Safe seperation at Mach 2

[mickjoebill]

What is a safe minimum distance between aircraft travelling at M2.0?
If one arcraft manoverers around another (for say a phot shoot) is their much turbulence?

Are stick inputs speed sensitive? Is making height adjustments of say 50 feet, difficult at Mach 2?


Mickjoebill

[Spot 4]

Well your never going to get to mach 2 in your Cessna now are you, and in any case learn the differance between their and there before dreaming.

Puddlejumpers........

[mickjoebill]

"Well your never going to get to mach 2 in your Cessna now are you, and in any case learn the differance between their and there before dreaming."


A rude, uninformative answer with as many spelling mistakes as my post!

But do you know the answer to the question?

Dreaming? no, planning.

Some forum!


Mickjoebill

[Always_broken_in_wilts]

Go on then...............I know I should'nt.........but planning what:p

all spelling mistakes are "df" alcohol induced

PS.........I think what spot 4 was trying to say was if you don't know the answer then the chaces are you aint never going to need to know the answer................unless of course you have sh@t loads of wonga and are about to pay for a "real quick" trip............however if this is the case i doubt the instructor will let you "pole" at those speeds as he pobably reads these forums and will already have your number:ok:

[reynoldsno1]

Mach number technique for longitudinal aircraft separation is often used by ATC and can be based on time (usually 10 minutes reducing to 5 if the preceding aircraft is M0.06 faster then the following aircraft), or if using RNAV, distance, usually 80NM, but can reduce to 50NM (RNP10) or 30NM with RNP4 + ADS...

I am not an ATC'er, so don't ask me any more...

[mickjoebill]

Thanks! I'm planning a air to air photo shoot using military aircraft. 2000 to 3000 feet seperation is about the (photographic) limit for this particular assignment.

Remaining Mach 2 questions
Safe minimum distance in regard to flying through other aircrafts wake.
Ability to control height within 50-100 feet?
Other factors in loose formation flying at Mach 2?
A reduction in speed to Mach1 make us safer or get us closer?
Anyone flown through a Mach2 wake at close quarters? Common event?

I'm a pro director of photography... wouldn't be much of a pro pilot asking these questions:)

My ppl? did that for a bet.


Mickjoebill

[Spot 4]

I did a visit to Eastern Radar in the late eighties: An F1-11 doing a `High speed run` up the North Sea got his own individual radar controller and it was all over in a few seconds (East Anglia to Scotland that is). At that speed once you have focused your camera the aircraft will be fuel priority and running for home. I would expect the min separation at that speed to be considerable. Not many mach 2 folks hereabouts, but you may get your answer.

[Chris Kebab]

I may be missing something here but what is the difference in a photo of an aircraft doing Mach 2 and one doing 250 kts? Assuming of course you are not simply filming the Mach meter.

Have you tried talking to the guys who will be actually flying these Mach 2 wonderbirds. What aircraft type is it?


As I said, your "assignment" and the need for speed has lost me a bit!

[whowhenwhy]

2000' up to FL450, 4000' above (not that we have anything that can get above FL450 and not stall-there's a challenge!) and 5nms. Course if we try to get 5 nms then we'll either end up with 50 or a bit of a mess! Happy snapping!:ok:

[mickjoebill]

So in irregular operations such as a air to air shoot can one get closer than 5 miles?
There are good answers to your queries regarding why at Mach2 (Mach 1 may be workable) and why I'm asking it in a public forum. Politics and time constraits come into it.

Anyone with experience flying close and supersonic? Better still anyone been involved in a supersonic air to air photoshoot?

Putting aviation law aside I'm looking for sound reasons why I can't get 2000 feet from an aircraft at Mach 1 to 2. OK, it is a tall order...but is it possible with saftey?
Understand limited endurance.
Altidude would be above 40000 feet.

