Stall warning on the Rallye is the slats! :)
Very true that hearing is disabled in a real emergency, but stall warning is useful for the operating ceiling too, which is where most of mine occurred.
I regularly fly 4 different aircraft, only one has a stall warning, the C-172s. I don’t miss it in the others. Besides, an audible alarm is of no use in a critical and stressful situation. At higher stress levels and when concentrated on a task, the brain starts to focus and cut off other stuff. The first thing to cut off is the hearing ability. You may hear things, but the brain don’t react to it, it renders all sounds irrelevant. It is better to learn the behavior of the aircraft at stall, and if you absolutely “need” an indication, a visual one is much better choice, or even better, a physical one (shaking for instance). Incidentally, slight shaking or physical rumbling of some kind is the natural indication of a stall, and that warning is not filtered by the brain even if you are half way into coma. It becomes part of the automated “muscle memory”.
just bumped into this old thread
Mooney_Driver wrote:
We just had an accident report published where a defective stall warning switch most probably caused a near ground stall condition which the pilot did not reckognize due to the lack of warning. He managed to crashland the plane and nobody was hurt but the plane was a write off.
I’ve been looking for this report but cannot find it. MD would you happen to have a reference where I could find it ?
The case of a stuck switch is a good case for having a switch on the speaker
Doing this is just asking for other trouble. I once witnessed a sim-session (full-flight) as part of the Jet-Transition training. During approach stall training, the PF lowered the flaps too far before gear extension. The nuisance reminder of gear led the instructor pull the CBs (for EGPWS I think). Recovery was fine, as stick shaker was not concerned by that CB. But on the subsequent approach, the PF did not start the flare and (according to the sim) crashlanded on the runway. He immediately turned towards the instructor and claimed: There was no radio altitude callouts! That was caused by the pulled CB’s that were not reset.
What else is on your speaker? Autopilot disconnect warning? Marker Beacon? Altitude Alert?
Another joke?
Airborne_Again wrote:
According to the certification regs an aircraft must clearly indicate to the pilot that a stall is approaching… This can be done either “naturally” e.g. by noticeable buffeting or by a technical device.
Yes; and this obviously is not up for the pilot to decide. Goes back to the original design specification of the aircraft. If it was designed with a stall warner, that’s your cue.
We’ve had issued with moisture getting (blown?) into the assembly or affecting the wiring. So on the daily it would fail the test, but after a few hours in the sun it would start to work.
You are right they are a very basic design, but adequate enough as it’s possible to adjust them pretty accurately to +/-x knots. I believe the requirement is for it to come on 5-10 knots before the stall, and once adjusted correctly, it’ll come on pretty reliably.
It’s a non-MEL-able item, so considered pretty critical! I.e. it fails, the a/c is grounded.
I had the existing stall warner fail a preflight check, twice, many miles away from base, so I flew anyway. It never happened again… But this is why I ordered a new one for the TKS installation. And that is how I discovered there are two different types…
The old microswitch is working fine, of course 
The case of a stuck switch is a good case for having a switch on the speaker I thought the TB20 had a CB on the stall warner circuit and just had a look and despite having about 1000 CBs it turns out that it is on a fuse.
I had a stuck stall warner making noise almost all the way on a 300 NM trip in an Arrow. While I believe in the safety of a stall warner in general, flying 2+ hours in that noise definitely detracts from safety. My 2 passengers were not impressed either. We never found anything wrong with the switch and as far as I know it did not happen again.
Neil wrote:
Another joke
Not at all. We don’t have a MEL on the Mooney obviously but I’d hesitate to fly with an inop stall warner. It is part of the certification and therefore imho required.
I so far have never had it go off unintended other than once at FL170 when Vs is a sight higher than on the ground and we tried to determine the absolute ceiling, but I have recently read a report of a take off accident on a short runway where the inop stall warner was cited as one of the reasons the pilot reacted wrong when the airplane did not behave as he expected shortly after take off.
