i watch aviation videos on youtube and sometimes in hairy situations you hear the automatic warning 'chime' come on -- 'altitude -- altitude -- altitude' when the aircraft goes below a certain threshold.

makes my hair stand up and I'm not even a pilot

i assume that threshold is programmable, is that correct?

would assume a Coast Guard UH-60 wouldn't want it set at 500' but an F16 would want it set a heckuva lot higher that 250' (more warning at higher elevation )...

any comments??

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I'm not sure its programmable at the user end, but someone made the decision of where it should engage. The voice referred to as "Bitching Betty"

Some units, typically found in smaller general aviation type aircraft, are capable of being programmed by the operator. The altitude warning systems found in larger “corporate” or airline aircraft are not.
You wouldn’t want one pilot setting the warnings to one limit and then another pilot getting into the plane and thinking it was set to another limit.

Yes, it is programable to a certain extent.

In my former airframe the altitude warning is biased on a number of factors, one of which is the alert threshold # you set on the radar altimeter.

Before other pilots jump in, yes, I know this is a very brief, simplified and incomplete answer. I have no desire to dig out my old manuals and type up a 3 page technical answer.

Im on the maintenance side of things. From my experience its based on how the plane is configured, in that things like the aircrafts airspeed, flight controls position (flaps retracted
vs correct trim), landing gear position (down vs retracted), rate of descent, angle of attack. all of these will affect the alarms or caution alerts.

simplified:
A+B+C+D = happy plane
or
A-B+C+D = angry plane

The ultra modern systems have a whole host of audible earnings, gear, flaps, terrain, rates of descent, etc, etc., of course terrain & ground contact are biggies.

As an example, the database knows where the runways are. Say you planned to ditch in the ocean, you’d have to turn the system off, or it’ll be screaming at you the last X number of seconds.

I can understand all the warnings related to safety, installed to make up for a lapse piloting or ATC missteps. Even in recent years there have been landings on a taxiway, and attempted takeoff from another taxiway. There was a bad one in Singapore a number of years ago, rushed, bad weather, night.

A modern system will be yelling at you if you try that stuff.

I can't speak for general aviation per se but in the Harrier you could set the alert altitude of the radar altimeter. It varied by mission - for ground attack we usually set it at 150-200'

Not a rotorhead, but the USCG helos I’ve been in, MH60, MH63 & HH3, didn’t have any type of alert for altitude. Granted I was only a passenger, but if you have ears with a mic on,you are hooked up to the pilots channel and can hear all their talk. and I only ever heard an alert when a hydraulic hose blew in the tail boom of the HH3.

I would assume it’s because they do a lot of work below 500’…

F-111 relied on the scraping noise...

quote:

Originally posted by MikeinNC:
Not a rotorhead, but the USCG helos I’ve been in, MH60, MH63 & HH3, didn’t have any type of alert for altitude. Granted I was only a passenger, but if you have ears with a mic on,you are hooked up to the pilots channel and can hear all their talk. and I only ever heard an alert when a hydraulic hose blew in the tail boom of the HH3.I would assume it’s because they do a lot of work below 500’…

Former CG Falcon pilot, now 757 pilot (although medically grounded at the moment). The radio altimeter in the CG helicopters are certainly used and can be set to varying altitudes so as to give a warning at a particular altitude or to actually auto-hover the helo. Not sure if the H65 can do this, but fairly certain it and the H60 can be coupled up on autopilot and auto hover at a set altitude. The radio altimeter is the only reliable instrument you have when out over the ocean and all you have is an estimate of the barometric pressure to set in your regular barometric altimeter. Especially when operating in hurricane or other low pressure situations offshore.

Falcon had a radio altimeter and I would use it constantly out over the water, both as a gentle reminder and as a warning to go-around or cobb the power and climb away from the ocean. Saved my life and the rest of the crew one night off Puerto Rico in hurricane Lenny.

My technique for doing low altitude ID passes or aerial deliveries was to set my altitude select at 100 feet above the altitude I was going to level off at so that I had a subtle 100 feet to go annunciation. Doing an ID pass at 200 feet I would set my radalt bug at 175 feet and have the copilot set his at 150 feet. That way if my radalt warning went off I would correct, if his went off I would add power and climb out to try it again.

We also would use the radalt on approaches to confirm actual height above the runway independent of the barometric altimeter.

None of the CG aircraft when I was in (82-02) had any of the enhanced Ground Proximity Warning systems that would integrate your position and radio altimeter data to give you the whoop whoop pull up, terrain terrain, or altitude warnings that you hear in some of those depictions. MikeinNC is correct in that regard.

