The Buccaneer

[Brian Abraham]

Reading a piece on the aircraft and says that it was cleared for aileron and barrel rolls, and rolls off the top - but loops were not permitted. What was the nature of the problem? (Article written by Grp Cpt Tom Eeles)

[ZH875]

The Navigator would spill his coffee.....



Could it have something to do with the high tail being put in the crappy airflow off the wings, and stalling?

[BEagle]

I can't remember. But a pilot who'd tried it and who kept the ADD on the 'steady' note att he top of the loop told me that the aircraft accelerated at an alarming rate from the inverted position and lost an enormous amount of height in the second half of the loop - he said he'd never try it again!

[lightningmate]

Beagle has the reason exactly. The RAE Buccanneers, the original Green & Yellow beauties, had clearance to fly loops for a trial, the reason for which escapes me after all the years. Enter at 5,000ft & 550KIAS not a lot of KIAS over the top then rapidly building KIAS and, significantly, Mach No on the way down. Providing the driver did not allow the speed to run away, effective air brakes on the Bucc, it was not dramatic. Let the speed get away, then even with full air brake the final 90 degs of manoeuvre back to level flight was a touch unpleasant - particularly for the rear-seater.

I guess I should also say that I am talking clean aircraft here, or in the RAE aircraft case, cameras only.

lm

[N10CM]

Hello All. I'm new and just registered. The problem after passing the top of the loop is gaining to much speed and nearing the speed of sound. The condition, once know as "compressibility" caused severe buffeting, loss of control, and could cause the stick to beat your legs black and blue. It was a serious condition avoid in the P-47 Thunderbolt, among other aircraft.

[Flying Lawyer]

Brian
Reading a piece on the aircraft and says that it was cleared for aileron and barrel rolls, and rolls off the top - but loops were not permitted. What was the nature of the problem? (Article written by Grp Cpt Tom Eeles)
Your question aroused my curiosity.


Explanation from Tom Eeles today:"The reason why full loops were never cleared for the Buccaneer was that, firstly, the tailplane was fairly small and had insufficient authority to generate a high enough rate of pitch to guarantee recovery as the aircraft accelerated downhill on the second half of the manoeuvre, and secondly, the aircraft could accelerate very rapidly when going downhill and quickly reach its limiting Mach No of .95. If this was exceeded by a fairly small margin, the manufacturers believed the whole tail would detach. Thus pull ups into a roll off the top, with the airspeed/Mach number decreasing, were OK, but not the opposite.
That said, with care a loop could be done perfectly safely.

FL



http://www.spyflight.co.uk/images/jpgs/buccaneer/buccs%20in%20echelon.jpg

[ZH875]

Did the Brick fly high enough to do a loop?. :)

[BEagle]

ZH - only spotters called the Buccaneer the 'Brick'.....

FL - I had a feeling the pitch authority of the tailplane might have been the main reason - good to have it confirmed by such an authoritative source.

Interesting that he said that it could be looped 'perfectly safely'....I doubt whether many people who did loop it did so twice!

[brickhistory]

Only done a few loops, doesn't agree with my tummy, particularly the bit at the top................:O


brick

[Brian Abraham]

FL, many thanks - no doubt about Pprune, it goes right to the source. :D
BEagle, from the way it was put I read "could be done safely if you really were on top of things (his "with care" statement) but not something you would want the average squadron pilot trying". Much as your mate experienced in your first post. :ok:

[ICT_SLB]

Lightningmate,
"The RAE Buccanneers, the original Green & Yellow beauties, had clearance to fly loops for a trial, the reason for which escapes me after all the years."

Could it be connected to toss bombing? Our ex-project pilot recalled doing similar evolutions in a CF-104 (a half-loop) only, in his case, he ended up with the "shape" still attached.....

[BEagle]

I was certainly never brave enough to try a loop in the Bucc - I was far too crap! We did a bit of tailchasing during my short struggle with the OCU course - and a lot of toss manoeuvres as well as tactical low level formation at which it was utterly superb.

For medium toss it was never necessary to get close to the vertical - and the excellent roll rate (second only to the Gnat!) was used to roll to over 90 deg AOB to pull down to the horizon to stop the climb, then a hard turn to escape. It formed part of the Buccaneer IRT in the Hunter T7A/T8B, if I recall correctly.

[chevvron]

Tailplane authority? One of our drivers managed to pull the thing off trying to avoid a police helicopter in Germany at 500ft. Martin Baker letdown worked fine though thank goodness.

[ZH875]

ZH - only spotters called the Buccaneer the 'Brick'.....
Spotters and just about the entire groundcrew on 12(B) Sqn, AKA 12 Flying Club, Lossiemouth Division.

