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Napisano: 01 Mar 2016 14:25
Norvezanin prica o svojim utiscima, to je ovaj lik [Link mogu videti samo ulogovani korisnici]
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Flying the F-35 – Experiences from the First Week
Citat:"I am left with many impressions after a handful of flights with the F-35 over Arizona. In this post, I will try to describe the feeling and perception I have developed flying the F-35 so far.
First things first; the aircraft is easy to handle on the ground. The brakes are direct and powerful yet predictable, and the nose wheel steering is precise. The steering has two «gears» making the process of maneuvering the aircraft in and out of its parking spot under the sun screens that the aircraft are parked under. I hardly noticed the cross winds when I took off for the first time. It was easy to put the nose of the aircraft where I wanted it when I raised it for takeoff. The aircraft was stable in the air from the second it lifted it off the ground, and requires no manual «trimming» on my part.
An odd experience I want to mention is the feeling of bringing up the landing gear. In the F-16 I really don’t notice it that much. In the F-35, however, there is no doubt that the wheels are being retracted. As my American buddy «Nails» said after his first trip: «It felt like someone hit the airplane with a hammer!» A solid and noticeable «CLUNK» tells you that the gear is up. It could possibly have something to do with the fact that the landing gear is quite huge.
With wheels up I quickly noticed another peculiarity with F-35; the aircraft has a kind of continuous quivering sensation. A kind of weak high-frequency tremor. A bit like the feeling you get standing on the top deck of an old car ferry where you can sense a weak vibration from the engine. This trembling is fairly constant until I begin maneuvering the aircraft more aggressively. That increases the force of the trembling until it is like driving a car on a graveled cottage road. This kind of trembling is often referred by the technical term «buffeting».
Buffeting can be a problem if it is too violent. In the T-38 training aircraft I once had an engine instrument (the tachometer) that was shaken out of the instrument panel. That is problematic. Vigorous shaking can also make it difficult to read the instruments in the cockpit, and thus prevent the pilot doing his job. In that case it becomes critical.
A more positive side to buffeting however is that it acts as feedback to the pilot. In modern fighters computers decide which control surfaces are to be moved and how much – «fly-by-wire». That means the pilot misses out on important feedback through the rudder pedals and control stick. How much I move them is not directly linked to what is actually happening with the control surfaces. The F/A-18, for example, moves the ailerons gradually in the opposite direction during heavy maneuvering, without me as a pilot really noticing. The aircraft is however still doing what I am asking it to do. Most Norwegian F-16s have little or no buffeting when maneuvering. That means that in the F-16 I have to use the instruments to get an impression of just much lift I am really demanding from the aircraft. I might be flying fast or slow – maybe dangerous slow – and the only hint I get comes from the gauges. In the F-35 I can physically feel whether I am operating the aircraft in its «good-zone» when maneuvering, or whether I am demanding too much from it and losing energy. I can also physically feel whether I am flying too fast or, worse, if I am flying dangerously slow in the landing pattern.
Critics have argued that the F-35 by definition is a slow aircraft, based on the balance between thrust from the engine and overall weight. However, when interviewed after my first flight, I said that I was impressed with the engine power of the aircraft. How can that be true? Am I bought and paid for by Lockheed Martin, or is it the Ministry of Defence that threatens government reprisals if I don’t provide «the official story»? I know that many have doubts regarding the F-35 when it comes to both maneuverability and engine power.
When I was a kid, my buddy Håkon and I would sometimes play «car trumps». The idea was to do to pull the card with the best car on it. The «best» car was usually the car with A) the most horsepower, or B) the greatest top speed (according to the card). My experience with aircraft so far is that the world is not black or white. «It depends» is an eternal mantra among pilots, and it is usually not easy to measure one system against another. Another point to consider is what data we are actually comparing. The F-16 manual for instance says that the aircraft is capable of going more than twice the speed of sound. I have flown more than 2,000 hours in the F-16 and have never been able to get the aircraft to go that fast. Is it not correct that the F-16 can achieve twice the speed of sound? Are we overstating the facts by claiming that this is the real performance of the aircraft?
I still claim that the F-35 is fast compared to the F-16, an aircraft I know well. Can this be explained as nothing but lies? I believe it can. The F-35 has a huge engine. Another important factor is that the F-35 has low aerodynamic drag, because it carries all the systems and weapons internally. The F-16 is fast and agile when clean, but external stores steals performance. It is never relevant to discuss the performance of a stripped F-16. Therefore, this is never as simple as discussing the ratio of thrust and weight alone.
