AAIB Bulletin: Morecambe Bay

[SASless]

Lets think back to the ERA 76 that crashed in the Gulf of Mexico a year or two ago.

Nice night, in cruise flight, very experienced crew, fully kitted out aircraft. Radar traces showed a very shallow descent until about 1500 feet before the radar contact was lost. No radio call...nothing unusual found (that I have heard).

Things happen in our business....some are very complex although seemingly straight forward at first examination.

A second example of why it is best left to the accident investigators rather than hash it out here....the 76 Crash in the Baltic where the hydraulic actuators bound up due to corrosion or whatever it was. That one too was thought to be simple and straight forward.

Bristow/Pan African lost a Bell 412 in Nigeria and no investigation has really been done on that one.

I would suggest holding a discussion of how varied systems function is valid and even discussing causes for spatial disorientation or similar things is also good.

That being said....those discussions have nothing to do with what really happened in this tragedy. As we hear more from the experts doing the investigation then more topics will be subject to discussion.

One man's opinon here.

[DeltaFree]

Autopilot

It seems unlikely to me that experienced pilots would put a fully serviceable aircraft in a 38 degree pitch and roll attitude. The first two things that spring to my mind are AIs and autopilot.
An error in the AIs could lead to the initial confusion, and the standby is not great, which possibly leaves the handling pilot believing he was straight and level when in fact he was nose down. Having recovered from such a dramatic UP at low level it would take any pilot several seconds to gather his thoughts and scan thoroughly away from the standby AI to assess rate of descent.
As with many helicopters the 365 is very lively with the autopilot out. If a pilot takes control with poor visual references expecting the autopilot to be on his side and suddenly realises it is not, then a significant UP will almost certainly occur.
These guys would be used to poor conditions, but with normally minor problems occurring at the wrong time, things were not on their side.
Only a couple of thoughts, there is a long way to go before we know the answers, if we ever do.

[Farmer 1]

On the 365N, the go-around function sets the airspeed hold to 75 kts.

That is all.

Power has to be adjusted manually, and heading controlled either manually or with the heading bug. The heading bug is on the P1 side.

For the go-around function to have any effect, the Coupler has to be selected ON, which would not be the case for an offshore approach unless it was a coupled ARA approach. Such an approach is normally only done if the weather conditions demand it, which I don't think was the case on this occasion.

I don't recall ever seeing anyone use the go-around function offshore.

I'm never one for making rash statements, but if the accident had anything to do with the go-around function, I'll eat my hat.

[cpt]

Farmer 1, I haven't flown the 365N for a while now, but I remember you didn't have to couple the autopilot to engage the "go around"
All you have to do, is to depress the switch on collective (or on coupler control pannel) only then it engages A/S mode at a preset value of 75Kts and also brings your bank angle back to 0°. Heading changes can then be done with a coupled lateral mode engagement or manually.

[Farmer 1]

Cpt,

We have different memories, and there may be variations in the types we have flown, but on all the 365 models I have flown, including that particular aircraft, without the FD or Coupler engaged, pressing the go-around button is completely ineffective.

If the FD is selected ON, pressing the button selects the A/S hold to 75 kts, and the horizontal beam bar appears, but only on the P1's side.

If the coupler is selected ON, the autopilot will input controls to the pitch channel to adopt the attitude for 75 kts IAS for the particular power setting.

The pilot must control the power, and would normally apply go-around setting (100% torque up to 75 kts).

Heading control, bank angle, etc. have nothing to do with the go-around function, it deals only with airspeed.

The only difference I can remember is some aircraft have the FD beam bars on both sides of the panel, but the go-around function has always been as I have described, including in the aircraft which crashed.

[cpt]

farmer 1,
OK, I agree with you in regard with the power setting and F/D bars but not on the rest. I'll try to find a technical doc on the "sfim 155" but I'm fairly sure of my memory.
I have seen some 365C equipped with the "sperry 7000" autopilot but I don't think it can be fitted on the "N", anyway,I also have flown on this particular helicopter and AP was a "sfim" in this time.

