Friday, September 21, 2018

Sortie Rate

We’ve discussed forward bases and sortie rates (see, "Forward Base" and "Sortie Rate And Response Time"), however, sortie rate is one of those issues that’s often cited but poorly understood by most people.  For example, everyone wants to discuss sortie rates for aircraft carriers – heck, even the Navy used increased sortie rates as a justification for the Ford class.  Of course, DOT&E and others have already debunked that claim!  Still, sortie rate is a common and attractive factor in many carrier discussions.  This blog discussed sortie rates for forward air bases and noted the tyranny of distance as it impacts sortie rates.

Unfortunately, sortie rate is a bit of a red herring that has only limited impact in modern war. 

Wait, what now?  Isn’t it obvious that more sorties equates to greater combat power?  Well, that’s only partially true and only in a limited sense.  Let’s look closer at this issue.

Let’s start by remembering what a sortie is.  A sortie is a single flight by a single aircraft to accomplish a single task (yes, the task might include multiple targets but it’s a single tasking).  Think about that phrase, “single task”.  Is that how wars are fought?  In single tasks?  No.  Wars consist of a series of operations – an island assault, a massed aerial bombing of factory complex, a mine laying operation, the seizure of a city, etc.  Each operation is planned, executed (hopefully successfully), and then the assets involved are redistributed and reallocated to the next operation.  Further, and this is key, most of the time the operation is a pulse of combat power, in the broad sense.

Now, let’s consider what steps are required to launch a sortie – the sortie chain, as it were.  In no particular order, the sortie chain consists of the following typical steps: aircraft maintenance, mission planning, aircraft tasking, pilot rest, fueling, ordnance loading, and asset assembly (tankers and EW escorts, for example).  All must come together in order for a single aircraft to launch. 

The sortie chain, like all chains, has a weak link or limiting step that determines the overall speed or rate of the chain.  For example, even if we could otherwise land an aircraft, top off the fuel tanks in minutes, and send it right back out to the runway for take off, we might be forced to do some routine maintenance prior to launching or risk having the aircraft crash due to a maintenance problem.  Or, we might be able to turn the aircraft around quickly but it might take a significant amount of time to plan and coordinate the next sortie and arrange for tanker and EW support.  Thus, the fact that a carrier (or base) can theoretically generate a given sortie rate is almost always irrelevant because the physical turnaround is rarely the limiting factor.  Maintenance, planning, coordination, and support are almost always the limiting factors – refueling and rearming are rarely – I would go so far as to say never - the limiting factors.

What’s important in combat is not the rate at which single aircraft can be physically catapulted off the carrier but the rate at which the operation can generate coordinated pulses of power.  Consider the battle of Midway in WWII.  The carrier aircraft – on both sides – were used in pulses of striking power.  Sortie rate was meaningless and irrelevant.

We see, then, that pulse rate is a far more meaningful concept than sortie rate. 

Thus, the Ford’s – debunked – claim of greater sortie rate is seen to be irrelevant even if it were true.  Carriers simply don’t fight by flinging individual aircraft off the deck as fast as possible.  They fight by launching coordinated group strikes in pulses and then they stand down until the next pulse – again, pulse rate rather than sortie rate.

The same holds true for an air base on land.  Aircraft are not sent on individual attacks against the enemy – they’re assembled into strike operations that typically require days or weeks of planning, reconnaissance, asset assembly, and so forth.  The theoretical sortie rate of the individual aircraft is meaningless.

So, we need to amend our thinking about sortie rates.  We need to start thinking on the higher level of operations rather than the lower level of individual aircraft.  We need to think pulse rate.  We need to think about the factors that impact pulse rate such as mission planning, reconnaissance, logistics, aircraft numbers, pilot pools, fuel storage, etc.

In short, we need to think about war from an operational perspective.

7 comments:

  1. You're mistaking peace time operations for war time.

    https://en.wikipedia.org/wiki/Operation_Focus#June_5,_1967

    "The Israeli jets then returned to Israel, were "quick-turned" (refueled and re-armed) in 7 minutes 30 seconds, and left in a second wave that attacked 14 Egyptian bases and returned with only minor losses."


    In a war, no carrier is going to mount an attack, and plan on replacing the engines of half its fleet when they get back, then mount another attack

    In a real war, you wont have the luxury of planning air operations weeks or days in advance, they will be planned, where not entirely reactive, in very short spaces of time, using whatever can be fielded.
    Maintenance will be handled in the rear, either through actually swapping aircraft, or carriers will be pulled off the line for a week, and everything will be stripped down and replaced, ready for the next conflict.

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    1. "In a war, no carrier is going to mount an attack, and plan on replacing the engines of half its fleet when they get back, then mount another attack"

      All I can say is to suggest that you read the history of carrier operations because, by and large, that's exactly how carrier ops are conducted - minus your hyperbole about replacing engines.

      Could there be a single example somewhere and somewhen in history that contradicts the post premise? Of course! That doesn't invalidate the premise. The premise stands.

      One can also make a pretty good argument that a pre-planned, one-time, quick turnaround is not "sortie rate". The term "sortie rate", as commonly used, refers to the the ability to sustain repeated sorties at a rapid rate. Your example is not that. It was a one-time, planned event.

      The premise stands!

      Delete
    2. See your "missions not deployments" post then.

      If a carrier group is planning to support a week long marine assault on an island, every part scheduled to be replaced in that week, will be replaced in the ready period before.

      A piece of the landing gear might be rated for 100 cycles before it is replaced and returned to the factory.
      In peace time, it runs 100 cycles and the aircraft is grounded until it can be replaced.
      In war, the piece will be replaced early if there is military utility in doing so.

      Delete
  2. I think the USN may actually be thinking in terms of single-aircraft taskings. As aircraft grow fewer in number, more individually capable, and far more expensive, single-aircraft taskings are the end state that these changes imply. And stealth provides a way to believe that single-aircraft taskings will work, and the Navy remains jealous of the Air Force's stealth successes during Desert Storm.

    The influence of Tom Clancy novels, Top Gun, and the like on Navy decision making should not be underestimated either. America lives by its myths, and adopts new ones rather readily. And they're the nearest things to facts that many politicians know.

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  3. I am not sure where you get your definitions but here is the official DOD definition of sortie.

    "In air operations, an operational flight by one aircraft." Ref: JP 3-30.

    It says nothing about single task. I will speak from my own experience that a multi-mission aircraft will often conduct multiple tasks in a single sortie: ASW, ISR, ASUW, etc.

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    1. "A sortie is a single flight by a single aircraft to accomplish a single task (yes, the task might include multiple targets but it’s a single tasking)."

      If you think what I said is different then go be a lawyer somewhere else. This is the kind of unproductive comment that does nothing to further the discussion.

      Delete
  4. "We need to think about the factors that impact pulse rate such as mission planning, reconnaissance, logistics, aircraft numbers, pilot pools, fuel storage, etc."

    You're correct on this part and weather and events on land and sea are factors as well. During WWII, several airborne drops were cancelled because the allies had already moved ahead of the planned drop zone.

    But, a sortie is a metric and most metric can be manipulated to make things look better than they are.
    Aircraft numbers is probably the biggest factor and one that isn't easily manipulated. Aircraft are either ready for combat or not due to a variety of factors, like damage or maintenance.

    Having a high sortie rate but only a few aircraft to sortie isn't going to win the next war.

    ReplyDelete

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