[lightningmate]

ICT_SLB,

Certainly not true Toss-Bombing related, although it may have been related to a proposed update the the aircraft Master Reference Gyro. We are talking nearly 30 years ago here.

chevvron,

That sounds unpleasantly familiar, if you remember, what was the aircraft serial involved in your recollection? I might dispute your detached tail plane assertion.

lm

[LOMCEVAK]

Just to add a little more detail, having had a "close friend" who looped the Bucc many times (I have to say that as Tom Eeles was the CFI when I was a student on the OCU). The problem is that tailplane power reduces markedly at high Mach numbers. If the speed is allowed to increase too much during the second half of a loop and you are at medium level, the resulting high Mach number results in little g being available, even at full back stick, and thus there will be an excessive altitude loss. As a complete loop was not required for the role of the aircraft, it did not have to be cleared as a permitted manoeuvre. As there was a safety related problem if the manoeuvre was mishandled, it was formally prohibited.

However, the first time that "my friend" tried it (from a 5000 ft, 550 KIAS entry), he selected idle and half airbrake as the nose came down through the horizon and levelled off in a very controlled fashion some 2000 ft above entry altitude. Having established a safe recovery technique, his next attempt was just to select idle as the nose came down through the horizon and to fly a controlled pull in the final quarter to level at entry altitude, typically about 100 KIAS below entry speed. This was repeated whenever a suitable opportunity arose although it did cause consternation for some navigators who had never seen the manoeuvre!

On an allied subject, the Aircrew Manual had a graph of minimum entry speed for a roll-off-the-top as a function of weight and altitude, the absolute minimum speed being 530 KIAS (from memory). During a display season I was happy with a clean aircraft at light weight to ROT from 480 KIAS and to vertical roll from 530 KIAS. I did work up a display sequence that commenced with a half horizontal 8 (half cuban in aerobatic terms), rolling on a 45 degree down line. However, that display requirment was cancelled so it was never seen in public and making base height was very critical on the angle of the down line. That display also included a 15-10-10 gear down barrel roll but that is another story!

[chevvron]

lightningmate: Not sure it may have been XV344 ex FAA(If someone has a list of RAE Buccs I may be able to be more accurate). Pilot told me he'd pulled 9g avoiding the helicopter. Are you ex RAE?

[lightningmate]

chevvron,

Certainly not XV344, she sits resplendently in the middle of the QinetiQ site at Farnborough.

I will offer you XN975, Buccaneer Mk 2 prototype.

I have worked at RAE Farnborough, serving RAF at the time, and wearing a green coverall.

lm

[chevvron]

Don't actually recall that one; I know we had at least two delivered in when withdrawn from FAA service and '344 was one; then of course there were three special builds '986, '987, '988. Maybe '975 had only recently arrived when it met it's end? Can't see '344 from my viewpoint; all we can see is a Puma and a Jaguar.
Obviously our paths must have crossed at some time; I may even have flown with you!

[lightningmate]

chevron,

You have clarified it was an RAE aircraft asset; hence, it was XN975 on 14 June 1978. A day engrained in my psyche!

The empennage did separate but not during any of the extreme manoeuvring. It was broken away as the aircraft impacted the ground and survived the fire by being deposited some 100ft behind the main impact area.

Regards
lm

[Flying Lawyer]

Tom Eeles has just written a book.

http://www.netbooks.co.uk/productimage/m_1844156885.jpg

Good reviews from friends who've read it.
I'm still waiting for Amazon to deliver mine - cheaper than in the bookshops.

[foldingwings]

There was a certain instructor on the Bucc OCU at Honington (1971) who introduced all new navs to the loop in a Buccaneer on their FAM 1 sortie - so he must have done it more than once and survived!

It went like this:

Pilot: Right Foldie, I'm now going to show you a loop in a Buccaneer!

Baby Nav (thinking catch question this): A loop is not cleared in the Release to Service! (thinking gotcha - ya can't catch me).

Pilot: Shut up, hold on, give me the heights and speeds on the way up AND on the way down!

I recall we entered at 5000ft and bottomed about 2000ft - the rest was a complete blur but I passed the sortie and subsequently, the course!

Foldie

[jindabyne]

Simple - enter at 5, and exit at 5. That was Chapple - not RN!

[david parry]

Was the C.M. at Lossiemouth midd 60s about some such manoeuvre???

[Gainesy]

Anyone recall the name of the Bucc display pilot who went to the Reds and then retired and went to Flight Refueling on Hunters?

[Africrash]

The pilot in question was John Myers (sp?)

Many years ago he let 2 sprogs, my sister and I sit in the buccaneer at the Jersey airshow several years in a row.

Crash

[Tim McLelland]

Wasn't there also some restriction on rolling manouevres because of possible roll coupling? Or am I thinking of something else?

