Just as another point of view,

I sometimes execute a run in and break at my home airfield as a nice way to end a sortie.
If I intend to do one, I always pre-brief ATC before the sortie and ask their permission.

I never break into the circuit if there are anymore than 2 other a/c in the cct.

Being ex-mil, I am tempted to use "Initials" and "On the break to roll/land" etc, but only I would know what they mean (unless there were anly other ex mil/current mil in the cct). My preferred "civvy phraseology" is:

"Long final, low approach to go around, request low level cct "

Verbose I know, but gives everyone else in the circuit the big picture. Air Traffic seem quite happy with this.

Although it is common sense, PPL's should be wary about run and breaks unless taught and demo'd. It is very easy to overcook it and stitch up others in the circuit by poor judgement. Watch that stalling speed too!

PS for those that know me, my home flying airfield is not Ice Station Zebra!!!! :rolleyes: :D

[ 06 August 2001: Message edited by: The Jaguar Fan Club ]

And as you are aware, a wing does not stall at a speed..........only an angle of attack.....which is almost certainly nothing like what you would expect during your completely unneccesary and pointless r&b manoevre in your Yak 50.

:eek: :eek: :eek: :eek: :eek:

Wow - I make that 4 years, 2 months, 28 days to respond -
good job Fast Erect is in a job that doesn't need swift
reaction times, eh?

I knew I had registered with pprune before 2003 :suspect:

.....post on page one by myself says I havent registered yet :confused:

Regards, SD..

Fast Erect

As you are aware, the IAS at which an aerofoil stalls varies with angle of attack and G so therefore a caution for PPLs who are taught "stalling speeds" and maybe want to "try out" a VRIAB is justified in my opinion. However as I said before, I recommend that pilots do not attempt a VRIAB unless correctly taught and demo'd.

Not really pointless as it was good to maintain currency between leaving the military and now routinely operating formations around the bazaars. :}

I have never flown a Yak 50...maybe a little more research and mature conversation is in order before you wade in with your big w*nky boots?

That doesn't read quit right. For a given wing there is only one critical angle of attack regardless of weight, G, etc (ignoring flaps and wor not). You seem to be implying that at another AoA, if you keep the speed up you won't stall.

Not quite.....I refer to Accelerated or "G" Stalls and I quote:

"This is a condition where the wing cannot produce enough lift to support the aircraft's weight and centrifugal force, in spite of otherwise flying at a reasonable airspeed and angle of attack. This can occur when an aircraft is in a tight turn, a high-G pull-up, or other manoeuvre where directions is changed with a significant amount of acceleration. This additional acceleration results in a high force that must be borne by the wings. In recent years there have been a number of accidents arising from Accelerated stalls in high-performance aircraft (e.g. the Jet Provost) that have been sold into the civilian sector from the military. Turbulence can cause an accelerated stall if the aircraft is flying below Vno (maximum structural cruising speed. If flying above Vno, turbulence can cause structural failure."

:ok:

Hi TJFC,
I suspect I've gawn off on one and that we agree. It is just the "and" bit I have issue with in that Wikipedia explanation you quoted. Ignoring the misleading bit about a stall being lift unable to support weight, you will never ever never stall at a "reasonable" angle of attack (where reasonable<crit alpha). An accelerated stall is merely the need for you to increase AoA past critical alpha to cope with the increased demands on the wing due to G/weight/etc.

:8 :O

TJFC,

I hardly think a Jet Provost is a high performance aeroplane. Get a grip boy and leave the military tosh behind

:E

High performance is a relative term.

In the world of SEP, a JP is a high performance aircraft - think C150 or Cherokee as the reference point.

If you want to play being an FJ pilot then join the RAF or if ex RAF then leave it all behind. A civilian airfield, unless covered by radar and empty airspace, is no place for military type games.

HWD

I used that Wikipedia explanation to try and keep things simple but obviously that was the wrong thing to do. In an accelerated stall it is the wing loading and NOT the AoA that is critical. With the same angle of attack, the airspeed at which the stall occurs will be increased by the square root of the G. therefore at "high" g, the aerofoil will stall at a higher IAS and lower AoA than a "standard" stall.

