Nasty habit of F16 A blk10

[s_ellebaut]

Your first post says "short wings", but as you yourself state afterwards, the later blocks got an upgrade in larger horizontal stabs (and bigger inlet from some point on), not the wings.
Also, the video you show is indeed of Dutch MLU (block 15 upgraded, sometimes referred to as block20). So not block 10 as you state in your first message.
Other then that, the flypast is not super low and/or super slow. It's a norma low level flyby for an event. The "waggling" you see is not because of unstable behaviour at low altitudes and low speed, its constant throttle+stick input from the pilots to correct positions in relation to his reference point in the large formation. Try flying formation with 1 steady airplane and note how many inputs you are doing to keep a steady position. Then try to imagine your reference point - the 1 previously steady aircraft - is now also correcting for that ones reference point. Now multiply that to a formation of 4 or larger aircraft in close formation. Then you get that video. Nothing wrong with it, nothing related to older blocks, or altitude, or speed IMHO.

It is known fact that an short span wings ( F-104 ) have trouble flying at slow speed because lift is obtain at high AoA . The video I show is an example of how "stable" is F16 and it has an higher speed.Later blocks got an upgrade in larger horizontal stabs so FLCS is more tuned up to them.You are right about speed in video , throttle adjustment .

I know short wings have low speed issues. But that has nothing to do with it in the video you posted. Also, you first talk about small wing on block 10 and later you change to small horizontal stabs pre block15. That's another thing completely.

You posted the video also to make your point about the unstable flying as you literally say "still it is not a very smote fly. Up and down cycle is present,not to mention lateral adjustments to fly in formation"; which again has nothing to do with the small wingspan but purely intentional corrections done by the pilot to keep close formation while remaining safe

[basher54321]

From Wikipedia :" Block 15 was the first major change to the F-16 with larger horizontal stabilizers. The FLCC began as an analog system on the A/B variants, but has been supplanted by a digital computer system beginning with the F-16C/D Block 40"- so it is another thing I guess FLCS it is more tuned up, as digital computer system, don't you?

Even though you have quoted from Wikipedia it is correct (for once) that the Digital FLCS came in at Block 40 and the Block 15 was the first production block with larger horizontal tails. That is the very reason I asked you in my very first reply (see above) if you were referring to the Horizontal stabilizers / horizontal tail (also known as Elevons) - because they are one of the major differences on the original Blocks 1-10.

[basher54321]

It is known fact that an short span wings ( F-104 ) have trouble flying at slow speed because lift is obtain at high AoA . The video I show is an example of how "stable" is F16 and it has an higher speed.Later blocks got an upgrade in larger horizontal stabs so FLCS is more tuned up to them. You are right about speed in video , throttle adjustment .

An ex F-104 pilot on here would likely disagree because in reality the F-104 had good slow speed handling. The issues at High AoA were nothing to do with having "short wings".

One reason the bigger Horizontal stabs were put on the F-16 were for the known Deep Stall issue - although it appears there was a bit more slow speed authority gained as a result.

[sima]

Your first post says "short wings", but as you yourself state afterwards, the later blocks got an upgrade in larger horizontal stabs (and bigger inlet from some point on), not the wings.
Also, the video you show is indeed of Dutch MLU (block 15 upgraded, sometimes referred to as block20). So not block 10 as you state in your first message.
Other then that, the flypast is not super low and/or super slow. It's a norma low level flyby for an event. The "waggling" you see is not because of unstable behaviour at low altitudes and low speed, its constant throttle+stick input from the pilots to correct positions in relation to his reference point in the large formation. Try flying formation with 1 steady airplane and note how many inputs you are doing to keep a steady position. Then try to imagine your reference point - the 1 previously steady aircraft - is now also correcting for that ones reference point. Now multiply that to a formation of 4 or larger aircraft in close formation. Then you get that video. Nothing wrong with it, nothing related to older blocks, or altitude, or speed IMHO.

It is known fact that an short span wings ( F-104 ) have trouble flying at slow speed because lift is obtain at high AoA . The video I show is an example of how "stable" is F16 and it has an higher speed.Later blocks got an upgrade in larger horizontal stabs so FLCS is more tuned up to them.You are right about speed in video , throttle adjustment .

I know short wings have low speed issues. But that has nothing to do with it in the video you posted. Also, you first talk about small wing on block 10 and later you change to small horizontal stabs pre block15. That's another thing completely.

You posted the video also to make your point about the unstable flying as you literally say "still it is not a very smote fly. Up and down cycle is present,not to mention lateral adjustments to fly in formation"; which again has nothing to do with the small wingspan but purely intentional corrections done by the pilot to keep close formation while remaining safe

I want to tell THAT: only because large stab is installed on block 15 and next blocks must been done changes in FLCS and smoother fly is obtain at low speed/and low alt. versus early blocks. also analog versus digital computer system .Never seed wing span varied.Title speak for what i ask: nasty habit of F16 A blk10 low and slow .Anybody ?

[basher54321]

I want to tell THAT: only because large stab is installed on block 15 and next blocks must been done changes in FLCS and smoother fly is obtain at low speed/and low alt. versus early blocks. also analog versus digital computer system .Never seed wing span varied.Title speak for what i ask: nasty habit of F16 A blk10 low and slow .Anybody ?

