Sikorsky S-92: From Design to Operations

[Gomer Pylot]

The purpose of having it offshore? Few helicopters spend all their time offshore. Most fly onshore at least part of the time. And even offshore, it's glaringly obvious that we are still flying into the water. Something to remind us before we do that is worthwhile, IMO.

If you're going to assume that pilots will fly approaches without radar just because they have EGWS, then you have to also assume they'll fly them without an operable GPS, or anything else. Please give us credit for following the regulations. What I'm beginning to hear from you is "If I don't have it, then nobody should have it". I hope the message is garbled in transmission.

[212man]

HC, thanks: I hadn't realised that! I'll mention it.

[HeliComparator]

Gomer

So I take it that you are saying that the only reason to have it offshore is to stop you from flying into the water? In that case I would say that EGPWS is not the tool for that. As previously discussed in this thread, modes 1 - 5 of the GPWS bit give no realistic protection from flying into the water, and the mode 6 callouts emulate AVAD but are not as effective for the various reasons discussed earlier. The terrain display tells you that you are going to fly into the water if you look at it, but then so does the radalt.

I agree that for some operations the protection onshore is useful - though not if you obey the regulations and fly IFR at the proper height, or VFR in appropriate conditions.

And one detail we haven't mentioned yet is that the effectiveness of the system is predicated on the aircraft's navigation equipment knowing where it is. One time that the best pilot in the world might fly into a hill is if the navigation equipment is telling him that he is somewhere where he is not. Unfortunately the navigation equipment is also telling the EGPWS that it is somewhere that it is not, so when the aircraft gets "lost" the EGPWS will not stop you flying into a mountain.

This was the cause of a very near terrain miss of an EGPWS-equipped UK-operated scheduled fixed-wing flying in Africa a few years ago. It transpired that the basic GPWS modes were supressed by the software because the E bit was telling it that it couldn't possibly be that near the ground as according to its database and its position there was lots of fresh air under it. They missed the ground by about 50ft, still in IMC.

To be fair that aircraft was using FMS position derived from VOR/DME at the time, and the VOR was faulty. I would hope its less likely to occur with GPS positioning, and in helicopters the EPGWS installation can use a separate GPS position source (though not necessarily). But even so its possible to have a satellite error which would effect both the aircraft's and the EGPWS's receivers equally. RAIM should help to reduce that but its not clear from the product spec how the EGPWS handles loss of RAIM.

The fans will no doubt think this is all very unlikely and they are probably right - I am just pointing out that the system lacks inherent robustness. It relies on an accurate position and an accurate database and neither of these can be guaranteed.

Regarding your accusation of jealousy, you are incorrect and in fact I have been generating a resistive force against the fitting of EGPWS to the fleet I fly, because I am concerned about its overall effect on the safety of our particular operation. I am confident that we will have it just as soon as the product becomes better suited to the operating environment.

HC

[helmet fire]

The arguement about placing too much faith in a system as a reason not to have an advancement is a frustrating one, and one that has continually thwarted the adoption of NVG in the UK and Aus. Lets penalise those who would use it properly to protect those who would abuse every system (including what they are doing now). Makes sense.

How about the perfect system?

EGPWS with updatable database. Rad alt hold auto feature (as detailed in my last post) with step down ability. Radar that generates image and data into EGPWS for processing and warning. SOPS to keep your bloody eyes outside and on Rad alt when low level in crap viz.

And for HC we can add a mandatory requirement for sea vessels within 100nm of HLSs to carry a mode 3C transponder and ADS-B that displays traffic onto the EGPWS, a bitchin Betty that is adjustable to the rad alt bug, FLIR/EVS image and NVG image mixed and melded onto a single flat screen pannel view for looking through the gloop day or night, a database that automatically updates from multiple sources, including for moving vessels picked up from radars that would be required to be situated at each HLS and beamed back into aircraft at top of descent, and of course Full CAT A. That about cover it?

Until then, lets avoid any further advance.

