Hands off the controls during carrier catapault launches

[Centaurus]

Talking to an aviation medicine doctor about somosogravic effect where pilots have been known to be fooled by perceived acceleration and react incorrectly. We discussed aircraft carrier ops and I pondered why naval aviators are seemingly not affected especially on catapult launches.

Personally I think that some accidents that have been put down to somosogravic effect are more the result of poor instrument flying ability rather than a medical event. The doc said naval aviators are especially vulnerable to this somosogravic effect (I hope I spelt it correctly) and said that is why just before a launch the pilots take their hands of the controls so as not be caught by this situation and therefore are not prone to pushing forward on the control column in response.

I thought he ws pulling my leg but he was serious. I thought the reason on catapault launches that pilots keep their hands away from the throttles and from the control column was to avoid involuntary moving these controls due to the force of the launch.

What is the true reason for pilots keeing their hands of the controls during a launch?

[Courtney Mil]

Both the effects you mention come into play. F4 (K model) had levers to hook the fingers of your left hand around to stop your arm (and the throttles) being dragged backwards by the acceleration. Piece of string set the stick position, but you couldn't let go of the stick in a lot of types. Many newer jets were, most certainly, hands off at launch.

[foldingwings]

Never did it myself but I know many who did in a Buccaneer and, as far as I recall, it was always a hands off catapult launch!

Foldie:cool:

[Schiller]

In the earlier jets (eg Sea Hawk, Venom etc), the relatively unsophisticated AH's tended to give a nose up and right turn indication during the acceleration. At night, this could cause accidents if the pilot didn't ignore the indications during the short period before the instrument re-erected. However, launching hands-off was not an relevant option.


The Buccaneer had very low pitch stability in the take-off/landing configuration. Several accidents occurred during trials which were ascribed to the pilot inadvertently moving his hand back under acceleration. Accordingly, the hands off technique was employed which cured the problem (at least, until the Mk2 with slipper tanks reached front-line service, but that was different). There wasn't any particular problem with this; you had to calculate the trim setting fairly carefully, and the setting was confirmed by an outside observer with a set of flip cards showing you what the tailplane trim indicated on the scale on the fin actually was. Once airborne, the aircraft started to climb as the speed increased (slowly, in the case of the Mk1!), so one usually placed one's hand behind the control column and eased gently forward, trimming the while, until the aircraft had accelerated sufficiently for one to grasp the shiny levers and aviate normally.

We kept our hands firmly on the throttles, though, throughout.

Dunno anything about the F4. Noisy beasts.

[chopd95]

I have no personal knowledge (my daugher delights in telling me that I know a little about a lot), however ......

Tom Eales " A Passion for Flying" p 45:

"The technique used for launching a Bucc was "hands off". a tailplane trim setting was calculated...........etc. This was set and the theory was that it would rotate the aircraft into the correct attitude for the initial climb without intervention from the pilot.Once positioned on the catapult........the pilot would lock his left arm behind the throttles to ensure they remained at full power, raise his right arm to accept the launch, then place it on his right thigh, close to, but not holding, the control column.
The acceleration was phenomenal, then everything stopped when you became airborne. It was like being fired into jelly. You then carefully took control.........!!!

[John Farley]

I pondered why naval aviators are seemingly not affected especially on catapult launches.

Don't forget the acceration effects stop dead as you leave the ship. In fact they stop so sharply the body even senses an aparent opposite effect which is the classic way to reboot ones senses. In the case of a nystagmus (involuntary flicking of the eyeballs) caused by very rapid rolling remember how the trick to sort out your head was to just do a very brief flick of the ailerons in the opposite direction? Immediate reboot.

[blaireau]

The F4K had a SPD (stick positioning device) on the forward centre console. Tail plane angle was calculated according to weight, end speed etc. On the catapult, the pilot positioned the stick with SPD declutched, to achieve required angle. There was an internal indicator and one of the deck crew displayed the actual tailplane angle (on a handheld board) to the pilot who adjusted accordingly. When it was correct, the SPD was clutched to that position.

Throttles were manually held at full reheat, and on cat firing, off you went for the thrill of lifetime (or one of them).

The SPD did slip occasionally, allowing excess angle on the tailplane. This was generally insignificant unless launching at MLS -.