Might be getting somewhere now. So basically you want to know if there were any analog FLCS changes with the move to the bigger horizontal stabs/Elevon, and if so were there significant changes to slow speed and low altitude handling?

You also want to know if the Digital FLCS that came in at Block 40 also changed slow/low speed handling over the analog FLCS ?

[sima]

I want to tell THAT: only because large stab is installed on block 15 and next blocks must been done changes in FLCS and smoother fly is obtain at low speed/and low alt. versus early blocks. also analog versus digital computer system .Never seed wing span varied.Title speak for what i ask: nasty habit of F16 A blk10 low and slow .Anybody ?

Might be getting somewhere now. So basically you want to know if there were any analog FLCS changes with the move to the bigger horizontal stabs/Elevon, and if so were there significant changes to slow speed and low altitude handling?

You also want to know if the Digital FLCS that came in at Block 40 also changed slow/low speed handling over the analog FLCS ?

YES,it is done some changes in response /rate time and displacement of flight control ?How was handling before that changes?Not so prompt , and over responsive i guess

[mor10]

When the Block 10 first came out it had the smaller tail. Block 15 introduced the larger tail, by about 30%. Most users would have replaced the small tails on the block 10 as soon as they could. IIRC from conversation here, the larger tail was needed to get more flexibility with CG and having to move fuel around to maintain better control and better ability to recover from a deep stall.

F-16A/B did have analog flight control system, but the mid life update (MLU) brought the digital system.

[s_ellebaut]

F-16A/B did have analog flight control system, but the mid life update (MLU) brought the digital system.

Not entirely true IIRC. In BAF MLU's for example the flight controls panel is still analog version.

[sima]

F-16A/B did have analog flight control system, but the mid life update (MLU) brought the digital system.

Not entirely true IIRC. In BAF MLU's for example the flight controls panel is still analog version.

Not my question

[johnwill]

The only FLCS changes made specifically for the big tail on Block 15 was to reduce the tail deflections by the same ratio as the tail area increase. That way, structural loads and maneuver effects would be the same as the small tail normal airspeeds. At lower speeds the increased tail area greatly improved handling qualities. At about the same time, FLCS changes were made to help avoid getting into deep stalls (Cat 1/3) and to recover (pitch rocking) from them.

In the video, those are big tail airplanes, no matter the block number.

I don't believe any analog airplanes were ever converted to digital controls. The first digital airplanes were Block 40, as already stated. The original digital control laws were identical to the latest (Block 30?) analog control laws. USAF insisted there be no changes at that time, so they could identify any flying quality changes as being due to switching from analog to digital computers, not control law changes. I don't have any knowledge about more recent control law changes, but I suspect there have been some.

[mor10]

The only FLCS changes made specifically for the big tail on Block 15 was to reduce the tail deflections by the same ratio as the tail area increase. That way, structural loads and maneuver effects would be the same as the small tail normal airspeeds. At lower speeds the increased tail area greatly improved handling qualities. At about the same time, FLCS changes were made to help avoid getting into deep stalls (Cat 1/3) and to recover (pitch rocking) from them.

In the video, those are big tail airplanes, no matter the block number.

I don't believe any analog airplanes were ever converted to digital controls. The first digital airplanes were Block 40, as already stated. The original digital control laws were identical to the latest (Block 30?) analog control laws. USAF insisted there be no changes at that time, so they could identify any flying quality changes as being due to switching from analog to digital computers, not control law changes. I don't have any knowledge about more recent control law changes, but I suspect there have been some.

I was no longer there when MLU took place on the Norwegian jets, but I was told that the fight control system had been updated. I will try to have this confirmed by some that was there at the time.

I stand corrected. Norway's F-16A/B MLU still have the analog flight control system. That means that my rusty flight control system skills only needs refreshing to work on it...

[sima]

The only FLCS changes made specifically for the big tail on Block 15 was to reduce the tail deflections by the same ratio as the tail area increase. That way, structural loads and maneuver effects would be the same as the small tail normal airspeeds. At lower speeds the increased tail area greatly improved handling qualities. At about the same time, FLCS changes were made to help avoid getting into deep stalls (Cat 1/3) and to recover (pitch rocking) from them.

In the video, those are big tail airplanes, no matter the block number.

I don't believe any analog airplanes were ever converted to digital controls. The first digital airplanes were Block 40, as already stated. The original digital control laws were identical to the latest (Block 30?) analog control laws. USAF insisted there be no changes at that time, so they could identify any flying quality changes as being due to switching from analog to digital computers, not control law changes. I don't have any knowledge about more recent control law changes, but I suspect there have been some.

Thank you.

[s_ellebaut]

F-16A/B did have analog flight control system, but the mid life update (MLU) brought the digital system.

Not entirely true IIRC. In BAF MLU's for example the flight controls panel is still analog version.

Not my question

Well excuse me your majesty. Didn't realise you had the sole dictatorship of this thread and I wasn't allowed to express a possible error in a reply given by a fellow forum user.

[sima]

You are excused . Serious now i put a simple question
and nobody give me a straight answer .Old hands on this forum are encounter SITUATIONS in respect with my thread when they flu F16 A blk10.

[krorvik]

If you expect all answers to directly answer your Q, also expect the quality of the final conclusion to diminish.

Often, the right path has necessary detours.