Mickjoebill

[BOAC]

MJB - never done formation at Mach 2 (the Lightning did not have enough fuel to get two aircraft close enough for that :O ) but I have at M1.3 and we gave it a wide berth just in case. I've experienced M1+ shockwaves and they bounce! I certainly would not go back past about 60 deg swept. It use to be reckoned that a supersonic fighter flying over a heli would remove the rotors! I would think, though, that 2000ft abreast would be ok at say M1.3, but not much fine manouevre left. M1.3 should cope at 40k+ a bit. I seem to remember (long time ago) IAS around 230-240kts at 40k and M1.3??

Hopefully a mil 'up-to-date' will help you, but I'm with Chris Kebab - WHY M2? Who on earth is going to know it wasn't 300kts? Unless of course you are after some sort of shockwave effect and I'm sure you'll be disappointed and out of pocket! If it is the high-altitude you are after, I suggest you use a computer :eek:

For info, the shockwave angle sharpens to become more of a cone as M increases, starting at almost 90deg at M1.0, so there should be little interference at a reasonable range, but as for 50-100 ft tweaks - I doubt it! Without going into complex flight 'bits', you have lowish control powers due to lowish IAS but high inertia due to high TAS, eventually getting to M20+ in orbit with ZERO control power!

Try writing to BAE or the Mil research places- they have done similar for supersonic weapons release trials. Whether they will tell you............. Post this whole thread on the Flight Test forum??


On second thoughts - on behalf of the forum mods - please do NOT duplicate this post on FTF. Best to post a brief link to this thread in FTF. If you cannot do that, or want the whole thread moved, let me know by Private Message

[Ghostflyer]

Just read BOAC's answer, if I'd done it before I'd started writing this I wouldn't have bothered, but might as well leave it now....

I wouldn't worry about the shock waves, they end up behind you, you are on the point !!

As to separation for filming, at high altitude we have bigger separation rools coz the jets don't have as much manoeuvre potential (higher inertia) available and even a slight heading / altitude changes by a fast mover make it hard for the other guy to get out of the way. You end up looking like a startled rabbit but with 40 miles/minute closure head on!

As to formation, a decent flight control system makes allowances for speed/mach and reduces sensitivity as required. Generally the snag is modulating power smoothly. 1% nozzle at 1300kts provides a lot more power differential than at 200kts. I have tried loose formation well supersonic and that isn't too much of a snag. Passing profiles aren't too bad on targets either, the snag is that inertia rools when you start to break away and a flight path change takes a longer than normal. Most AD pilots have seen the bottom of another aircraft getting rapidly closer as the other guy begins his break away.

Hope that helps a bit,

Ghost

[Fox_4]

M2.0 formation photo shoot is pretty unlikey now unless you can hire a couple of concordes. Recently did a loose formation M2.0 run about 1nm sep. Photo wouldnt look that different to a much slower speed though since we were up above 40k. Contrails looked very cool though.

Would be better getting some sort of low level M1+ run I would think. Get a sense of speed from the ground rush.

Formation supersonic is not a problem. Initial buffet going trans sonic but as long as you have power available to modulate and hold position you could almost be going any speed.

Its not a magic barrier! Thought that myth vanished when Chuck Yeager did his stuff.

If you are running 2 fast jets for the shoot then all this talk of minimum seperation does not apply. Get in close on the wing, hang out loose (couple of hundred feet) or go out to a mile or two. You drive the shoot, pilots drive the platforms to get the shots. We dont mind doing it either as long as we get a copy.

Wouldnt recommend flying thru jet wash as a habit anyway but most probably you will feel loads of turbulence, you may get uncommanded roll, pitch or yaw moments, worst case flame out an engine! As for how close you could get, check out the reds and that might answer your question.

Lots of hilarious (not) answers to a genuine question in the last few posts. I thought people on this forum might have been a bit more welcoming to someone who may never get thru the mach. Bit like a harrier mate huh :ok:

Best of luck with the shoot

[mickjoebill]

"I wouldn't worry about the shock waves, they end up behind you, you are on the point !!"

