
Jeff Rhodes - Taylorsville, GA
RV-9, 7 - going fast
BC-12D - going slow
jrhodes@v1salesmgt.com
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 05:01 AM.
|