@aviation_enthus, can you give this discussion a rest for 2 days (and reply only if you have done more research on the threat matrix) as yours and other replies are getting too detailed and they contain too many assumptions, for my comfort. See this 101 page RAND pdf:
Air Base Attacks and Defensive Counters: Historical Lessons and Future Challenges
1. As part of any war planning, most professionals assume that their own air bases will be under attack at some point and will need xxx minutes to repair before air operations resume at a yy sortie generation rate (that recovers and launches zz aircraft per hour).
(a) There is a trade-off in investing too much on base infrastructure (vs just buying more fighters). As some have pointed out that any hardened hangar can be destroyed by any missile large enough.
(b) I would assume that unless the hanger is built into a mountain, an IRBM would certainly do the job of destroying even a HAS.
(c) ALL capable air forces need to retain the ability of their squadrons to generate a large number of air missions—ISR, strike, close air support, air refueling, airlift, and aeromedical evacuation—day and night without minimal interruption.
2. The US Department of Defense is moving ahead with plans to formally build a
backup air base at Tinian Island, located just 100 miles to the north of its giant and highly strategic U.S. military airbase on Guam, known as
Andersen Air Force Base. This is because the Americans assume that any forward air base will be under attack at some point and will need xxx minutes to repair. And expect the enemy to do this at intervals. IMO, it’s up to Australia’s defence professionals and their policy shops to decide how much of their actual capability for dispersal and runway repair they want to declassify.
3. Sweden established the manpower intensive road runways (as alternative bases with the introduction of the Bas 60 system in the late 1950s). The Six-Day War in 1967 (where the Egyptian Air Force was grounded by a quick surprise attack on air bases) and the introduction of long range attack aircraft (primarily the Su-24) inspired further development, resulting in the Bas 90 system. Improvements in the Bas 90 system included construction of short backup runways in the direct vicinity of the air bases and further dispersion of ground operations. Like Sweden, Taiwan also plans for dispersals to generate air power when under attack; hardening is just a small part of the discussion.
My issue has not been with the threat perception, but rather the perception I have formed about what you seem to think would make a difference in outcome.
For example, if an aircraft hangar were to be built with sufficient hardening to require what is commonly referred to as a "bunker buster" penetrator as opposed to just a regular bomb or PGM, then one would be taking about a structure where the ordnance had to penetrate through 50+ metres of earth, or 5+ metres of reinforced concrete. Now consider the engineering and construction difficulties and costs involved with building numerous aircraft hangars where the outer wall/roof is 5 metres thick. In fact, such construction would likely complicate it's function as an aircraft hangar because the hangar doors would need to be reinforced to a similar standard, otherwise attacks would target the doors to damage what is inside. BTW that was the original tactic used in GWI by coalition strike aircraft to attack Iraqi HAS, hit the hangar door first, then send a second munition though the now opened hangar door. Now try to imagine the steps and kit required to open and close doors the size of an aviation hangar bay door, that are heavy/hard/strong enough to be the equivalent of 5 metres of concrete...
In the past hardened aircraft structures made a bit more sense, because they could provide protection from indirect hits as well as shell fragments and splinters. It also used to be much more difficult in getting a direct hit on a target, even a fixed stationary target like a building. Now though, it would be reasonable to assume that a hardened military structure is likely to be hit, possibly multiple times, by PGM's which have become both more plentiful and inexpensive.
4. Agreed. As some in DT have pointed out, there are too many parts of an airbase (given its huge size that can be a target). Australia just needs to have a sensible plan for runway repair and dispersal as a risk reduction measure.
(a) In any air campaign, Australians would execute a runway repair and dispersal plan. But the threat matrix is different between Australia, Taiwan, Sweden or Singapore.
(b) With its KC-30A tankers and C-17s, Australia has some ability to deploy fighters relatively quickly to air bases in Malaysia and Singapore over long distances is unique to a middle power. The ADF executes this mission with such skill and apparent ease that Australians and many others within ASEAN largely take it for granted.
5. IMHO, some limited hardening of select aircraft shelters may make sense (if your airbase is within mortar range of the enemy, like Singapore). The majority of Singapore’s hangers are not hardened against bunker buskers, as precision munitions are pretty common these days.
6. Singapore’s 505 Squadron, Air Base Civil Engineering Squadron, works closely with the national agencies to convert public roads into alternate runways. Singapore also operates on the assumption that our air traffic control towers will be destroyed; which is why we have
Mobile Air Traffic Control (MATC) Towers and Mobile Arrestor Gears for the roads we will convert to runways.
7. Camouflage, decoys and deception plans are almost as important as hardened shelters — as cost effective alternatives (if the threat matrix allows).
8. And Singapore is a country that regularly practices dispersed fighter operations from alternate runways, like public roads (especially with the new F-35Bs); and has a known C- RAM capability (but the exact nature of its intended use in operations is classified). Setting up alternate runways is time consuming but we do practice that at regular intervals.
9. Singapore’s use of the Elta EL/M-2084 Multi-Mission Radar is a declared capability — the classified part is range and types of interceptors to be used in these defensive systems.
