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I am working on a modeling case study in which I am using a realistic disaster response operation situation after a major earthquake in Chitral, Pakistan.

In this regard, I am using Chitral Airport as a local response center from where the transportation of relief to different affected areas will be realized.

I want to have an estimate of the number of cargo aircraft (such as C-130, C-17 or others in the inventory of neighbouring countries i.e. China and India) which can be handled on Chitral Airport in one hour.

So, the estimation quantity is total number of aeroplanes handled (landed and accommodated) per hour.

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By looking at the said airport, one can pretty easily see that the limiting factor will be the offloading time of a cargo plane. The Apron is very small, and can only handle two, maybe three in maximum of cargo planes.

I'm not an expert on cargo handling, but a rough estimate would be about an an hour per plane for the C-17 size aircraft. A single operation would, with taxiing, take about 1,5 hours. Since the apron can only handle the aforementioned 2, max. 3 planes at a time, separation during flight would not be an issue.

So my best guesstimate would be a maximum of a bit less than two operations per hour for large aircraft, given the weather will not limit flying. Smaller planes could operate on much shorter interval, half and hour maybe. Then again, two large cargo planes would pretty much block the apron anyway, so adding smaller planes to the mix might not help much. edit: As the comments suggested the cargo was forwarded via air, this would complicate the equation. A single load of a C-130 would translate into about 4 Mi-17 loads which is manageable, but a fully laden C-17 would require a whopping 15 Mi-17 flights (X. Managing 2 cargo plane takeoffs and landings and tens of helicopter operations on such a small area as the Chitral airport is not safe.

You should take into account what kind landing and t/o weights Chitral can handle. If that turns out to be a limiting factor, there would not be much sense in operating large cargo planes half empty to/from there.

edit: Since some comments mentioned the unprepared field capability of C-130 and C-17, and it was also suggested that offloading chould be done outside the apron, I must stress that the unprepared field capability does not mean that the planes can taxi, take off and land everywhere. The load bearing capability of the surface used must be taken into account even if planes landing gears were designed to be able to operate on all kinds of surfaces! You do not want to bring the operation to a halt simply because a plane sunk its wheels to the ground. Once that happens, they need to be lifted out.

Also runway length can be a restriction. Even though (if I understood correctly) Chitral would be the destination of cargo, the landing distance requirements might be a limitation for heavy landings.

Taking all of the aforementioned aspects into consideration, large planes might not be the optimal choice after all. You should also think about the ground logistics. Running the ops at max efficiency will kick up considerable ground traffic.

X)Cargo capacities: C-130: 20000kg C-17: 77000kg Mi-17: 4 000 kg internal or 5000kg external

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  • $\begingroup$ Actually we are not using land transportation, we are using helicopters for last mile delivery, so according to your suggestion, in 4 hours the airport should be able to handle 12-13 C-130 airplanes (full of humanitarian ration) $\endgroup$ Oct 20, 2023 at 13:11
  • $\begingroup$ Keeping in mind that we are also using the airport for Mi-17 helicopter operations (although a cricket ground nearby can also be used) $\endgroup$ Oct 20, 2023 at 13:13
  • $\begingroup$ The C-130 can use unprepared runways. Can it also use unprepared aprons? There are several fields next to the airport, but I cannot tell if they are flat. $\endgroup$ Oct 20, 2023 at 17:35
  • $\begingroup$ According to US department of defense, C-130 can be operated using unprepared fields. Regarding surrounding fields, if you use the 3D view of the Google Earth and zoom in, as far as I can see, they are flat. $\endgroup$ Oct 20, 2023 at 18:10
  • $\begingroup$ By the way, defense.gov/News/News-Stories/Article/Article/1648322/… is the link to the relevant DoD website $\endgroup$ Oct 20, 2023 at 18:11
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Assuming you are sending aircraft which can unload on unprepared surfaces, and the flood plane to the east of the runway is a suitable surface:

The main limiting factors are

  1. Safe separation. This might be about 120 s between when the leading aircraft finishes taxiing and when the following aircraft lands.
  2. Taxi time. Assume the typical taxi is 700 m at 7 m/s. Then add 100 s for taxi.

Unloading time and departure time are not relevant because you probably do not have enough cargo aircraft to fill up the space east of the runway (after demolishing small obstacles.) Unloading can be simultaneous. Just leave your empty aircraft there until no more are landing.

My estimate is about 16 aircraft per hour. You will have a tough time finding 16 aircraft ready for this mission.

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    $\begingroup$ Does this answer assume as much taxiing, marshaling, and unloading on X acres of basically flat ground, as on the same area of paved tarmac? Sounds unrealistically optimistic. I've operated C-130's on unpaved surfaces for this sort of thing, but they were a far, far cry from a hastily prepared patch of flat ground. And even then, not nearly as efficient as operations on a paved ramp. $\endgroup$
    – Ralph J
    Oct 21, 2023 at 4:40
  • $\begingroup$ Is the estimate of 16 aircraft/hour based on that many C-130's? Or C-17's? Or 16 Cessna 206's? How long do you assume each aircraft takes to unload when reaching that estimate? How many aircraft are assumed to be unloaded at once to arrive at that estimate? What is the relationship between the numbers stated as the "main limiting factors" (i.e. 220 seconds) and the conclusion of 16 aircraft/hour? How can the statement "unloading time ... {is} not relevant" be justified? The difference between 48 hours to unload each aircraft, or 4 hours, or 40 minutes, or 4 minutes, seems highly relevant. $\endgroup$
    – Ralph J
    Oct 21, 2023 at 4:53
  • $\begingroup$ So how much C-130 do you suggest will be able to land on the said airport @RalphJ? $\endgroup$ Oct 21, 2023 at 5:29
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    $\begingroup$ @Engr.MoizAhmad Given the very limited data presented, I think Jpe61 gave you a very good answer, and I don't have anything much to add to it. $\endgroup$
    – Ralph J
    Oct 21, 2023 at 6:04
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    $\begingroup$ @AnonymousPhysicist aircraft operations are complex, a simple equation cannot take into account all considerations. And: should there be more than ten operations per hour on a single runway airport /-field, with many pilots unfamiliar with the place, you can bet you behind there will be marshallers there. Loads of them. $\endgroup$
    – Jpe61
    Oct 21, 2023 at 17:51

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