[HeliComparator]

Helmet the other argument is "lets fit every new piece of kit we can get our hands on, without proper evaluation and regardless of whether there is any overall safety benefit or hazard, especially if it comes in a shiny box and draws pretty pictures in the cockpit and regardless of whether its a bit of recycled fixed-wing kit that is far from optimised for our application". You may subscribe to that argument but I don't.

I can assure you that I am all for technological advancement - I currently fly one of the most technically advanced civil helicopters and I am waiting with baited breath until I get TCAS II. But EGPWS leaves me cold.

HC

[excrewingbod]

Out of interest re the pictures posted by 212man, there seems to be a lot of information displayed on the RH screen. Does this pose any problems, considering the size of the screens? I presume the screens are approx 6 inch x 8 inch in size?

[helmet fire]

I see your side HC, and there is strong logic in most of it. Its your use of arguements inferring that idiots will abuse the system as a reason for rejecting the technology that I was picking on. The rest of it, including your summary above, is generally sound and has spurred along a much needed debate.

Wether or not any new technology is ready for use in any particular operating environment is a subjective (generally) viewpoint that we make based on our eperience and operating environment (culture, terrain, weather, and budget). That will differ across the board, hence some will go for it now even if it is just because it looks good, and some will wait until they feel the system is justified.

The good thing about debating it here is that new ideas surface and are explored, and everyone gets to learn a little bit more about the technology in order to make thier choice have more integrity.

It is clear that you feel it is not ready for the offshore environment. Perhaps you could simplify your reasons why into a wish list for the manufacturers to consider incorporating - because if they dont respond to a reasoned customer wish list they wont sell as many as they could.
Cheers

[212man]

Excrewingbod, yes it's a bit messy. The use of an FLI would have simplified things a bit: do I really want my TGTs displayed on my PFD? But I guess we then end up back in the debate about display philosophies.

Something along these lines would be my preference (with apologies to HC for pinching his photo!)

[charron]

212man??? am I missing something with your preferred PFD? What's with the HSI?

Why are you guys so sentimental about interpreting images? If I was sarcastic I'd be asking why instead of a round HSI with a trackbar and pointers don't you just display an image of a magnetized needle floating on cork on that fancy LCD screen.

With a little experience most pilots have graduated to navigating from an arc or map display. Really, what you want to know is where you are and where you are going and what else is around you. The HSI was a mechanical instrument to help you do that by giving you a number of clues from which you could take your finger and put it on a paper map. Now you can just look at a map image with a GPS finger pointing to your position within 10 meters, relative to your route and destination and any terrain, and yet you still want to look at that needle on the cork.

Here's what the poor unwashed that are still flying Jetrangers have to look at. They don't even care about an HSI because they've realized that it is just an inferior horizonal presentation and there are a lot of superior and cheaper ways to do that. Maybe someday you will catch up with your S92 or EC225.

Charon

[212man]

Thanks for the briefing on how to navigate. I wasn't specifically referring to the HSI. Anyone who knows me will be able to confirm that I practically never display an HSI if I can avoid it. I suppose if I wanted to be sarcastic I'd ask why you want an LCD screen showing you a piece of paper

Ignoring the HSI, the overall concept is clearer, less cluttered and able to show more information. One thing I confess not to know is whether that lower half can be configured as an arc, and therefore show a RADAR. If not, then that will be a shame when eventually EGPWS is fitted (will have to chose either or, rather than both as in the 92.)

[helmet fire]

charron,
what is that system you have shown there, and who made it? is it integrated with the garmin? Can it display radar imagery as well?
thanks

[charron]

Looks like a Garmin 430 (radio stack) coupled to the Garmin MX-200 MFD (Instrument panel). From the Garmin web site, yes, the MX-200 will display radar, or anything else you want. From the label above it looks like it displays TCAD. Nice size. The DG looks about as important as a wet compass now.

Google searched the MX200 and found that United Technologies, that owns Sikorsky, has one installed in their corporate S-92 in the lower center panel between the RTU (Radio Tuning Units?). Now why would they do that?

