rjbob

My Feedback: (8)

I have (had) been very successful doing inverted flat spins with my Rookie I...until 2 days ago at Speedworld. To exit the spin I only needed to pull the power and dump the nose with up elevator in order to pick up the speed I needed to pull out.

Well...it didn't quite happen that way Sunday! The plane was high enough at the start of my attempt at the exit that I had time to try several different methods to get it to drop the nose but to no avail.

When we got to the place where the Rookie became earthbound (crashed), I was extremely surprised that the damage was minimal due to the relatively slow vertical speed of the descent.

Any thoughts?

BTW...anyone got extra tail fins and a canopy?

Bob

Thud_Driver

My Feedback: (1)

Thrust vectoring on the Rookie/Rookie II will always get it out of those flat spins. Pretty much mandatory for the Rookie II to recover. Did you have that hooked up??

You might want to check all the internal glue joints. The last time I had a "soft" crash with the Rookie II, most every glue joint needed to be redone.

seanreit

My Feedback: (60)

Bob, I have almost quite doing anything but regular flight modes on my Rookie II, because there have been a couple of close calls that have just flat scared me. I have not been able to find consistent exit of spins on this airframe. Although I have made it so far out of every one I entered, there has not appeared to be rhyme or reason as to "When" it exited. Dropping power and letting the "nose drop" does not always end up with "nose drop". Even though I'm cg'd for that. I have never been able to figure out why.

Sure sorry to hear about this.

rjbob

My Feedback: (8)

Thanks for the reply...
The thrust vectoring was switched on.

rjbob

My Feedback: (8)

Thanks Sean...the plane will fly again, though.

GREAT meeting you!

Thud_Driver

My Feedback: (1)

If the vectoring was on, you need to be at a high power setting for it to do anything. Pulling the power off negates any real effect from the vectoring nozzle and you're into a purely aerodynamic recovery. My recovery technique is vectoring on (if not already on), max power, & close to full pitch input which pretty much jams the nose down.

DelGatoGrande

My Feedback: (23)

..repair the plane and give it a go again![8D]

Airforce7

My Feedback: (31)

Bob, you just described exactly what happened to me at CA Jets back in 2006. Sorry to hear about this. I bought a new canopy and repaired the fins myself using thin ply inserted from the bottom to re-strengthen them. From a straight down inverted flat spin you need full power with full down to get out. On a side note, I only have single axis vectoring (pitch) and I can control the spin rate with my rudders. I usually stop the spin before I get out.

ela

What about the direction of the spin? There is a small torque when adding power and some says it really makes a difference which way you spin.

Thud_Driver

My Feedback: (1)

I can talk mostly to the Rookie II. In the inverted Harrier (slow descenting hover inverted) I have to hold some right rudder to keep it from rotating (could be a thrust line problem). But I can move the nose right or left with the rudders and can thus either rotate as in a nose high slow spin or just hold it straight. Usually, I just steer it around to where I want the airplane. In an upright flat spin, the rudders on my Rookie have no effect and it spins to the right. Recovery requires full power and thrust vectoring to get out. It will usually not recover aerodynamically - I've tried from nearly max altitude and on rare occasions it will kick out of it. The recovery with full down thrust (max power) and full down elevator requires one full turn and the airplane does almost a full roll to straight down during that turn. That's my airplane, others probably are different.

These are not classical spins and I don't much do them because the thrust vectoring snap/spin maneuvers seem more interesting. I've not seen thrust make much of a difference in spinning except as to where you can hold the nose with vectoring. In the above mentioned flat spin, I can release the elevator/vectoring to neutral and reduce the thrust to idle and it doesn't make a lot of difference.

For their size, the rudders on the Rookie are very powerful - you can do rudder rolls - so I'ver never noticed torque effects.

Tom Antlfinger

My Feedback: (24)

Bob:

Presuming there was no mechanical breakdown like a servo locking or not working, and presuming you did spins with prompt recovery before, indicating C.G. was where it should be, an incorrect recovery would be the most common cause.....incorrect recovery technique has killed many full scale aerobatic pilots.......