[Farmer 1]

OK, Cpt, I await with interest.

As regards the automated "wings level" bit, that is not what you want when you go around from an ARA. In that situation, an immediate 45 degree turn, one way or the other depending on circumstances is required, if memory serves correctly.

I can't remember the autopilot manufacturer, I'm afraid.

[tomotomp]

The AAIB says the helicopter (G-BLUN) had taken off from Blackpool, north-western England, to serve offshore gas platforms in Morecambe Bay. When the accident happened at 18:30 the aircraft was flying from the Millom West rig to the North Morecambe platform at 500ft (150m) above sea level on its third sector of the evening. The first officer was the pilot flying, and the visibility, at a reported 3-5km in rain, was marginal according to UK Civil Aviation Authority regulations for operations of this type at night, says the bulletin

This taken from Flight International, didn't see that in the report(jurno licence i presume)

[212man]

I guess the statement stems from the reported fact that the vis passed to the crew was 4km, and the minimum required (as stated) was 5 km. That could be construed as marginal by some, I suppose.

[hostile]

CAT-A T/Offs & landings

If you look at the AS365 FM SUP1 "Cat A" section para 2.1, we have to think if this is a common use? I dont think so. I've been involved very many times a conversation for this. Are you even able to make training for the copilot's in this kind of procedures?

"...The take off and landing procedures must be performed by the pilot in the RH seat."

Hostile.

[Droopystop]

It will be interesting to see what the AAIB have to say on this one as I think most of us here are thinking "there but for the grace of God go the rest of us".

But as an aside, what are the thoughts on the use of autopilots in this environment.

On the one side autopilots reduce work load and is very good at doing what it is told to do. But at some point the aircraft has to be uncoupled to do the landing bit. How easy is that transition at say 300', 45kts at night with poor visual references? So is it better to have more stick time to get your "hand in" for the landing, or is it better to let George fly until the last minute?

At least one manufacturer of modern machines is insistant that their aircraft are flown coupled at all times (quite how this can be achieved offshore remains a mystery to me). So do we disobey the manufacturers recommendations to keep our hand in or do we go by the book?

[verticalhold]

From memory the conditions these guys had were second only to a rig radar at night to minima in a flat calm in my list of hated airborne conditions. Accurate speed control is absolutely essential, and is the easiest to get wrong, or have go wrong.

Its a long time since I last flew offshore, but the weather and workload appears not to have been reduced, An approach into the black pit with few external references is extremely hard. Add other potential problems and the situation can rapidly turn into a crisis. P2 was an experienced pilot with not much offshore time, it appears he knew when to ask for help, P1 a vastly experienced offshore operator had probably gone through many a night go-round. I don't know the fit on this aircraft, but I doubt any holds would have been used on such a short sector other than alt.

The AAIB will still keep pulling the aircraft to bits to find the truth. If the aircraft had a fault and the particular part was not utterly trashed in the impact I'm sure they will find it.

[AuxHyd]

The 365 is normally flown with the coupler on standby (green CPL annunciator on the A/P control panel). Any mode including G/A can then be engaged. But with the standby light out no coupling is available.

A failing attitude indicator can kill, see the NTSB report below:

http://www.ntsb.gov/ntsb/brief.asp?e...12X19083&key=1

Question is: can we adequately simulate and/or train to recognize and react to such a failure?

[Farmer 1]

The 365 is normally flown with the coupler on standby

Not with this operator, AuxHyd. Not unless they have changed the SOP fairly recently.

[SASless]

What would be interesting to know about this flight would be the layout of the field, location of the heli-decks and the existing wind data. Having that information.....think through what the crew might have been seeing as they made their rounds in the field.

I can remember many a night shuttling in the Ninian Field in the lovely weather that exists there and having to make the takeoffs on instruments, get turned around towards the next stop and having to use radar to find the next rig/platform....even if just a mile or two apart from each other. That was back in the good ol' days of Decca which was not much help shuttling (or in cruise either). Depending upon the wind....it could be an easy trip over to the next deck upwind of your takeoff point and the other deck was in sight the whole time. With the wind from a different direction one would have to depart into the black void and get turned around to travel down wind to the other rig then get turned back into the wind for the landing which was more more work.

