What does Turweston know...

[2Donkeys]

What does Turweston know, that Duxford does not

Lovely day out at Turweston yesterday, where the Vintage Aircraft Club's fly-in was very well attended.

The airfield was simultaneously operating on the hard runway, and a parallel grass strip, without undue drama and my mind wandered all the way back to Duxford last weekend.

So was Turweston breaking the rules, or has Duxford misunderstood the rules, or is there another answer?

[Mike Cross]

The same happens at Kemble and many other places. However it is normal for the two runways to be treated as one for circuit purposes, i.e. you do not have simultaneous take-offs and touchdowns on the two runways. At Duxford that would effectively be formation take-off or landing as the two are so close together.

The AIP says
Although Duxford has parallel runways they are not available for simultaneous use and are to be treated as one runway

Duxford and Kemble will both offer you "hard or grass", your choice.


Mike

[2Donkeys]

Mike

You may have misunderstood the point I was attempting to make.

Duxford was forcing aircraft to go around if either the hard or grass runway had an aircraft occupying it. This included the case of an aircraft wishing to land on the hard, when another aircraft (which had also landed on the hard) was vacating over the grass runway.

By contrast, Turweston was allowing departures and arrivals on either runway, regardless of who or what was on the surface.

This included one particular episode in which a Yak made a rather late decision to go around with both runways occupied with vacating traffic.

Amongst other exciting things seen was a Gyrocopter landing at one end of the hard, with an aircraft vacating further up the runway. Not dangerous, but not kosha either at a non-ATC airfield.

[BEagle]

Rules of the Air prohibit landing if the runway is not clear of other aircraft unless ATC authorise the landing. To do so is only permitted in daylight hours, if the runway is of sufficient length, the second aircraft has been warned that the other is still on the runway and can keep it in sight until it has cleared the runway.

The important part is that only Air Traffic CONTROLLERS can approve such a landing - indeed, any landing. FISOs and A/G radio operators (such as at Turweston) will advise pilots of the position of other traffic, but it is the pilot who has the sole say in whether or not to land at an aerodrome without ATC. Hence if there’s someone else on the runway at Turweston when you land, you will be at fault, not the A/G radio operator.

Whether the grass taxiway at Turweston can in fact be considered to be a runway, I wouldn’t care to comment upon. Only the asphalt runway is listed in Pooley’s as a runway, although the aerodrome diagram does describe the parallel section of grass as ‘Grass Twy and Runway’.

[Prof Denzil Dexter]

AFAIK, the runways at Duxford are close enough to each other to be treated as one. Thats why ya cant land two aircraft on the same runway at the same time, because Rule 17 of the ANO says so. But two aircraft CAN take off on the same runway simultaneously. Work that one out!

Also, both grass and hard at Duxford are licensed, whereas I'm not sure if the grass at Turweston is licensed. Therefore, is it a runway, or just an old bumpy bit of pasture that they use for the alighting of aerial craft?

[Mike Cross]

2D

Strictly speaking of course the AFISO can't force anyone to go round. He has no authority to do so. It's your decision not his.

Agree with you that stopping a landing on the hard when it had been cleared by the preceeding seems over-cautious but perhaps he didn't have a clear view and was playing safe.

Prof DD is talking Rule 17 of the Rules of the Air, not the ANO, which includes the wording (b) A flying machine or glider shall not land on a runway at an aerodrome if the runway is not clear of other aircraft unless, in the case of an aerodrome having an air traffic control unit, that unit otherwise authorises.

Turweston has no ATC so landing while the previous a/c has not cleared, while it may not be dangerous, is illegal. :ooh:

Mike

[max roll rate]

Well I don’t know if we broke any rules but the day ran very smoothly and the end count was 109 visiting aircraft.
As far as the use of our grass goes it is unlicensed and was not used by any aircraft requiring the use of a licensed runway,
I don’t remember or indeed condone any pilot that landed after as we are only ag operators, and i know that we would only indicate that the runway was vacant and give a surface wind so no clearances were given, I would also point out that we never gave this information to departing traffic if either runway was in use so they were not used together, I am sorry if you think we did wrong but most people I have talked to thought the day was safe
and fun which is the main reason I am involved with aviation.

p.s I think the landing roll of charitys cricket is about 5ft !

maxalpha :uhoh:

[Flyin'Dutch']

Hi Max

Did not read in the initial post any criticism on Turdy. More a query why some other fields seem more retentive.

May be 2 Ds can elaborate, rather than us reading tealeaves?

FD

[Wide-Body]

2Donkeys

Your “quote” “”” This included one particular episode in which a Yak made a rather late decision to go around with both runways occupied with vacating traffic.””””