Hands were on the controls, but imputs were not made until after the cat stroke and aircraft rotation was complete.

[Bubblewindow]

Personally I think that some accidents that have been put down to somosogravic effect are more the result of poor instrument flying ability rather than a medical event

While I agree to this to a certain extent, having been part of an investigation after a crash which was finally attributed to the pilot suffering this phenomenon and not relying on his instruments, I'm also of the opinion that the pysical and physcological affects can be extremly overwhelming.

Not being a driver I've experianced this affect as a pax during a low level abort due to WX. While low level in a Hawk we encountered low cloud and immediately pitched up to break cloud cover. To this day I'm convinced we pitched so much that we inverted and we're flying back towards our original direction from which we came, still wrong way up, but in fact we broke cloud cover and my driver completed a roll (just for the heck of it). So I can see how these sudden effects can act upon the body and mind.
But (I'm contradicting myself now :confused: ) thankfully the guy up front knew his ass from his control column and flew on instruments.

I'll get my coat ,

BW

[ex-fast-jets]

I did a few cat launches with the USN.

It wasn't "hands off".

But it wasn't "hands gripping" either!!

It is a fairly violent manoeuvre, so one does what is right - keep hands close and on, but go with the flow!! If control inputs are needed, then do it - if not, then let God take control!

It all happens quite quickly, so natural responses seem to me to work OK!

I didn't see a need for a decisive "on or off" dictat!!

But there will be others with a whole lot more experience than I who might offer an alternative opinion!!

[glojo]

Not my place to offer an opinion

But this is what I have always seen

[Navaleye]

I heard a story that after a couple of Bucc crashes on Victorious, either Blackburn or Boscombe sent a test pilot to fly the Bucc Mk1 to prove that it was pilot error. He went into the drink on his first launch but luckily lived to tell the tale.

Further investigations were made and procedures adjusted! :mad:

[david parry]

Yep JDE from Boscombe Down and ( S who was a RAF 801 squadron observer) to 801 squadron on Hms Victorious, was on deck ,when he went in. Off Singapore. Also when the other one went in G and E, from 801 squadron whilst we were on a workups off the Lizard ,before deploying.

[Edmund Spencer]

Forgive the slight thread creep but the sea harrier launch off the ski jump needed careful stick handling. The trim and nozzle angle was calculated for the conditions and AUW etc and usually resulted in a launch with no pitch input required until the acceleration mode.
This was completely different from the land based take off where a large back stick movement was needed at nozzle rotation to avoid bashing the nose!
A certain GR 3 pilot never quite got the hang of this during his time on HMS Hermes in the Falklands and ended up clearing his wing at least twice with enormous amounts of instantaneous AOA.
Poor fellow even managed to land in the catwalk!
Never was an RAF officer happier to procede ashore to Stanley.
ES

[4Greens]

In the Scimitar the routine was closed fist behind thrust levers to prevent any inadvertent dragging back. Hold the stick normally but with your elbow into your stomach/chest.

[SpazSinbad]

A4G Skyhawk Catapult Launch as per NATOPS was to have correct trim and flap setting. A handle next to throttle was swung down so that at full power the pilot could grasp both the throttle and this handle to prevent throttle slipping during launch. Also the throttle friction grip was wound to 11 (as per 'Spinal Tap').

The pilot brought right hand cupped into the pit of stomach awaiting the slow backwards drift of the stick (under hydraulic control so movement slow during catapult stroke) to grasp the stick as it reached stomach just as the aircraft left the bow, to fly nose up in a positive rate of climb. Then the throttle catapult hand grip swung back out of the way and throttle grip loosened for ordinary flight. And trim trim trim. Flaps up wheels up.

Night catapults were fraught with niggles such as those highlighted here:

Dark Night Takeoffs (http://aeromedical.org/Articles/dnt.html)

Click thumbnail for the bigger pic (11): http://i98.photobucket.com/albums/l261/SpazSinbad/th_NightCatOtolithFailure.gif (http://i98.photobucket.com/albums/l261/SpazSinbad/NightCatOtolithFailure.gif)

[Basil]

Thread drift warning.
Whilst we're mentioning general illusions; flying into Frankfurt 25? one night , busy crossing road traffic on finals gave visual illusion of aircraft drifting :ooh:
Back onto instruments until past road!

