g force tolerance

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Davey
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g force tolerance

Post by Davey » Sun Aug 21, 2005 10:16 pm

Hello.
I am 17 and hope to be a pilot in the air corps in a few years time..
I was just wondering about g-force tolerance..
I recently flew in a Robin Aircraft and pulled 2.5G and it felt pretty weird,and i was wondering if that was because it was my first flight and do you get more tolerant of Gs as your experience progresses??
I am not the best at theme park rides(probably a childhood mental thing) would that affect my G tolerance??
Does anyone know how many Gs air corps pilots would be expected to tolerate??
Cheers,
Dave :D :D

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Heliops
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Post by Heliops » Mon Aug 22, 2005 12:18 pm

Technical Specifications

Aircraft Pilatus PC-9M Advanced Turbo Trainer
Engines 1 x Pratt & Whitney Canada PT6A-62 turboprop.
Max T/O Weight 2350 kg for aerobatics, 3200 kg maximum.
Cruise Speed 500km/h at sea level, 556km/h at 6100m.
Max Diving Speed 667km/h, Mach 0.73.
Service Ceiling 11580m (38000ft).
Crew / Passenger No's 2 in tandem on Martin-Baker Mk.CH11A ejection seats.
Range 1220km at max. cruise speed,1540km at long-range cruise speed (390 km/h)
Endurance Two sorties of 1h plus 20min reserve or 4h 30min at 203km/h. g-limits: +7/-3,5 at aerobatic weight; +4,5/-2,25 at max. take-off weight.
Armament Two 0.5inch machineguns, Two 2.75inch Folding Fin Aerial Rocket pods.
Height 3,26 m.
Length 10,14 m.
Entered Service April 21st 2004
Exterior: Span: 10,19 m, Wing area: 16,28 sq m, Wing aspect ration: 6,29. 4.36 m.



Hope this helps you :D

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alphaLaura
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Post by alphaLaura » Mon Aug 22, 2005 3:17 pm

Heya; I recently flew an Extra 300 and I pulled +5g / -3g's during some crazy-ass tumbling maneuvers. Yes, feeling stronger G forces after experiencing the normal +1 or +2 G's is a little strange at first. The bottom line is, just like with most other things, your body adapts swiftly to them. The second time I felt +5g's during my lesson in the extra, it clearly felt more comfortable than the first time... So, even after ten minutes I had adapted a little.
The forces you feel in a rollercoaster are identical to those you feel during flight - just of a different magnitude (strength).

Seriously, all it takes it practise and repetition; your tolerence is expanded the more you feel g-forces. And, there are ways and means of fighting them too: remember to tighten your stomach muscles lots during positive forces. Make sure you completely relax during the negative forces.

So the point is: don't worry. You get used to these things quick.
The hardest thing about flying is knowing when to say no.
I OWN THE SUN

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Post by ceatach » Mon Aug 22, 2005 3:37 pm

alphaLaura wrote:So the point is: don't worry. You get used to these things quick.


Says the girl with about 7 inches between her brain and her heart.
Some people just cant take g-force. People have a threshold beyond which they go sleepy. I saw a programme about the german air force screening potential pilots. They threw a bunch of guys in one of those big spinny things and spun it until the guys passed out to test their tolerance. Some guys passed out at 3g others took 7 g with no suit.
They told the 3g sleepers to go away which might suggest to me that you dont get used to these things quick..... :wink:

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Post by Flyer1 » Mon Aug 22, 2005 10:00 pm

Well I certainly found that the more I flew the more I climatised to the G forces. When I first started flying I wasn't reallyl a fan of the whole idea of G forces. But now I don't mind them in the sligtest.

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Post by The Termignator » Mon Aug 22, 2005 10:14 pm

It's quite normal to feel anxious and uneasy when exposed to high g-loadings for the first time. It's something that your body wasn't designed to handle and a combination of nerves and unfamiliarity for the first few loadings can accentuate the problem.

However, your body does become accustomed to it and your tolerance will increase as you go along. An important point to remember is that the greater your tolerance, the easier it will be to concentrate and learn what's going on during these manouevres.