I don’t know if the YAK you saw initiating a GA was the same as mine.


I had a particularly good view of a YAK making a go around at Turweston. I saw the whole episode somewhat differently. Yak making proper circuit with regard to noise at Turweston. Another a/c flying a tighter circuit (inside the northern village) caused the yak to position to a wide base and longer final. Tiger moth Landing on grass had vacated as spam can continued for a safe and perfectly legal landing. As a frequent visitor to Turweston the YAK commander had seen a/c land vacate and backtrack the grass. With this in Mind the YAK pilot deemed it safe to continue the approach. Air ground then issued the instruction to the spam can pilot to continue to the end of the runway. The level of performance of a YAK 52 means that a Go – Around can safely be flown from the flare. Air-ground then said to YAK “surface wind followed by aircraft vacating right”. The YAK commander not wanting to do a land after initiated a go-around manoeuvre. On this occasion the go-around was initiated at 300-250 feet. (It was not done a full power due to consideration for a very noise sensitive airfield.) At which stage the tiger Moth pilot was having a cup of tea and the Spam can pilot was safely vacating the runway.

Turweston AG are very good at handling the volume of traffic. They let pilots make appropriate decisions for themselves thus allowing a high movement rate with a great degree of safety. Perception of an incident is a very personal thing, however without explaining all of the facts it can be highly misleading to other readers. It is very easy to do especially with the cloak of anonymity.

Regards,

Wide-Body
:\

[Mike Cross]

Max

Not suggesting for a moment that you did anything wrong.

Just pointing out that the incident mentioned by 2DAmongst other exciting things seen was a Gyrocopter landing at one end of the hard, with an aircraft vacating further up the runway. Not dangerous, but not kosha either at a non-ATC airfield. was actually illegal if the vacating aircraft really was still on the runway. So it's not a particularly good argument to use re Duxford.

If it did happen as described it would be the landing pilot's responsibility not yours.

Mike

[2Donkeys]

Fun though this discussion is, I have not learnt anything.

I already knew that it was illegal for the gyrocopter to land on an occupied runway, and I am well versed in the Rules of the Air and the ANO.


My question was rather different, and I refer you to the thread title :cool:

I am keen to hear why Duxford feels duty bound to treat its two runways with enormous care, whilst all manner of simultaneous operations were occurring at Turweston.

I ask again:

"So was Turweston breaking the rules, or has Duxford misunderstood the rules, or is there another answer?"

[BEagle]

Perhaps your question should ask whether the pilots visiting Turweston were breaking the law, whereas those visiting Duxford were not?

A/G operators provide assistance, NOT clearance - it's the pilots' responsibility to observe the law.

PS - I agree that Turweston Radio is an exceptionally helpful unit. But remember that it is NOT an Air Traffic Control unit.

[2Donkeys]

I guess I was hoping for a more detailed answer.

Both runways are visual only.

By my reading of the rules (CAP168) Turweston's runway is probably type 1 (800 metres declared TORA and 18 metres wide). This runway requires a lateral strip of 30 metres from the centreline.

By my measurements, this puts the grass taxiway/alternative runway outside the strip. So landings on the grass whilst the hard runway is occupied is potentially not a problem...

At Duxford, the lengths are 1522 x 44 m making it a type 3 runway, requiring a lateral strip of 75 metres

Once again, a rough measurement of the map suggests that the grass runway is more than 75 metres away from the tarmac centreline, but simultaneous use is specifically unavailable as directed by the AIP.

What is the difference making one acceptable, and the other unacceptable?

Is it the fact that landings on the grass at Turweston are unlicensed? If so, could Duxford create additional flexibility by permitting unlicensed simultaneous use of its grass?

Does this ring any bells for anyone?

[IanSeager]

It is a while since I've been to Duxford, but don't some of the Classic Wings flights use the grass runway? If so unlicensing that runway would I guess force them to use the hard for public transport flights.

Ian

[2Donkeys]

A landing can be unlicensed on an otherwise licensed runway.

All that would be required would be for Classic Wings to land only when the tarmac was free. Anybody landing on the grass when the tarmac was occupied would be landing unlicensed.


FWIW, ICAO Annex 14 seems to be the best source of recommendations in this area.

Under 3.1.10, Duxford's runways would need to be 210m apart to qualify for licensed simultaneous use. They are clearly closer than that, so that Duxford's position starts to look understandable.

Turweston's runway and taxiway would need to be 120m apart to see licenced simultaneous runway-like use of the type seen on Saturday. They appear to be considerably closer than that.

Not sure what one should conclude from this... Interested in a professional opinion