Fast erect
Define "performance" aeroplane...The JP was selected by the RAF for its "performance". Over 300kts, +6.5g, pressurised with a service ceiling of over 36000ft (on the mk 5 obviously) and fully aerobatic seems perfectly within the bracket of performance to me. :rolleyes:

Working Hard
The majority of those undertaking "war games" do so for the preserve of our military aviation history and are properly trained to do so with adequate agreements in place at home airfields to take account of the differences. What radar has to do with it I'm not sure...:suspect: With your kind of attitude we would have none of these vintage types flying at all and Duxford would be another field full of "spamcans" or houses! :*

I really truely didn't realise that :uhoh: Why would the air seperate from the wing if the relative wind was below crit alpha? :confused:

Have we not been here and done that?

http://www.pprune.org/forums/showthr...Run+and+breaks

Love

F.

HWD

Think outside of the box...

In a standard stall, when the critical alpha is reached or exceeded, the relative airflow around the aerofoil is disturbed and lift is reduced.

An accelerated stall is not the same as a "Standard" stall. The problem is that the increased wing loading means that the aerofoil is not producing enough lift to oppose the effect of gravity or "g". This is why there is a relationship between IAS and G. The higher the g, the more airspeed you need to generate more lift to counteract the wing loading. Think of it as a "heavy" aircraft. You would need a faster Vr to get airborne at heavy weight than at light weight because the wing needs to produce more lift to overcome weight/gravity.

Hope that is a bit clearer...

Hi again TJFC,
Ordinarily I would, but it is raining quite hard you know.
Sorry to drag this out :O Yes, I consider that obvious to any pilot and isn't quite the issue I have.
I suspected this was a mis-understanding due to terminology.

My use of the term "accelerated stall" implies that the wing did stall, that seperation occurs, but at Vs * SQRT(G or difference in weight). Also, that this seperation only occurs at crit alpha. It is also very nasty stall because inevitibly it is effectively power on stall in a prop and hence a tip stall.

The Jaguar Fan Club - post deleted

alpha
 

TJFC

Whilst I agree with you over your use of R & Bs (I found them invaluable at maintaining currency with and practising for low-level aeros for display purposes - in the correct circumstances, naturally, before anyone jumps on that), I have to take issue with your comments re "accelerated stalls".

The wing will always stall at the same AofA, whatever the wing loading. After all, wing loading is only a function of lift. What you should be looking at, for your argument, is what happens when you increase the wing loading at a given airspeed. The only way to do this is to increase the alpha and hence the lift. When the alpha reaches critical, then the wing will stall. As an aside, on conventional SEP etc, AofA is proportional to elevator and hence stick position. Have a look at the stick position next time and see when the stall occurs for various 'g' loadings!

regards

TAC

RIAB's are a military technique used to recover jets on fuel minima efficiently and expeditiously whilst coping with formation aspects. Something I doubt very much that the likes of Fast Erect has ever had to cope with. By the sounds of it, the only fast thing about him/her is their username.

Why therefore start claiming they are about 'oneupmanship' etc, my dear freind you do make yourself sound like a prize @rse talking like that. If you cant cope with a bit of punchiness and finesse then I do really think you are in the wrong profession.

Let me guess, you prefer a radar - ILS with a couple of procedural holds for sh!ts and giggles, on standby instruments of course no doubt.

I really look forward to your reply as I expect it will be as pompous and as mundane as your previous posts, and allow me a few more giggles.

Yours

DS

Everyone can hide behind some fancy pseudonym on here and claim to be whatever.

Most professional jet pilots I have met though are nice and erudite happy to talk to non jet pilots in a professional manner taking into account the latter's lack of specific knowledge.

Yet to meet one that has to resort to the sort of language and attitude that some self proclaimed experts display on here.

As TheAerosCompany has already pointed out, TJFC's explanation of the accelerated stall is not what most people understand it to be.

RIABs at non military fields are an emotive subject due to the accident at North Weald a few years back.

It is therefore not surprising that some are anxious about this procedure; maybe especially if it is done by non(ex)military pilots.

And me :O

Dutch...

The North Weald accident was not caused by a RIAB. The radio transmissions may have been indicating that but that is not what the aircraft was doing.

m

Well, when teaching formation flying in our PA28s, we also teach breaking formation to join the circuit. No high energy manoeuvre this, it is simply a level turn from the deadside onto downwind with each aircraft in the echelon delaying the break from formation by the briefed interval.

