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Global Aviation Magazine : 60 Years of the Hercules

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Global Aviation Magazine : 60 Years of the Hercules

Old 17th Nov 2015, 02:55
  #3921 (permalink)  
R4H
 
Join Date: Apr 2015
Location: UK
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Smudge hydraulic control

Smudje. Only done in Sim. Loss of all hydraulics to flying controls needed the combined and co-ordinated input and strength of both pilots to control the aircraft. I would look for completely calm or no w-wind runway and spend all day setting up about a 20 mile final approach and cross all fingers and toes. Asymmetric power inputs were too slow to cause a reaction and it was too easy to lose it!!!!!
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Old 17th Nov 2015, 12:01
  #3922 (permalink)  
 
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Angle of bank (AOB) doesn’t in itself place any stress on the aircraft. G (G) does. As a simplified explanation imagine that the wings are trying to clap above the aircraft but we fasten the wings such that they can’t do that. The wings try to move up but can’t and the fuselage lifts under the wings. In level flight Lift (L)= Weight (W) and the load factor G = 1. In order to maintain level flight as AOB is applied the vertical factor of the L vector will be < W which always acts vertically therefore L has to be increased to ensure that the vertical factor of L will be = W. 60 AOB needs 2G for level flight.
Up to 60 AOB the slope or curve of G required for level flight is quite shallow but once we get beyond 60 AOB the curve, and therefore G, increases quite markedly.
The formula is cosAOB = 1/G so if max allowed G is 2.5 cosAOB = 1/2.5 and then for max G in level flight maxAOB = 66.5 degrees. Lockheed placed a G limit on aircraft then an artificial AOB limit of 60 AOB ensuring max G required for level flight is 2G and aircraft doesn’t need to be overstressed to maintain level flight.
You will notice that level flight keeps being mentioned. This is the only parameter used for AOB and G fatigue calculations. If you don’t want to maintain level you can bank to any angle, pull any G less than 2G and descend actally applying less stress on aircraft than doing a 60AOB level turn. (AOB and G required for level flight is completely independent of weight or speed so applies to all aircraft at all speeds)
Lockheed set an AOB limit and a limit is a limit but exceeding that limit at less than the aircraft G limit isn’t in itself placing undue or extra stress on the aircraft (assuming that rudder input is co-ordinated to balance turn).
Thanks R4H, not being COMPLETELY narcissistic, I appreciate you've done that for everyone and reiterate that I am aware of the aerodynamics . . .

My point remains that the clever folks at Lockheed knew that when they set the limits. Your point in the last line is, for me, the clincher. How many times did you see the ball perfectly in the middle on a high AOB manoeuvre? (Honestly).
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Old 17th Nov 2015, 12:21
  #3923 (permalink)  
R4H
 
Join Date: Apr 2015
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Overstress

One of the problems we had was losing NVG sorties because of checks required after a supposed overstress during the day sortie, typically Fighter Evasion. The g meter wouldn't show an overstress but the fatigue meter would have clicked a count below an overstress and so an overstress had to be assumed and checks carried out. As the g meter was all the pilot had to go on, and the difference between g meter and fatigue meter wasn't consistent between aircraft, I suggested that I took each SF frame on a quick sortie, squeezed into a turn until g limit was reached on g meter or fatigue meter showed a count. We could then mark g meter with a limit line, reducing the number of overstresses and / or wasted manhours checking for something that might not have happened, and saving sortie cancellations.
Refused. As I would be flying to an deliberate overstress it wasn't allowed. Possibly 1 count per frame as opposed to possibly several with uncalibrated g meter but common sense wasn't allowed.
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Old 17th Nov 2015, 12:23
  #3924 (permalink)  
 
Join Date: Apr 2010
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I trust that R4H was not looking at the ball whilst conducting such manoeuvres!
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Old 17th Nov 2015, 12:29
  #3925 (permalink)  
 
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Maybe there was a tuft of wool stuck on the windscreen at his eye height, of course it might need calibrating for side by side seating.
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Old 17th Nov 2015, 13:20
  #3926 (permalink)  
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Unusual Attitudes ...

