FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1947
1947 - 1442.PDF
228 FLIGHT AUGUST 2STH, American Newsletter Accident Investigations : First Flights of Four New Aircraft Types Ev " KIBJTZER I?1 OUR new aircraft of widely different types have flown' lately. The Army have announced the flight trials andsome details of the B.50, which is the Pratt and Whitney-engined development of the B.29. It is powered with four Wasp Majors which have given it an increased performance all round. Its speed, range, and climb are up, but the operational load is much the same, due to the restriction of the size of the bomb-bay, and the extra 15,000 lb load is taken mostly in the form of fuel. Other modifications include reversible pitch airscrews,, increased flap area, power-boosted rudder, and thermal de-icing. It is presumably going into production in limited numbers. Boeing have also flown the first Stratocruiser. The other Army type is of a very different design. It is the Kellett twin-engine, twin-rotor XR-10 helicopter. This has two 525 h.p. Continental engines with inter- REEPERCUSSIONS from the three DC-4 airline acci-dents which were mentioned in the last News Lettercontinue. As a result of them the President's special Board of Inquiry has issued several recommendations which deal with length of runways, aircraft loadings, landing aids for bad-weather conditions, and the heights at which high ground should be crossed by commercial aircraft. The great differences in take-off weight between hot and cold days due to the changes in the fuel load have been re- emphasized, as have the effects of ground temperature on take-off run. The airlines are naturally watching future regulations very carefully. With the present narrow margins on payload they cannot afford to have take-off weights reduced much more, and some serious arguments are boiling up between the operators and the Government. The installation of landing aids, however, is largely a meshing rotors and an all-up weight of 10,997 lt>. Its ^/natter of finance, which in turn is a matter oi: Congres- service ceiling is said to be 18,800ft and its hovering ceilingj/%?r5nal allocation. To give some idea of the gap that must 6,000ft with a useful load of 2.793 lb The rate of ctmlr*' vet be bridged, the President's Board has recommended -V The twin engine, twin rotor Kellett XR-10 helicopter for the American Army. There is accommodation for a crew of two and 10 passengers. Another photograph appeared in " Flight " July 24th, 1947. is 1,650 f.p.m., and the top speed 121 m.p.h. at sea level. The other big helicopters that are now being developed over here are the Navy's McDonnell XHJD-i, which has two Pratt & Whitney 450 h.p. Wasps, and the Piasecki XHRP-i with one 600 h.p. Pratt & Whitney R-1340. The all-up weight of the former is quoted at 11,000 lb, and the latter as 6,700 lb. In each of these the machine has obvious commercial possibilities, as there would be seating for 10 or 12 people. Cruising speeds would probably be in the neighbourhood of 100 m.p.h., and they would be ideal for short-haul feeder-line services. This is definitely a case where the Armed Services are subsidizing a potential commercial type—to everyone's advantage. It would be nice to hear that the Royal Air Force was equally far-sighted. The fourth new type to fly is the Martin 3-0-3 which has done one flight. This is a pressurized version of the 2-0-2, which latter machine is now undergoing a 150-hour accelerated service trial. The idea is to do at least 10 hours per day in all weathers and at least 25 hours at night. The crew consists of both Glenn-Martin and Civil Aero- nautics Authority employees, and the tests are part of the C.A.A. acceptance requirements. The original 3-0-3 speci- fication called for an all-up weight of 35,000 lb against the 2-0-2 weight of 38,000 lb; a cruising speed of 287 m.p.h. against 263 m.p.h.; and two Pratt & Whitney R-2800 CA.18 engines as opposed to the C.A.3 engines of the 2-0-2. installations to a value of 13,428,000 dollars; the House of Representatives has approved ex- penditure of 5,930,000 dollars, while the Sen- ate, which appears more anxious to reduce taxes than improve airline safety, has approved a mere 571,706 dollars. The picture is fur- ther complicated because nobody has yet agreed as to the type of aids that should be installed ! So far as the '' height above terrain '' regula- tions go, the enquiry into the accident of the Pennsylvania Central DC-4 tnat hit a hill dur- ing a let-down on the Washington D.C. approach, has produced some rather startling evidence regarding altimeter error which is still being examined. But as a result of the Special Board's recommendations, the Civil Aero- nautics Board has taken immediate action to make '' terrain proximity indicators '' manda- tory by January 1st, 1949. The airlines may fit any approved type, whether radio altimeters or radar, and several lines have already installed them. Regulations governing the height at which high ground must be covered have also been revised, and the minimum height now required is 2,000ft. The investigations on altimeter error, results of which may have been published by the time this appears in print, may well explain other fatal accidents in which aircraft collided with high ground. In addition to the President's Special Board, the Civil Aeronautics Board have been carrying out their own very thorough enquiries into the accidents, and some interipi reports have been published. In the case of the La Guardia. crash, their first findings were very guarded, and t wisely did not as yet attempt to give a specific reason for the failure of the machine to take-off. This was not the case in the report of yet another governmental enquiry, that of a Senate investigating Sub-committee who blamed the pilot for a number of wrong decisions. It may seem strange that there should be so many different enquiries going on at the same time, but that is the way things are done here. Sometimes this is to the good, but more often one is tempted to think that the public—for whose benefit sudi committees exist—i§ more confused than enlightened. Personally, I would think that the final C.A.B. report on this particular accident would be the most reliable. In the case of the Eastern Airline DC-4 Maryland crash —-which was obviously the result of structural failure— trie-papers reported that the C.A.B. were considering the theory that the elevator trim-tab cable may have broken
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