Thanks Ghost Flyer,
I was wondering about turbulence if we slowly manouvered into the other guys shock wave.
Since the camera wil be hand held could one expect severe turbulence that would turn the backseat into a blender? Camera weight would be in the range of 4 to 8 kilos.


"As to formation, a decent flight control system makes allowances for speed/mach and reduces sensitivity as required. Generally the snag is modulating power smoothly. 1% nozzle at 1300kts provides a lot more power differential than at 200kts."

So is it a fiddle to match speed of the aircraft we are shooting? Camera ship is different aircraft type to subject aircraft. Subject aircraft is mostly sticking to a flight plan.


"I have tried loose formation well supersonic and that isn't too much of a snag."

Good to hear. How loose? less than 2000 feet?

"the snag is that inertia rools when you start to break away and a flight path change takes a longer than normal. Most AD pilots have seen the bottom of another aircraft getting rapidly closer as the other guy begins his break away."

Ok. Dynamic breakaways will be at the bottom of the wish list.


"Hope that helps a bit"

Very constructive thank you.


Mickjoebill

[DamienB]

mickjoebill - after 'last chance' air to airs of Concorde doing her stuff over the Bay of Biscay next Wednesday are we? Which French fighter jock have you bribed to do the intercept? ;)

[mickjoebill]

Concorde?

More chance of an air to air shoot with Air Force One :)


Mickjoebill

[DamienB]

Well that's you on the MI6 monitoring list for putting 'shoot' and 'Air force one' in the same sentence.

Oh... ******.

[BEagle]

Black Omegas heading your way, Damien??

[Flap62]

You do have to wonder why someone with the "clout" to get a photo shoot of 2 dis-similar types in formation at M2+ at 40K+ is asking how to do it on this forum !!

If it's for real why not give more details?

If it's for real why not ask the pilots that are going to be doing it?

If it's for real then the group staffs (or their equivalent) will give guidance - probably using advice from ETPS/OEU or equivalent.

I have to side with the first reply to this thread. If we want to have a discussion about formation at high mach, fine. What we don't need is someone with a camera bag, scanner and Iron Maiden t-shirt using this forum as a break from dungeons and dragons.

Edited for tooping

[Training Risky]

Air Force 1... shoot..... bomb-making..... Pakistan.... Al-Qaeda..... London...... State Visit..... Anarchy.....

That's my career fu**ed then!;)

[mickjoebill]

Since a +Mach 1 air to air film shoot is a unusual practice getting advice from a wide range of sources as quickly as possible is prudent.

There could be a seemingly minor point from a pilots perspective, that completely screws the shoot. No point finding that out weeks down the line.

We don't have weeks anyway.

The more perspectives the better.

Do you wear the Iron Maiden T shirt over the G suite:)


Mickjoebill

[LOMCEVAK]

mickjoebill,

You are being very candid about aircraft types. OK, I accept commercial sensitivity is possibly an issue for you (or is it being flown not quite in accordance with someone's rules?!) but if you want advice you are going to have to be up front!

One word of caution. If the 2 aircraft inadvertently get too close and you get shockwave interaction, there is a possibility that the aerodynamic moments produced on one or both of the aircraft, probably in roll but possibly in pitch or yaw, may exceed the contol authority available and thus the motion may not be controllable; a collision could result.

Good luck - I hope that you will post the pictures here after the event!

[BEagle]

From my limited supersonic time on the Gnat, Hunter, F4 (and b£oody nearly so in a Vulcan......oops!), I'd say that unless you've got a very capable flight control system, the stick deflexion required and high inertia in all planes will make close formation quite difficult at high IMN.

Please explain what you're trying to photograph - and why on Earth you want to do it at M2?

Unless it's some form of high speed cruise missile or something weird from Area 51..


Oh No - Echelon's black Omegas outside. Wasn't me - the big boys did it....aargh latex gloves and vaseline.....!!

