Dear Louise,
In general aviation helicopters there, in the moment, really is only one significant audio/visal warning- the LOW ROTOR RPM. Dependent on the type of helicopter, it can be an intermittent series of beeps or a continuously blowing horn.
If operating under IFR (Instrument flight rules) most helicopters incorporate a GPWS or more commonly AVAD system which will notify you (a sweet women's voice) of a pre-set altitude and than again at 100 ft above ground. These audio alerts are important for the final approach when there is an increased workload on the pilot.
As you state, noise in the helicopter cockpit is generally a concern. However, more modern sound proofing and communication systems do increasingly take care of the noise. The cockpit layouts become simpler through EFIS systems (Electronic Flight Info Systems) alias glass cockpits.
But it may be surprising that even modern helicopters very much rely on visual warnings rather then on a combination of audio and visual warnings. One of my guesses would be the development cost.
If you need some expert info, try contacting FLIGHT SAFETY INTERNTIONAL. They have some very experienced people there.
The most modern next generation aircraft in the moment is the Bell 609 Tiltrotor. If you would like some expert info on this, please e-mail me to
[email protected] and I will give you some contacts.
Your question about serial tasks, I don't quite understand what you may be talking about, but if you are referring to sequenced reactions, here are some points.
Helicopter pilots are generally very self-dependent, since a lot of the work is single pilot and often there really is, unlike in airplanes, not much time to run through endless chcklists.
However, since more and more helicopter operators, escpecially in the transport sector, have to comply with changing rules, checklists become more of an issue. In most 2 crew operations checklists are adhered to fairly strictly.
One drawback is that because of uncoordinated use or timing, the task of actually flying the aircraft is overshadowed by reading checklists. I think the contributing factor for this is that many pilots use the checklist rather as a DO list, which defeats the originial purpose.
I hope that was what you were aiming for.
Please feel free to ask any questions regarding this topic. I think you have started a very interesting thread here.