There are tried and trusted techniques to combat positive G-loadings, where the blood will drain from your head and upper body and pool in your legs. Burying your chin in your chest and saying 'hook' while straining your abs and legs is one technique used to combat positive g. It's not uncommon for guys to black out during extreme positive manouevres (unlimited aerobatics, for instance). First thing is the 'strange' feeling that you describe, followed by pronounced tunnel vision, followed by unconsciousness. This normally rectifies itself when the aircraft is unloaded...and hopefully you won't have made a nice smoking hole in the ground at that point.

Unfortunately, there's nothing you can really do about the negative stuff: it's extremely unpleasant and all you can do is relax and take it.

Fortunately for you, the Air Corps guys have it a lot easier than aerobatic jocks. They 'cheat' when they pull positive G in the PC9s: they're wearing pneumatic g-suits that stem the flow of blood to the legs during positive loadings. I'd imagine there's little or no negative manouevres in Air Corps flying, though I'm open to correction on this.

Another couple of points to note: fatique and hunger will reduce your tolerance substantially; shorties are more g-tolerant that tall people; and women tend to be more g-tolerant than men.

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Post by Heliops » Tue Aug 23, 2005 11:00 am

alphaLaura wrote: The bottom line is, just like with most other things, your body adapts swiftly to them.
So the point is: don't worry. You get used to these things quick.



Say that to F-15 F-16 or Military Pilots who G-lock

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Heliops
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Post by Heliops » Tue Aug 23, 2005 11:06 am

quote]
They threw a bunch of guys in one of those big spinny things and spun it until the guys passed out to test their tolerance. [/quote]

Its called a Centrifuge.

I saw that programme also, very interesting indeed. I understand that the EF Typhoon pilots wear a specail G-suit that lets them tolerate up to 12-13+G as they suit is insulated and modelled on a dragon fly apparently scientists discovered that there is some gel in the fly's body that lets them tolerate extreme G Loads and the used their findings from the Dragon Fly to make the G suit for the EF Typhoon.

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Post by Dutch Roll » Tue Aug 23, 2005 11:16 am

The whole thing on tolerance depends on the fitness of a person and a persons size,the smaller the distance between your head and heart the better,as ceatach and termignator mentioned.Thats why Tom Cruise got to be in the Top Gun Academy flying F14's!!!!! The G-suit really just the pants and covers stomach,contains bladders that fill with air when the pilot is experiencing high G,the added pressure from the air keeps blood in the upper body where it is needed.

Postive G-leads to black out,.blood drains and pools as termignator mentioned

Negative G-leads to red out,bloods pool in the head before you pass out!
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Post by Bob » Tue Aug 23, 2005 12:14 pm

I don't think g-forces is much of an issue in the aircorp

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Post by conor_mc » Tue Aug 23, 2005 1:46 pm

If you've only really sampled positive G in an aircraft once, then don't worry about it - you probably will get over the unpleasant feeling simply by virtue of the fact that, with experience of flying the manouevre yourself, you'll learn to anticipate the G force.

First time an instructor threw me into a 60 deg +2G turn, the sensation was very unexpected and a bit uncomfortable. No problems with steep turns now though - you still get the same feeling but you know what to expect.

It's a bit like driving a car quickly over a hump-back bridge - if you're the driver you'll tense up your stomach muscles. Your passenger will curse you if they're not expecting it! :twisted:

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Post by Heliops » Tue Aug 23, 2005 1:46 pm

did you know that if Tom Cruise had really applied to Fly F14's in reality he would have been denied as he is too small! :lol:

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Post by Dutch Roll » Tue Aug 23, 2005 1:48 pm

lol!! very true!
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Post by conor_mc » Tue Aug 23, 2005 1:51 pm

Bob wrote:I don't think g-forces is much of an issue in the aircorp


You'd be surprised - if you've ever watched a gunnery exercise down at Gormanston, they must be pulling significant G's as they level out of the dive and into a very steep climb.

My Dad (ex-army officer) flew backseat in a Marchetti for one sortie, many moons ago. He was pretty stunned by the G's anyway.

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Post by ceatach » Tue Aug 23, 2005 2:16 pm

conor_mc wrote:My Dad (ex-army officer) flew backseat in a Marchetti for one sortie, many moons ago. He was pretty stunned by the G's anyway.


How many g's can the Marchetti take? I was surprised to read the pc-9 can take +7g. I remember the old fouga magisters. They were a kick ass display team and they only took +5g...

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