A few stalls...

[Pilot DAR]

https://youtu.be/VpYI0PU6P-g

I flew about 40 stalls, and all configurations, in a modified Cessna 208B Grand Caravan Friday. Here's a video made by the Engineer who was right seat to me. It was a really bright day, so some instrument face reflections. But, you can see on each of the instruments what's happening.

The requirement was to demonstrate the airplane with the modifications was "spin resistant" (equivalent level of safety). So (in accordance with an approved flight test plan and on a flight permit) I approached this stall configured with full flaps, 75% power, brought the plane to the stall, and as the nose dropped, applied full nose up control, and held it against the stop for at least three seconds. After that, I lowered the nose (Indeed, full nose down for a moment), and the bank angle had to be controllable within 60 degrees, which it was. The slowest speed I saw during this stall was 41 KIAS (Cessna's correction chart does not go that low, so KCAS not known). The airplane passed all of the stalls during the testing, though this was one of the more demanding.

As we were lighter weight, and a more aft C of G, a few of the stalls required full nose down control to be applied and held to initiate recovery. Other stalls I was required to demonstrate were with 30 bank, slipped one ball out, 75% power, which the plane handled similarly well.

[Tinstaafl]

How was it modified? And why the 'spin resistant' certification, instead of the more usual spin recovery requirement?

[Pilot DAR]

The Caravan was modified with the addition of a tailboom, belly pod, and wingtip booms for survey work. These required STC approval, thus flight testing. In addition to the stalls, and handling, I flew about six hours of "shaker testing" where an electric motor powered eccentric shaker shakes one wingtip pod at different frequencies, and at increasing airspeeds to investigate flutter resistance.

The spin resistance rather than flying actual spins was based upon agreement between my client, and Transport Canada, based upon my recommendation. In my past experience flying spin tests on modified Grand Caravans, I found that although they can be recovered as described in the design requirements, it's often an exciting ride, approaching Vne, and more than 2G in the dive recovery. With a forward C of G, when spun, they recover going close to straight down, accelerating a lot. I suggested that as the Caravan tends toward being spin resistant anyway, holding it in for a turn just to prove it will come back out has more risk than benefit, when it's agree sufficient to show that it's really hard to get into a spin, and a prompt recovery gets it back out much more quickly, and with less speed and G that holding it in for a turn.

In addition to the stall in the video, I was required to demonstrate just about every other conceivable stall entry, so show recovery was benign and easy. I was reminded during this testing, and the video shows, that depending upon what you're doing (and probably shouldn't be in a Caravan), you can get yourself in a situation where both full nose up and full nose down elevator are being applied and momentarily held within second of each other. It's a weird feeling to be holding full nose down on a 4 1/2 ton plane!

[fitliker]

You can play a tune on the stall horn of most Cessna aircraft . The Caravan is not as easy as a 172 to play well , but it can be done . You would be surprised at how many people have never played a tune on the stall horn of a Cessna . Or flown a fully stalled aircraft down for a few hundred feet .

[RichardJones]

I flew a Cessna 188 Agwagon years ago. While we were working so was the stall warning, to the extent it became a distraction. I tried bending the reed of the sensor down. Still annoying so most of us just stuck a half a match stick to stop the reed contacting.. We flew by feel..