In most modern commercial aircraft like the B757 and others, the radio altimeter is connected to many systems that we rely on as described in the 5G thread by sn3guppy. Much more integrated into the various aircraft systems than they were in the CG aircraft. Probably have it now in the Commandant's jet but that is most likely the only one, and its strictly for VIP transport not operational missions.

Semper Paratus!

There are a number of different warning systems in aircraft, including a wide array of aural warnings that include voice buzzer, bell, tone, tritone, horn, siren, clacker, etc. In the 747 Classic there are over a thousand dials, switches, gauges, lights, indicators, tones, etc, in the cockpit. There are a lot of ways to make indications unique and recognizeable, because there is so much data presented.

Aural warnings may come from multiple systems. Voice warnings might include EGPWS (enhanced ground proximity warnings) that have seven basic thresholds or modes; these are sliding scales that look at not only proximity to terrain, but closure rate, aircraft configuration, phase of flight, etc. During an approach, for example, warnings might include, "Don't sink," or "Glide slope," or "Too low, terrain," or other warnings, depending on a matrix that combines multiple metrics. An aircraft at 500' or 800', for example, might get a warning if flaps aren't configured, or if landing gear isn't extended, but only at certain power settings, terrain closure rates, etc. Terrain warnings also occur based on time to impact, not necessarily distance; the warning may occur at a greater distance with a high closure rate, or a lesser distance with a slower closure rate.

Aural warnings are available for windshear conditions, and might include, "Windshear, Windshear," or "Tailwindshear."

Aural warnings are available for TCAS, or traffic collision avoidance systems, and are based on both proximity and distance, as well as closure rate. The timing for providing warnings and even corrective action depends on not only both aircraft, the equipment each carries, their settings at any given time, relative motion between the two, velocity, etc.

Some systems include fuel warnings, fire warnings, etc, with voice alerts. There are numerous warnings that are differing tones; overspeed in most aircraft is a clacker. A terrain alert is a "whoop whoop" sound, followed by a a voice call-out. A fire is a bell. In some aircraft a tri-tone is used for certain levels of emergency notification. Notifications might be a ding. A warbling tone often accompanies an autopilot disconnect.

Configuration warnings "Gear," or "Flaps" may accompany takeoff or landing configuration alerts, or might accompany overspeed warnings for the aircraft configuration (too fast for gear or flaps, for example).

Other warnings include a stick shaker, which vibrates the control stick or column when approaching a high angle of attack (stall), as well as corrective devices like stick nudgers, pullers, and pushers for stalls or overspeed conditions.

Some systems use varying tones in duration or pitch, or identifiable by sequence. Notification of passing over certain beacons on the ground includes a tone or alert, a well as lights, or other indications.

So far as being able to adjust or configure these warnings, the answer is no, in most cases these are not serviceable or adjustable by cockpit crew, or the operator. Come are configurable by pin connection, software, etc, and are unique to operators. Some warnings can be inhibited or silenced (first action in a fire is to silence the fire bell, to focus on the fire). A flap problem often requires using an inhibit switch or feature to prevent nuisance warnings that may occur based on terrain logic ("too low, flaps," etc). There are override and inhibit features which are manual in some cases, automatic in others (some are inhibited automatically during takeoff, for example, to prevent distraction).

Some call-outs, such as from a radio altimeter, occur automatically, while others occur based on the selection of the radio altitude, by the pilot (setting 200' above terrain on a category one instrument landing approach, for example, may have an aural call out "approaching minimums" at 300' and "minimums" at 200' based on pilot selection, for example).

Altitude alerts vary by aircraft and system, but typically chime and include a light when approaching within 1000' of an altitude which has been selected manually, or programed, and will typically alert again within 300' of approaching, or deviating from that altitude. Other altitude alerts may occur during descent, such as when the radio altimeter goes active at 2,500', then at 1000', at 500', approaching minimums, then at 50, 40, 30, 20, and 10'.

Some warnings are information-only, others require immediate action. A terrain warning will get immediate attention, and "Terrain! Terrain! Pull up! Pull up!" along with a whoop-whoop alert will make your hair stand on end, and demands an immediate escape maneuver, typically pitching up 20 degrees or more, applying max power, retracting speed brakes, and so on. A TCAS (traffic alert) resolution advisory also demands a response on a time schedule, and takes priority. A windshear alert will get your attention. Other tones and sounds and warnings and alerts maybe informational, and simply increase situational awareness in the cockpit environment.