[david parry]

Think i read you could only do a 180 roll and stop/delay then another?? in the MK1 not a full 360 roll. I stand corrected!!!

[greywings]

Tim,

You are absolutely right; roll/ yaw coupling was identified as a potential hazard. I used to give the Buccaneer aerodynamics lecture on the 237 OCU conversion course, and RYC was covered in some detail. In fact, looking at my Buccaneer MKII Aircrew Notes, Sections 14 and 15 (Aerobatics and Inertia Cross-coupling respectively), all the previous points about loops, etc are covered in depth. Although Tom's comments about why we didn't (?!) loop the Bucc are quite correct, any maneouvre that involved large control deflections at low speed / high AOA had to be treated with some respect, otherwise the spotty-faced youths could end up in trouble.

My most challenging discourse on the Buccaneer's aerodynamics was when I had to give it to the Boss of ETPS. Although he listened attentively he seemed satisfied with the explanations which was something of a relief.

GW

[BEagle]

......otherwise the spotty-faced youths could end up in trouble.

I note that old 237 OCU attitudes towards students never die.....:(

I recall "If above 400KIAS and +4G, use no more then half aileron". There was also a very clear aerodynamic brief during groundschool about why 'nose high' rolls-off-the-top were prohibited; only 'nose low' were allowed.

[greywings]

Oh Dear,

We are feeling a little touchy today!!

[Gainesy]

Crash, many thanks, that's been bugging me for ages.:)

[India Four Two]

Considering some of Beagle's previous comments about 237 OCU, I thought he was being quite restrained ;)

[greywings]

Crumbs, I hope that doesn't mean the poor chap didn't enjoy himself on the OCU.

I did. I was fortunate enough to be there when we had a great bunch of instructors and studes (and they didn't even mind being called spotty-faced youths!!).

Those were the days!

GW

[BEagle]

greywings, actually I thought the groundschool was very good indeed. Particularly the aerodynamics sessions.

But the 'learning environment' during the flying phase was, regrettably, a different kettle of fish. Lots of little things added up to make students feel regarded as unworthy even to enter the doors of the place.

"Dining In Night. Limited places, so priorities are:
1. Those who didn't go last time.
2. Those who did go last time.
3. Others.
4. Students"

Nice to find that pinned up on the noticeboard one morning....

237 OCU - an outfit which flew 100% of its allocated hours and graduated 33% of its allocated students.....:hmm:

Although there were some notable exceptions - such as the legendary 'firm but fair' Bruce C who was a superb instructor.

[greywings]

Crumbs,

That must have been after my time. I think anyone who went through in the mid-70's should have a very different tale to tell.

Anyway, all water under the bridge now, and we should be content with happy memories of having flown a great aeroplane with a wonderful bunch of people.

It is interesting how strong the affection is for the Buccaneer even after all this time.

BTW, how is the officer Chappell these days? I remember giving him his first ride in the back when he was converting as a QFI on the OCU. I think it gave him a completely different perspective on life!!

Yours aye,

GW

[Brian Abraham]

BEagle, OT but you do take me back re dining in nights. The instructions we were given as students was "Not permitted to attend but you do pay your mess share". (Dark Blue)

[greywings]

Come on, chaps, let's stick together.

We had a good time, flying a great aeroplane - a British aeroplane - and if we can't get beyond complaining about how we were treated at dining-in nights 30-odd years ago, something is seriously wrong!!

GW

[BEagle]

GW, yes, obviously different eras!

Last time I saw BC, he was at St. Athan as the resident fast jet TP - and seemed to have aged about 5 minutes in 20 years.

Thundering around at low level in the mighty British beast was an epic experience - I think my most enjoyable trip was with my fellow student in the back during 'WS FAM2', when we were sent off to look for things to attack! Licensed hooliganism!!

Least favourite was HI NAV 4, one Saturday morning in November. Launched off and into low cloud, up to high level for rather a pointless triangular navigation exercise (offset TACAN was a godsend though) - the 3 student crews in a 20 min stream. Back to Honington, a GCA and overshoot due to Wx below limts, then another GCA to land at Mildenhall. 40 min IF - and none of us had Instrument Ratings. 2 of us landed at Mildenhall, the other went below his limits and landed at Honington. Then a slow bus journey back to Honington before they grudgingly admitted that the Wx wasn't going to improve, so let us stack. We did at least then have Sunday off before a week of low level navigation.....:ok:

[david parry]

Try being Victualled in on a Pusser war canoe,:) you would never drip again about mess dinning :ok:

[greywings]

Thanks for those memory-jogging comments.

Great to hear that BC continued doing what he did best. Not sure how he would have taken to flying the bucket and spade brigade to the Canaries five times a week!!

GW