Primarily for general aviation discussion, but other aviation topics are also welcome.
By TopCat
FLYER Club Member  FLYER Club Member
#1845744
Rob P wrote:@TopCat

https://publicapps.caa.co.uk/docs/33/CA ... on%203.pdf

Page 103

Yes, thanks. That's the new one. I already have that. I was wondering if the OHJ diagram and introduction of the word 'suitable' has changed from the older version. Which I have somewhere.

'Suitable'. Now there's a word agreed on by a committee, if ever I heard one.

No wonder we need EC to avoid circuit traffic now :roll:
Rob P liked this
User avatar
By foxmoth
FLYER Club Member  FLYER Club Member
#1845747
Directly over the numbers is workable in a LH circuit but in a side by side aircraft RH circuit you need to be far enough out that you can actually see the runway (though not necessarily the numbers) from the left seat.
By A4 Pacific
#1845750
In the days long before CRM, a BEA aircraft with a particularly ‘superior’ captain at the controls realised they had just landed at the wrong German airport. He turned to the wireless operator and said “you’d better tell London we’ve landed at Hannover not Hamburg.” To which the wireless operator replied, “oh I sent that message 10 minutes ago captain.” :roll:

I want to know how EC would have helped here!
By TopCat
FLYER Club Member  FLYER Club Member
#1845753
foxmoth wrote:Directly over the numbers is workable in a LH circuit but in a side by side aircraft RH circuit you need to be far enough out that you can actually see the runway (though not necessarily the numbers) from the left seat.

Agreed. But not a runway length out.

The really important time to be able to see the runway is as you approach crosswind on the deadside, as this is when you'd be looking at any departing traffic.

29 RH (and 07 RH on easterlies) at White Waltham are frequently in use and I fly a side-by-side low wing aircraft. I don't think it's remotely difficult to fly the OHJ tight and still have a good view of the runway.

The problems I'm banging on about here relate to the way a lot of OHJs are flown extremely wide, with inaccurate position reports. At busy times, this makes it harder to see other joining traffic, because it can be almost anywhere in the ATZ, and also be unnecessarily alarmed by aircraft reporting where they are not.
By TopCat
FLYER Club Member  FLYER Club Member
#1845758
FWIW, if traffic permits, this is how I usually fly the OHJ and circuit for 29RH at White Waltham:

Image

I was a bit fast on the approach that day, used up more runway than I'd like, as you can see from where I vacated :oops:

TBF, the OHJ height is 1200', and the circuit is at 800'. It would be harder to keep it as tight as that if it was 2000' and 1000' respectively. But I do my best :pirat:
HansGruber liked this
By TopCat
FLYER Club Member  FLYER Club Member
#1845771
Cub wrote:@TopCat
I see you passed through the c/l and reestablished the FAT from the south. Is Heywood Farm a new avoid?

Not that I'm aware of. I tend to avoid flying over occupied buildings that close in just out of habit, especially if I have any power on. If there's nothing ahead of me I might go inside it on a glide approach.

ETA: No.
#1845781
Rob P wrote:@TopCat

https://publicapps.caa.co.uk/docs/33/CA ... on%203.pdf

Page 103


That OHJ diagram and the diagram on page 104 for crosswind join both show the joining aircraft should be going over the upwind numbers at circuit height.

During my PPL course when doing go-arounds I was taught to not go above half circuit height until crossing the upwind numbers to give height separation to any traffic entering crosswind over the upwind numbers (as shown by the Skyway Code diagrams).

So with an 800 ft circuit that gives 400 ft height separation over the upwind numbers, which might be 300 ft if both aircraft had 50 ft altimeter errors where one was under-reading and the other was over-reading. It might be a bit less in bumpy conditions.

If aircraft doing a takeoff followed the same principal in a strong headwind or with a very long runway there would be no collision risk at the upwind numbers, particularly if the aircraft taking off was a high wing aircraft and the joining aircraft was a low wing aircraft so one or both could not see each other through a wing or engine cowling.
i.e. procedural separation.

A problem with that is some pilots habitually choose not to join crosswind over the upwind numbers, and prefer to do it further upwind, and the aircraft that is taking off (or on the go-around) has resumed climbing towards circuit height, so the procedural height separation has been reduced.
Yes there are many forum debates on who is right/wrong with that.
Perhaps that is why in recent years one popular airfield published its join as an OHJ and explicitly stating flying crosswind over the upwind numbers! At least at that airfield there is no doubt.

Some airfields have a bit of mayhem influenced by noise abatement procedures.
By Hooligan
FLYER Club Member  FLYER Club Member
#1845865
GAFlyer4Fun wrote:
Rob P wrote:@TopCat

https://publicapps.caa.co.uk/docs/33/CA ... on%203.pdf

Page 103


During my PPL course when doing go-arounds I was taught to not go above half circuit height until crossing the upwind numbers to give height separation to any traffic entering crosswind over the upwind numbers (as shown by the Skyway Code diagrams).


Which makes perfect sense to me. In the document linked by Cub recording mid air collisions in the UK, is one I remember that occurred at Biggin Hill in 1978, involving a Rallye going around from an approach to runway 29 and a C150 rejoining overhead - the accident report makes for interesting reading.

https://assets.publishing.service.gov.u ... G-BEVX.pdf
GAFlyer4Fun liked this
User avatar
By Human Factor
FLYER Club Member  FLYER Club Member
#1846400
...neither is 4 miles from the threshold "final"...


Spotted this earlier. Actually it is (CAP413 refers).

As to the OHJ, I'm not a fan and never have been. It's an anachronism from when the signals square was the only form of A/G communication.

IMHO, the safest join is an initials join to a VRIAB done properly. This has dual advantages. Firstly, it allows a joining aircraft to skyline any existing circuit traffic and fit in appropriately rather than effectively aiming for a fixed point in space (circuit height over the numbers) and then wondering how the hell to slot in if someone is downwind. The VRIAB can be extended as required or at worst blow through and try again.

Secondly, it also gives faster slippery aircraft a good opportunity to slow down rather than trying to slow down in a descending turn (not possible in a Nanchang for example). Keep in mind that 90kts is as slow as you want to be flying clean and this gives you no margin to slow further if required to "slot in". No use appearing in the overhead at that speed as it will accelerate as the nose goes down and there's very little excess performance to be had if you put the gear down early.
#1846410
Visual Run In And Break.

Certainly a good idea in a ground to air defence environment! :lol: Great in high energy aircraft. I used to do them in an Islander. Even starting from vne it wasn’t quite the same! Lacking a certain ‘je ne sais quoi’ :roll: :D
Last edited by A4 Pacific on Wed May 12, 2021 11:01 am, edited 2 times in total.
PaulSS liked this