2 engines one pilot/ one engine 2 pilots

[widgeon]

So which would you regard as safer flying over water at night ?. ( accepting that 2 engines and 2 pilots would appear to be the safest )
Do the stats suggest that engine failure is the initiating factor in most accidents ?

[NickLappos]

The data says that people make more accidents than engines, even with singles. That being said, there is a saying that the IQ of more than 1 person is the sum of the recipricals of their IQs!

Actually, two pilots, with the proper crew training, are a very potent weapon against crew error mishaps.

Here is some data :

http://www.ogp.org.uk/pubs/341.pdf

[GLSNightPilot]

I agree with Nick. I prefer 2 pilots and 2 engines, like everyone else, but if I had to choose, I'd take 2 pilots every time. I've been doing this for a long time, and I've never had an engine failure. The other pilot has saved me, & I've saved the other pilot, lots more than once. Flying into the water with the engine(s) running will be more likely to kill you than an autorotation, day or night.

[Time Out]

Helicopter Safety Advisory Conference 2002 and earlier (http://www.hsac.org/2002stats.htm) are somewhat relevant and might be of interest.

[tecpilot]

Difficult question and old question.

In the last years helicopters and their equipment was very improved. Much more than on the decades before. The use of NVG, GPS, FADEC, Autopilot (now better "Flightdirectors") gives the pilot much more possibilities to make the flight successful and safe. The older times with the chart on the leg, trying to spot the location in the small white or red lights of the instruments and flying the ship only by hand are gone. Shure we have a lot of ships without autopilot, but GPS (mostly with moving maps) should be standard today. One pilot is today able to fly the ship nearly under all circumstances alone. The second pilot is mostly a "controller" and the use of Crew Resource Management should give a advantage in safety. But no one can really count the CRM advantage. Most examples of the CRM guys coming from planks. They haven't great experience in helos and mostly they couldn't imagine the kind of missions a helicopter have to fly. And a lot of accidents, are crew misunderstanding accidents. I think a second pilot couldn't hurt but isn't necessary under all circumstances. With a 50 years history helicopter operations are proved. Keep it simple...

I hate all the statistics comparing singles and twins. You could find any possible messages, if you like, in statistics. Look at AMPA Safety Report (http://www.ampa.org/AMPA_Safety_Report.pdf). :8

Single or twin, it's a question of the kind and the circumstances of your mission.

[C4]

2nd pilot is quite often just another statistic in the crash!!!

[zalt]

While personally favouring twins on long overwater flights, it is worth noting that the value is subverted if the aircraft is operated without regard to single engine performance capability.

A classic case last year:
https://www.nasdac.faa.gov/pls/nasdac/STAGE.AIDS_BRIEF_REPORT_PUB?EV_ID=20020812022649C&NARR_VAR=

Note this FAA database is due to be down for maintenance latter today. However the gist of the accident:

Bo105 N8197X of PHI operating in GoM from Boothville, LA, 12 Aug 2002:

"THE PILOT WAS UNABLE TO MAINTAIN ALTITUDE AFTER SHUTTING DOWN THE NUMBER 2 ENGINE AFTER A LOSS OF OIL PRESSURE. THE PILOT LANDED THE HELICOPTER IN THE GULF OF MEXICO WITH THE EMERGENCY FLOATS DEPLOYED WITHOUT CAUSING ANY DAMAGE TO THE AIRCRAFT. THE PILOT AND PASSENGERS EXITED THE AIRCRAFT INTO A RAFT AND WERE SHORTLY PICKED UP BY A BOAT. THE LOSS OF OIL PRESSURE WAS CAUSED BY A LEAKING OIL SEAL IN THE NUMBER 2 ENGINE OUTPUT SHAFT. "

Alternative terminology:
Landed = Ditched
Exited = Escaped
Picked Up = Rescued
I'm suprised that the 'emergency' floats were not renamed 'standby' floats!

Anyone know if the aircraft was recovered and put back into service?