Thanks Sigfan Roy! I was a GM, but rode on the deployed H63 on my WMEC. When I was in Buxton(cape hatteras) my boss sent me with the Ecity H60 to help identify local ships often. I only rode in a H3-F once for a PR thing..stupid me volunteered to be plucked out of the water…love learning new things….I guess the pilots just didn’t have it on or had it turned down.

This message has been edited. Last edited by: MikeinNC,

The radio altimeter warning in the Falcon was just a light that would illuminate, there was no aural warning. A chime for the altitude select but that was tied to the baro altimeter. I can only assume that the helos' worked similarly, although I was never helo qualed. So you wouldn't have heard anything, but they would have seen an indication if they went through an altitude that they had set. Most of the time you set it so that it doesn't go off unless you goobered up the maneuver and needed to make a correction or climb out. With both pilots monitoring the altitude and if all goes well you wouldn't get the light because it was set as a warning instead of a target.

I was on the Valiant when we lost an H52. both pilots and the flight mech survived! I was in CIC and felt the crash and of course heard the General Quarters immediately afterward. I was wanting to go to flight school and talked with the pilots who deployed with us a bunch. They credited all that dunker training for saving their lives. Despite that I went on a few helo rides but never had the stones to fly them. Those helo pilots, flight mechs, hoist operators and especially those rescue swimmers are studs.

Great topic!

I see various videos of landing and can't figure out why that voice keeps telling the pilot he's retarded.

Retard! Retard! Retard!

How rude!!!!!

Whats up with that?
.

That’s an Airbus thing.

The thrust levers on Airbus fixed wing aircraft operate in an unconventional manner as opposed to other manufacturers. On takeoff, they are pushed forward and “click” into a detent. They remain in that detent (normally) until landing when the (you guessed it) RADIO ALTIMETERS sense your height above the runway. At that point, an aural annunciation of “RETARD, RETARD” is sounded, letting the pilot know he needs to pull the thrust levers back out of the detent to the idle position. (Which is fully aft.)

From the time the levers are moved to the forward detent at takeoff, until they are pulled back for landing as described above, they do not move. They stay in the detent. The flight computers determine the appropriate thrust setting and apply it. (Basically)

As the saying goes on the aural tone... “The first time is a verb. All subsequent annunciations are nouns.”

If you maybe carried a bit too much speed over the threshold and floated, the radio altimeters sometimes keep send that signal. You could get called a “Retard” for quite a few seconds. However, if you pulled the power back too soon, you’d smack it on...and Fifi would then become a judge of your landing and her before mentioned comments to you suddenly would become reality. Lol

My personal best was six.

quote:

Originally posted by Sigfan Roy:

The radio altimeter warning in the Falcon was just a light that would illuminate, there was no aural warning.

Only one of the airplanes that I ever flew had a radio altimeter. That was years ago, I definitely remember a red light, and I can't remember for sure but I think that there was a warning tone that was routed through an "aux" channel on the audio panel, so the audible warning could be selected or silent.

The airplane that was equipped with the radio altimeter was a Cessna 182 that I flew every Friday morning, on a run from the 28th parallel (Sebastian Inlet) up the Atlantic coast to the 31st parallel, somewhere in Georgia. It was a weekly survey flight with a marine biologist on board, flown at low altitude, 200' MSL, just offshore. I would set the warning for 200' and if I kept the altitude within a small window, the red light would flicker on and off, so it was easy to monitor the altitude for the flight while keeping my attention outside, for traffic.

The answer varies widely by the aircraft's particular avionics installation, and in some aircraft, by the mission profile loaded into the computer.

Short answer...yes it can be programmed, sometimes by the pilot or other flight crew member, sometimes by an avionics technician. Nearly everyone can pull the circuit breaker to silence it...something that has been linked as contributing cause in more than once incident.

There are a bunch of warnings and/or cautions that get triggered by various settings, circumstances, and situations in an aircraft. 99% should not concern a passenger.

With the exception of setting a radio altimeter, very few other warnings or callouts are user configurable. Most aural annunciations with the radio altimeter are not user-configurable, either.

quote:

Originally posted by MikeinNC:
I would assume it’s because they do a lot of work below 500’…

Most of the general aviation rotorheads I know get a nosebleed if they go over 500’ AGL.

quote:

Originally posted by sigmonkey:
F-111 relied on the scraping noise...

...but then, the Aardvark is a Prehistoric beast--LOL!