Audio Emergency Warning Systems FAQs
An Objective User Review Of The Most Commonly Posed Questions On Audio Gear, Stall, Overspeed Warning Systems
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Q)    I have never thought I would need or even wanted one of these units.  I guess I thought they were kinda like "training wheels" for my Mooney.  Just how much better do you really think they are over my stock gear horn?
Your point about the "training wheels" is well taken and along with the lack of education concerning what really goes on in a cockpit when a plane lands with the wheels still up in the wells is a major thrust of this web site and articles now appearing in THE MOONEY PILOT, ABS (American Bonanza Society), and the likes of Aviation Consumer.  It is becoming more and more clear that pilots simply can't either hear or (just as importantly) interpret the meaning of the seldom heard monotone gear or stall warning horn soon enough (if at all) to do any good.  This is especially complicated by the ever increasing use of highly effective ANR headsets which themselves tend to block or blunt the typical gear warning horn's tones. 
Facts are, most pilots simply don't hear the gear horn often enough to be able to mentally interpret its meaning quick enough to do any good.  We are all condition to direct verbal and visual commands in our daily lives.  Audio warnings are the next best thing to a nit-picky if  not anal co-pilot.  

Q)    Since you apparently have interviewed numerous pilots who have joined "The Club", what do they tell you and how many of them end up installing one of these units?
Nearly to a man, they say that they simply "didn't hear the horn" or at least understand it's meaning in time.  Most of the time the way the factory's OEM stock throttle position micro switches or airspeed switches are set, the average pilot only has a few seconds to both hear, interpret, and affect a remedial action before it is too late.  All this takes place at the most busiest time in piloting a retract when way down into the actual "flair to land." So considering the facts, it is no wonder we don't have more gear-up incidents than we do.  Our study finds most pilots were wearing headsets and many of them were sophisticated ANR versions.  But in retrospect what they were actually saying to us is that they didn't have time to mentally interpret the meaning of the obscure horn in time to do anything about it! 
Also, the stock SonoLert gear horns can go "INOP" and in the course of normal maintenance, are rarely actually checked.  We think the bulk of the "Have" G-Up Club Members are mostly guilty of antiquated hardware than true carelessness.  

Q)    What is the main difference between the P2 and ACI's Gear Alert systems?
The P2 Audio Alert System (AAS) hooks into your static system and acts or is triggered on airspeed. While it is pre-set, it is also adjustable (in 5 mph increments) to suit your particular model.  It alerts you verbally and visually (see lighted button to left) to "go-off" if your wheels are still in the wells below a certain pre-selected airspeed.  We find it is nearly impossible to "fool" it into not giving you adequate verbal warning in time.  Besides the aural message, it has a visual warning light mounted on your panel. 
ACI's 2037 Gear Alert System on the other hand, has a microwave/radar like transducer/transmitter mounted on the belly which is pre-set to trigger the audio alarm if your wheels are still in the wells below approx. 150' AGL.  Again, it is hard if not nearly impossible to "fool" this system as well. 
Both systems are totally independent from your existing gear horn (which remains intact to work as normal) and both work amazingly well and are nearly foolproof in real world flying situations.  Both systems deliver their audio messages through your headsets and/or cabin speaker and take a day or slightly longer to install, and at $1,295, both are about the same price.   However, the cheaper ($495) Voice Alert offered by ACI is NOT a stand alone system.  It simply acts as a "repeater" or companion unit to your pre-existing gear horn and is triggered by your existing micro switches and/or airspeed the same triggering system that currently drives your existing gear horn. 

Q)  Which unit is best and which one do you recommend?
We think both units are equally effective and each has strong points and maybe weak points.  We offer both units and the choice is yours.  However, we strongly recommend you research both by reading our separate fact sheets.  Some pilots like ACI's system because it is not airspeed dependant and some pilots like the P2 because it is nearly impossible to set down most retracts at a speed which would "fool" it not to give ample warning.  Some argue that they worry operation in hilly or mountainous terrain may "fool" the ACI ground clearance sensing unit while others worry that they could approach too fast so as to "fool" the P2 unit which senses airspeed.  We find in most all approach circumstances, it is nearly equally hard to "fool" either unit, and in any event you should be glad you have a viable economical choice over the stupid ineffective monotone gear horn!  Read the data on both and the choice is yours.  But  make sure to install one or the other today before it is too late... We offer detailed evaluations and facts on both the P2  and  ACI's Gear Alert.  ACI's cheaper Voice Alert is NOT a stand alone system and relies only on your pre-existing throttle trigger micro switch and operates in harmony with your gear horn.

Q)    Can these units be "fooled" into not giving an alarm in time, and if so, which one is the most reliable?
For all practical purposes no, they can't normally be "fooled" and both are nearly Murphy-proof.  Only in extreme situations such as arriving at an aircraft runway located up on an extreme abrupt plateau or just after a large deep canyon would "fool" the ACI unit's ground proximity measurements temporarily.  Likewise, if you approached a runway at an extremely high speed such as 20kts or more higher than normal could temporarily "fool" the P 2 into thinking your weren't attempting to land but merely making a low pass.  In 99% of the approach instances either unit will give you adequate warning and either is far better than what you have on-board now.

Q)    Can I install one of these units myself?
Probably not.  Neither manufacturer advises their units to be installed solely by private owners and the typical installation is beyond what the FAA allows without direct A&P/IA supervision.  Getting them wired to the avionics (intercom/headset/speaker) wiring loom typically takes an astute maintenance shop or an avionics shop, and isn't something most owners would want (or should) tackle.  In addition both require the aircraft to be up on jacks.  The P2 system should be calibrated for your specific model aircraft and both units should be flight tested prior to being put into service.

Q)    How much shop time does it take to install one
Typically it takes about a full day (8+/- man hours) or slightly longer to affect a good installation on both independent units (slightly less for ACI's Voice Alert repeater unit), as some new wiring has to be run and usually some interior panels have to come out for the wiring.  If two mechanics or one with a helper is on the job, it can be done in the same day.   

Q)    What is the main difference between the cheaper ACI Voice Alert unit and the others?
The $495 ACI Voice Alert only acts as a "repeater" and isn't independent from your existing gear system. If your throttle micro switches or other triggering mechanisms fail or not warn you in time, this unit would also be susceptible.  We think it is far better than the stock monotone horn but obviously not as good as either of the totally independent units.

Q)    If these are so effective, why doesn't the factory or FAA mandate this technology to be installed in new Mooneys or other retracts?
Good question.  If you follow history, much of the FAA regs are "written in blood" in fact fatal or serious accidents tend to drive FAA regs.  Typically with most OEMs there is a cost and tradition situation and existing SonaLert horns are cheap when compared to these units.  We sincerely doubt most retracts could be certified (all over again-fresh) today without some type of a audio warning system on-board.  We also find the FAA considers a typical gear-up incident to be a non-life threatening event and for the most part, not considered an "official" life threatening accident per se.   They are standard equipment on some retracts currently being certified and many airframe manufactures ARE considering these units now. 
The more the buying public knows about them the more you will see they will start demanding them as they work exceedingly well and make good sense.  However, in our opinion, advertising them at an OEM level may be seen as spotlighting a weak point for existing retracts, and some un-enlightened marketing folks feel safety issues are a "hard sell" anyway...  Until it is too late, that is...  All in all, our bet is that you will see more of this technology out there in the near future.   

If you your questions aren't addressed here, please Email us or call (941-486-1969, or 941-484-0800) with your questions or comments
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