Orbiting on Final
 

Has anyone ever had to do this ? And if so, what is the correct procedure ? I'm raising this question in the light of an AAIB report at Southend
http://www.aaib.dft.gov.uk/publicati...0l__g_babb.cfm

Orbits on Base and Final
 

When I was flying into Luton, I regularly orbitted on left or right base to allow faster jet traffic to land (sometimes a whole stram of them if it was about 6.00 pm) while I waited for a gap in traffic to emerge.

I have also orbitted on final when it as been apparent that there is insufficient time for somebody slow in vacating to clear the runway before I arrive, thus an orbit saves a go-around and a full circuit and having to slot into traffic again.

I have also been in the VCR at Luton on one accasion when a Streamline "shed" did an orbit on final for 24 while a (I think) Monarch 76 went the full length and backtracked to B1. Again to avoid a go around and a full circuit.

(Edit on 13/7) Having now read the report in full, I still consider an orbit to be a perfectly normal manoever, esp under my circumstances above where traffic of greatly differing speeds are mixed. Obviously the first thing is to arrest the descent and get good flying speed with as much power as it takes, rememebering carb haet off and perhaps even carefully cancelling a stage of flaps.

DGG

Not read the report yet. Never done it as a pilot, wouldn't tell anyone to do it as an ATCO. It should be a go-around as normal, with any turns made (probably to re-position late downwind) only when the aircraft is in a safe configuration to do so.

I saw an Aer Lingus do it once, on final into Dublin. :eek: It was below 1000ft at the time.....prob about 2 miles from the threshold (at most!) :eek:

I nearly crashed my car while looking at it :O

At least he knew noone was coming up behind him, as it was in class C.

I just wondered if asked to do this, what the correct procedure is ? i.e do you remain in approach config / speed and use pitch to maintain airspeed and power to cancel descent, or would you retract flaps and return to normal cruise speed ? I was never taught it as its not on the PPL and it sounds damn risky to me.

This is not something that I would be happy to accept, I would rather do a proper missed approach and go around.

Shy_one

There is another way to look at this, although described as an "orbit" so most people imagine a 360 turn at low level, my view is that if asked to do so and only if 1,000 AGL or above, I break off in the direction requested to fly a short crosswind leg, then turn downwind to get a view of the faster traffic that's passing me (and to leave enough room before I turn "base" and join finals again behind him).

It's nothing complicated, just a "mini" circuit. If the manoeuvre was required for spacing for traffic ahead, then a 360 orbit at or above 1,000 feet AGL is no problem. I don't change the config of the a/c at all, just apply enough power to stop the a/c descending and go all the way round.

Below 1,000 feet, follow a standard missed approach and fly accordingly telling the tower that I'm unable to orbit.

Only about halfway through the report (makes for some sad reading...:() but the chap was NOT instructed to orbit, but to break off the approach and fly a heading (north).

Sounds dangerous to me. You're on final, which means that you're flying in a high-drag configuration (full flaps, possibly the gear down) and just a few knots above the stall speed when straight and level. All of a sudden you're going to increase power (torque effect, balance...) and you're going to make some turns. In a turn, the g-loading on the aircraft increases, and are you really remembering not to exceed 20 degrees bank here, and not to push the plane around with the rudder?

It sounds like a great opportunity for the classic stall/spin scenario, even more than the turn to final.

In such a case, first put the power on, get rid of the drag (retract gear, partially retract flaps), increase speed, then turn. And by then you'll find you're doing a go-around anyway. So turn crosswind and join downwind (might be late downwind) for a new attempt.

Yes very sad
 

I also wonder if he applied throttle incorrectly during the manoeuvre ? I.e. he cut power to 900rpm rather than applied 2000rpm.

Very sad.

I had to orbit on final at Southend of all places a few years ago when a Shed landing ahead of me shed a tyre: it managed to vacate the runway but they wanted to send a vehicle out to pick up debris.
I was at 300 ft and was told to orbit right for 24.
Even though at the time I had over 400 hours, this was way out of my comfort zone so I told ATC I was going to clear to the NE and re approach a bit later.
Highly inconvenient as I was on my way to France and was dropping in to Southend to clear Customs and it would have been tempting to continue to orbit: However it would have meant cleaning up from approach configuration, perhaps even retracting the gear and all the time the ground looked awful close.....
I really feel for the poor student on his second solo having been given unusual instructions in an unusual way...........
Cusco

EDDNR and 172driver are spot on.

I have been asked to do excatly this at SFB and St AUgustine in Florida as a solo student and twice at Ronaldsway in the Isle of Man.

Key things:

1) Watch that airspeed no matter what your configuration
2) Ensure you stay off the final approach path

However it is a terrible chain of events and the RTF from the ADC and APC was not exactly polished. Still they are only human and accidents do happen.

I have been asked to do it several times, in the States, in RSA and most recently at Norwich IIRC!

Not really a big deal, roll on bank in the direction requested (generally left) and pull!

Stik

Very sad the accident, but are people really saying that they cannot conduct a 360 turn in the approach configuration safely?