Our local experience with many flights on Kangaroos, and Hotspots with similar planforms to the Rookie is that as long as you got C.G. right on or preferably 5-10% forward of recommended, recovery should be prompt with just releasing of the controls back to neutral and with power off......these were done with no available thrust vectoring at the time......our method of entry was a full power pullup to a safe altitude, then power off, hit hard full down and hard left or right rudder with aileron neutral......Sean Reitmeyer saw me do this numerous times at FIJR back in 2004 or 2005 with my Green Bay Packer HotSpot.....if you did hit it with power just before it broke into the spin, you could hover it, once again without vectoring........Then let it flop over into a cool spin.....

To recover, just release everything and it should fall out, nose down and stop rotating.......Why? The nose is heavier than the tail, measured from the pitch axis, if the C.G. is set correct, and the neutral rudder should stop the rotation......but what happens if it doesn't stop rotating, usually due to a not-so-perfect entry, especially adding too much aileron and holding it in too long, or getting to low, too fast when dumb-thumbing takes hold??......most guys will either pull up elevator if the spin was inverted or push down elevator if it was upright......if the plane is still rotating, that accelerates the rotations(what is called an accelerated spin or aggravated spin by full scale guys), much like a spinning figure skater when the arms are pulled in, to a point where the rudder is insufficient to ever stop the yaw(rotation) and in she goes......No problem doing planned accelerated spins as a show maneuver since you are expecting and can plan your recovery early.....I now do spins with my Kingcat and Bobcat and the rules are the same......planned entries are simple and safe most of the time, it's the unexpected ones that get you.....

So if you get into a spin that doesn't recover like you expect it to with neutralization of the controls, you check POWER OFF which decreases the angular momentum, MAKE SURE AILERONS ARE NEUTRAL, then STOP THE ROTATION with opposite rudder, and finally give PROPER ELEVATOR, depending on upright vs inverted spin, to pull out of the dive....takes a while to get this drill down, so best practice it as very high altitudes first just to get your thumbs in order.....you can run out of altitude pretty fast....

After owning a full-scale Decathlon and Pitts S1-T for 7 years and doing hundreds of upright and inverted spins while practicing for IAC competitions, the one thing all my instructors pounded in my head was stop the yaw with rudder before pulling or pushing elevator when recovering a spin or you may well die......

Gene Beggs, longtime aerobatic unlimited competitor and instructor down in Texas, published an excellent monograph on Emergency Spin Recovery back in the 80's I think it is still available thru the IAC.....I think a couple of more recent monographs from other aerobatic instructors have also appeared, all available thru the International Aerobatic Club or maybe even Amazon....great reads if you really want to undertand pilot-induced departure from controlled flight............

Tom

rjbob

My Feedback: (8)

Hi,Tom
I am familiar with spins in full scale aircraft also. I have a few hundred hours instructing aerobatics. I own N73PA, (8KCAB).

The spin I entered with the Rookie last Sunday seemed to "lock in". I had time to try several methods with both power on and power off...but to no avail. I even tried the Gene Beggs method. I still remember his ads in the IAC magazine.

Thanks form the info.
Bob

Tom Antlfinger

My Feedback: (24)

Hey Bob:

Please excuse my preaching to the choir....

I knew you flew full scale but not sure if you had gotten into aerobatcis.....I used to own 1978 8KCAB N2885Z, and 1986 Pitts S1-T N49337....

The scary thing with spinning my jets is the speed at which they come down, once they are pointed nose down and still rotating.....2 key things with Gene Beggs are power off and let go of the sticks, but I also dare not forget to push on the correct rudder to stop the yaw, which means I must quickly assess which way it is spinning and is it upright or inverted....sometimes very hard to tell on my KingCat since both inverted and upright, the nose is only a few degrees off vertical going down with normal spin....definitely easier to assess a flat spin.....

There is a big difference with and without rudder recovering my KingCat from any spin, which builds up lots of angular momentum with those long tail booms and the heavy Pegasus sitting way back.....if I just let go of the controls without full opposite rudder, it takes about 3-4 turns to recover and gets very scary cuz it comes down like a greased manhole cover, but if I let go (neutralize elevator and aileron with power off) and bang in full opposite rudder, it will recover in 1/2 to 3/4 turn.....that is, if I hit the correct rudder....