Maybe someone who's seen that S92 panel (info from the last HAI) can post a picture.

Charon

[HeliComparator]

212 / Charron

The EC225 FND picture that 212man posted shows the FND in HSI mode because its flying an ILS. HSI mode is the only appropriate mode to show ILS localiser information. There is also a sector mode (arc mode if you like) on this screen but that is for displaying VOR or Area Nav information, with radar overlay if desired. The fundamental difference is that ILS indications have no concept of range or distance off track, whereas of course VOR and Area Nav indications do.

Don't forget that each pilot has another whole screen devoted to map-type nav display - it can either be configured in rose mode (where you are at the centre of the screen) or in sector (arc) mode where you are at the bottom of the screen. In either case you can have radar overlay on this screen as well, or even EGPWS if you really want it.

I normally fly around with the FND in HSI mode, primarily using it for heading reference only, and with the NAVD in sector mode showing area nav + radar, but that is just personal choice. For instrument approaches it would be something different depending on the approach.

helmetfire - measures are in hand to inform the manufacturer where the problems lie in EGPWS for offshore, and more importantly what the suggested solutions are.

[Hippolite]

Sikorsky honours PHI as first S-92 operator to reach 10,000 fleet hours


LAFAYETTE, La., Nov. 16 -- Sikorsky Aircraft Corp. today celebrated a milestone by PHI, Inc., as the Louisiana-based company became the first operator in the world to achieve 10,000 fleet hours with the Sikorsky S- 92 helicopter(TM). Sikorsky Aircraft is a subsidiary of United Technologies Corp

Since the 1950s, PHI has flown Sikorsky helicopters, offering services to the offshore oil and gas, onshore mining, international, air medical and technical services industries. Sikorsky delivered the first two production S- 92s to PHI in late 2004 to provide service to BP in early 2005. PHI currently flies six S-92 helicopters, with two more scheduled to be delivered before year-end. PHI also flies S-92 helicopters for BHP Billiton, an Australian petroleum and mining company. PHI uses the S-92s to service deep water production platforms off the coast of Louisiana, primarily in the Mississippi Canyon region.

"Sikorsky and PHI have a long history, and the S-92 has become the popular choice for offshore, VIP and medical evacuation missions. This milestone represents a significant contribution to these services and Sikorsky looks forward to a bright future of milestones for the S-92 and PHI," said President Jeffrey Pino.

The S-92 was the first helicopter in the world certified to the latest Federal Aviation Administration and European Joint airworthiness safety standards. The aircraft is the winner of the Collier Trophy, and features a Rotor Ice Protection System available on S-92 helicopter military variants as well as commercial aircraft.

[JimL]

EGPWS and Offshore Operations

One of the problems with the discussion of EGPWS in this thread has been that views have been expressed with assumptions that have not been stated in the posts, or stated and not acknowledge by those who have then responded. Let me explain what I mean:

Helmet fire, who commented extensively on the Cat A thread, introduced the subject by suggesting that instead of investment in performance, we should concentrate our investment on CFIT measures (it was never clear to me exactly what investment would be traded but assumed it was it was R&D and capitol against running costs of larger engines). However, this remark was made in the context of Offshore Operations as he qualified it with the phrase “full Cat A over all rig types”. HeliComparator then continued the discussion by expressing some reservations about the use of EGPWS for Offshore Operations.

The discussion then moved to a (very detailed and knowledgeable) discussion, between HeliComparator and Nick Lappos, about the efficacy of the 6 modes that are the basis of the GPWS part of the EGPWS. This discussion introduced (with no real follow up) the subject of construction and integration of alert and warning messages in the cockpit (for those who aren’t aware of it, the equipment being used a the centre of this discussion is the EGPWS on the S92 which uses the facilities contained in the ‘box’ as the generator of cockpit voice warnings - basic aircraft as well as EGPWS, TCAS etc.).