[AuxHyd]

Farmer 1: So why would anyone not want the coupler on standby? Time to change the SOP, perhaps?

[soggyboxers]

Sorry, nothing to do with the AAIB report, but there's just too much misinformation about Dauphin autopilots appearing here to let go without comment. All the Dauphin models from the SA365N to the N3 have a standard fit SFIM 155 automatic pilot and a CDV 85 flight coupler, unless specified with something different from the factory. This can be found in Section 10.6 of the 365N RFM (different reference for 365N1 - N3 models). The coupler control unit enables either coupler or flight director (or both) modes to be coupled to the AP. If only FD is armed and selected, the appropriate mode will be connected to the flight director bars on the ADI and the pilot will have to manually fly the bars to centre them. Of only CPL is armed and selected, the autopilot will provide control inputs when an appropriate coupler mode (e.g. HDG, ALT, AS) is selected, without any FD command bar input (and on many 365 models the FD command bars are displayed only on the Captain's ADI). Normally both CPL and FD modes are armed and selected as required. IN GA mode (selected either on the coupler control unit or the collective button), the wings are rolled level and a pitch attitude for Vy are selected, the pilot manually pulling appropriate GA power (whether toruqe, Ng or delta Ng depending on model and temperature).
When instructing on the Dauphin simulator, I found that most pilots wanted to fly the aircraft on an ARA using ALT and HDG modes, but then when they had to carry out a GA, suddenly found themselves acclerating level as they pulled power. I find that for an ARA it's normally easier to couple HDG and AS, then if a GA is necessary, use the heading control to turn away from the rig and allow the airspeed to be held by the AS coupler mode, whilst just pulling appropriate power on the collective. Using the GA mode for most ARAs at the go around point is pointless as it rolls the wings level at a time when you want to be turning away from the rig.
None of the above implies that any autopilot mishandling occurred in this accident. I have no idea and await the outcome of the AAIB investigation. It's just that there seem to be a number of slightly confused posts on the coupler and flight director modes on the Dauphin. I'm told that Scotia in UK don't send their pilots to Helisim for annual recurrent training. Is this true? If so, it's an unforgiveable error on their part, when a fully certified Cat D simulator is available at Helisim to practice many failures which it is not possible to do on the aircraft. Even in the much-maligned Nigeria, pilots from all companies are required to carry out annual recurrent simulator training if there is a certified simulator available for the type.

[Blind]

I've been very reluctant to post here as speculation is not always healthy and we must wait for the full AAIB report but.........

I'm told that Scotia in UK don't send their pilots to Helisim for annual recurrent training. Is this true? If so, it's an unforgiveable error on their part, when a fully certified Cat D simulator is available at Helisim to practice many failures which it is not possible to do on the aircraft.

Unfortunatly this is correct and I really hope this changes. In Aberdeen alll the L pilots go to the Sim in Norway every 6 months yet only a small handful of the L2 pilots go to the sim annually. The UK S76 and Dauphin crews do not go to the sim. The S92 crews do use the sim at the moment. A number of command courses have been run over the last 18 months and the L crews had the benefit of a week in the sim yet the L2 crews did not. I do not know how this can be justified.

I think this is dreadful and hopefully changes soon.

[madherb]

Sim Recurrent Training

A question, slightly off topic, relating to Blind's post - do clients, in this case major oil companies, not require annual sim recurrent as part of their operator audit and approval process? The OGP Aircraft Management Guide section 10.5.1.7 encourages the use of full-motion simulators if available.

M

[Teefor Gage]

Originally Posted by madherb

do clients, in this case major oil companies, not require annual sim recurrent as part of their operator audit and approval process?

In some cases they more than 'encourage' it, but some companies seem to need more encouragement than others......!!