Echoing a comment by 212man on another thread, this was a incident and is not listed on the NTSB database. I wonder how many ditchings are similarly downgraded on both singles and twins? Wx may not have been a factor in the incident as the report states, but it was surely a factor in the survivabilty that day.

Another reason this is interesting is that oil seal leaks are a hot topic at the moment with the oil company safety community. One manufacturer is now claiming gearbox oil seals effectively never leak.


Edited to reattribute reference in other thread

[Mars]

Zalt:

This BO105 flight was conducted in accordance with FAR 135.183(d) which, once again, appears to be an alleviation from the fixed wing rule (see the previous discussion on FAR 91.119(d)).

Conclusion; two engines equals twice the probability of an engine failure with the same outcome.

This incident, and the latest B407 accident, both occurred to the same oil company (albeit different divisions). This is not a company which will suffer such incidents/accidents without pressing for an improvement in operational standard (which might translate into equipment and crewing). In the North Sea this has led, in the past, to a change in regulations.

Recent Stats for the GOM (5 year window) appear to indicate that about 50% of all accidents have a primary cause due to human factors and 27% have a primary technical cause; 17% of all fatal accidents have an engine related cause and 23% are flights into water (which may have been CFIT); 7% of of the single engine accidents were at night.

(The only engine failure on a twin leading to an accident was multi-cause - tail rotor failure.)

All accidents for the last three years were single-engine, single-pilot.

Draw your own conclusions.

[zalt]

I assume the (typically) shorter GoM sectors increase the number of take off, landing and deck related accidents.

[Gomer Pylot]

A couple of notes. There are more single-engine helicopters in the GOM than all other types combined. All the accidents I see are single-pilot, whether one or two engines. There have been accidents involving 2 pilots, but not many, and not lately. The PHI incident where the tail rotor separated on the 412 is an exception, but from what I read the fact that there were two pilots was what kept them both alive, and only minimal damage to the helicopter during the incident.

I don't think there is a typical GOM operation or leg length. I've flown jobs where I did > 100 takeoffs per day, and 3 miles was a long flight. I've also flown jobs where almost every flight was > 100 NM. All things considered, I suspect that if you average everything, there are more takeoffs per helicopter in the GOM than in the North Sea. But the regulations are very different. I don't defend all our regs, but you must remember we have to live with the ones we have, and fly to the edges of them. That's just a fact of life (sometimes death) here. If you're afraid of flying single-engine helicopters in poor weather, better stay across the pond.

[Mars]

Gomer Pylot:

The thrust of your argument is not in question - your conclusions however, appear to be rather fatalistic.

This is not just a discussion about pilots, there are also passengers to consider and, because of this, there are a number of questions that should be asked: Do the regulations require revision? Do the operating standards need to be improved? Does there need to be a change of emphasis from 'get-the-job-done-at-any-cost' to the inculcation of a safety culture into the work force?Nothing will change until there is an understanding that, of the three, the last is the most important.

It is my understanding that a number of years ago it was decided that, when dispatching an EMS mission, the flight crew were not briefed on the condition of the casualty. The reason; to avoid the aura of the 'angel-of-mercy'.

Although being a pilot is at the pinnacle of job satisfaction, the pleasure should come from a mission completed safely and not just a mission completed.

As has been said on other threads, the single most important element of the whole risk assessment process is the safety target. If all of the stake holders in the GOM are satisfied with the accident and incident statistics - this debate is at an end.

[Gomer Pylot]

Not everyone is satisfied. But those with the money, thus the power to change the regulations, appear to be satisfied. This includes the major oil companies, all of which use single-engine ships here. Zalt is simply wrong when he says in another thread that they don't. I guarantee you that single-engine, single-pilot hellicopters will continue to be used. I don't know anyone who even suggests otherwise. Providing better equipment, such as GPWS, TCAS, etc is what we need to be pushing for, along with increased weather minimums. I've flown countless hours at 500/3 in a 206, and the margin is razor-thin. But the FAA standard is merely clear of clouds, unless the ops specs dictate higher. Thankfully most do, but they're still too low.

[Mars]

Gomer Pylot

I disagree with you that the major oil companies are satisfied - quite the opposite.