Audio Emergency Warning Systems An Objective Review Of

Audio Emergency Warning Systems
An Objective Consumer Review Of: "Specific Message" Audio Gear, Stall, Overspeed Warning Systems

While different in design and triggering methods, both the P2 and ACI's Gear Alert audio gear warning systems give you a clear specific audio/verbal message in your headsets and/or over your cabin speaker if your gear isn't down when set for landing. Except for the simple ACI Voice Alert (which is only a "repeater" using your ship's existing triggering device such as throttle position micro switch), both the P2 and ACI's Gear Alert Systems operate totally independent from your pre-existing gear horn. Scroll down for more specifics and/or read more about them in their separate P2 and Gear Alert fact sections.

When it comes to flying retracts, it has been said that the infamous Gear Up Club has two sects:
"Those who Have, and those Who Will..."

Dan L's story is "real". He is a Pennsylvania based Mooney savvy 5,000+hr IFR pilot who has owned over 20 aircraft, gets good recurrent training, and proudly flies his TLS/Bravo regularly. Yet...

Like many we talk to, Dan reported he couldn't hear and/or identify his seldom heard gear horn soon enough...
This particular "gear up" resulted in over $50,000 in damages and 4 months down-time. Need we say more?

Nearly every member of the "Have" sect of this infamous club tell us that they never thought it could happen to them. However, just when they forget this worry, perhaps when they are tired, or when distracted by something as simple as cockpit or radio chatter, or having to extend their downwind or keep more power up on final than normal, well... Lets just say they get to join the ranks of "the other" sect of The G-Up Club and inherit a few bent blades to adorn their fireplace mantle or office wall!

"We think these state of the art audio gear and stall warning systems are so impressive and obviously effective at increasing safety, that we wonder if most retracts could be FAA Certified today (fresh-all over again) without this type of "specific message" audio warning technology installed?"
MOA's The Mooney Pilot Magazine, November 04

Having a "gear-up" incident seems to be a latent concern that just about every smart retract pilot carries around with him; and for good reason. For the most part, it's probably that same nagging worry tucked deep into our psyche that keep most of us from joining the infamous "Gear Up Club" in everyday flying. However nowadays we know more about how the human brain interprets messages and today's state of the art warning devices are far more effective than simple gear horns. On top of that, the typical monotone gear warning horn commonly found in most general aviation aircraft (including Mooneys) is usually mechanical and functions relative to throttle position-not the best choice. As the FAA/NTSB statistics clearly point out, that type of warning is often too late. According to an FAA Advisory Circular, over 30% of all landing accidents are still due to the fact that the landing gear was not extended. This type of accident can happen to anyone. It only takes a small distraction (especially if you fly single-pilot), and it's too late!
Note: Pictures above are real. They were taken shortly after this TLS/Bravo was landed "gear-up" at its home town airport by a Mooney savvy experienced pilot wearing ANR headsets who reports he simply couldn't hear the stock monotone gear horn. He promptly ordered a audio gear warning system.

The more we know about human psych/physical reactions as relative to how most OEM stock gear warning monotone horns operate, the more we find many times pilots aren't actually being given a fair warning of impending scraped aluminum event soon enough for it to be effective. Most retracts like Mooneys have a antiquated monotone cabin horn (usually made by SonoLert) which is triggered off the position of the throttle-not airspeed or altitude above the runway. This type of trigger and horn arrangement was about as good as it got back in the '50s and 60s when these airframes were certified. Today, we know better....Lots better!

"When it comes to flying retracts, there are those who have and those who will..."
An Old Retract Pilot's Wife's Tale...

Also back when your Mooney was certified many pilots didn't wear headsets (especially today's highly effective ANRs) which tend to blunt-if not hide the monotone horn's tone to the background to the point of making it nearly meaningless. Frankly, we doubt if you could certify a new retract nowadays with the same antiquated horn system as it has proven to be ineffective time and time again, if not next to useless except under just a perfect set of circumstances. It's a well-proven fact it takes a certain amount of time for the human brain to both recognize and interpret the meaning of the seldom heard gear (or stall) horn. The typical "GU scenario/event" takes place at a time where the aircraft is low and slow and nearly every pilot is preoccupied. Thus in this situation, every nanosecond is precious. It is much easier and quicker for the brain to both hear, interpret, and then ACT on the spoken words, "check gear" as nearly every GUp Club Member pilot so affected will tell you!
Check the product evaluations below as well as our Audio Alert FAQs and GUp Club sections for more details.

