Maneuvering Speed

[dcat127]

So I was flying the other day during the middle of the day, on a warm day with scattered clouds and gusty winds. It made for what I call a bumpy day here in the northeast, or probably a normal day in Texas. Most of my flying experience is in trainers that you probably could not overstress them if you tried, at least not without pointing the nose straight at the ground and the maneuvering speed is fairly close to cruise speed. I have recently acquired a Saratoga and that is what I was flying. On a Saratoga as well as many high performance airplanes there is a significant difference between cruise speed and maneuvering speed. What constitutes as rough air for the purpose slowing down to maneuvering speed? I did ultimately slow down, mostly because I am a wimp and do not like turbulence, rather than that I was worried about the plane. I recently got a co detector that has a g-meter built it. I forgot to look what the peaks were the other day, but from previous experience, turbulence feels a lot worse than a g-meter thinks. So at what point do you slow down to maneuvering speed?

 

[bonefishpete]

When the lap belts start tugging uncomfortably?

 

[AvNavCom]

As long as you're within the green arc and you're not making full control-surface deflections, you should be fine in any turbulent air. If the turbulence is of sufficient intensity that you're making full deflections to maintain control, then you need to be at or below your maneuvering speed (adjusted, of course, for the aircraft weight) to ensure a stall before damage to the aircraft.

To answer your question, if I'm getting thrown around to the point that I'm having difficulty maintaining altitude or directional control, then I'm absolutely going to fly below maneuvering speed. I'm generally inclined to be cautious, so if there's moderate turbulence I'll probably drop it to the listed maneuvering speed, which is going to be higher than actual (since I don't ordinarily fly at max gross) but well within the green arc and close enough to the real maneuvering speed that I can rapidly slow if needed.

 

[Learnin’ to fly…]

Not the most scientific, but the rules of thumb I was taught was “if it is comfortable for a passenger, it is comfortable for the airframe”. As with lots of aviation wisdom, Im sure there is some good and some questionable in that advice. In my view, that framework has you pull the throttle more than you “have to” for the airframe, but probably the right amount for your (comfort, concussion avoidance, tailbone comfort…). For most GA flights, the difference of a few kts is negligible to how fast you’ll get there.

 

[MauleSkinner]

I recently got a co detector that has a g-meter built it. I forgot to look what the peaks were the other day, but from previous experience, turbulence feels a lot worse than a g-meter thinks.

This is something you need to keep in mind…unless you have fairly recent aerobatic experience, you probably don’t have any kind of “feel” for g-loading. It feels a lot worse than it is.

That doesn’t mean use caution. Flying through an inversion layer or flying in the vicinity of terrain or convection can result in significant changes in turbulence.

 

[Ed Haywood]

I feel 2G in my butt, 3G in my arms and upper body, and 4G in my head. At 5G your face feels like it is sliding off. 6G gets you things like tunnel vision and G-LOC unless you are highly trained.

Smoothness is important. As long as you don't jerk the controls, you should feel the force building up in time to catch it. Easing off the controls brings relief.

When I take pilot friends up, I usually do some steep turns to 3G so they can see what it feels like. Since normal category GA aircraft are rated to at least 3.6G (I think), that is a useful sensation to have in your memory bank.

Unless your G meter records peaks, you will read it too late. I have a lot of hours pulling G's and I have to decide before a maneuver to watch the meter. It's just not something you think of in the moment, unless it is sustained.