Given the above topic of conversation ... this makes interesting reading



Image Credit : Flight Global

Originally Posted by Flight Global
While being operated at roughly 15,000ft, “the aircraft exceeded the targeted angle of sideslip until it departed controlled flight,” the report states. It “momentarily inverted, before being recovered after losing approximately 5,000ft of altitude.”
USAF AC-130J Ghostrider Incident April 2015

Coff.
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Old 17th Nov 2015, 14:23
  #3927 (permalink)  
R4H
 
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Finstall

Reading he bits on Ghostrider it would seem his rudder inputs led to finstall. The fin is just a wing (quite a big wing) on its side and all aerodynamics apply. Once in finstall IIRC it could be recovered but at extremes the rudder could end up blanked and recovery virtually impossible.
Finstall was never mentioned during my time on the aircraft but I'm sure there is mention of it in Aircrew Manual. Having had the guy mishandle the Tac T/O EFATO in the sim I had a play and the sim reacted as advertised. No time to play with recovery actions as sim then exceeded movement limits and exercise ended.
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Old 17th Nov 2015, 15:14
  #3928 (permalink)  
 
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The only time we mentioned Finstall was double asymmetric on the OCU. We then mentioned the drill IIRC

Pull the Flap Control c/b
Select 20 % Flap to get the high Rudder Boost pressure, apply and maintain at least 5˚bank towards the live engines.

Not necessarily in that exact order. I quit the OCU in 1982 so memory is not as sharp as it was.

Yep, the point of loss of control was when the sideslip vector masked the rudder.
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Old 19th Nov 2015, 16:10
  #3929 (permalink)  
 
Join Date: Jun 2001
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The discussion re AOB limits is as revealing as it is interesting.
I certainly remember flying with pilots who would react like a wounded elephant if airspeed was a knot or two above the limiting extension speed and the other pilot requested "Gear Down" but the same pilot would think nothing of exceeding the AOB limit at low level.
Why would such an attitude exist?
Are limits not limits? Are they there only for the guidance of (apparently!) wise men, or are they there for a reason?
I was always very suspicious of a pilot who selected which limits he deemed to be worthy of his attention and others which he happily ignored!
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Old 19th Nov 2015, 17:31
  #3930 (permalink)  
 
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Thoughts on flying Albert

When I first got to fly Albert, it wasn't the handling that bothered me but slotting into a crew and hearing all those voices on the intercom. I found the a/c was good in pitch but more sluggish in roll, needing rudder to prevent adverse aileron yaw when manoeuvring tactically.
4 months with 1312 Flt really taught me to fly the aircraft and 'perfected' the wing down technique when landing with a max crosswind.
Instrument flying was not ideal but perfectly hackable, I seem to remember that the Hdg bug and Flight directors were inaccurate.
3 engine work was fine but 2 engine work seemed perverse, satisfying of course, but perhaps something for the sim.
Formation and AAR Rx was good fun, challenging at times, but was proper polling for a change. The change of technique to lock the ailerons and use the rudders to manoeuvre in close line astern was well taught and was easy to grasp.
Strip work with or without NVGs was flying the numbers and a good teamwork exercise.
Overall it was a remarkable aircraft, with mostly fantastic people, that I was lucky to fly in so many roles: Route, AAR, SAR, MRR, TS/TacAT, to marvellous and not so marvellous places.

AOB: Once, after a 500 ft run and break with max (but no more) AOB, I was bollocked by some Senior Nav in the OM for being low and having too much bank, because that is what he 'saw' from the ground!
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Old 19th Nov 2015, 22:01
  #3931 (permalink)  
 
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Mr Ripley, et al,

That's some great input to handling Albert, which few of us have ever had the chance to do. For some, like myself, a limited experience as a glider pilot etc meant I had opinion, though no grounds for judgement on what was happening to the aircraft I was in. I really believe that whilst many, FJ etc pilots, will talk of "trash haulers" etc, that comment is mainly based on ignorance of the different, yet equally challenging roles Albert has played throughout a long career with the RAF. I can only equate to a lot of the effort to "operate" Albert with a quick mention of doing an hours fighter affil with A* H****n in the LH seat. I hung out of the LH para door that day, and was about as much use as an ashtray equipped motorcycle, the front end crew to a man left the aircraft on shutdown with sweat drenched clothing. No, not the Gulf, Norway in February. It's not all AA and ACC. I knew you drivers airframe knew something thanks all for bringing me home every time !

Smudge
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Old 19th Nov 2015, 22:41
  #3932 (permalink)  
R4H
 
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AAR

Forgot about the joys of AAR. Only went behind VC10 and Victor. Wash behind the Victor could lead to you overcompensating with roll. As mentioned use of small rudder inputs was easier to correct. If you just relaxed on all the controls the wash would anchor you nicely in position.
AARI from RHS was an interesting exercise. Getting in then leaning far forward in the seat, hunched over the controls, head bent up, staring at the basket while talking through the exercise when almost all you could see was the basket.
Three long haul AARs. Day AAR in Mediterranean from UK then on to Oman, night AAR from UK south of Azores then on to Guyana, day AAR from UK, south of Nova Scotia then on to boat drop off South Carolina. Last one should have been a landing in Nassau but ended up diverting into Charleston.
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Old 21st Nov 2015, 19:06
  #3933 (permalink)  
 
