Flight Testing

[ChiefPilot]

I just recently started testing my -6A, so with only a handful of flights I cannot claim to be an expert. Instead, I can share my findings so far along with some (perhaps uneducated or naive) opinions.

I decided long ago to wear nomex/helment/parachute during the phase one testing. The only real downside is that I endure grief from others who didn't and think it might be overkill - but for me, it's not about the odds: it's about the stakes.

And the stakes are why I will take my plane to it's documented limits in as many ways as I can think to do so. I will be carrying my wife, my sons, friends, and family in this plane in phase two - shouldn't I, as the manufacturer, have some reasonable assurance based on collected data about how the aircraft behaves? Shouldn't I know not only how the aircraft flies but how it falls (stalls)? Shouldn't I know not only how well the autopilot works but also how it fails (altitude hold with idle throttle, for example)? The key here is, I think, to work up to the limits and not just start there. "Go from the unknown to the known, slowly" is the idea.

I know a lot of folks just "fly off" the 40 hours. And that's fine - there's nothing wrong with that. For myself, however, I want to know what will happen if we stray off the happy path, and that means exploring the corners of the envelope to verify each system (airframe, engine/prop, instrumentation, avionics) doesn't contain any big surprises.

[ChiefPilot]

Originally Posted by smiller

Yeah I think I would discourage testing to see how many g's your freshly-built plane can tolerate before a wing snaps off! If however you plan to routinely pull X g's, I'd want to test that (at altitude, solo, away from populated areas, with parachute, assuming you can free yourself from the out-of-control plane if something does snap!).

If your aircraft is rated at 6Gs at 1375lbs (or whatever), I'd hope it gets tested to that if you're doing aerobatics with the appropriate measurements taken before/after to determine any changes caused by the stresses.

My reasoning for this is that if you only plan to pull 3.5Gs, what happens when you do but accidentally exceed that due to speed, wind gust, a sneeze, or whatever? You'll likely be a test pilot at some point - better to do it when prepped and ready for a failure than not, no?

[Mel]

Originally Posted by ChiefPilot

I know a lot of folks just "fly off" the 40 hours. And that's fine - there's nothing wrong with that.

I'm afraid I'm going to have to disagree! There is something VERY WRONG with that.
When that happens, for the life of that aircraft, every flight becomes a test flight with totally unknown parameters.
Do you want to take you family and friends on a test flight every time they enter the cockpit?

[ChiefPilot]

Originally Posted by Mel

I'm afraid I'm going to have to disagree! There is something VERY WRONG with that.
When that happens, for the life of that aircraft, every flight becomes a test flight with totally unknown parameters.
Do you want to take you family and friends on a test flight every time they enter the cockpit?

I was trying to be diplomatic and not offend anyone. My bad.

Myself, no, I don't want to take friends/family along on test flights which is why I'm doing the whole test card/envelope expansion/flight test program. Thus far, it each hour-long test flight has taken at least 90 minutes to plan/write down and walk through several times. Ugh.

[Ironflight]

Originally Posted by ChiefPilot

Thus far, it each hour-long test flight has taken at least 90 minutes to plan/write down and walk through several times. Ugh.

That means you're doin' it right!

[pierre smith]

Originally Posted by Ironflight

That means you're doin' it right!

+2...amen brother

Have fun while you're doing it.

Best,

[aussieflyer1]

I just finished my transition training with Jan Bussell at OBE, what a great guy to do your first RV flying with.
He takes you through the whole envelope of what to expect in stalls power on/off stalls, landings, even turn back after take off. (which seem very achievable in the RV.
The only wing drop I experienced was doing a climbing power/on turning stall when going to the left and air speed around 80mph the left wing dropped, just ad right rudder, release your grip on the dtick and the RV just snapped back to level flight (very comfortable) in the opposite direction, at the stall just release the stick to centre and with the P-factor the RV snapped back to level flight on it's own.

Remembering I now have a whopping 2.8hrs in RV flying but after flying with Jan I feel ready for the basics in flying our own RV6A.

Great job Jan!!!

[esco]

Originally Posted by ChiefPilot

Thus far, it each hour-long test flight has taken at least 90 minutes to plan/write down and walk through several times. Ugh.

I've read both AC NO: 90-89A and the Flight Test portion of the plans several times, and I'm still developing my plan. I estimate when I'm done, the ratio will be three hours planning, updating, and documenting for every hour flying.

In a previous life it was 8 hours of maintenance for every hour of ops; 3-1 feels like I'm cheating!

[SmilingJack]

One thing I found nice was the new EFIS recording everything! I was able to focus on test profiles and not have to write much down during the flight.

After the flight, downloading data and plotting the data added several hours, but I do think having this capability enhances the flight portion so you can accomplish more during the flight.

It also is a way to prove what you thought you saw or did right or wrong

It probably put my ratio up to 10:1

[ChiefPilot]

Originally Posted by SmilingJack

One thing I found nice was the new EFIS recording everything! I was able to focus on test profiles and not have to write much down during the flight.

After the flight, downloading data and plotting the data added several hours, but I do think having this capability enhances the flight portion so you can accomplish more during the flight.

It also is a way to prove what you thought you saw or did right or wrong

It probably put my ratio up to 10:1

Totally agree - I didn't figure this time in before but making charts and looking at aircraft and engine performance data is fascinating. Data porn, some might call it. I'm paying particularly close attention to the engine data (CHT & oil temp) to see when the engine is actually "broken in".