Over flying at 500" AGL

[ozbendigo]

I fly a trike 45 - 50Knts cruise.

 

I understand the need for 500' AGL ciurcuits, even though in Bendigo that takes me over heavily tree areas for 3 legs (N, E & S) of my circuit. And if I am following a GA aircraft, that can be a fair way out from the strip - with no chance of a glide back.

 

My problem in understanding the new separation procedures is:

 

How far out from the airport (or circuit) do I let down to 500' AGL to be able to over fly at this height?

 

If I approach the airport from the west I have to fly over the city - technically the city boundary is on the airport boundary.

 

Cheers John

 

4.6.4 CAAP 166-1 effective 3/6/10

 

States " For low performance aircraft...it is recommended that the aircraft overfly midfield at 500' above aerodrome elevation" I read it as they don't want us to overflying at 2000' and conflict with higher and faster traffic.

 

They way I am interpreting this new procedure - is that I must arrive at the airport at 500' to overfly at 500' and then join the circuit at 500'

 

 

[Spin]

Do you not have any local procedures that address this issue? Sounds to me as though a 500' circuit conflicts with safe operations, especially if you are forced to fly a wider circuit so as not to cut off faster traffic flying at 1,000'.

 

 

[ozbendigo]

It has been suggested that I fly my circuits at 800 -1000', but this would seem to defeat the purpose. I try to restrict my circuit training to times when the strip is not so busy. Then I can fly quite tight, close circuits.

 

 

[facthunter]

Trike at Bendigo.

 

The way any 3D pictorial presentations show it, you would operate at 500' AGL and close in to the airport boundary. ( or perhaps even inside it). The other end of the spectrum operate at 1500' and a wider circuit. This tends to even out the considerable speed disparity. Bendigo is a problem vis-a-vis the built up areas around the airport boundaries. Under the new rules you have more options as to where you will join the circuit.

 

Re descending, don't descend onto other traffic (although you have good visability). Your biggest issue is having aircraft overhaul you on final. As you turn final (and a bit before) you should be aware of all the other traffic, as on FINAL is the only time that you are tracking in the same space as everybody else. This is the best I can come up with . Hope it helps. Nev

 

 

[ozbendigo]

NEV - The way I read the new joining procedures - is that I have to be at 500' AGL before I arrive at the airport and then over fly at 500' so that I don't conflict with other circuit traffic. This is impossible from the west because of the city and problematical from all other directions because of the bushland surrounding the airport.

 

If I fly closer circuits am I guilty of overtaking if I complete my circuit more quickly that other aircraft?

 

 

[JayKay]

Ozbendigo, as I understand it, you have to overfly the airfield 500 feet ABOVE the highest active circuit height (eg 1000 feet above ground level if it's only you in circuit, or 1500 feet above ground level if someone else is flying 1000 foot circuits, or 2000 feet above ground level if there is a 150+K aircraft in circuit at 1500 feet above ground level).

 

You then have to descend to your circuit height (500 feet) on the dead side if joining crosswind or descend to 500 feet when clear of other circuit traffic if joining on any other leg and you must enter the circuit AT YOUR CIRCUIT HEIGHT (ie not descend in circuit).

 

If this conflicts with other regs (eg overflying built up areas) then your circuit entry points become limited to those that are legal.

 

Remember that published local airport circuit rules generally take precedence over the general rules, so check out what the local rules are for your type of aircraft.

 

 

[alf jessup]

John,

 

I don't have the problem with trees like you do but most times i overfly at 1500 ft approaching from the dead side of the circut and call overhead xxxx joining midfield xwind and then decend down to 500 on a far tighter circut that the big boys, i am usaully at 500 by my mid downwind and well inside the ga circut within gliding distance of the chosen runway.

 

I spoke with a most of the operators out of my strip and they confirmed they were happy with that.

 

I guess you might want to talk to them about what you want to do, just remember our circuts are far tighter ie downwind and base leg compared to the faster boys and you can slide in infront of them most times if you let them know your intentions.

 

When i am joining a mid downwind circut i always make sure i am at 500ft before i pass their downwind track, but i dont have any trees to worry about.