Thridle Ops Des commented on the transfer of Protection Modes from fixed wing to helicopter in onshore operations where the Protection Modes are reasonably similar but Malabo (with onshore and offshore experience) called into question its efficacy offshore.

It appears to me that while it may be necessary to ensure that the Protection Modes for onshore operations are re-examined and validated, it is absolutely essential that the Protection Scenarios for Offshore Operations are constructed so that the Protection Modes can be established. This requires that the offshore practitioners cooperate with the RTCA HTAWS in providing a detailed definition of the profiles that exist in Offshore Operations.

Other than when flying VFR, we have to use IFR procedures which constrain us into corridors or areas which are specified both horizontally and vertically and in which vertical separation is assured. Simplistically, 1000ft above obstacles (2000ft in mountains) in the cruise, decreasing in the descent to a minimum at the MDA/MDH/DA/DH which is based upon the accuracy of the aid in the vertical or lateral extents in providing obstacle clearance. Because the vertical extent of the obstacle environment offshore is non-complex (basically no obstacles higher than 500ft) we have a single MSA/LSALT of about 1500ft. The reduced obstacle clearance provided at an airport or heliport for the descent phase has to be assured by methods of surveying and safeguarding established by the State.

Specifically for offshore operations; in Europe (and I suspect elsewhere) descent below MSA/LSALT can only be achieved when on an approved procedure; this could be an en-route descent or an ARA approach but in both cases, safeguarding (in essence) is achieved by providing lateral separation from obstacles by using the weather radar - for en-route by establishing that there are no obstacles in the arc, and for approaches by ensuring that an approach and go-around corridors are free from obstacles. As en-route descents are not always associated with an immediate landing, the MDA is usually limited to 500ft.

Although not certificated for that specific purpose, the weather radar has provided us with an excellent tool for obstacle separation in a period where there was no other practical solution. The use of a real time display (weather radar) has been necessary because we usually seek to let down in an obstacle rich environment - both fixed and mobile. The MDA/MDH is set only against the MSL and not adjusted for obstacles and therefore lateral separation has to be assured. The function of the radar cannot be replaced by a synthetic visual display unless it also has real time acquisition of obstacles. Where there will be development in the future (but only for approaches to landing) will be in the provision of more accurate positional data and (hopefully) vertical guidance obtained with the use of GBAS or SBAS.

The discussion on this thread has been conditioned by an expression of sentiment which appear to be representative of most pilots; if we cannot see what is in front of us - i.e. we are visually constrained by the weather or by being IFR in or above cloud - we would like a representation of the physical world to be presented to us synthetically (using synthetic visual devices); hence towards the end of the thread pictures of annotated moving map displays appeared. The provision of data for navigation and situational awareness is achieved with the use of FMS type devices - in the past, as Reflex has said; it was with the use of moving map displays - i.e. Decca.

The main use of the ‘E’ function of the EGPWS is to provide situational awareness and warnings in those cases where the flight is in danger of breaching (in most cases substantially) the IFR terrain (rising ground) separation - perhaps caused by being temporarily unsure of position or not applying the appropriate vertical separation (usually resulting from being off track). We are fortunate in Offshore Operations that the terrain is always flat (give or take the sea state) and, if flying below MSA/LSALT, the main hazard is the obstacle environment (which we have already established rarely if ever exceeds 500ft).

However, and as stated above, that obstacle environment is not static and, unless there is real time updating, cannot be provided on the ‘E’ function of the EGPWS. It is therefore not clear what ‘E’ brings to the party for offshore operations; conversely, and because the display is so beguiling (see 212man’s post) it provides in HeliComparator’s words “a passing resemblance to reality…that existed some months ago”, it introduces a hazard which we would not permit following an appropriate Risk Assessment.