In any case, technical discussions aside, I was impressed by how steep the F-35 climbed after I did a «touch-and-go» on my first flight. Without using afterburner, and with more fuel on board than the F-16 can carry, I accelerated the aircraft to 300 knots in a continuous climb. Acceleration only stopped when I lifted the nose to more than 25 degrees above the horizon. I do not think our F-16 could have kept up with me without the use of afterburner. I was also impressed with how quickly the F-35 accelerates in afterburner. On my fourth flight I took off using full afterburner. The plane became airborne at 180 knots. At that point I had to immediately bring the engine back to minimum afterburner to avoid overspeed of the landing gear before it was fully retracted (speed limit is 300 knots).
Another first impression is how stable the aircraft is when flying in close formation. I have flown a handful of different fighter aircraft, and I have never had an easier job of maintaining close formation with another aircraft. The F-35 feels stable and predictable when making minor adjustments – much the same feeling I have driving a large American SUV. Still, when I move the stick or the throttle, the handling is both quick and precise (A SUV with a V8 – at least!). Overall, flying the F-35 reminds me a bit of flying the F/A-18 Hornet, but with an important difference: It has been fitted with a turbo.
The final point that I want to mention in this post is the experience of sitting in the cockpit. After reading about poor cooling and high noise levels in the cockpit, I was of course curious. I was pleasantly surprised. The «office space» was cool and comfortable, but above all, I was surprised by how quiet it was compared to what I’m used to. Is comfort important in a fighter jet? I believe it is. Not only during long missions that can last up to 10 hours, but also in daily exercises. It is obvious that a noise-insulated cockpit reduces hearing loss for pilots over time. I would also argue that it improves flight safety because it makes it easier to hear what is being transmitted on the radio and because noise becomes tiresome with time.
I’m saving a little for a later. Just the landing pattern is worth a small post in itself!”
A ne znam gde da se nadju svi tekstovi( ako ih ima ?) . Ima stranica na Norveskom odakle sam citirao prvi tekst. ima tamo i ovo u fazonu onih busting myths ali samo na Norveskom [Link mogu videti samo ulogovani korisnici]
Dopuna: 01 Mar 2016 14:40
Evo ima i ovo, danas objavljeno. Poklapa se sa ovim sto su rekli Holandjani skoro o boljem ubrzanju i napadnim uglovima [Link mogu videti samo ulogovani korisnici]
The F-35 in a dogfight – what have I learned so far?
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Citat:So how does the F-35 behave in a dogfight? The offensive role feels somewhat different from what I am used to with the F-16. In the F-16, I had to be more patient than in the F-35, before pointing my nose at my opponent to employ weapons; pointing my nose and employing, before being safely established in the control position, would often lead to a role reversal, where the offensive became the defensive part.
The F-35 provides me as a pilot greater authority to point the nose of the airplane where I desire. (The F-35 is capable of significantly higher Angle of Attack (AOA) than the F-16. Angle of Attack describes the angle between the longitudinal axis of the plane – where nose is pointing – and where the aircraft is actually heading – the vector). This improved ability to point at my opponent enables me to deliver weapons earlier than I am used to with the F-16, it forces my opponent to react even more defensively, and it gives me the ability to reduce the airspeed quicker than in the F-16.
Update: Since I first wrote this post, I have flown additional sorties where I tried an even more aggressive approach to the control position – more aggressive than I thought possible. It worked just fine. The F-35 sticks on like glue, and it is very difficult for the defender to escape.
It may be difficult to understand why a fighter should be able to «brake» quickly. In the offensive role, this becomes important whenever I point my nose at an opponent who turns towards me. This results in a rapidly decreasing distance between our two airplanes. Being able to slow down quicker provides me the opportunity to maintain my nose pointed towards my opponent longer, thus allowing more opportunities to employ weapons, before the distance decreases so much that a role reversal takes place.
To sum it up, my experience so far is that the F-35 makes it easier for me to maintain the offensive role, and it provides me more opportunities to effectively employ weapons at my opponent.
