Aerobatics

Forums: 

Anyone ever do loops in their 320/360 . Did 5 hours of  training this past weekend at Patty Wagstaffs school in their xtra 300 . Instructor doesn’t see any issue with doing them in my 360 so was just wondering if anyone else has done it and any pointers they may have ? 

After taking my aerobatics

After taking my aerobatics training I have since done loops , rolls and Cuban 8’s in my 360 . I’m happy to report it handles them all with ease and zero issues . It performs very similar to the extra 330 I trained in . No need to roll the throttle off on the downside of loops . A nice steady pull out is fine and does not spool up to excessive speeds . I’m fully confident in the capabilities of the 360 to perform light sport aerobatics with zero issues . It’s very safe and a lot of fun . 

Legacyl2k's picture

Have you spun it yet.  I have

Have you spun it yet.  I have been flying acro for years.  Most acro accidents end up by entering into a unplanned spin.  If you have good spin data I would be greatly interested.  As far as I know their is not much formal data on Lancair spin behavior.  I have done some test points for upright spins in a small tail 360.   I have no inverted data.  The lancair 360 shows poor spin recovery characteristics.  The three points tested on this one airplane.  3 entries total: Power off entry for all, 1 kt/sec deceleration all, first to wing drop, second to 180 deg, third to 360 deg before recovery.  The plan was to do a final point to three full turns.  Recovery from point three took two and a half turns to break the stall which was beyond our planned limit.  CG for this airplane was at 18% MAC.  It is my opinion that spinning a 360 at the kit mfg recommended aft limit with half fuel would be unrecoverable.   Just thought I would comment in order to expand the knowledge base.

Mike

I have not spun it as The POH

I have not spun it as The POH does not recommend spins nor has it been tested. I believe from the research I’ve done that the 360 “can” be difficult or slow to recover from a spin . As you pointed out it’s dependent on CG . The CG fuel and loading limits are published in the POH and for sport aerobatics , from my experience and that of the manufacturer these limits are perfectly fine . Also in my experience and training so far I cannot imagine how I would get into an unintentional spin scenario to begin with . In light sport aerobatics with proper understanding of flight management there isn’t really a possibility of an unintentional spin unless you are very reckless or simply don’t know what you are doing . Recovery is very basic , simple and straightforward from any botched aerobatic maneuver . Example : while practicing loops I pulled a little to hard at the top of the loop and produced an accelerated stall . No more G’s while upside down .  I simply released back pressure,  let the nose fall,  leveled the aircraft and pulled out , no issue . I’ve botched maneuvers seven times while practicing and with proper recovery technique there is zero chance of an unintentional spin and the aircraft acts exactly as it should . No different than the extra or citabria I trained in . In numbers , roll rates , entry speeds and recovery from botched maneuvers it handled very similarly to the Xtra . It’s not a plane to fear for light sport aerobatics ( with proper training )  as so many falsely attest too . It handles  and responds exactly how it should and is a pleasure to do light sport aerobatics in . 

You are wise to seek advice,

You are wise to seek advice, prior to transferring your excellent training in the Extra, to an untested envelope in your Lancair, which was designed for another mission.

I wrote a detailed explanation which was accidentally deleted when I went to search for Grampa Pettibone on spins. I’d be happy to discuss further, from engineering flight test and aero medical perspective, if there’s interest.

Bill Miller
 

Grampa Pettibone describes an unbriefed post maintenance  check flight mishap in an F14:

The pilot quickly decided that the spin had developed to the point he needed to attempt the alternate recovery procedures. He reached for the roll stability augmentation switch and found that both the roll and pitch switches were off. He switched both back on and put the stick right and aft in accordance with the alternate recovery procedures. 

During the departure the RIO tried to communicate with the pilot but heard no response. The pilot could hear the RIO but could not respond because his mask was hanging off of his face due to the high G forces. The pilot saw that the angle of attack gauge was full white, which indicated 30 units, and that his airspeed was below 100 knots. He sensed the nose pitch up and then down, as if the aircraft was about to recover. The yaw rate seemed to be slowing. The pilot put the stick forward and right in an attempt to fully arrest the spin. 

The RIO also noted that the yaw rate decreased to 90 degrees per second but then stayed there. As the Tomcat descended through 7,500 feet, the RIO said, "We're out of here," jettisoned the canopy, and initiated command eject. The RIO's seat fired but the pilot's did not. The pilot initiated his own ejection on the second attempt at an altitude of less than 3,000 feet. He was in a poor ejection position because of the effort required to reach the lower handle and sustained minor injuries as a result. The stricken aircraft rolled out and actually pitched up before water impact. Both crewmen were rescued by the carrier's SAR helo. 

Grampaw Pettibone says: 

What in tarnation was these boys thinkin', putting the fangs out like this on a post-maintenance check flight, not to mention one that gave the crew a hint the aircraft might not be 100 percent in terms of handling ability? And I'm not even gonna mention the fact--well, dang it, yes I am gonna mention it: Flying without briefing, especially when something as high-risk as ACM is involved, is just plain unprofessional. No wait: That don't get it. It's more than unprofessional; it's foolish.

We used to teach spin testing

We used to teach spin testing at USN test pilot school. Prediction in this dynamic and disorienting environment is  a very complex mathematical challenge in engineering flight test mechanics and dynamics, with an experienced team. We used well tested aircraft, with thousands of spins in operational training.

You are asking the right questions prior to entering this high risk flight test environment, but I have heard there’s minimal data because of loss of the test prototype- but not sure which models were tested. From training, in Naval jet trainers, I know the risk for spin entry is maximal at the inverted low speed stall/ departure from controlled flight/ spin entry / at the top of the loop. Spin modes include steady state, oscillatory, upright and inverted, across a wide envelope of weight and balance. Also, it’s reported that aerodynamic variation between multiple builders makes it harder to standardize or predict spin behavior and recovery, between builds.

You might also review mishap reports where engine failures were caused by very mild aerobatic, low positive g flight in training scenarios.

Bill Miller

old Naval Test Pilot , Flight Surgeon USNR(ret)

sounds like grampa Petibone

I think the discussion is

I think the discussion is healthy, but I must wonder, why in the world would you intentionally enter a spin in any aircraft that was not specifically designed to spin and recover?

harrelson's picture

I've done loops and rolls in

I've done loops and rolls in our 320. I would, however, be reluctant to fly aerobatics with anyone who claimed that an accidental spin was "impossible"

 

Bill