In a recent discussion with someone who has been closely associated with the introduction of EGPWS with a major airline we were frankly surprised at our diametrically opposed views vis-à-vis the ‘E’ function (but only with regard to offshore operations). His view was that the real benefit of EGPWS rested with the ‘E’ function and there was less-and-less reliance upon the GPWS functions (the six modes enumerated by Nick and HC). As he saw it, the problem with the GPWS functions was that in order to remove the ‘spurious alert’ (the real GPWS killer - how many before the CB is pulled), the parameters of the ‘Protection Mode’ had been widened with the consequence that only the real extremes are being signalled.

For me this raised a ray of hope because it is becoming clear that if we can establish, with some accuracy, the modus operandi (map normality) in the relatively simple terrain and vertically limited obstacle environment that obtains offshore; we can define the ‘protection scenarios’ and establish the ‘protection mode’ that can reduce CFIT offshore. However, until and unless we can provide real time updating (which is not beyond our capabilities) the ‘E’ function remains out of scope for offshore operations.

Just as a taste of what we could consider in establishing the definition of offshore operations, here is a short bullet list of items. Please feel free to use it as an Aunt Sally:

Some information for offshore operations:

• obstacles rarely if ever exceed 500ft;
• pilot tend to use the radar as an aid to navigation - in some cases as a crude synthetic vision device;
• the radar is a part of the approach aid suite;
• radar is not certificated for navigation or as an approach aid;
• it is likely that pilots will carry over current radar practices to the EGPWS (as a pseudo synthetic vision device);
• in a number of world-wide locations, IFR is the norm;
  • by day the main hazard is associated with the cloud break below 500ft - i.e. low cloud base and obstacles (usually obviated by checking the approach sector is clear on the radar)
  • by night hazards also include lack of contact with the surface (drift down associated with fixation of the rig) or inadvertent IMC in the final stages of the approach and when flying level;
  • universal limits appear to be 200ft and 0.75nm (although some States permit a closer MAPt);
  • the MAPt limit is defined by the necessity to miss the target on a go-around;
• IFR descents can either be associated with a landing site or en-route (both should be associated with an approved procedure);
• the point where the gear is selected up or down is dependent upon the helicopter type and its limitations.
• the offshore landing site is always a helipad/helideck - i.e. of limited size - this means that the approach always takes the form of a decelerating manoeuvre with a terminating ground speed of zero;
• the landing site mostly sits beside a large obstacle - the presence of which must not trigger an alert;
• the landing site is never on the terrain floor (i.e. sea level);
• the helicopter rarely flies below x ft (100ft in the North Sea) above the terrain floor except when in the final stages of landing and where the ground speed is less than y kts;
• approach angles are steeper than fixed wing or for onshore approaches;
• the take-off is always associated with a spike on the Radalt as the helicopter leaves the deck (the first reading after the spike can be used in the ‘altitude sample and hold’ buffer - Mode 3) which detects descent after take-off;
• sinking below 50% of the take-off height is rare;
• weight on wheels defines the end of a sector - when offshore, that is all that is needed to define the sector (at the moment it is WOW and 30% Tq);
• shuttling can occur with wheels up or wheels down - it is difficult to delineate take-off from approach on some sectors;
• shuttling can occur at any altitude at or below 500ft (VFR)
• inter-rig flying - other than shuttling - is usually conducted at or above 500ft

[HeliComparator]

Wow JimL - fantastic post. I hope those interested in EGPWS take the trouble to read it properly as you have summarised the whole shebang. But can you tell us numpties what is "RTCA HTAWS"?

Hopefully you will get some feedback on your bullet points at the end, as the worldwide variations on operation rules and standards can be surprisingly large.