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Obviously an IFR devotee R4, here's a view from the bubble



South Atlantic with a proper tanker

Smudge
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Old 22nd Nov 2015, 07:38
  #3934 (permalink)  
 
Join Date: Aug 2012
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R4H ,
Thank you for your C130 handling descriptions , a good read . Having only see Albert flying from outside ; it’s good to be able to compare the handling qualities with a UK built 23 tonne T/prop . Much lighter I know , but similarities there are .
Your x-wind explanations hit a chord . Did the relatively narrow u/c track make much difference ? We had a wide track and a low wing , and in the Hebs and Northern Isles preferred a kick off drift method , keeping if possible the into wind wing down . But ‘horses for courses’ .

‘‘’Doesn't say much for me but in Falklands my Co-pilot was called Bambi - as he was the best friend of Thumper!!!! We all have bad spells - but 4 months of it!!!!!! Didn't help when crew were already giggling on the approach) ‘’’ .

‘Fraid I strongly disagree with your self assessment sir . ‘’ Thumper ‘’ was hard earned and should be proudly worn . Not to mention excellent leadership and superb CRM . ‘’Crew giggling on the app’’. …… good crew comms , shallow rank gradient , and an happy team , follow you anywhere …. Not to mention stressing you up nicely !
How many times with Cavok , 10kts down the strip , de-stressed …. Thump .
Howling x-wind , rain , low cloud , min fuel , dark night , wipers slapping time , alternate out , stressed … Perfection !

Formation tales appreciated . Were you a Green Barrow ? Any tale welcomed , having seen them at ‘Music in the dark‘ at Middle Wallop , quite a sight and sound from the ground . 4 Ks in close formation pirouetting to music , against a summer sunset with dramatic cloudscape , at a venue with little ambient light pollution . Thank you .

Rgds condor .

P.S. forgot to ask was the Ks normal G limit only 2.5 ?
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Old 22nd Nov 2015, 11:19
  #3935 (permalink)  
 
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This video taken by the OC 59 Cdo RE. Falklands 1982 last part is a C130 landing at Stanley airport after the runway was repaired

https://www.youtube.com/watch?v=37K_UrlzK4g#t=1269
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Old 22nd Nov 2015, 15:56
  #3936 (permalink)  
 
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The maximum G is 3, but 2.5 with flaps at 50%. These limits are reduced with some fuel/payload combinations.
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Old 22nd Nov 2015, 19:28
  #3937 (permalink)  
 
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Condor 17, how prescient of you. ISTR that R4H was indeed one of that fabulous Royal Air Force premier formation team The Green Barrows. I'm damn sure I enjoyed informing SWMBO at a Lyneham families day, that the Green 4 ? Captain was someone I had had the pleasure of accompanying "down route"! Now, have we done the Greens yet chaps ? As Condor suggests, could be some interesting tales.

Smudge
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Old 23rd Nov 2015, 09:16
  #3938 (permalink)  
 
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The Greens

Excuse my ignorance but who/what, is/was The Greens
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Old 23rd Nov 2015, 10:29
  #3939 (permalink)  
 
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Aeroid

"The Green Barrows" - Hercules display formation, 4 Hercules often led by the inimitable and never forgotten S** V**** ... a Gentleman of the first degree
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Old 23rd Nov 2015, 11:11
  #3940 (permalink)  
R4H
 
Join Date: Apr 2015
Location: UK
Posts: 61
Barrows

Often flew with SV on Barrows. I flew Co and concentrated on visual nav and positioning while he concentrated on the handling. A gent to fly with. Buck House flypast, wx dreadful. Singleton snake climbs then to Manston. Wx marginal and he called it off - good call. Wg Cdr PBUH was auth and flew as pax in one of the ac. Back at Lye he commented that he was surprised we hadn't gone for it!!!!!!!!! He couldn't say anything at the time as we were lead and shouldn't have said anything afterwards.

On recovery to Lye Heathrow offered us the chance to fly down runway as 4 ship - PBUH piped up from back that it wasn't briefed and we shouldn't do it - what a chance missed!!!!

For a practice before the event we did a singleton flythrough a week earlier. Wx was just ok so with SV flying I was map reading over London with 50,000 maps. Canary Wharf was on the run and there was a LO there to keep residents informed. London ATC informed a police heli that we were running in as he was in the area and he said he would hold low. After passing his comment to ATC was that if he had known how low we would be we could have done his job for him!!!!
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