Number Of Sorties Research Articles

Optimized Air Force Flight Scheduling Considering Pilot’s Mission Efficiency

Human and material resource planning is one representative example of Operations Research. Resource planning is important not only in civilian settings but also in military ones. In the Air Force, flight scheduling is one of the primary issues that must be addressed by the personnel who are connected to flight missions. However, although the topic is of great importance, relatively few studies have attempted to resolve the problem on a scientific basis. Each flight squadron has its own scheduling officers who manually draw up the flight schedules each day. While mistakes may not occur while drafting schedules, officers may experience difficulties in systematically adjusting to them. To increase efficiency in this context, this study proposes a mathematical model based on a binary variable. This model automatically drafts flight schedules considering pilot’s mission efficiency. Furthermore, it also recommends that schedules be drawn up monthly and updated weekly, rather than being drafted from scratch each day. This will enable easier control when taking the various relevant factors into account. The model incorporates several parameters, such as matching of the main pilots and co-pilots, turn around time, availability of pilots and aircraft, monthly requirements of each flight mission, and maximum/minimum number of sorties that would be flown per week. The optimal solution to this model demonstrated an average improvement of nearly 47% compared with other feasible solutions.

System simulation for availability of weapon systems under various missions

In this paper, estimates for availability of weapon systems (fighter aircraft and weapons) during battles are obtained by system simulation. The weapon system is viewed as a system with fighter aircraft that includes both fixed wing aircraft (called simply aircraft) and rotary wing aircraft (helicopter) and weapons as its entities. The functions of the system are basically the military missions. The system is modeled statistically with various probability distributions. The parameters of the probability distributions considered are the system characteristics, which are being inputted. The outputs are the number of fighter aircraft attrited, the number of serviceable fighter aircraft available, and the tons of weapons available for use at the end of each day. The availability of fighter aircraft is obtained as the ratio of the number of fighter aircraft available at the end of each day to the number considered on the first day of the battle. The factors that affect the availability are: the number of missions, the number of sorties in each mission, the tonnage of weapons used in each mission, the battle damage rate considered for each mission, the unreliability of each fighter aircraft, and the repair rate. Further, the admin and logistic delays may affect the repair process. The logistic delay includes delay in transportation due to variations in terrain and weapons replenishment. The availability of weapons is calculated as the ratio of the tonnage of weapons available for use at the end of each day to the tonnage available at the start of each battle day. The availability of weapon system is obtained as the product of the availability of fighter aircraft and the availability of weapons. The results are analyzed in terms of graphs of availability for battle days along with certain statistical measures. From the results of this simulation it is possible to plan combat missions based on criteria such as high priority targets to be attacked and effectiveness of missions for specific air-battle scenarios. Further, the simulation will help towards the design of an improved system which could focus on the factors affecting the availability as brought out in this simulation and their relative significance. © 2005 Wiley Periodicals, Inc. Syst Eng 8: 309–322, 2005

Discrete-event based simulation of airbase logistic provision model

By means of a simulation technique, we developed and implemented a model of the provision of logistics at an airbase; the results of the simulation are analysed. This model is constructed to evaluate all factors affecting the sorties of military aircraft from an airbase. All factors include logistic provision, takeoff, landing, maintenance and repair. Under the constraints of limited resources and inevitable consumption, the objective of the model is to setup an environment with which methods for increasing the average number of sorties of aircraft from an airbase can be analysed. The constraints of limited resources refer to logistic support personnel, repair engineers or required equipment; the inevitable consumption includes damage in combat, operational mistakes or depletion of fuel and ammunition. The simulation of the model is designed on the basis of discrete-event orientation. Given a specific interval with various constraints, the average sorties of aircraft from the airbase are simulated. The simulation, implemented with the SIMSCRIPT 11.5 language, is tested with various input data. The outputs of the simulations are analysed and compared. With such simulations, the problem of resources allocation and distribution in an airbase can be effectively controlled and programmed. The proposed model and the simulations can be beneficial to the management of the logistic support system at an airbase.

