Stall warning assembly and wing access hatch with ER fuel tanks

[bertschb]

I'm a new builder and I'm currently working on the leading edges for my RV-14A wings. I'm also installing the Sky Designs ER fuel tanks. One of the modifications you have to make with the ER fuel tanks is to shorten the leading edge wing skins by two rib bays (and extend the fuel tanks by the same two rib bays). The part of the leading edge skin that is removed is where the factory stall warning assembly and access hatch plate goes (see diagram below).

Since I would need to cut new holes in the shortened skins to add the stall warning and access panel further outboard on the wings it made me question whether I should install the factory stall warning at all. It appears many people don't install the stall warning because of the AOA built into the pitot. My dilemma is I've only flown Cessnas and only have experience with "old school" stall warning systems.

First question - Is the access hatch shown below ONLY used to get access to the stall warning assembly for removal/maintenace?

Second question - I'm not planning on using a dash mounted AOA display. I'm used to the audible stall warning sound in a Cessna. Does the Garmin GAP26 pitot and G3X system generate an audible stall warning like a Cessna?

If the answer to both questions is yes, I don't think I'll install the stall warning assembly or the access hatch.

Thoughts???

 

[Reflex]

If I understand correctly, yes...the only thing the panel is used for is access to the microswitch on the mechanical stall warning. (or in my case a camera).

Can't answer your second question, while I'm using AOA, I'm not going to use the dash mounted display.

Best of luck,

Fred

 

[DerekS]

The second question is a yes. Progressively faster beeps until solid tone at stall.

Only downside is if you have a pitot/static blockage you also lose the stall warning and have to rely on gps speed with a fudge factor for wind to determine speed

Derek

 

[rocketman1988]

The second question is a yes. Progressively faster beeps until solid tone at stall.

Only downside is if you have a pitot/static blockage you also lose the stall warning and have to rely on gps speed with a fudge factor for wind to determine speed

Derek

Why? The wing can be stalled in any attitude or airspeed, so the speed indicated doesn’t really matter. Most RVs will give more than adequate notice before the stall occurs. I would suggest that if you aren’t comfortable with the recognition of an impending stall, you should get with an instructor and go practice. Cover your instruments and learn the aircraft.

 

[iamtheari]

The square access cover is only for the stall switch unless you make use of it for something off-script (like a camera). The stall switch isn’t necessary. The separate AOA indicator isn’t necessary. The G3X Touch will beep at you plenty to warn of a stall based on the AOA/pitot system, and show the AOA indicator on your PFD when the number is within a configurable range.

I fly with a variety of stall warning systems and the G3X Touch AOA-on-PFD is my favorite. Second place goes to the J-3 Cub, where the lower door can be left open in flight and will start to close itself as you near a stall. By the time you finish Phase 1, you should know your plane so well that you can smell the stall.

How much usable fuel do those extended tanks gain for you?

 

[BobTurner]

Why? The wing can be stalled in any attitude or airspeed, so the speed indicated doesn’t really matter. Most RVs will give more than adequate notice before the stall occurs. I would suggest that if you aren’t comfortable with the recognition of an impending stall, you should get with an instructor and go practice. Cover your instruments and learn the aircraft.

Because the AOA systems rely on pitot plus a second pick up data, to work. I would say the only downside of AOA is that they need to be calibrated in flight, so in general they cannot be counted on for the first flight. Except for that, I’d say ditch the standard stall vane I have both, and I totally ignore the standard vane as the AOA is always on first. I’d remove the vane if it wasn’t so hard to get to on the finished wing.

 

[bertschb]

...Second place goes to the J-3 Cub, where the lower door can be left open in flight and will start to close itself as you near a stall. By the time you finish Phase 1, you should know your plane so well that you can smell the stall.

That's pretty funny!

The Sky Designs ER fuel tanks have a capacity of 68 gallons in the RV-14 vs 50 for factory tanks. And no, I'm not installing the ER tanks so I can fly for 6 hours straight

 

[DerekS]

Why? The wing can be stalled in any attitude or airspeed, so the speed indicated doesn’t really matter. Most RVs will give more than adequate notice before the stall occurs. I would suggest that if you aren’t comfortable with the recognition of an impending stall, you should get with an instructor and go practice. Cover your instruments and learn the aircraft.

Good advice for any pilot.

I did not install the stall vane and I'm happy with the choice, however I stand by my position that there is a reduction in redundancy with not having the vane that the operator should to be aware of.

Even with a stall warning , in addition to the aerodynamic warning, plenty of folks manage to kill themselves with the stall spin. The AOA is a better mouse trap replacement for the vane stall warning, but it is no longer independent from the pitot / static system.

Pitot/Static issues are not that uncommon, and indication failures are not always immediately evident. The stall warning will give you 5 knots earlier warning, it gives a signal that is much harder to miss than the aerodynamic burble and is fully independent. If you are the ace of the base, it won't matter. If you are on your first flight in a while, distracted, on AP reading a chart etc, the vane gives you a few more seconds to figure out somethings going on before it gets exciting.

Without the vane, an airspeed failure will be accompanied by a stall warning failure, and you need to pay extra attention to what the plane is telling you. This is also where GPS speed comes in handy, to double check that your speed feel hasn't gotten rusty.

Derek

 

[Taltruda]

That's pretty funny!

The Sky Designs ER fuel tanks have a capacity of 68 gallons vs 50 for factory tanks. And no, I'm not installing the ER tanks so I can fly for 6 hours straight

You don’t need to fly for 6 hours straight to want the additional fuel.. landing at an airport that doesn’t have fuel, or tankering fuel though a field with overpriced fuel are just a couple of reasons to want the larger tanks. You don’t always have to fill them, but there are times when it would be nice to top off cheap fuel or have options..