OK for a second solo it is a step too far (probably) but for an experienced PPL its too dangerous - surely not. Accepting all the ATC issues that orbiting brings why should a 360 turn in any configuration be beyond the skill of a PPL?How do these people manage to turn finals without falling out of the sky?

The report made for some very sad reading. It did remind me of my early solo flights and how taxing it can be at that stage.

My very first solo flight that I made. I had a change of runway presented to me whilst on the downwind leg.. I coped with that fairly well.

My second solo almost ended in disaster. It went wrong from the word go. I realised after take off that I hadn't set the flaps for take off configuration.. A very small thing, but it did upset me.. The landing was one of those that just floated on and on... I lost my nerve and applied full throttle, forgeting to make sure that the nose didn't pitch up!!! :eek:... So from just that one experience. I can understand what may have been going on with the poor student in this case. It can just take one small thing to throw out a whole flight.

It took another four hours of instruction before I went solo again. We went through all sorts of situations that could happen on the landing approach and practiced like crazy. All I can say is that from that time onwards I could deal with anything that was thrown at me... It was worth spending the time and money on this, and I am grateful to this day of what my instructor did for me on this aspect. I wish that a lot more work was done on the landing phase and situations that are likely to develop.

My instructor drummed it into me that I was in charge of the aircraft and it was my responsibility to do whatever I felt happy with in whatever situation. If that meant letting ATC know that I'm unable to do something, or feel that it is outside my experience. Then I should say so. That includes changing runways (that applied to my early solo time) That still applies with my standard PPL in certain situations.

What would I have done if I was this chap with low hours... I would have probably done what they had asked. As soon as I had confirmed that. I would have increased the throttle to full power gained speed, cleaned the aircraft up, and returned to circuit height. Although I must say that I wouldn't be happy about it. My concern would be what they were going to do with me next... Hindsight would have told me to say to them that I was going to go round. By far the safest situation and it allows me time to settle down into a procedure I know well. I suspect that my instructor would have approved of that.

Astral

Backpacker - What's this 20 degrees AoB limit you mention? I suspect that's just a bad habit a nervous poor instructor taught you.

As one of my old colleagues said - light aeroplanes are predominantly very forgiving machines - given sufficient airspeed you can pretty much throw them around as much as you like. With the emphasis on the sufficient airspeed - manouevring at 45 deg AoB will only increase your stall speed by just less than 20%, a speed that you should be able to achieve very quickly with a burst of power from a normal approach speed.

Knight, I'm actually on an aerobatics course right now where we do 75+ degrees bank turns with full power. Just keep pulling and increasing bank, maintaining altitude, until the aircraft stalls... :-) (Do not try this at home though.)

During PPL training, the 20 degrees bank was the limit when doing the turn to (short) final, with (almost) full flaps, low airspeed and low power. At least, you had to plan your final turn so that it could be achieved with 20 degrees bank, whereas the downwind to base turn, with more speed, could be achieved with 30 degrees bank.

Obviously it's all got to do with g loading. And with nervous instructors, too...

Even my aeros instructor (who happens to be a display pilot too) gets rightfully nervous if you start manoeuvring aggressively, on final, with full flaps, low airspeed and low power settings.

Still, if you planned your turn to final wrongly and 20 degrees doesn't cut it, like you say, it's better to put a bit of power on and roll on 45 degrees of bank, than to try and force the aircraft around with the rudder while maintaining 20 degrees.

having just completed my first solo, reading that sent a chill down my spine. a very sad story.

i'd feel unhappy about orbiting on finals too.

safe flying everyone :ok:

Backpacker - Glad you're getting some experience poling an aeroplane around properly! In my own opinion, the idea of a "bank angle limit", especially one as low as 20 degrees, is a thoroughly stupid idea. Yes, by all means, teach students that the turn onto finals should be "gentle", but imposing an artificial limit just introduces an extra distraction - sapping mental capacity by forcing them to monitor an extra parameter, and potentially introducing the problem you mentioned, whereby a student would sit at 20 deg AoB and try to kick the aircraft round the corner with rudder, rather than increasing speed slightly and manoevering the aircraft properly. It also seems to introduce a horrible mindset where people seem to think that the aeroplane will drop out of the sky if manoevered at anything above 30 deg at any flight conditions.

I personally would be an advocate of introducing low speed agressive manoeuvering as a compulsory part of the PPL (if not some mild aerobatics), just to give people some idea of where the limits of an aeroplane actually lie. Just my opinion!

If you stay under 20 degrees angle of bank for final and climbing turns it means the increase in stall speed is negligible (6.41%) so you don't have to worry about increasing speed. You can bank as steeply as you like - just make sure you have the speed to avoid the stall and power to keep the speed/altitude combination required.

If you don't believe me watch a glider pilot turning final: If they need to tighten up the final turn, they'll roll on as much bank (45+ degrees) as needed increasing speed by the requisite amount instinctively. But then glider pilots do spend a lot of time a couple of knots above the stall in, for power pilots, what is a steep turn.

Bottom line: Keeping to 20 degrees angle of bank in final/climbing turns in the circuit is a good safety guideline - but not a physical/aerodynamic limitation.

OC619