The AoB and interval used for the break must be the same for all members of the formation; you can start with a gentle 30 deg turn at 5 sec spacing and, as experience is gained, tighten it up to about 45 deg and 3 sec.

There should be no need to use more than about 1.4 g to break a formation of light aeroplanes into the circuit.

Sorry HWD, and you!

Anyone got the link readily available on that North Weald accident so that we can reacquaint ourselves with the circumstances?

*takes deep breath*

Ok, a couple of points to put to bed.

My whole "argument" was based on the fact that an accelerated stall can take place at a higher IAS than a less experienced would expect due to the effects of G. Now that we have the correct definitions of the phenomenon (cheers TAC), I don't think anyone is in any doubt about what they are. I was trying to expand on the point first raised by HWD and I accept that my comment reagarding varied AoA was confusing and incorrect. However the whole conversation has raised the issue of linking IAS, wing loading and stalling amongst the GA commuity here, which can only be a good thing. Indeed in an article about stalling, Brian Lecomber describes the classic stall accident as "...a slightly accelerated stall, the aircraft weighing more under G..."

Secondly, WorkingHard it is clear from your posts that you enjoy being antagonistic and are yourself not immune from throwing insults. My comment was rather in the heat of the moment at your whole attitude and nothing whatsoever to do with being "unstable". As a result it has now been retracted from my post. I am sure SRG medical division would welcome your comments if you are concerned about a licensed person's mental state. :rolleyes:

Flyin'Dutch' - Quite a sweeping statement regarding "self proclaimed experts" and attitudes on PPRuNe. My comments were not intended to be elitist or patronising, and I apologise if that is how they came across. I have to say though that there are many aircrew, and other aviation "professionals" who DO conduct themselves in a petulant manner both on PPRuNe, and in person or the RT. It's not as rosey out there as one might think..just have a look on some of the other threads on here, and in CHIRP!

Anyway..hopefully we have all learned something...

regards
TJFC

What is a Run and Break?

Dutch,

http://www.aaib.dft.gov.uk/cms_resou...pdf_500463.pdf


Fly safe people.

F.

Quite right Jag fan type, WorkingHard should have worked harder at school, as a prowler around these parts for a number of years, he has shown himself to be totally anti military (check out his low flying posts) and to have several, rather well defined chips on his shoulder. Even though, I seem to recall that he claims to be ex militray himself. (Bluntie no boubt)

Ignore him, he will no doubt be getting all hot and bothered reading my post, trying to think of some (un)witty retort.

I am all ears

DS

The wing will stall at critical angle of attack. End of story.

Ta ta

Hi again TJFC,
Well yes, the discussion is with merit, as is any exchange leading to a clarificationand (just checkout the Carb Heat thread for a prime example :} ;))at least now I better appreciate that there maybe different definitions knocking about
:ok:

Well DS sorry to disappoint but I am not likely to get hot and bothered. TJFC very magnanimous and truly appreciated, my comments also retracted. I do have opinions as do all of us and I try and keep "personal" out of it. I am ex mil (very long time ago) and do not agree with low flying all over the UK and I have always made that clear. Similarly I have always made clear the blaming of everyone but the military for the woeful inadequacies of the equipment, the supply chain et al is also something with which I disagree. So DS there you have it, a candid history if it really intrigues you.
TJFC I referred earlier to radar from the perspective that this would better enable a complete vision of traffic in the area for your proposed re-join. I have never done it, don't want to and still think that it should be at places where traffic is very restricted or non existant. just my opinion.

IO540 wrotePut simply, a military manouevre to reduce the chances of being shot down whilst on a long straight final.

The pilot will fly at high speed along the runway, either from a low level approach or from a dive from the overhead, before breaking off into an abbreviated circuit of oval shape.

The idea is that a fast moving object is hard to hit, and once on the oval downwind/base/final is never in a straight line long enough to get a decent aim for any enemy fire.

There will be those that say this is too simplistic but there we go :rolleyes:

The high G part is where the pilot hauls back hard on the stick at the end of the initial high speed approach, in a steep climbing turn onto mid downwind.