When I firsrt started doing these things in jets, I was routinely pulling when I should have been pushing, hitting the wrong side rudder, feeding in aileron and not bringing power back to idle....if I don't get the sequence right in that 8-10 seconds, I know it will be junk....still dyslexic with these things if I don't practice them regularly.....sort of like my inside/outside rolling cirlcles.....[:'(]....I start way up, pinhead in the sky-high, when I start doing them again in spring when I haven't flow for the 4-5 winter months here....

Back about 2003, I saw the guys inverted flat spin a HotSpot at Michigan jets into some tall grass.....just cracked the fins and scratched the canopy as it was coming down slow like a Frisbee....next day, they had it backup in the air.....

Tom

rjbob

My Feedback: (8)

Thanks form the input, Tom.

My Rookie may have been a teeeeeeeeeensy bit on the aft CG side. After it's fixed I'll attend to that issue.

Bob

Tom Antlfinger

My Feedback: (24)

Right on Bob.....I used to run my C.G. on the Hotspot a full inch in front of the recommended.....my buddy almost lost his with a slightly aft C.G......the nose just won't fall thru.....goes into that pancake or frisbee mode.....I remember a full scale test pilot rode one of those Velocity birds with the canards all the way down into the swamp while in pancake mode and survived.....can't remember if he was rotating or just slowly floated down, a few degrees nose up and wings nearly level....story was he actually crawled out of the cockpit onto the forward fuse, trying to force the nose down......sounds pretty gutsy to me if true.....

carbunkle

I heard about that, he almost spilled his coffee..

erbroens

Flat spins with Rookies, Hotspots, etc... have been always like this. They are great fun, until the day you hit the ground.

Best way to do it is as said above, using vectoring thrust and power well over idle to get out of trouble without losing too much height.



and talking on this subject , a interesting story on flat spins and delta jets :


''Three F-106s were on a ACM (Air Combat Maneuvers) that day when 58-0787 went into a flat spin and according to procedures, Captain Gary Foust bailed out at 15K feet. One of the accompanying F-106 pilots, IP Major Jimmy Lowe, observed the ejection and also observed 58-0787 straighten out right after ejection and reportedly transmitted "Gary - you'd better get back in it!". Major Wolford got a call from the sheriff about an airplane sitting in a field with the engine running and wanted to know how to shut it off. The sheriff was advised to just let it run out of fuel. The plane was resting gear up, engine running, on a small amount of snow, with a slight downhill grade and as the snow melted under the aircraft, it would creep forward some, which had the sheriff rather excited. A depot team from Sacramento Logistics Center, McClellan AFB came in, took the wings off, put everything on a railroad flatcar (a railroad set of tracks was conveniently located about a mile from the landing site), and shipped it to McClellan AFB, CA where it was repaired. Colonel Wolford said he'd like to have flown it out of there but after the aircraft was lifted up, the under side damage was greater than thought. The Stable Table had exited the bottom through the 05 panel area and crunched its way back to the rear of the plane ruining the armament bay doors. ''

thinwing

Bob....like we discussed it was obviously caused by that piece of tape to repair nose crack!!!!!LOL.....kpc

rjbob

My Feedback: (8)

I told you that GREEN tape wouldn't work right.

carbunkle

I saw that a while back, unbelieveable luck ! One thing I noticed that was left out of the story was how he poped the drag chute to try to help get out of the spin and it just wrapped around the rudder I believe, but it obviously must have come off some how..

erbroens

I may be wrong, but in this pic the landing chute seems to be in place.. It may be possible that the pilot opened the speedbrakes as a way to slowdown the airplane to bail out, or perhaps he used it to try to get out of the spin. maybe someone in this forum know about this guy so we can email him to ask what happened..



Enrique

carbunkle

It took some searching but I knew I had read something about poping the chute.. top right column>

erbroens

let´s unleash a fraction of the power of the internet... ... just found a pic of the drag chute of the F-106... to me still looks like if it was undeployed ... or not?

carbunkle

I agree it doesn't appear to have been poped from the pic, but I knew I read that it had.. Maybe that was just embelishment to the real story on the part of the wittnesses..