[ex-fast-jets]

A certain GR 3 pilot never quite got the hang of this during his time on HMS Hermes in the Falklands and ended up clearing his wing at least twice with enormous amounts of instantaneous AOA.
Poor fellow even managed to land in the catwalk!
Never was an RAF officer happier to procede ashore to Stanley.

I am only aware of one occassion when he cleared his wings on launch - and that was because his launch distance - which was questioned - was wrong for his weight and the WoD. It was a Wings bad decision, and not a fault of the pilot. Fortunately, because he was aware that his launch distance seemed inadequate, he was well ready to jettison his wing stores, and so saved the jet and himself from a watery grave because of one of the many bum management decisions which where so readily available on HERMES at the time. He should be applauded for his actions, not offered implied criticism. In fact, if my memory is correct, having flown clear from the ship, he flew clean wing to support his formation partner on an operational sortie, rather than returning to land and abort the task.

His "landing in the catwalk" does not give fair comment on the weather pertaining, or the operational pressure. He actually just put one outrigger off the edge, and tilted slightly - and the jet was very quickly righted by deck personnel. So let's not make an assumed conclusion that the fault was all attributable to the pilot. Again, if my memory is correct, he landed heavyweight with bombs on the wings, rather than jettisonning them into the sea after a sortie when targets were not available.

But, yes. I think he was very pleased to get ashore. It was he who gave HERMES the Crab title "RIRB" - Rat Infested Rust Bucket.

The Ship was, in fact, OK. But its management was lacking in very many ways. Thankfully for many, the magnificent Chinook "Bravo November" was not pushed off the back of HERMES into the sea - which was a very real threat - because the crew took the option of going ashore unsupported, which was the only alternative open to them following the demise of ATLANTIC CONVEYOR. And what a great job that one Chinook did!!

Yes, more thread drift, but the previous comment needs to be put into context.

[Abbey Road]

I don't think anyone has mentioned it yet, but I am sure it is somatogravic, not "somosogravic", illusion. :ok:

[Navaleye]

BomberH

I seem to recall he was carrying BL755 at the time which were swiftly sent over the side. No harm done and a good result and a working aircraft for the next day.

[Feathers McGraw]

glojo With the F-18 the FBW flight controls are designed to do the right thing on their own, so require that the pilot does not hold the stick during the cat stroke. The cat will not be fired unless the pilot's hand can be seen gripping the canopy grip as shown in the video. The salute comes first followed by gripping that handle.

[Centaurus]

I don't think anyone has mentioned it yet, but I am sure it is somatogravic, not "somosogravic", illusion.

Oops!. Thanks for the correction. I couldn't find the word in my el cheapo dictionary and took a punt. Thought I had away with it too. Just testing of course:E

[david parry]

Tut ! Tut! The Crabs calling the Happy H a RIRB:{ saw loads of cockies on board and some two legged rats. But never any rodents. But I suppose the FAA boys, are not used to the hotel life, of the RAF;)

[exMudmover]

Edmund Spencer

“A certain GR 3 pilot never quite got the hang of this during his time on HMS Hermes in the Falklands and ended up clearing his wing at least twice with enormous amounts of instantaneous AOA.
Poor fellow even managed to land in the catwalk!
Never was an RAF officer happier to proceed ashore to Stanley.”

You are wrong and BomberH is absolutely correct. And a Sea Harrier pilot also landed in the catwalk on Hermes -- was he also a “poor fellow”?

You are clearly ill-informed about the facts of life in the South Atlantic in 82. Just remember that this RAF pilot, whose reputation you impugn, was flying the difficult and dangerous Ground Attack and Recce missions throughout the war, rather than the low-risk Air Defence operations in which the Sea Harrier pilots were engaged for most of the time.

[glojo]

Surely this is all just banter? No one, but no one is suggesting ANY pilot was incompetent, excreta happens, mistakes are made, this was a time of high level stress and far better to laugh in the face of adversity..

I guess my military sense of humour is from the homophobic 60's (not blooming 50's.... cheek) and I just took this as the usual inter service banter? Picking on Fleet Air Arm appears okay, but woe betide ANYONE that dares to throw a little bit of banter in the opposite direction.

