Ask anything Thread
- Thread starter Jeff Head
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The number, placement, size and function of aerodynamic surfaces in an aircraft design varies from one model to the other, and sometimes two aircraft that seem to look alike have arrived to their final configurations via completely different routes.
The E-2 Hawkeye was developed to enable the aircraft to operate from the older modified Essex-class aircraft carriers. These ‘smaller’ carriers were built during World War II and later modified to allow them to operate jet aircraft. Consequently, various height, weight and length restrictions had to be factored into the E-2A design, resulting in some handling characteristics which were less than ideal.
For example, did you know that the aircraft family (E-2 and C-2) had 4 stabilizers in the tail, but only three of them have rudders? Partly due to the fact that the engines were designed as non contra-rotating, for maintenance and refit purposes.
Now, with regards to the four fins, the radome disrupts the airflow behind so they help stabilize the airflow and act as fences for the outboard fins. Alternatively they could have extended the fuselage length, but they didn't go that way. The three rudders provide sufficient control in single engine operation, yet are overpowering when both engines are working, which caused early control problems and stability augmentation had to be implemented. So, the E-2 and C-2 feature a pretty robust rudder authority limiter as part of that augmentation.
Now, Yak-44. The aircraft never flew, so we don't know whether the planned aerodynamic design worked or not. With regards to the stabilizers, this is a bigger aircraft with a bigger tail and fuselage length (especially when compared to the radome size). It is possible that inner fins were not needed for the tail to function properly. Or it's possible that inner fins were indeed needed, but a prototype never flew to test that assumption.
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Brumby
Major
You are making a very distinctive differentiation between the E-2 and the other platforms in terms of capabilities. Do you have anything substantive to offer to back up your assertion?
Well, excepting perhaps the Saab 340 based Erieyes, the Hawkeye does have less of almost everything than the competitors mentioned: lower ceiling, shorter endurance, lower antenna gain (smaller array + longer wavelength), probably less transmitter power and passive ESM sensors. You can add the Israeli CAEW to the list, too.
Its UHF band radar (the others are either L or S band) does have certain benefits though which can be expected to mitigate the antenna gain disadvantage to a large extent. Thanks to resonant effects aircraft RCS is generally much higher in this frequency range (this is especially true of VLO designs) which means detection performance won't suffer anywhere near as badly as it otherwise would.
Its UHF band radar (the others are either L or S band) does have certain benefits though which can be expected to mitigate the antenna gain disadvantage to a large extent. Thanks to resonant effects aircraft RCS is generally much higher in this frequency range (this is especially true of VLO designs) which means detection performance won't suffer anywhere near as badly as it otherwise would.
Brumby
Major
No doubt endurance and ceiling is a function of platform. The E-2 is a carrier based platform and none of the others are and so any direct comparison is misleading. For example, the E-2D has a stated endurance of 4 hours and on station time of 2 and a half. With refuel it is seven and five respectively. In comparison a land based platform will typically have 10. However if you vector a land based platform 2000 kms out to sea, there will be no on station time left if you account for the return trip. It is this reason why China is developing a carrier based version.
Most importantly all modern day platforms is about enhancing situational awareness through better battlespace management and engagement through fused data and networking using virtual models. The E-2D is the central node in the USN CEC architecture where it fuses information from the entire echo system such as AB's, F-35Cs, F-18s, Growlers et al through its TTNT network. There is no comparable system of such a scale and technologically developed that is out there.
You challenged the statement that an E-2D is less capable than other platforms, and that a direct comparison is misleading.
However, from a real-life operational perspective, an E-2D will be expected to challenge opposing land-based AWACs aircraft.
So a direct comparison between AWACs platforms is completely relevant.
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And why are you invoking a strawman argument against land-based AWACs having to operate 2000km from an airbase?
Your own operating figures have the E-2D at a radius of 500km from the carrier, even with refueling.
In a competition between AWACs aircraft, range does matter.
Brumby
Major
The primary function of the E-2 is to be the eyes and ears of the CBG and specifically to be the central node for CEC. It's main function is not to challenge other AWACS - that is a silly argument to be making. All AWACS principally are to provide situational awareness of an assigned area of operation. The CBG's main domain is at sea. A land based AWAC if assigned to provide situation awareness against a CBG's sphere of operation has to operate at distance from land and hence station time becomes an important consideration and limiting factor. Land based is fixed but a carrier platform is mobile. It is therefore not a straight forward comparison just on raw endurance number but on station time becomes an important operation metrics in any given scenario.
Strawman argument is so often invoked but seldom understood as in your case. Calling it a strawman doesn't make it so because you say so. What I have done is to point out the issue of equivocation between two different platforms that are primarily affected because their base of operation is fixed vs mobile. In simple layman terms, it is an apples and oranges comparison. Carrier platform rightly so is endurance limited because it is operating from limited space. However this drawback is offset by the fact that it is able to operate near from its base of operation since its base is mobile. Ultimately it boils down to on station time. Land based platform has the inverse matrix.
You have a habit of stating things I said which I did not. This is another example. When did I ever quote a 500 km operating radius?
There are a bunch of operating metrics that matter and some of them are classified and so we don't have a way of comparing. I have pointed out on station time vs simply endurance.
Since I am at it, I will expand on the other known metrics. The other factor being quoted is operating ceiling. Whilst we know helicopter operating ceiling limitation makes them less than ideal for AEW, this issue is different to the platforms being discussed. The optimum ceiling for radar range for AEW is at 31,000 feet. Whilst some of the other land platforms can operate up to 40000 feet there is no material benefit from the standpoint of range detection. The E-2D is able to operate at 33000 feet and so is well withing radar optimum ceiling.
Finally, the single objective measure of performance that we can apply as a comparison is detection range. In this respect, the E-2D has a detection range in excess of 555 km (source: Air international May 2019 edition). None of the other platforms such as A-50, Wedgetail, E550A, and Erieye exceed 400 kms.
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There are flaws in your reasoning.
In a real-life scenario, the purpose of a CBG is to project power onto land, not to remain far out at sea.
That means opposing battle networks come into play, of which the respective AWACs platforms are a key element.
So that is why I say the AWACs are challenging each other.
And if a CBG remains safely in its domain (far out at sea) - it is of little use in the real world.
I agree time on station is very important, which further underlines the advantages of land-based AWACs and land-based tankers.
You can run the numbers yourself with notional operating locations in the Western Pacific, the Middle East or in Europe.
But in a high-end conflict, it is not feasible for carrier aircraft to operate next to their mobile airbase.
That places the carrier at high risk of being sunk.
So it forces carrier aircraft to operate much further away from the carrier, with the subsequent reduction in endurance and time on station.
Yes you did.
Below, you state a transit time of 45min and 60min respectively for an E-2. At cruising speed, that translates into a 500km operating radius.
It's not my fault you didn't realise what you've actually written