Surviving a mid-air canopectomy

[chief4192]

How or why I failed to fully latch and secure my canopy on my Waiex B taildragger before takeoff is irrelevant to the discussion of how to get safely back on the ground in this situation. I’m told that the three other pilots who have also experienced this situation are not available for comment, so my description of how a Sonex flies without a canopy will hopefully provide enough information to be of use to anyone who may find themselves in the same quandary. (I know, do your checklists carefully and thoroughly…)

I had just climbed and turned back out of the pattern, then leveled out and gained speed to 120 mph when my canopy was ripped from the airframe in a thunderous crash of shattering plexiglass. The airplane immediately pitched somewhat nose up, but I had good authority and I assumed I could probably land the airplane somewhat normally (first mistake). Continuing back downwind (but on the opposite side) I rejoined the pattern and lined up on my takeoff runway. I noted that I was below the 5-degree VASI for the runway and planned a shallow descent until I intersected the glidepath. That was, however, the last time I noticed the VASI as the airplane was pitching up more and more as I slowed and descended. At this point, doing about 90 mph, which without thinking I automatically considered too fast for a safe landing (second mistake), and getting more and more concerned about my very poor forward visibility, I decided to feed in some flaps both to help slow me down and to pitch the airplane forward. After several seconds and about 10 degrees, I realized things were rapidly getting worse, not better.

Then I got lucky. My left leading edge clipped the top of a tree, which instantly told me I was still lined up pretty well, but no more than 75 feet AGL and only 150-200 feet from a cross road with poles and wires, well short of the runway! Immediate full throttle helped me pull us over the wires but couldn’t keep us in the flying envelope. Neutral weight-and-balance and all that full-throttle air on control surfaces helped keep the plane level, so we did two pancakes separated by a 50 foot bounce on the safety field short of the runway. Not a scratch on me, but those wonderful titanium gear legs are NOT available as used parts. Not a ripple in the firewall and no cracks I could find in the engine mount. A strong airplane!

If I had to do it over I think I should have opted for a high-speed wheel landing and worried about the speed once I was on the ground. Landing without a hard-surface runway seems much less straightforward. Knowing the stall speed in this configuration would be invaluable, but recovery from a test stall before landing might involve some other bad behavior.

The loss of the canopy not only affected the trim attitude of the airplane, it severely compromised the lifting body configuration of the Sonex airframe. My sinkrate as I set up on approach must have been close to double what it normally was, as I could have impacted the ground hundreds of feet short of the end of the runway if not for my “lucky” warning.

My hope is that no other Sonex pilot ever has to endure this, but please have some idea of what you might do in a similar situation.

I’ll also post a few parts for sale in the appropriate section

[CaptainXap]

!!!!

Congratulations on surviving!

If this were to happen to you again, is there anything you think you would do rather do differently? From your description it sounds like you feel you would have been better off keeping more power and speed until you were over the runway?

[sonex1374]

Jim’s experience has several really valuable lessons for us to take away. In an emergency we need to not fall into the trap of treating it like a business-as-usual situation. Over the hours of normal flying, we train ourselves to unconsciously work to the same typical outcomes: a standard patter, at typical airspeeds, with a shallow approach angle, to a touchdown near the threshold, on a paved runway. Any one of these things might need to be ditched to get us on the ground safely.

For example, we may have a partial power failure that allows us to fly a somewhat normal pattern, but halfway through the power fails completely. Recognizing that a partial-power loss will likely become a total power loss and planning accordingly will keep us closer and tighter to the landing area. Or, we may be high in the pattern and be tempted to fly a little further out on downwind before turning base to bleed off some altitude, only to find that now with the headwind we can’t glide back to the threshold. Might have been better to stay close to the runway, add flaps in right away, and accept a touchdown half way down the runway instead. In Jim’s case, the plane sans-canopy required a much higher approach speed to overcome the huge increase in drag.

In an emergency situation we have to be mentally prepared to modify our normal practices. We can hedge our bets by creating normal practices that also work well in a emergency (e.g. tight power-off approaches), but training for emergencies is the only real solution. Training for unusual situations allows us to think through the thought processes and decisions we’ll need to make, but at a time of our choosing where we still have options to keep us from damaging ourselves. Working through these cases in advance helps us quickly get to an acceptable solution in the heat of the moment, when we don’t have time to think it through.

It’s a truism that we don’t rise to the occasion, but rather we fall back on our level of training. Part of our training has to be aimed at recognizing when to throw normal out the window.

Jeff

[13brv3]

Congrats on a successful outcome, and a HUGE thanks for sharing the observations with us! It's certainly more extreme than I would have expected. Knowing what you know now, if you had been wearing a chute and had the altitude, would you have jumped or attempted a landing? If you weren't at an airport, that may even change the thinking.

Thanks,
Rusty

[Waiex 0194]

“the airplane was pitching up more and more as I slowed and descended. At this point, doing about 90 mph, which without thinking I automatically considered too fast for a safe landing (second mistake), and getting more and more concerned about my very poor forward visibility”

I’m so sorry you lost your plane, but very glad you lived, and are willing to tell the tale. With all the confounding inputs you were managing in the final moments, airplane acting like it’s behind the power curve but indicating way fast, what if the airspeed reading was dramatically high due to the loss of the canopy. Was your static sense in the cockpit?

[chief4192]

Good question, as it ended up feeling like being behind the power curve.

I had twin vents just aft of and on either side outside of the cockpit so pretty sure my IAS was fairly accurate. I think my biggest problem was a lack of correlating inputs in my normal panel scan. My normal inputs of sight picture, VASI, RPM and airspeed had always worked fine for me, but now a big part of that array was missing. Although I wouldn't normally chase a VSI to fine tune a glideslope on approach (it bounced a lot at high AOA on my plane), it could have been a lifesaving correlation for me, if only to inform me that things were seriously not normal. Like they say, "It's better to be lucky..." It would have been better to be better prepared.

I'm happy to see that my sad story is generating some thought and discussion, as I hope being better prepared for unusual situations may someday help another pilot

[BRS]

What weight (solo or with pax)?
What engine?

The comment about inaccurate AS has me curious as well. I don't suppose you were flying with an ipad or other device that was recording your gps speed. Perhaps MGL data file?

[edit] I just saw your Garmin GPS. Did it have a recording feature of data?

[Scott Todd]

Even if it was vented behind the panel, the canopy opening would probably not affect it a noticeable amount. Swirling air won't affect it unless its directed at an opening with lots of velocity. For other readers, when venting behind the panel, we usually plug the end and drill several tiny holes around the tube within a few inches of the end. I've flown literally dozens of experimental airplanes with it vented behind the panel and it doesn't move with opening windows, doors, etc. Remember, it reads static pressure. By definition, its the same pressure the fluid would feel at rest. Behind the panel, there usually just isn't much air movement.

[jowens]

Thank you for sharing your experience!!

[chief4192]

The two vents I referred to were literally static ports located just aft of the junction of the cockpit and the tailcone. And sorry, no data file available. Please trust me, the memory is vivid. Just writing about it gives me a mild case of the butterflies.