ALL pilots that served in that conflict were a credit to their uniform which was NOT any shade of blue... It was a tatty shade of green :)

[noprobs]

Forgive the slight thread creep but the sea harrier launch off the ski jump needed careful stick handling. The trim and nozzle angle was calculated for the conditions and AUW etc and usually resulted in a launch with no pitch input required until the acceleration mode.
This was completely different from the land based take off where a large back stick movement was needed at nozzle rotation to avoid bashing the nose!
In the GR1/3, full use was originally made of the variable nozzle stop, resulting in little requirement for pitch input at the point of nozzle rotation. Using a chase-around graph, adding data on aircraft weight as configured, temperature and pressure gave an optimum airspeed and nozzle angle for takeoff. The nozzle stop was set to the calculated angle and a bug set on the ASI to show the speed. After initial acceleration with the nozzles at 10 degrees, on reaching the bugged airspeed, the pilot moved the nozzle lever to the stop. Latterly, pilots were taught to follow a simpler procedure, using a spinwheel calculator, but with a standard 50 degree nozzle angle for takeoff that might need elevator input . My Sea Harrier experience is limited, but I don't remember it being too different when taking off from a standard runway. I do remember, again from limited experience, that the ski-jump looked very close when using the calculated line-up point.

Returning closer to the original question (but still not back to the catapult) there was an interesting film of early trials of the Harrier from a flat deck. The camera was positioned near the rear of the superstructure, giving an oblique rear view of the takeoff. The aircraft lifted off in the normal Harrier manner, with combined lift and downward-vectored thrust keeping it airborne. As it left the end of the deck, the thrust ceased to impinge on the surface, and the aircraft sank. The pilot reacted by raising the nose, the changing attitude being apparent as the aircraft disappeared from sight in front of the bow. On film, a series of heads appeared from right of shot trying to see what was happening, before the jet accelerated and climbed back into view. :eek:

[glojo]

I was hoping to hear from ex Vixen, Buccaneer or Phantom pilots as my memory is not what it was as an outsider looking in...

I am sure I can recall the pilot acknowledging the Flight Deck Officer with a salute but then I cannot recall if the hand went out of sight... We know the procedure for US pilots and going back to that last remark by the previous poster... The Vixen would regularly disappear below deck level and then immediately re-appear with its pedal to the metal.... Every launch would see an expensive wire strop being donated to Davy Jones Locker :(

Flight deck operations on a conventional carrier was a sight to behold and those that think they could simply hop aboard a carrier for a few weeks of flying are with the very greatest of respect simply talking a good fight.....

[david parry]

Seem to remember most of our Buccaneer pilots on the Cats ...... tapped both hands on top of there white helmets twice and then placed the palm of the right gloved hand on the side of the perspex... before the FDO lowered his green flag.... isc

[blaireau]

F4 pilots saluted the FDO, got his nod, then put their hand back on the stick. White cape leather gloves were often retained for better visibility from the FDO's perspective.

[Courtney Mil]

Indeed. The F4 cat launch was 'hands on'. The accelleration would have moved the stick aft if you didn't hold onto it.

[aeromariner]

Not a whisper from a Gannet Driver?

[c-bert]

I was always led to believe the F/A-18 launches are hands off because the aircraft's computers manage all the necessary inputs until weight off wheels.

[GreenKnight121]

Longer, actually... it all depends on what you told the computer before taxying to the catapult.

[Edmund Spencer]

BomberH
Been offline for a long time.
I meant absolutely no offence. The RAF No 1 Sqn were the most incredibly courageous fellows.
You guys were flying around at low level against capable ground to air fire and I have the utmost respect for what you achieved.
I remember small things like Jerry Pook storming down the deck, when I was in the cockpit at alert five in my sea harrier, absolutely refusing the attention of the very worried medical people after he had ejected from his harrier due fuel loss to ground fire.
I remember McCloud describing the 20mm shell that hit him squarely on his front windshield and actually cracked it. (Right between his eyes.)
I remember the awful worry when we thought we had lost Glover. And worst still when we had strafed a helicopter which could have contained him.
I remember the amazing, was it Styvesen, who ejected and was prepared to fend off the enemy with his 9mm. Turned out they were sheep! We were so incredibly happy to get him back.
Bomber, in the Fleet Air Arm it is usually a bit of a jape if you land in the catwalk or have a misdemeanour on landing. Everybody understands that operating off the flight deck is incredibly demanding. You guys in the Falklands had to try to get your GR3s to work on a moving platform!! You did spectacularly well and will always deserve the huge respect of your fleet air arm counterparts.
My comment was just something we would have a beer about in the bar.
I profusely apologise if you took it otherwise.
ES

[Navaleye]

was it Styvesen

I think you meant Bob Iveson?? I think he made the mistake of trying the same thing twice.