[coley chaos]

Forgive me for saying this on what seems to be an important topic, but didnt that lovely damsel Katie from Blue Peter go supersonic in an Tornado F3 together with an F3 tv/chase aircraft, they seemed to be in tight formation as the wing commander was explaining how she was going faster than the earths rotation.
Tight formation refers to the aircraft ! :O

[mickjoebill]

Someone mentioned Concorde. Not me..:)

I've heard..

Incredibly, no motion picture footage can be found recording what Concorde was designed to do fly on the edge of stratosphere. None exists in any of the major archives including BAE, BA, ITN ect.

Most air to air shots, are by learjet at well below 40k.

Photo shoot by Tornado in the 1980s. Beautiful (still) picture, black sky above slight curve of the earth. This is the shot that sums up what concorde was all about!

So why not shoot it now? Using latest High definition video from back seat we can shoot 30 frames per second (5.9mb per frame 6 million pixel) images. Suitable for large screen digital presentation in aerospace museums ect.

A few messages have been in the last 2 weeks with RAF chaps with important sounding titles who seem jolly keen in looking into the matter :)

PAX on board for the last flight around BoB is an issue. (although web rumor indicates a formation! of concs was photographed with pax)

2000 feet horizontal seperation gives us the shot. 1000 feet better.

Apparently Conc needs to go above Mach1 at +55k for tech reasons.

The background is the understandable commercial interest to retire Conc without anymore fan fair.

Most insiders say it is highly unlikely Conc will fly again after 26th Nov.

Reports state that BA gave the PM Concorde for £225k for 6 hour return trip to NY. On that basis we would need £100k of flight time.

Looking for experiences from as many sources as possible to avoid a silly fckup or getting airborne and getting nothing.

There has only been 28 days warning of Concordes last flight.



Mickjoebill

[mickjoebill]

Thanks for all your replies.

3nm is as close as we are allowed to go, not much good for what we want.

Just one political and PR opportunity left. Don't hold your breath.



Mickjoebill

[The Ripper]

BOAC,

You are correct about shock wave effects on helos. After the cease-fire was announced in Gulf War 1, the Iraqis were allowed to fly choppers for "humanitarian reasons".

When it became apparent that they were being used to squash the rebellion in and around Basra, and when requests to fire were denied by AWACS, some of us discovered that a "high speed VID" was as effective as any ordnance...

Until "they" figured out what was going on and set the floor at 10,000 feet.

Whatever.

[SpinSpinSugar]

Well, I believe the last one is now down in Filton.

So did you get your footage?

And who's back seat were you sat in with your camera?

Cheers,

SSS

[PA38]

"Air Force 1... shoot..... bomb-making..... Pakistan.... Al-Qaeda..... London...... State Visit..... Anarchy"

Have you ever heard of Echelon?? cos they know of you now:ok:

Oh ****** it... where can I buy a M82A1 Barrett bet that got bells ringing:D

[mickjoebill]

Best clearence we could get was 3nm.

Thanks for the responses, more bizzarre questions may follow so you haven't heard the last of me.... but after Dec 17th I will fall silent on the subject.





Mickjoebill

One thing for sure, here is only one pic of concorde at 55000 feet or so, taken in 1985 from a Tornado that managed 3 minutes at that height.

No motion pictures available of Concorde supersonic and high.

Next target Dec 17th 100- years of flight celebrations .
Ironic the celebrations are sponsored by BA and BAE non?

Dubious allies this time are The Sun, Daily Mirror and BBC.




Mickjoebill

[BOAC]

mjb - just one more question - how are you going to get the Wright 'Flyer' up to 55,000'?:p

[mickjoebill]

Just like the moon landing and George Ws visit to Bagdad, we'll do it in a studio:)

From the book of Silly rounded averages...
Wright Flyer to Concorde first flight average increase in max altitude 700 feet per year and average increase in max speed by 20 knots a year

Concorde to present day, average decrease in max altitude of 900 feet per year average decrease in max speed by 40 knots a year.

Pull up! Pull up! Pull up!


Mickjoebill