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Porteous Loopy
17th Mar 2022, 12:38
I was originally taught formation rejoins in a side-by-side cockpit, but have subsequently forgotten what I was taught and have only used a different technique suited to tandem cockpits.
Using my technique would put either me or the student blind on lead as we increase AoB on the rejoin line.
Can anybody remind me what technique is best for side-by-side cockpits?

Thank you!

sycamore
17th Mar 2022, 13:24
For any rejoin ,you must be below the other aircraft,and at least a `span `out..Depending on a/c type,usual line is nose/spinner-wingtip,and no further forward than elevator/rudder ...If either you or student go `,blind`,then that is an automatic `Breakaway/Out,` and call.
Strongly suggest you get hold of an instructor and `refresh`,otherwise it `could end in tears......!

Porteous Loopy
17th Mar 2022, 13:45
Oops, sorry. I didn't mention that I am an instructor and have been teaching rejoins for 20 years or more but in tandem aircraft. In the tandem environment as AoB increases both cockpits can still see lead whilst on the line. In a side-by-side cockpit the pilot on the far side, away from lead, has their eye line lowered so the opposing coaming/side wall obstructs their view, so this cannot work. Hence my question, what technique does work? I cannot remember what I was taught during UK EFTS.

Big Pistons Forever
18th Mar 2022, 04:19
as we increase AoB on the rejoin line.

I would suggest that that is your problem, not which seat you are in.

Porteous Loopy
18th Mar 2022, 07:47
I would suggest that that is your problem, not which seat you are in.

Yes, that seems to be exactly the problem. Not an issue on straight and very low aspect rejoins, of course. In higher aspect scenarios one solution would be to go very low (to maintain tally for the low seat occupant), this would then create a significant upwards closing vector which would be hard to quantify without visual cues and therefore hard to teach and replicate safely. I noticed in the past that trainees who understood the visual cues were quickly able to nail efficient rejoins.
I don't have the brain power to reinvent anything and people must be teaching this every working day, hence me asking what technique people use and teach. Does anyone have any written down guidance they would be willing to share with me?

ShyTorque
18th Mar 2022, 21:18
Do you mean rejoining the formation, or rejoining the circuit?

If you mean rejoining the formation, the RAF reaching in my time was to normally join up in echelon. Firstly find the wide echelon line, then slide in diagonally to get the correct spacing. If briefed to join line astern, move straight in from below.

Big Pistons Forever
19th Mar 2022, 02:27
My last formation instruction was for a guy with a Yak18T. Before that it was all in Nanchangs and Yak52's with tandem cockpits and clear canopies. With respect to rejoins I taught them the same way on the 18T. The only difference was that you had to be lower when flying cross cockpit (i.e. left turning rejoin) either way you kept lead just above the cowl. I emphasis that bank angle determines the line so less bank if you are going ahead of the bearing line, more bank if you are going behind the line. At the tip in drive lead to the other side (right side of the canopy for a left turning rejoin and vice versa) and then using bank angle put leads wing tip just touching the top of the vertical fin. Manage smash ( ie closing speed) with power. At the tip in you want your airspeed to be about 15 % higher airspeed than formation speed as you get close to station the power comes well back to wash the smash off and then returns to what would be a normal power to hold position on the wing as the airplane stabilizes.

Just like landings a good approach = a good outcome. I want to see the student get on the bearing line early and then ride it in. Bad or worse dangerous rejoins, are always a result of an unstable flight path as the wing airplane closes on lead

Cole Burner
19th Mar 2022, 14:29
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/639x445/bd_formation_join_d8313956bc5ce09f2d1c768698ceae82eef38095.j pg
RAF Bulldog Instructors Guide - Formation Break and Rejoin

Porteous Loopy
21st Mar 2022, 10:01
... be lower when flying cross cockpit (i.e. left turning rejoin) either way you kept lead just above the cowl...

This seems to be the key. It's discouraged in the environment I was in most recently because of the resulting upward vector after the bloom potentially jeopardising a non-compromising adherence to sticking below lead at all times at all costs (or at least making it harder to judge potential compromisation), but it seems pragmatic in side-by-side cockpits.

... At the tip in drive lead to the other side (right side of the canopy for a left turning rejoin and vice versa) and then using bank angle put leads wing tip just touching the top of the vertical fin. Manage smash ( ie closing speed) with power. At the tip in you want your airspeed to be about 15 % higher airspeed than formation speed ... I want to see the student get on the bearing line early and then ride it in....

Seems to be exactly the same workcycle I use ... HEIGHT - LINE - SPEED, using the same parameters and control techniques.

... Bad or worse dangerous rejoins, are always a result of an unstable flight path as the wing airplane closes on lead ...

Absolutely agree. Even after flying stable approach path, risk can be further mitigated by stabilising in a key position before moving UP - FORWARD - IN in clearly defined stages. This also provides an explicit, measurable and teachable/gradable workcycle.

Porteous Loopy
21st Mar 2022, 10:02
Cole Burner. Thank you so much for this! Do you by any chance have another paragraph which describes the technique for turning rejoins?

Big Pistons Forever
21st Mar 2022, 16:12
I would suggest you check out the FAST site. There is some good material that you can download

Reference Material | Formation And Safety Team (http://flyfast.org/content/reference-material)

Porteous Loopy
24th Mar 2022, 07:27
Thank you. Original question now answered: it's normal to climb on the turning rejoin line in side-by-side cockpit.
New question: Why do some people use rudder/skid for lateral movement in station keeping rather than aileron/bank-on-bank-off? The open source information from all military formation flying I've seen is unanimous in using aileron and I cannot find anywhere where someone has written down the skidding technique.

Big Pistons Forever
24th Mar 2022, 16:43
Skidding is not a recommended method of station keeping. What I do see with pilots new to formation flying is unconsciously holding a bit of rudder away from lead and then banking into lead to hold positions. I think newbie’s feel more comfortable when the airplane is yawed away from lead,

This is poor practice and potentially dangerous so it should be corrected ASAP. The easiest way is to make the student take their feet off the rudder pedals after the airplane is stable on the wing.

Porteous Loopy
28th Mar 2022, 09:13
Skidding is not a recommended method of station keeping. What I do see with pilots new to formation flying is unconsciously holding a bit of rudder away from lead and then banking into lead to hold positions. I think newbies feel more comfortable when the airplane is yawed away from lead, this is poor practice and potentially dangerous so it should be corrected ASAP. The easiest way is to make the student take their feet off the rudder pedals after the airplane is stable on the wing.

Big Pistons Forever, we seem to agree 100% on most things, and I certainly agree with you on this. There is, however, an alternative school that is actively teaching use of rudder for lateral movement in station keeping. I am hoping that someone who subscribes to the 'exclusively rudder for lateral movement, with NO use of aileron apart from keeping wings level' school could explain the reasoning, history and environment where this technique evolved or was developed. I'm sure that there will be greater minds than mine and hidden factors at play which explain the differing techniques.

ShyTorque
28th Mar 2022, 11:19
In a slow climbing turn, a low powered aircraft flying on the inside of an echelon could get very close to a stall/spin situation if a lot of rudder was used for positioning. Been there, Bulldog.