Accidental takeoff during step-taxi testing in the Catalina

[cowlove 33]

I was checking the flaperon rigging/balance by doing an extended step taxi at about 5300RPM, and she just hopped right off the water.  By the time I stabilized the attitude, reduced power, and let her back down, she was in the air about 4.5 seconds.   

 

I was half-smart, and had listened to all the advice to be prepared for inadvertent flight before any high speed taxi.  I had adequate fuel, the plane was mechanically airworthy, and pointed in a reasonable direction.   However, the plane's annual condition inspection had expired, so I filed a NASA form 733 describing the incident. 

 

...and then changed into clean underwear

 

At least I'm not in bad company.  Happens even to the pros-

 

https://www.youtube.com/watch?v=UYy5CGHbrtk

 

http://youtu.be/Lrb5vWZSCrs?t=2m29s

 

 

[cowlove 33]

...and it's a good friend who will come find you at the bar and bring you a NASA Form 733

[akflyer 1427]

I would have round filed the form... but thats just me .

 

I still streaks on the water, I would call it a high high speed step taxi

 

[EDMO 1078]

Unless you are caught red-faced, it never happened!   Unless, you post a photo for the Feds! 

EDMO

[IFMT 36]

Well you know it flies. Now wring it out!

[SuberAvid 617]

5 second rule should apply

[akflyer 1427]

Technically, you never left ground effect, the way I see it you were flying a WIG hovercraft.... no ticket or paperwork needed to fly

 

 

[EDMO 1078]

The Russians were using this "Ekronoplane" type watercraft years ago - they even had a huge jet with 6 or 8 engines that flew routes over the Black Sea, but it never got out of ground effect, so technically it was a flying boat.  I made a VHS tape for UAA Aviation class in the 1990's showing every type from what looked like a clipped-wing Cherokee taking off from a concrete ramp to the Huge Jet flying cargo across the Black Sea.

EDMO

Edited 19 Dec 2014 by Ed In Missouri

[RDavidson 183]

The high speed taxi test is the dumbest thing the FAA circular for test flying has you do! It puts you right in that area of almost flying and a landing at a high rate of a speed.

I did the high speed taxi test in my Starduster Too and explored both edges of the runway when I tried to slow down. I got into a PIO with the rudder pedals. After confessing my hair raising event to the Starduster forum a friend on there told me he did the same thing, then confessions came out of the wood work! Just about everyone did the same thing, and most said they would never do a high speed taxi again!

Looking back, it was inexperience with a short coupled landing gear to Tailwheel distance that caused the high speed swerving...my friend told me to take my shoes off so I could feel the rudder pedals. He was spot on! With my shoes off I could feel that I needed very small inputs and that my shoes were probably hitting the brakes inadvertently. Anyway, a good trick to file away for another day! And if you happen to land in Arkansas your lack of footwear will help you blend right in with the locals! Ha!

Good on you for filling out the NASA form...I say overload them with paperwork! It might keep them busy in the office instead of out looking to bust somebody!

I like your plane! It is going to be fun!

See ya, Ron

Edited 20 Dec 2014 by Ron

[EDMO 1078]

Not being a water-pilot, I would guess that the Catalina would be in the same class as Kitfox, and Ed Downs, in his book, "Flying the Kitfox", warns against doing any high-speed taxi until you are legal and ready to fly.  He states that if you leave the ground, your best option is to continue into the pattern and not try to put it back on the runway until you are ready and set up for a normal landing.

EDMO

Edited 20 Dec 2014 by Ed In Missouri

[akflyer 1427]

on wheels I would say yes unless you are at a dry lake bed and you have miles of runway in front of you.. generally on a big lake you have lots of time to get it figured out and set it back down, however, I do fly off a few places that once you put the throttle to the firewall your committed to get off the water or eat the trees.

 

[cowlove 33]

Liftoff was at 45 seconds on the chart, at about 42 knots airspeed. The throttle was abruptly closed after about 1 second in the air, and the clumsy finish of the flight is readily visible as a 2.1G impact after 6.1 total seconds in the air. The smaller series of acceleration spikes before touchdown is a sequence of pilot induced oscillations after the pitch change caused by the abrupt power cut.   Maximum height was probably about 4 feet.  

 

I was not monitoring the airspeed as closely as I should have, the water was glassy smooth and I didn't have any good indication that I was accelerating that quickly at such a modest power setting.   That thing gets of the water a lot easier than I thought! 

 

 

[cowlove 33]

Yeah, I'd definitely studied up on both sides of the debate for/against high speed taxi tests.   The plane felt very stable and docile on earlier slower step-taxi tests- absolutely *GREAT* water handling qualities and beautiful roll control.    Given that, I opted for the set-back plan in case of accidental takeoff.  

 

I rehearsed the response a good bit-  making a gradual power reduction while holding a stabilized attitude.  Alas, when the moment came, I chopped the power like a madman and oscillated in pitch a little bit before just freezing the attitude and letting it sink onto the water pretty hard.  

 

The glassy conditions may have been another strong factor for opting for the go-around plan, or for waiting for another day. 

 

Lessons learned!

Edited 21 Dec 2014 by cowlove

[cowlove 33]

...and I'm definitely not a pro, but I think the high speed taxi question is pretty different for a seaplane.  Water handling qualities are such an unknown and (in my mind) have so many more variables, I think it's pretty important to be comfortable all through the envelope before committing to a water landing. 

 

The advice I got from some local EAA guys was to treat the thing like a jet ski for a month and put 10 hours on her exploring water handling before even thinking about flying.  I'm now at about 2 hours, and I think that's still the plan.   With a closer eye on the airspeed indicator, and a speed limit of about 35 KIAS!  

[EDMO 1078]

The best news is that nothing was bent, broken or bleeding - another good landing after a short test run.

EDMO

[cowlove 33]

I got a lot better at keeping it on the water  Her water handling continues to impress me, and it's good experience exploring the... ah... interesting trim/attitude response to throttle inputs.   For the record, the big throttle changes in this video aren't a normal course of action- I'm just getting a feel for said pitch/yaw changes.    Getting there!

 

http://youtu.be/ByxihXovej8

[marksires 484]

Nice video, looks like it gets off even glassy water pretty easily.  Looks like fun plane!

Mark

[akflyer 1427]

Looking good.  That are you using to embed the graphs?  Your taking a much more analytical approach to this than I would   10 hrs of high speed taxi times seems like a bunch more opportunity to  find a stick in the water etc.  A few step taxi sessions just to feel out the power / thrust line issues and I wouldn't be able to keep it on the water.  That plane wants to fly!

 

[cowlove 33]

I used to do computer stuff, so I used a bunch of homebrew scripts the use freeware tools to make the embedded graphics.   The orignal data comes from a little homebrew EFIS computer that collects engine stats, AHRS, GPS, and air data.   The real first flight may never happen in a timely manner, but when it does, it will be well instrumented and documented

[jjbaker 73]

Thanks for bringing this thread back to life. I hadn't seen that plane yet. Waaaaaaay cooooool!