FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1963
1963 - 0436.PDF
. , -- . . >. 416 FLIGHT International, 21 March 196* The Baxter, Wood- house and Taylor full - pressure suit tested at RAE (see first news-item) Flight Systems Human Engineering On Shew Some recent developments in the field of human engineer ing (not man-machine relationships, but personal equipment) were recently demon strated at RAE Farnborough by the Human Engineering Division of the Mechanical Engineering Department. Main subjects were full-pressure suits, underwater ejec tion, explosive decompression, breathing dynamics and safety harness. Explosive decompression was demon strated with a dummy in a Type B full- pressure suit, strapped to an ejection seat, mounted horizontally in a small pressure chamber and suddenly decompressed from lOlb/sq in to llb/sq in (8,000ft to 60,000ft) in 0.2sec. The pressure-drop was created by breaking a Melinex diaphragm between the test chamber and a larger reservoir. With this equipment it was possible to measure accurately all performance, such as the time taken for the visor to shut. The dummy, made at Cardington of moulded foam rubber, is unique. It is realistically weighted, articulated and shap ed, and the internal organs can be repro duced by pockets of water. To simulate breathing systems under the full range of operational conditions, RAE have developed an artificial breathing ma chine more advanced than that produced by the Royal College of Surgeons. The system employs a mechanical pump simu lating human lungs, controlled electrically from an Advance SG.88 VLF function generator. Control outputs on the genera tor are shaped by black patterns painted on plastics discs rotating over a photo electric sensing device. Breathing under physical strain or during speaking can be accurately reproduced, to test masks, helmets and regulators. Parachutes and harness were illustrated by some high-speed films of ejection of a Folland seat from a sled on the RAE track at Pendine. One shot showed almost Assessing the move ment - freedom of a pilot wearing the RAE Type 8 suit. Range of arm move ment is plotted from the extent to which he is able to slide the rods INDUSTRY International full deployment of the parachute before the dummy reached ground, after ejection at 640kt. Two forms of stabilizing drogues for free fall at high altitude, and some heavy-cargo parachuting, were shown. Underwater ejection tests carried out at the RN underwater ballistics establishment at Glen Fruin were shown on film. Live subjects wearing underwater breathing equipment were ejected from a submerged Sea Vixen cabin variously mounted nor- mplly. vertically and inverted. The Martin- Baker compressed-air system was used to eject the seat from the cabin, pushing aside the canopy if this had not departed of its own volition within the air bubble. The navigator's side-window is arranged to collapse inwards to equalize internal and external pressure and facilitate canopy release. The pilot's canopy is retained dur ing ditching to deflect the wave of water and allow the crew to remain in a relatively friendly environment for as long as pos sible. The oxygen system provides some underwater breathing capability. Because the fully equipped man, even with Mae West inflated, is negatively buoyant at more than 100ft depth, and modern aircraft may sink to 100ft in 20sec, an automatic initiation system, with manual override, is required to trigger the com pressed-air ejection at about 15ft. The live subjects emerged from the cabin quite sedately and floated to the surface, where automatic dinghies spread under neath them (not very accurately) and lifted them clear of the water. The RAF Insti tute of Aviation Medicine has been co operating in this work. Development of special clothing and breathing systems for protection at high altitudes and after cabin pressure failure is a continuous process. RAE consider that 400 to 450kt i.a.s. and Mach 3 at high altitudes represent the limits for escape, respectively because of air blast and dyna mic heating. After loss of cabin pressure, the present outfit of pressure jerkin with sleeves, anti-g trousers and partial-pres sure helmet allows safe descent from 100,000ft to 40,000ft in 5min. Ultimately, a return to 30,000ft within 15min becomes necessary, the actual time limit depending to some extent on the age of the man and the height at which the emergency occurs. The full-pressure suit, on the other hand, gives rather better margins, allowing some 30min for the return to 40,000ft and an indefinite stay at that height. The problem is to meet the environmental conditions (resistance to a lOkt wind at — 40°C or temperatures up to 60°C) and provide a garment which will form a wearable overall for everyday flying when not pressurized. This it will have to be for 99 per cent of its life. When inflated the suit must give mobility sufficient to allow normal cock pit tasks to be performed. Several types of suit have so far been made in small numbers and tested. The RAE Type B, a canvas suit with soft Meli nex bubble snapping up over the face to meet an arched rear portion standing over the back of the head, has been made by Frankenstein. Baxter, Woodhouse arid Taylor have produced a more elaborate garment with ball-joints instead of capstan bindings at the shoulders and wrists, and with a rigid, visored helmet. This is designed to attain the 51b/sq in pressure which is the ultimate target. Pressurizing air is fed through an umbilical connection into the normal ventilated suit, so that the incoming flow is evenly distributed over the body. The visor snaps shut in a matter of milliseconds after a pressure-drop and suit pressure is then regulated at the outlet point by an adjustable valve located con-* veniently on the thigh. RAE have made dummy ejections with the suit from a rocket sled at speeds of 300 and 400kt, and dummy parachute descents from a balloon with the suit inflated and slack. Most recent trial was a live para chute descent from the balloon at 1,000ft Company News Mr Charles Barter, /VIBE, who recently retired from South Marston after SO years with Vickers. During the war he managed the company's "on site" Spitfire Repair Division, based at Oxford; and he was actively associated with two famous aeronautical events—the RAF long distance flight in 1936 and the Supermarim Swift speed record in North Africa in 1951 Avco-Ultra Agreement Signing of "a broad licensing agreement" between Avco Corporation and Ultra Electronics Ltd was announced in London on Monday, March 11. Mr Jack L. Bowers, vice-president and general manager of the Avco Electronics Division, Cincinnati, Ohio, stated that it permitted the British company to utilize certain patents, developments and tech niques for communications equipment. Avco Electronics and Ultra Electronics had been working together, under a joint study agreement signed last year, in the field of communications and electronics The new agreement would "increase the- wide and growing capabilities of both com panies in advanced communications tech niques." Frankenstein/Beaufort Post Mr S. G.l Williams recently resigned from the boa-d \ of Miles Marine and Structural Plasties! Ltd to take up an appointment on March 1S with the Frankenstein/Beaufort group is companies. In his new post he will bel responsible for the promotion of hone| and overseas sales of protective and survival § equipment.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