The P2 "Specific Message" Audio Advisory Gear/Stall/Overspeed Alert/Warning Systems

As it stands there are two totally separate manufacturers of audio gear and stall/under-overvoltage systems for certified aircraft such as Mooneys. P 2 Inc. offers an independent Audio Advisory System (AAS) dependent on specific airspeed and airspeed "history" as well as your landing gear position-namely whether it it locked down or not. It is armed once you take off and reach a pre-designated speed and then is on high alert watching if you lower your gear BEFORE your airspeed drops below a pre-set speed. If the gear isn't down, a clear commanding male voice is piped into your

intercom/headsets and cabin speaker to tell you to "check gear" as well as VISUAL WARNING (through an illuminated enunciator) advisories. Likewise, if you have lowered your gear it informs you that everything is OK by saying, "Gear is down for landing." In addition, it provides a verbal stall and overspeed audio advisories which we think are a welcome addition to the basic gear warning. The P2 functions by continuously monitoring airspeed and other inputs and converts them into the appropriate message.

We think this type of specific message verbal audio alarm is damn hard to ignore and equally hard to fool into not sounding at the appropriate time. That isn't to say that if you approached the runway at 90-100Kts and tried to force it down well above normal touch-down airspeed you couldn't "trick" the P 2, but in all practical situations it is nearly fool-proof.

We like the P 2 system and can highly recommend it. It isn't however something the average owner can or should install as it involves breaking into the static system and your avionics wiring harness. Typical installation takes 8+ hours and requires both a knowledge of your airframe and basic electronics. At some $1,295 it is a bargain as it is less than 1/2 of the average deductible and the average gear-up incident puts your ship down for 3 months or more and can easily raise your insurance premiums substantially. It comes with complete instructions and a competent shop should be able to install the P 2 system in less than a day.

Aircraft Component Inc's Unique "Ground Proximity Sensing" 2037 Gear Alert System

The Gear Alert System consists of 3 components, a ground sensing transducer ( approximately 3 inch by 4 ½ inch by 1inch ) that mounts on the belly of the aircraft, a small electronic unit that mounts anywhere in the aircraft, and a small switch that mounts in the instrument panel. Pushing the switch performs a self test of the system. If the electronics are working, the pilot will hear the voice message "TEST OK" in his headset. The ground sensing transducer is a microwave device much like a radar.

When the aircraft descends to about 150 ft above the ground, the transducer senses the presence of the ground. The electronics then look at the gear down light to determine if the wheels are up or down. If the system determines that the aircraft is close to the ground and the wheels are still retracted, the pilot will hear the voice message "CHECK LANDING GEAR" in his headset. The system can also be hooked to the existing throttle switch system. Anytime the throttle is retracted with the wheels up, the pilot will hear the warning message. Any time the existing stall horn sounds, the voice message "STALL, STALL" will be heard.

The Audio Econo Champ: ACI's Voice Alert
An Add-on "Repeater" Audio Warning System Who's $495 Price Should Make Even The Most Miserly Retract Plot Happy

While not a true independent gear/stall warning system, ACI's Voice Alert uses the pre-existing sensors already in place in your aircraft to trigger instantly recognizable voice warnings directly into your headset whenever your OEM stock stall or gear horn sounds. We think this is an order of magnitude superior to the simple monotone horn that were placed in the cockpit where they would sound for everyone in the airplane to hear. Studies show that times have changed as today most pilots wear headsets which block out much of the sound from the cabin, making it more difficult to hear the warning horns mounted in the aircraft. In fact, we find Active Noise Reduction (ANR) headsets are designed specifically to block out the background cabin sounds including the warning horns which must be heard.

At $495, the economical Voice Alert's audio warning is piped directly into your headsets and over the cabin speaker whenever the existing stall horn sounds. So with it installed, the pilot will hear the instantly recognizable voice message "STALL, STALL" from the built in speaker, and directly in his headset and if the gear warning horn sounds, the pilot will hear the voice message "CHECK LANDING GEAR, CHECK LANDING GEAR" alerting of the problem. Thus there will be no more confusion over which horn is sounding as these voice messages are in addition to the original gear/stall warning horn sounds.

The Voice Alert consists of a small electronic unit about 2 1/2 inch by 3 1/2 inch in size that can be mounted almost anywhere in the cockpit. The installed weight of the unit is less than 1 lb. The unit is supplied as a complete kit consisting of the electronic unit, a pre-wired cable assembly, and all the connecters and mounting hardware. The only other item required is a 1 amp fuse or circuit breaker. Installation is easy, and can be preformed by an A&P mechanic of an avionics shop in generally a day or less.

Due to the fact the (simpler/cheaper) Voice Alert depends on your existing aircraft sensors and micro switches it is in essence just a "repeater" audio warning system. It is not as foolproof as either of the totally independent stand alone systems. But if you don't spring for one of the other units, at $495 there is absolutely no excuse not to at least have this form of audio warning technology in your retract today...