 

I think approaching at 1500 from the dead side of the circut would be your best option as you can lose hight quite quickly in the trike once you have called overhead, just remember that the fast aircraft are doing their circuts at 1500 ie big twins and regionals.

 

Hope this helps.

 

Cheers

 

Alf

 

 

[ozbendigo]

JayKay - I wish there were some local rules!

 

4.6.4 CAAP 166-1 effective 3/6/10 States " For low performance aircraft...it is recommended that the aircraft overfly midfield at 500' above aerodrome elevation" they don't want us to overflying at 2000' They way I am interpreting it - is that I must arrive ar the airport at 500' to overfly at 500' and then join the cuircit at 500'

 

John

 

 

[ozbendigo]

Thanks Alf, I will talk to the other operators and see how they feel about me flying inside their circuits. I have basically been following the same entry procedures that you have and have become very familiar with them.

 

My concern is what I see as a major change for below 55knt aircraft in the new regs. that have just come into force on the 3/6/10

 

4.6.4 CAAP 166-1 effective 3/6/10 States " For low performance aircraft...it is recommended that the aircraft overfly midfield at 500' above aerodrome elevation" they don't want us to overflying at 2000' and conflict with higher and faster traffic.

 

They way I am interpreting it - is that I must arrive at the airport at 500' to overfly at 500' and then join the circuit at 500'

 

John

 

 

[alf jessup]

John,

 

My concern is that my main runway is 1527 meters long and i personally dont like joining a midfield at 500 (unless there is little traffic in the circut) as some high performance aircraft could possibly be passing through 500 ft at 750 meters down the runway.

 

Talk with the locals and see what they are happy with you doing as your safety is as much improtance as theirs, 500 ft over the trees doesnt sound safe to me if mr rotax decided to quit on you.

 

All us trikers here use much tighter circuts than the rest of them and everyone is happy about that.

 

Cheers

 

Alf

 

 

[ozbendigo]

Thanks Alf

 

I think the local discussion is a good idea - I will get onto it. Will call in and say hello next time I am in Sale

 

Cheers John

 

 

[Guest Crezzi]

Its not really a new requirement - blame the 2005 NAS2C partial implementation of the USA regs. 500ft circuits were not "standard" prior to that. In the US, a maximum level speed of 55kts is part of the definition for their 103 category ultralight that requires no certification, training or licence whatsoever. Hence they are kept at 500ft to avoid any conflict with "proper" aeroplanes. The situation here was completely different but nobody in authority considered this when imposing the American regs lock stock & barrel.

 

Back on topic - approaching a great many airfields from several miles out at 500ft is dangerous as the OP observes. The number of aircraft which can't manage 55 kts S&L is relatively small but if flying one I'd always go for a standard overhead join instead - its most definitely not prohibited by the regs. If its capable of >55kts S&L then do 1000ft circuit - it can still be closer in as thats also allowed by the regs.

 

Hope that helps

 

John

 

 

[Bill Hamilton]

Its not really a new requirement - blame the 2005 NAS2C partial implementation of the USA regs. 500ft circuits were not "standard" prior to that.

Folks,This statement is not correct.

 

We have had multiple circuit heights for longer than I have been flying (which is longer than I care to remember) with 500' as the minimum. 500' is derived from another regulation about minimum heights for flight, other than for the purpose of takeoff or landing.

 

With 500' as the "recommended" (not mandated) height for the "low and slow", if you, as pilot in command decide that 500' is too low, based on your operational safety evaluation of your particular circumstances (AGRADE in CRM-speak), you have a legislated responsibility, as the pilot in command, to act on that decision.

 

The cultural shift that must take place in Australia, if we are going to improve our safety standards to the safety outcomes level of the US (which leads everybody else --- with one exception, gliding) is to get away from mindless "compliance" with some "one size fits all" "rule", and start thinking.

 

You now have a wide variety of ways you can conduct an arrival at an airfield in Class G airspace, by intention the system is now very flexible in low traffic density airspace ---- as the pilot in command it is your responsibility to decide your course of action, depending almost entirely ( there are still some restrictions, cf; straight in approaches) on your operational position.

 

Typical is the shift to thinking required for the new recommended radio calls ----- I look at threads, with all sorts of variation on "who will do what to whom when" use of radio.

