FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1987
1987 - 2114.PDF
Altitude (ft x 1000) 60 n Mask alone Mask and pressure jerkin Mask, pressure jerkin and anti-g suit and combined pressure suit Above The limits of protection against hypoxia (lack of oxygen) provided by partial pressure breathing systems. Below Underwater immersion trials per cent in the USA wear corrective spec tacles. Improved tests of dynamic visual acuity have been developed, using bands on TV screens covering the full colour frequency spectrum. Assessments of optimum colours for electronic cockpit instruments and colour compatibility with night-vision goggles have been made, as well as testing optical ceramics, used in nuclear-flash protection goggles. Human performance in sustained operations is important in both civil and military operations. Long duties, irregular work/rest cycles, and time-zone crossings must be simulated. Performance degradation must be identified, and optimum routines established. Medica tion can make a real contribution, as proved by experience in the Falklands campaign. Sleep and rest experiments continue to become more important, and facilities are being expanded for monitoring brain activity during rest and sleep (EEG), muscle movement, and breathing data. The IAM's 24hr work stations can test responses when crews have been subjected to substantial changes in time routine. Tests involve monitoring a TV screen which can show instrumentation for pilots or synthetic radar pictures for controllers. They are done at various stages of wake fulness and under the influence of drugs, hypnotics, and stimulants. Military simulations of operational endurance have been run for up to six days, but ten-day simulations are planned for next year which will go beyond what can be done safely in field exercises. Work on sleep/work patterns in selected airline crews between Heathrow, Munich, and San Francisco has been carried out in conjunction with Nasa Ames and the Institutfur Flugmedizin in Cologne. Work continues with the Japanese on polar routes. The IAM is equipped with an immersion pool for simulations of aircrew survival criteria. Insulation garments can be a problem in a hot cockpit. "They are supposed to be worn when the sea temperature is below +10°C," says Air Cdre Ernsting, "but in the military context they might be better avoided in everyday use if there is every prospect of a quick pick-up". The IAM has been making further stud ies for the CAA of insulation garments in relation to civil North Sea operations. Underwater escape, particularly from helicopters, is a matter for concern, and the IAM is doing work for the CAA on the subject. The large single -escape door on the side of helicopters is less effective than having all windows as means of escape, even with a smaller gap to squeeze through. Disorientation is a real problem in a non-upright cabin under water. Single high-powered lights are often counter productive. In the murky water they can only be seen at a short distance in spite of their power and, worse, a halo of water "fog" is created about them, which obscures escape paths. Added to all this, the quality of sight, with the eyeball surrounded by water and light abnormally refracted, is very poor. "The use of proper goggles transforms underwater escape." A major problem is holding one's breath voluntarily, certainly at water temperatures below +5°C, according to the Royal Navy. Just as smokehoods are under consideration for the passenger cabins of fixed-wing aircraft, so short- term breathing systems may be important for aircraft that are likely to end up below water. Consideration is being given to a fully immersing cabin rig. Heat loss and transfer from immersed mannikins is assessed internally, using a cheap garden fountain pump and a small domestic drink heater. Vibration has led to work on improved harnesses and seats, and attempts to correct a most important area—pilot posture. Ernsting says: "There is particu lar difficulty in designing successful vibration isolation systems. One solution can merely lead to another problem, because of the range of disturbing or harmful harmonic responses possible in various parts of the body. You must do the seats and the instrumentation together, otherwise the body can be steady, but the instrumentation is illegible." Noise alleviation is important, both to avoid ear damage and allow commu nication. "The Harrier G.5 is one of the noisiest cockpits that we have had." Good ear-cup fit and sealing can effectively reduce high-frequency noise, but active means are necessary for low frequencies. One development is anti-noise. A micro phone within the cup picks up local noises and inverts its phase, for feedback through a telephone strategically located elsewhere in the cup. The IAM advises the CAA on new oxygen systems, so it has also been assess ing self-contained smokehoods for cabin staff. It is also advising the CAA on speci fications for passenger smokehoods, having already conducted joint exam inations with the UK Accident Investigation Branch, the CAA, and the Services' Joint Staff. On fire and combustion products, the IAM aims to act as a focal point for advice—not having the in-house toxic expertise, but knowing what to ask for and where to get it. In many cases information is requested from the chemical defence establishment at Porton Down. The major problems are predicting human reactions and taking account of panic and negative panic (freezing to the spot). The IAM would like to see more attempts at panic-proof designs and procedures—tested by "tough" subjects, who could generate and cope with realistic jam-up situations in escape trials. In this way potential blocks could be demon strated more readily than in straight "time-to-evacuate" trials. Many aspects of aviation medicine require research on a broad front to solve a "total" problem. It demands not only a well designed and scientific approach, but will often also involve the personal participation of AIM staff. The present Commandant made the first live rocket- boosted ejection from a height of only 250ft, while its research director has been to 140,000ft in a chamber to test a pres sure breathing ensemble. D FLIGHT INTERNATIONAL, 17 October 1987
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