A Naturalistic Study of Young Children's Explorations Away from Caregiver

29 child-caregiver pairs were observed in a public park without the adults' preknowledge, to examine the effects of mode of locomotion and age of child on exploration. A clear relation was found between child exploration and both age and walking vs. crawling ability. Ability to walk seems to be the most important determinant. No effect of age was found on mean length away or number of explorations away from caregiver among walking children ages 12-36 months. Age differences, however, were found in mean distance (computed from measurements taken every 10 sec) to caregiver. On this measure children who were more than two years old tended to be farther away. The divergence between the two measures 'mean length of distance to caregiver' and 'mean length of exploration' may be explained by group differences in the amount of time spent in vicinity of the caregiver. No differences were found in a number of sorties or time spent away between groups aged 12-18, 19-24, and 25-36 months. The duration of sortie was lower in the youngest age group. The younger children seemed mainly to make short and brief sorties punctuated by equally brief moments of proximity and tended not to return from their longer sorties. The older children made fewer and longer sorties and they returned regularly. The findings are compared in some detail with the findings reported by Anderson (1972a, b).

Optimum plan for a level attack against a possible deployment of ground anti—Aircraft gun

In this paper, we consider a situation where a certain defender’s target on the ground is threatened by an attacking enemy aircraft and the enemy has number of sorties of such aircrafts. The defender has got a mobile anti-aircraft gun system which can be positioned anywhere within a finite distance from the target. The mathematical model has been formulated for the case when the attacker’s aircraft flies at any heihgt within a given range above the ground in a level course in a direction which coincides with the line joining the gun position and the target. Depending upon the location of the anti-aircraft gun and height of the attacking aircraft, the total damage inflicted on the target by the attack is calculated for all the surviving sorties. Also for the best possible deployment of the gun, the optimum height for the attacker at which it can inflict the maximum damage to the target is determined.

Rhythms in the Breeding Behaviour of the European Wren

Two nesting cycles of the European Wren Troglodytes t. troglodytes were studied by means of recording apparatus at the nest augmented by direct observation. Data were obtained concerning nest-building and -lining, egg-laying, incubation, feeding nestlings and roosting. The first incubation probably began in the afternoon. In both nestings under-brooding was compensated for by an unusually long session after an unusually long recess. The relationship between the hourly amount of brooding and temperature is represented by a curvilinear regression from a maximum of about 75 % around 40° F. With rising temperature recesses tend to increase in length and sessions to decrease. The average session-plus-recess, defined as the incubation-cycle span, was found to remain constant, independently of environmental conditions, within certain restricted limits of diurnal variation. This span differs for different individuals. During the first brood Wrens frequently settle on the eggs well before sunset but after the hatch the length of the working day increases slightly in the morning and considerably in the evening. During the incubation period in 1952 the male apparently visited the nest on several days between 08.00 and 12.00. Hatching of all the eggs in one nest took about 21 hours. In 1951 the male went to the nest several times with food on the day of the hatch but did not give it to the nestlings. He fed the first-brood chicks only during the second week of the nestling period. In 1952 the male never fed the nestlings of the first brood. Regular interruptions in the day to day increase in the frequency of visits during the nestling period may have been due to physiological strain. Daily trips with food for the nestlings showed approximately 5-hourly peaks of activity in 1951 and 4-hourly peaks in 1952. Probably these represent an endogenous rhythm. A diurnal decline in tempo with a ratio of about 3 : 2 was noted in the number of sorties by one incubating female and in the foraging sorties of both females during the latter part of the nestling period. The evidence suggests another endogenous rhythm. During the early phase of the nestling period, activities showed a major morning and minor evening peak, but later this effect almost disappeared. Brooding of the young decreased by 6%-8 % daily. At one of the nests the male helped increasingly to feed the chicks as the female's efforts decreased but reduced his efforts as hers increased. This inverse relationship suggests that the importunity of the nestlings is of importance in regulating the amount of food brought to the nest. In polygynous birds, such as the European Wren, the male may act as a reserve available to forage for the young in adverse circumstances. Polygyny in the Wren is integrated with other adaptations including multiple nest-building and persistent song. It implies family-size adequate to maintain the race but not too large to be beyond the capacity of the female to feed. One of the nests was visited by the female on a number of occasions after the young fledged. The fledglings roosted in the disused nests of other species.

Mass Departure of Locust Swarms in Relation to Temperature

FLYING swarms of locusts often cannot be effectively attacked from the air because of the danger to the aircraft. Attention is therefore focused on the circumstances in which a swarm will remain on the ground. In Kenya the desert locust, Schistocerca gregaria (Forsk.), roosts overnight in trees and shrubs and usually takes to flight at some time during the morning. The prediction of the time of take-off is important in deciding the number of sorties an aircraft can make before the locusts leave, and therefore the number of aircraft required and the distance from which they can usefully operate.