"Put simply, a military manouevre to reduce the chances of being shot down whilst on a long straight final"

Funny enough it has an additional purpose these days in heavily impacted areas, noise abatement. A Fighter dragging it in from the initial all dirtied up makes a loud, long footprint. Coast in from the initial from a high altitude at fast speed and you reduce the number of times the duty officer has to pick up the noise abatement hot line.

Another very valid reason for a run and break which I haven't seen addressed here (if it has been, I missed that post) has to do with situational awareness in a formation. In a close formation, the lead pilot knows where the formation is in space and where the airfield and other traffic is, etc. The other pilots know where Lead is and that's about it. They may have periferal awareness of their location over the ground, but may not have total awareness of the active runway, where they are in relation to it as they approach, other aircraft in the circuit or approaching.

By leading the formation to disassemble via a run and break, Lead hands the pilots off to their own navigation from a known point - over the runway. They therefore know excatly where they are going to be when Lead calls for the break and they know what they need to do to get on the ground safely - because it's the same every time (left or right traffic not withstanding).

To try to break up a formation otherwise, especially if the flight doesn't go off exactly according to the brief, would probably require esoteric radio-hogging descriptions of angles and distances to the runway and a pretty loose and wooly seperation of the aircraft in the vicinity of the airfield. I was forced to do that at an airfield when someone not associated with the formation I was leading decided he knew our situation better than I and denied us a run and break. It took 10 minutes of maneuvering and radio calls to get the other guys to the airport and properly sequenced for landing. And then he bitched me out for all the chatter on the radio.

Having done it plenty of times both ways, I much prefer a run and break because I know where I'll be when I break from the formation. I've done the "seperation away from the field" bit and couldn't actually find the runway until I was on final behind the preceeding aircraft - not great for establishing complete awareness of the airport and other traffic.

Just another thread to this thread's bow!

Pitts2112

At risk of getting shot down in flames, I have seen both 'Run and Break' and the more standard 'civil' joining procedures. IMHO that neither is inherently more risky than the other. The key aspect in both situations is that everyone knows and plays by the rules. From a military perspective, there is no better way of expeditiously joining the cct, fitting into the pattern and then landing. It is safe, expeditious and minimises noise footprint.

Picking-up on the previous noise footprint point, I once saw a VC10 do a run and break at a particularly environmentally sensitive German airfield. Ordinarily, the Ten would have peaked the noise meters at about 95db when dragging itself along on a 3deg ILS; the run and break produced 82dbs.

Regarding the North Weald incident, I find it quite astounding that anyone can relate a properly performed run in and break with this mid-air.

Why is that then?

Frank, presumably because that's not what the Yak pilot did. The direct cause of the accident was neither pilot seeing the other until it was too late. The Yak pilot initially called visual on the Cessna, but lost sight of it not while performing a RIAB, but while he was doing whatever he was doing in the vicinity of his house at 100 feet. The AAIB report suggests that if the Yak pilot had done a standard RIAB in accordance with his intentions expressed on the radio, the Cessna pilot would have known where to look. The A/G operator would have also had a better idea of what was going on, which understanding may or may not have influenced subsequent matters, but the absence of which cannot have helped. And if the Yak pilot had not broken off from a standard RIAB to become involved with some very low-level flying unrelated flying in the vicinity of his house, and not explained by his RT calls, it is reasonable to assume that the Yak pilot could have maintained visual contact with the Cessna.

Quote: "The Yak pilot declared his intention to carry out a 'run and break' with a time frame of 'thirty
seconds to initial'. It was thus possible for others listening on the frequency to be aware of his
intended flight path, which was to descend and make a right turn in order to align his aircraft with
the runway before carrying out the run down the runway and then break right to join the circuit
downwind. By making the left turn and descending to such a low height, he deviated from that
flight path and placed his aircraft in a position relative to the Cessna, which was not expected by
the Cessna pilot or by the radio operator."

I have to say, even though I know roughly what a R'n'B is, I wouldn't actually have a clue where I should be looking! Would he be high, low, infront, behind, straight, turning??

You most certainly wouldn't be looking at a right base position for an aircraft that has just flown the wrong way up the base leg after performing a low pass.