 

The fact is, you are all correct, for your particular time, place and operation, if you, the pilot in command, decide that is the appropriate "communication" **at that time.

 

Remember, there is a vast difference between "communicating" and what has all too often (particularly with self styled "professional" pilots) mindless chanting the mantra, aka "complying with mandatory radio requirements" --- without ever actually communicating with another aircraft -- let alone their own brains.

 

Read CAR 166 in its entirety very carefully ---- but not with a "mandatory" mindset, and note the most important provision, that you must operate safely (although it says it in a few more words)

 

Regards,

 

** Project Service Centre - Charles Sturt UniversityCommunicating.ppt

 

See Item 4 on the list. Not about aviation at all, but "communications" in another context. Have a look, and have a good hard think about what good "Radio Communications" really means, compared to "radio procedures".

 

AGRADE ---- Aviate (don't forget to fly the bleeding thing) Gather the information Review the information Analyze the Alternatives Decide on a course of action Evaluate to outcomes --- hopefully at your leisure and learn something for next time you decide to commit aviation.

 

 

[Guest JRMobile]

Thanks Bill

 

That is the best summation of t he 3 June changes I have read to date!

 

 

[Guest Mark_hwltt]

Hi,

 

The important thing to remember is the " it is recommened".

 

The safety of the aircraft and pilot is more important than total obedience to the rules.

 

Your circuit height and distance from the field should enable you to glide to field incase of an engine problem.

 

I fly a very underpowered aircraft and I still fly 3 legs of the circuit that are suitable to the performance I have and fit in with other aircraft and you don't have to overfly the field its up to the pilot to determine the wind direction and strength and use the "most into wind runway" or one with a suitable croswind component.

 

Mark

 

 

[facthunter]

Joining the circuit

 

Glad you made that point Mark. Why the obscession with overflying the field? Is it really the SAFEST way to do it? In some circumstances I THINK NOT. example doing a midfield overfly at a height where a climbing aircraft (ON T/O) is likely to collide with you. Remember THAT is when the visibility over the nose is non-existent..

 

Also, for almost the entire flight any aircraft makes it will spend the majority of the time being unable to glide to any aerodrome in the event of engine failure.

 

Your purpose on arrival at an aerodrome is to enter the traffic pattern and make the landing in the safest way. and with some sort of ORDER so that others may have a fair idea of what you are doing. That is the purpose of all these rules/ suggestions/ recommendations/ radio calls etc

 

The way I see it you could just about fly around the airport boundary at 500' and no-one could really object. As I said in my previous post ALL the diagrams show the faster aircraft as higher and doing a bigger circuit. You're lucky, you will have your section of sky to yourself.(except at aerodromes where there are cropdusters and/or helicopters, but you can't win them all). Nev

 

 

[Yenn]

Just bear in mind that some of the aircraft we share the circuit with do not have much forward visibility, especially downwards. To stay safe with them you want them on finals to be lower than you, which is easy as most of them come in at 3 degrees and most of the slow planes are coming in on a much steeper approach. The last place I would want to be is from a 500' circuit coming in at 3 degrees. A sure way to get run over.

 

 

[facthunter]

"Run Over".

 

Good point Yenn. I mentioned the need to look out thoroughly for any aircraft that might conflict as you are approaching the position where you would commence turning to intercept final, in my earlier post, but it needs to be really emphasised. A low power approach in these slower aircraft would normally be a steep approach, so you could be descending into the path of an aircraft coming from behind at a faster speed. It should be noted that this is the only time that you would be in conflict with this faster traffic. Whether some would consider that you are cutting in on them might be an issue for the unaware.. The whole thing will work OK if good judgement and lookout is exercised.

 

By the way, I don't see speed variation as being anywhere near as effective as extending downwind. This is your last real chance to change the spacing between you and someone you are getting too close to.

 

The other thing is that everyone should have an escape route in mind. Things we kick around here for weeks and still don't get a clear answer to, are the sort of decisions that you could/will have to make in seconds, sometime. Nev

 

 

[Guest Mark_hwltt]

{Quote]

 

Where does this paranoia about needing to be within gliding distance to the landing strip in the circuit??? God if you are that paranoid why are you in the damn thing in the first place. Just fly and communicate a safe circuit with the best separation possible and the 500' and 1000' circuits are a bloody good start.