HC

[Thridle Op Des]

I have to agree with JimL, the issue has been talked around a bit without addressing specifics and I think that we now have a good list of considerations. I do think that a couple of other subjects need to be added to the pot.
WOW works well if you have W's. I recollect the efforts BHL went through with trying to give the 212 a sensor which told the Decca when the aircraft was on the ground. It was a real dog's dinner and regularly got damaged by deck nets and became more of a safety hazard.
As JimL has alluded to; it is hugely more complicated to tell the helicopter's navigation suite which phase of flight the aircraft is in and tune the 'enviroment sensors' accordingly. The differentiation between the two working environments of 'Offshore' and 'On Shore' needed to be made. What works on the North Sea or somewhere in the viscinity of Eket does not necessarily work for the EMS guys trying to find the hospital.
Fundamentally a pilot needs to know when he is in danger and how soon it's going to happen, be it other traffic or the terrain. Nuisance warnings will only create negative attitudes towards the efficency of the system. GPWS went through the same birth pains when it was developed and required several tuning cycles to minimise the spurious messages. I can still remember the AVAD irritating me on a day VFR shuttle when the inhibit button had either been forgotten or not pushed hard enough, however on an IMC ARA it was a good friend, especially at night, though I always found it strange that you would do one of the most demanding IMC-VMC transitions in the aviation world during a night ARA and inhibit one of the safety systems which would tell me that I was heading towards the sea with low airspeed, while trying to pick the deck out from the other mass of lights.
I am deeply suprised at comments from HC about the incident he describes where the navigation system displaced the EGPWS database. In the suite we use in the A330, we need to be in what is known as 'GPS Primary' or 'Nav Accuracy High' to be able to use the EGPWS function. If there is a Nav Accuracy Downgrade then the EGPWS should be inhibited by design.
The whole thing about Terrain Clearance Floor is important, as JimL says you don't need to know about the obstacle you are landing on. There must be a way for the EGPWS to inhibit the destination location since the navigation suite is programmed to take you there. Going back to the recent Zurich flight, while being vectored around bits of Germany and Switzerland, we only saw a few brown and green bits of EGPWS terrain since the aircraft knew we were using runway 28 for the approach. We only saw things that were important.
I am also very disappointed at the quality of the S92 Nav Display with the EGPWS overlay. It seems very curious that the best use of colour has not been employed and the system is giving information that is somewhat redundant. Maybe its the type I am now flying, but generally I feel a pilot should be given information that he either requests through selection or is required for the safe maintainance of flight trajectory. Does the sea really need to be blue?
On a slightly different note; with reference to mobile rigs, we even get affected by this issue. Singapore departures to the North East require special performance consideration to clear mobile obstacles in the channel between Malaysia and Singapore when activated by Notam, Due to the jack ups passing on their way in and out of port.
Regards
TOD

[JimL]

EGPWS and Offshore Operations

HeliComparator,

The information about the RTCA HTAWS SC-212 can be found here:

http://www.rtca.org/comm/Committee.cfm?id=66

For those who do not wish to visit the site and read the documents (which include the TOR and Notes to the first meeting), here is the outline of the task followed by some paragraphs from the TOR.

SC212

Helicopter Terrain Awareness and Warning System (HTAWS)

SC-212 is established at the request of the Federal Aviation Administration. A review of helicopter accident data for a ten-year period (1994 thru 2004) indicates that controlled flight into terrain (CFIT) is a major contributor to these accidents. Development of Helicopter TAWS (HTAWS) performance standards to reduce the accidents resulting from CFIT is necessary. To accomplish this SC-212 is tasked to develop:

1. Helicopter Terrain Awareness and Warning System (HTAWS) protection scenarios appropriate to VFR and IFR helicopter operations (to be captured as an Appendix in the final Document)

2. Minimum Operational Performance Standards for Helicopter Terrain Awareness and Warning System (HTWAS)

and from the TOR:

REQUIREMENTS ASSESSMENT:

A review of helicopter accident data for a ten-year period (1994 thru 2004) indicates that controlled flight into terrain (CFIT) is a major contributor, especially those resulting in fatalities. This data suggest that CFIT accidents can happen during day, night, under both visual meteorological conditions (VMC) and instrument meteorological conditions (IMC). The National Transportation Safety Board (NTSB) recognizes this trend and has recommended installation of Terrain Awareness and Warning System (TAWS) for certain helicopter operations. TAWS were originally developed for airplanes operating into/out of airports and these systems have been modified to better support helicopter operations. However, a comprehensive analysis of helicopter accident data has not yet been conducted to define the most beneficial alert/warning functions that support unique helicopter operational scenarios and envelopes. For example, helicopter operations are conducted predominantly under VMC, at lower flight altitudes, and into/out of remote/unimproved locations without runways, lighting, or NAVAIDS. Consequently, existing TAWS performance standards are insufficient for adoption in helicopters. Development of Helicopter TAWS (HTAWS) performance standards that provide the most benefit for these unique operations is necessary to reduce the accidents resulting from CFIT.