In the defensive role the same characteristics are valuable. I can «whip» the airplane around in a reactive maneuver while slowing down. The F-35 can actually slow down quicker than you´d be able to emergency brake your car. This is important because my opponent has to react to me «stopping, or risk ending up in a role-reversal where he flies past me. (Same principle as many would have seen in Top Gun; «hit the brakes, and he’ll fly right by.» But me quoting Top Gun does not make the movie a documentary).
Defensive situations often result in high AOA and low airspeeds. At high AOA the F-16 reacts slowly when I move the stick sideways to roll the airplane. The best comparison I can think of is being at the helm of ship (without me really knowing what I am talking about – I’m not a sailor). Yet another quality of the F-35 becomes evident in this flight regime; using the rudder pedals I can command the nose of the airplane from side to side. The F-35 reacts quicker to my pedal inputs than the F-16 would at its maximum AOA (the F-16 would actually be out of control at this AOA). This gives me an alternate way of pointing the airplane where I need it to, in order to threaten an opponent. This «pedal turn» yields an impressive turn rate, even at low airspeeds. In a defensive situation, the «pedal turn» provides me the ability to rapidly neutralize a situation, or perhaps even reverse the roles entirely.
The overall experience of flying the F-35 in aerial combat is different from what I’m used to with the F-16. One obvious difference is that the F-35 shakes quite a bit at high g-loadings and at high angles of attack, while the F-16 hardly shakes at all. The professional terminology is «buffeting», which I also described in an earlier blog post (English version available). This buffeting serves as useful feedback, but it can also be a disadvantage. Because the buffeting only begins at moderate angles of attack, it provides me an intuitive feel for how much I am demanding from the aircraft; what is happening to my overall energy state? On the other hand, several pilots have had trouble reading the information which is displayed on the helmet visor, due to the buffeting. Most of the pilots here at Luke fly with the second-generation helmet. I fly with the third-generation helmet, and I have not found this to be a real issue.
What I initially found to a bit negative in visual combat was the cockpit view, which wasn’t as good as in the F-16. The cockpit view from the F-16 was good – better than in any other fighter I have flown. I could turn around and look at the opposite wingtip; turn to the right, look over the «back» of the airplane and see the left wingtip. That´s not quite possible in the F-35, because the headrest blocks some of the view. Therefore, I was a bit frustrated during my first few BFM-sorties. However, It turned out that practice was all it took to improve the situation. Now I compensate by moving forward in the seat and leaning slightly sideways, before turning my head and looking backwards. In this way I can look around the sides of the seat. I also use my hands to brace against the cockpit glass and the canopy frame. With regards to cockpit view alone, I had an advantage in the F-16, but I am still able to maintain visual contact with my opponent during aggressive maneuvering in the F-35. The cockpit view is not a limitation with regards to being effective in visual combat, and it would be a misunderstanding to present this as a genuine problem with the F-35.
On the positive side I would like to highlight how the F-35 feels in the air. I am impressed with the stability and predictability of the airplane. Particularly at high AOA and low airspeeds. It is a peculiar feeling to be flying the F-35 at high AOA. I can pull the nose up to where my feet «sit» on the horizon and still maintain level altitude. I’m also impressed by how quickly the F-35 accelerates when I reduce the AOA. High AOA produces lots of lift, but also tremendous induced drag. When I «break» the AOA, it is evident that the F-35 has a powerful engine. The F-35 also makes a particular sound at this point. When I quickly reduce the AOA – stick full forward – I can hear clearly, even inside the «cockpit» how the F-35 howls! It seems like the «howling» is a mix of airflow over the wings and a different kind of noise from the engine. Maybe this isn’t all that relevant, but I still think it´s a funny observation. Another aspect is the kind of reaction I get when I push the stick forward; the F-35 reacts immediately, and not delayed like the F-16. Looking at another F-35 doing such maneuvers is an impressive sight. The various control surfaces on the airplane are large, and they move very quickly. I can monitor these movements on the screens in my cockpit, and I´m fascinated by how the control surfaces move when I manipulate the stick and pedals. Especially at high AOA, it is not always intuitive what control surfaces move, and by how much.
The final «textbook» for how to best employ the F-35 in visual combat – BFM – is not written. It is literally being written by my neighbor, down here in Arizona! We have had many good discussions on this topic over the last few weeks, and it feels very rewarding to be part the development. I would emphasize the term “multirole” after experiencing this jet in many roles, and now also in a dogfight. The F-35 has a real bite! Those in doubt will be surprised when they finally meet this “bomber.”
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