 

David

 

I don't know about paranoia (or if I'm Parnoid) But my instructors over the years ( which include Hang gliders, sailplanes, Ultralights, and Fixed wing GA) always taught good airmanship which included being aware of the glide of your aircraft and using that as an guide to your circuit pattern - a safe circuit -

 

Call me paranoid but I carry a First Aid Kit, Fire Extingusher & EPIRB hopefully they are a waste of money and never have to be used on myself or my friends.

 

Mark

 

 

[Spin]

David it's that GA - RA thing again, I see from your list of aircraft that you have a GA background. When I did my RA conversion, tight circuits you could glide in from was one of the first things hammered into me by the CFI who is an old time ultralight pilot and he wasn't alone in that belief. I suspect the same applies to the trikers.

 

 

[facthunter]

Fair comment.

 

David, Could happen and would be especially unwelcome if some were flying "Boeing" sized circuits to start with. Lots of U/L's climb cruise and glide at almost the same speed, so the available variation is not much. You can "dirty" up a plane early If it's flapped, but you use lots of fuel and unless you know what you are doing you get out of NORMAL sequence, delay some checks and run the risk of omitting some vital action. You get away from SOP's , and that is when things start to go pear shaped.. that is the other side of the coin. Nev

 

"

 

 

[Guest ozzie]

OK lets toss a twin engined Scottish Pioneer into this. as far as speed goes it should be at 50ft. :)

 

 

[Guest davidh10]

FWIW, I can confirm that in my training, I was told that when flying downwind or descending on the inactive side of the runway, I should be within glide distance of the runway.

 

It won't work for base, as for a normal powered descent, you will be past the glide slope for an unpowered descent, even before you may have to extend downwind for separation.

 

Any time you are descending, with the engine revs lower than cruise, there is the potential for icing, given the wrong conditions, so I think this may be a factor. I was told not to run the engine below 3000RPM if the air temperature was below 17 degrees, for that reason.

 

I certainly had the power pulled on many occasions while overflying, joining or flying downwind and had to quickly select a runway to glide onto, and then land on it. It was only done once on base, and yes, I had to use a little bit of power to clear the fence.

 

 

[Guest ozzie]

Still no mention of those rotary winged types or are they now considered as just another aircraft as far as speed vs circuit hight.

 

 

[Guest Crezzi]

We have had multiple circuit heights for longer than I have been flying (which is longer than I care to remember) with 500' as the minimum. 500' is derived from another regulation about minimum heights for flight, other than for the purpose of takeoff or landing.

You have a lot of experience in this area Bill - where was it written that 500' circuits were recommended prior to NAS2C ? The many complaints at the time of its implementation were that it was safer to fly 1000' not that 500 was too high.

 

Why the obscession with overflying the field? Is it really the SAFEST way to do it? In some circumstances I THINK NOT. example doing a midfield overfly at a height where a climbing aircraft (ON T/O) is likely to collide with you. Remember THAT is when the visibility over the nose is non-existent..Your purpose on arrival at an aerodrome is to enter the traffic pattern and make the landing in the safest way. and with some sort of ORDER so that others may have a fair idea of what you are doing. That is the purpose of all these rules/ suggestions/ recommendations/ radio calls etc

I would argue that in a lot of cases an overfly and descent on the INactive side is the safest way precisely because it does allow you to identify traffic already in the circuit. If you have blind spots manoeuvre see traffic (including departing). This allows you to enter the circuit at an appropriate time to ensure seperation.

 

In my experience the conflicts occur when a Drifter is at 1000' at 50 knots with a Baron or a Cessna roaring up his bum. We create the conflicts by poor decision making and practice, in short the Drifter should not be in a 1000' circuit at a busy GA airport, unless he is the only one in the area at the time.

Sorry but again I don't agree. You are assuming that the Drifter and the Baron would be doing the same sized circuits at 1000ft. Why would that be the case - the circuit size would vary according to the performance of the aircraft.

 

Cheers

 

John