TERMS OF REFERENCE:

The special committee should develop a work program, with schedule and milestones, to accomplish the following terms of reference:

A. Review the Terms of Reference (TOR) during first plenary meeting of the special committee and propose any recommended changes for RTCA PMC approval.

B. Review Helicopter CFIT accident data to define the most beneficial alert/warning functions that support unique helicopter VFR/IFR operational scenarios and envelopes, while minimizing nuisance alerting. Emphasis should be on helicopter VFR operations into/out of remote/unimproved locations without runways, lighting, or NAVAIDS.

C. Using scenarios developed in Item B. above, develop Minimum Operational Performance Standards for Helicopter Terrain Awareness and Warning System (HTAWS). Where possible, for consistency with existing TAWS equipment design/operation, utilize performance standards, alerting, and testing methodology as presented in Technical Standard Order (TSO) C-151b.

D. Develop recommendations to FAA Rotorcraft Directorate, ASW-100, regarding HTAWS installation guidance.

E. Develop recommendations to FAA Flight Standards, AFS-200, regarding HTAWS operational guidance.

[212man]

I think the fact that the value of the 'E' in the offshore role is debatable or not currently reliable is only valid up to a point. Until such time that every mobile vessel has some form of real time position update that EGPWS can use to update itself, it is bound to have small risk of missing obstacles. Used in conjunction with RADAR the risk must be considered very small though, and by definition, no worse than current practice.

I think the thrust of effort must be towards refining the classic GPWS modes. I fear that in an attempt to avoid nuisance warnings, and the syndrom of them becoming normal and therefore ignored, the thresholds have been set unrealistically high/low (no pun intended!) leading to insufficient protection over water. Rates of descent, for instance, can be artificially generated by rising ground. Over water they have to be actual RoD, which means that only in extreme circumstances will a threshold be breached.

Maybe, instead of a LOW ALT mode, there could be an Offshore mode?

[tistisnot]

Training

7000+ offshore hours, 12 years N Sea, and only 236 ARA's recorded (including simulator). less than 20 a year ..... Oil companies no longer pressure anyone to get on the installation, go home if need be (SAR / Emergency evacuation may have the equipment / accept more risk).

Don't even think of flying over an unidentified 'blob' below 500' ASL if IMC on approach. Avoid it, or change the approach track. Unless the customer insists to get on everytime then the wx radar is fine for obs avoidance.

Brain / GPWS modes comes down to the usual - stick to the numbers when doing your first night approach for six months (take the training trip if offered!), beware of descending turns at night and in IMC (loss of airspeed / increased ROD) and use an AVAD / GPWS to awaken those on slow gradual descents, or a competent PNF to forewarn you. Beware of two sets of eyes OUTSIDE the cockpit in the final phases - one always on instruments, and clear division of duty in the OM for handover of control / duties for landing.

But primarily as Geoffers has already said - training - it is the company's responsibility to ensure their pilots are properly trained - therefore more LOFT / CRM with realistic scenarios using equipments that are fitted in the sim!! How many of you EGPWS operators have received any instruction / been tested on such items in a simulator? Shockingly few I would suspect but that's where the answer is ... training and procedures, and instructors who accept, condone and insist on the use of Company SOP's. Let's include these life saving pieces of equipment regularly in the training set-up. (Yes it's difficult 'cus no-one is prepared to pay for all those different versions, and it's a headache with the software for Helisim / Flight Safety and it's difficult dreaming up yet another scenario ... but it may save someone's life .... )

Nuff