FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1941
1941 - 2155.PDF
SEPTEMBER I8TH, 1941. FLIGHT MECHANICAL FLIGHT COMPUTOR Flight Planning a Matter of Minutes : New Performance Computer By HARRY WILKIN PERRY A LL the mathematical work of making calculations for /A and during a flight, with the possibility of errors, is *- -*• obviated by a recently introduced computing machine developed by Librascope, Inc., of Burbank, Cali- fornia. With this new instrument a pilot can determine within a minute or two, right up to the moment of taking off, the most efficient operating conditions for a flight of any distance under any set of variable factors such as gross weight of aeroplane, altitude, air temperature, wind direc- tion and velocity, course of flight, engine revolutions per minute, horse-power, and elapsed time of flight. Setting the computor to accord with the known existing factors indicates at once on dials the relevant engine speed, manifold pressure, brake mean effective pressure, carburet- tor air temperature, ground speed, air speed, drift correc- tion, and total fuel consumption for the total flight dis- tance. Thus the pilot can operate the engine at the most efficient speed and power to drive the airscrew at the best speed for maximum fuel economy to make the trip in the scheduled time. Charts an Alternative This work, which is essential for flight-planning on scheduled airlines and could greatly improve the efficiency of any bombing operation, can also be done by using charts which make it possible to do the calculations simply by selecting the correct points on graphs and reading off certain figures. An illustration of such a flight-planning chart is shown. This was developed by an engineer of the Civil Aviation Department of Australia for use on a Lock- heed Electra. But for much flying no planning, even by chart, has ever been done, and the subject has been rather neglected. The new mechanical computor makes it possible for any pilot to plan his flight, completely and minutely before leaving, providing he has good weather information about wind speed and direction, and the computor will be used on all elaborately equipped airlines. But it will never entirely supersede the flight chart, as this is so much simpler and cheaper and will always be useful for some of the airlines with less "gold braid," such as the taxi and charter companies. The computor consists of a panel of dials, as shown in the accompanying photograph, a board of adjusting pointer knobs, and internal interconnected mechanism which moves corresponding dial pointers through mathe- matically predetermined distances to give all necessary in- formation for efficient flight. It relieves pilots and opera- tions departments of the need of making flight-plan com- putations by methods that require much more time. Re-planning1 in Flight As the instrument is of small size and light weight and is contained in a convenient case, it can be carried in the aeroplane and resettings or corrections made during the flight as wind, temperature, altitude and other variable conditions change. Fuel consumption can be reduced as much as 20 per cent., it is claimed, when the manifold pressure required to maintain allowable mean effective pressure is known for all cruising speeds. The b.m.e.p. indicator gives instant warning if the horse-power neces- sary to maintain schedule will be injurious to the engine. By making corrections at check points on the course, the time of arrival at destination will be indicated almost to the second. If fuel is becoming exhausted and a quick decision must be made regarding choice of a landing field, the computor will show the best altitude, horse-power and air speed to cover the maximum distance with the remain- FACE OF THE LIBRASCOPE FLIGHT COMPUTOR. By setting the dial pointers to various values of power, altitude, timeand wind speed, the corresponding figures for ground speed, indicated air speed, total distance, fuel consumed and other quantities can be read off instantly.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