[622]

IIRC correctly (and slightly back on thread) the Sea Harrier FRS1 (or may have been the Indian FRS51) had a retractable lanyard in the instrument panel that clipped to the control column and released via a simple trigger.
Stick held back against this during take off (I havent a clue what mode of take off!) and then I assume released once in the air.

..I don't think I imagined it! :confused:

[Gulfstreamaviator]

Sorry if I am too technical, but on the W2 carriers there are many crane like things hanging over the side.

What are they, and are they on modern carriers too.

Thanks

Glf

[Navaleye]

They were there to allow aircraft to be stowed partially off the flight deck without it falling off. The idea being that the wheels/cockpit/engine was on the deck and the tail secured to a mooring hanging over the side.

[Not_a_boffin]

HF radio masts. Still have HF but implemented in a less demanding way.

Just seen Navaleye's last. Spotting outriggers also a possibility depending on what you're looking at.

[Gulfstreamaviator]

Too many and looked like cranes, so an overboard support would be logical.

Bit frightening but possible solution to limited deck space.

Glf

[walbut]

622
I dont know about the Sea Harrier but the RN Phantom FG Mk 1 aircraft had a similar lanyard which attached to the rear of the stick. I think it was called the Stick Positioning Device and contained a console mounted friction clutch/brake which could if necessary be over-ridden by pulling harder on the stick. I can't remember how it retracted, possibly with a tensator type spring inside the body. I don't think the aircraft was launched hands off, the SPD just took some of the load and reduced the risk of inadvertantly pulling back on the stick as the catapult fired.
It was made by what was then HSA Brough. As a young graduate apprentice working in Mechanical Test I did a lot of the endurance testing which involved sitting in a chair, attaching the lanyard to the rear of the stick, setting the position, pulling the stick to override the brake, rewinding the lanyard, over and over. I think I had to check the breakout load every hundred operations. It probably would not be allowed nowadays in case the tester suffered a repetitive strain injury. Back in 1970 it wasn't an issue.

Walbut

[swordfish41]

If there are a lot on either side and they look like cranes they are indeed radio aerials. They are lowered during flying operations. Otherwise raised. Will try to post some pics, but not usualy succesful.

[SpazSinbad]

For 'Gulfstreamaviator': HMAS Melbourne with aerials UP c.1977 to 1979. Otherwise they would be horizontal except for the large bent crane immediately aft of the island which is stowed as is.

Click thumbnail picture: http://i98.photobucket.com/albums/l261/SpazSinbad/NewerAlbum/th_MELBOURNEaerialsUP.jpg (http://s98.photobucket.com/user/SpazSinbad/media/NewerAlbum/MELBOURNEaerialsUP.jpg.html)

[ex-fast-jets]

Welcome back!!

No offence taken!

If you were flying SHARs on the same adventure, then we probably already have shared a beer in the same Wardrobe!!

This forum generates comment from those who do not always share the same knowledge as some who have close and personal experience of the subject thread title. And the "Nom de PPRuNe" used by most does little to clarify the person with whom you are dealing. So, with the inevitable thread drift, I felt obliged to offer comment.

But, it is now over a year since the previous comments - I was, quite simply, defending the reputation of one of my colleagues, and I certainly respect fully the efforts of all of the HERMES SHAR pilots, who did some outstanding flying, day and night, under difficult circumstances; different from that experienced by us CRABS, but we all suffered from the same "Management" difficulties!!

Indeed, during my time on VX-5 at China Lake with the USN, I shared experiences (and duty-free liquor allowances!!) with Gordon Batt who was on VX-4 at Point Mugu - we next met on HERMES and he paid the ultimate sacrifice off the bow of HERMES in 82.

I hope he is not forgotten.

[swordfish41]

http://http://i576.photobucket.com/albums/ss203/swordfish41/Ark32.jpghttp://i576.photobucket.com/albums/ss203/swordfish41/Ark32.jpg