Gazelle: Flying, operating, buying
Loose Nut, many congrats on your Gazelle purchase, in my opinion, if you don't need to carry pax or rent it out, you've made the right choice. . .I too went through this loop last year but decided the best way forward was a 'genuine' civil variant as it posed no artificial CAA restrictions for its intended use.. .Ref your conversion, make sure they give you an in-depth explanation of Fenestron Stall/Yaw Divergence/Loss of T/R Authority (I've heard it called all 3) as it's caused the destruction of several helicopters by the unwary. Another gotcha is Jack Stall which is a high-speed phenomenon; you should have this demonstrated to you - but a few TRTOs don't. Again, ask for a thorough explanation. Finally, it's your first turbine so take time to do a thorough technical course, the Gaz has several quirks you need to know about to ensure safe and 'inexpensive' operation.. .Hope this helps, and most importantly, enjoy it; it's an expensive toy but it beats the *&^% out of flying one of Franks machines! J. . . . <small>[ 12 March 2002, 10:58: Message edited by: Heliport ]</small>
There is an outfit based at Stapleford Aerodrome (M25 / M11) area called MW Helicopters (01708 688115). While I'm sure they are not just there to offer advice and information, they are regarded as the Gazelle experts and looking at the work they do with ex military machines, they really have a passion and love for these excellent helicopters. Worth giving them a try and I'm sure if you need work done on your gazelle it would be well worth building up a rapport with them.
p.s. You seem to have done a bit of research while buying your aircraft, I'd love to know what the basic hourly rates worked out as for Gazelle, 206, R44 - All inclusive.
p.s. You seem to have done a bit of research while buying your aircraft, I'd love to know what the basic hourly rates worked out as for Gazelle, 206, R44 - All inclusive.
Loose Nut, are you the MD of TLC by any chance? Sound like an familiar story. . .There was a thread on thisa very subject about 4 monbths ago. Check it out under the search option.. .I was also a Gaz QHI with 3000hrs on type.. .. .I wouldn't recommend the fenestron stall demo unless the instructor has either (a) experienced it himself before, or (b) he is an ex mil beefer.. .If it goes wrong you've got egg on face. It's a benign manoeuvre but a most unforgettable experience and not for the faint hearted.. .Your main hassle will be running costs, you have to have a mini bowser attached to the fuel intake!. .Permit to fly can be workable without breaking the rules, but you'll learn all about the pro's and con's of that from the latest thread on the subject.. .If u r the MD of TLC we can chat when you next visit us!!. .No jack stalling now <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />. . . . <small>[ 12 March 2002, 11:35: Message edited by: Heliport ]</small>
TC, I don't know of anyone who's daft enough to try to demo Fenestron Stall, do you? Hence my recommendation that he gets a 'thorough explanation'. Jackstall is a different kettle of fish, just needs to be demo'd at height and with empathy for the machine. J
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Loose Not. .Thanks for taking up my suggestion to tell us about your new acquisition. Great post.
I still fly Gazelles occasionally and if I was in a position to buy my own helicopter, it would be my first choice.
As Special 25 says, MW Helicopters at Stapleford specialise in Gazelles and are the established leaders in the field - well worth speaking to about maintenance or if you have any problems.
SW at Redhill may also be good (your man's an ex- RN Observer I think) but I think you are their first customer - that sounds bad, I didn't mean it to!
)
I wish you many hours of happy and safe flying - and look forward to more contribtions to Rotorheads.
[ 02 March 2002: Message edited by: Heliport ]</p>
I still fly Gazelles occasionally and if I was in a position to buy my own helicopter, it would be my first choice.
As Special 25 says, MW Helicopters at Stapleford specialise in Gazelles and are the established leaders in the field - well worth speaking to about maintenance or if you have any problems.
SW at Redhill may also be good (your man's an ex- RN Observer I think) but I think you are their first customer - that sounds bad, I didn't mean it to!
)I wish you many hours of happy and safe flying - and look forward to more contribtions to Rotorheads.
[ 02 March 2002: Message edited by: Heliport ]</p>
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You are a lucky man, the gazelle is the MG of the skys and is just great fun to fly. All the problems discussed should not cause any problem whatsoever just make sure you have been briefed on the possible problems. Apart from that enjoy it, it is a fantastic aircraft to fly.
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What is the reason behind the restriction on taking passengers. Surely either the aircraft is fit for civil use or it isn't. does this mean you can only fly either solo or with an instructor / examiner
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Dear all. This Fenestron stall business worries me. I managed about 450 hours on type in the AAC and loved ebvery minute of it(apart from the seats). A good friend of mine (serving QHI 4000hrs+) said that Fenestron stall is a myth concucted up by someone many moons ago who probably lost tail rotor authority withwind from right rear which we all know the Gazelle doesn't like. According to him, while at Boscome Down they tried all sorts of nasty things to induce it and nothing happened. Has anyone out there actually experienced it? I never did.. .PS. Nice buy though, lovely to fly and quick, many congrats to the lucky new Gazelle jockey
Loose Nut - don't fret over the Fenestron Stall bit, there isn't a demo for it anyway. The demo that is given to AAC Gazelle drivers is about running out of tail rotor authority in a high hover over Belfast, at night, downwind and with a dodgy geezer in the other seat trying to keep an eye on the bad boys. The Army Gazelles are operated at very high AUM and don't have a huge amount of spare performance. . .. .Jacque Stall, that well known Frenchman, is a sort of advanced warning of retreating blade stall - the hydraulic jacks are not man enough for the job (aerospatiale claimed it was a design feature) so when the areodynamic back loads are high (high speed, high disc loading) the jacks give up the struggle temporarily and the aircraft pitches nose up and rolls to the right. Lowering the lever and unloading with the cyclic will rectify the situation quite quickly. In your day to day flying you will never get close to jackstall as long as you don't try to dive to VL at MPS and pull hard.. .Aerospatiale released a video of a French Test Pilot and a UK mil pilot recovering from sustained yaw rates of 120 deg/second, so Fenestron stall doesn't exist in the way it is alleged to either.. .Enjoy your Gazelle, I loved flying it and only wish I could afford one too!
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Thanks to everybody who replied for which I am much the wiser, it sounds like the Gazelle is just like one my cars - fast,thirsty,exspensive to maintian and will bite if you get cocky. Its half the price of a civvy model so at least I have a head start, I will let you know how it transpires and its great to know I have some more contacts if needed.. .Cheers.
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ravenx - As the CAA will only issue a permit to fly, they can stipulate under what rules you may fly it. They will not issue a certificate of airworthiness because it is a different mark of Gazelle than the civilian variant. It was operated by the military on a Military Aircraft Release and alright for military pilots to fly, but once sold off they are treating it the same as an ex Vulcan Jet. Interestingly the CAA CAP document that defines Permit to Fly states that aircraft over 2730kgs are covered. The Gazelle weighs considerably less, but they have invoked the same restrictions. It will all be tested in the courts at some point, but not before the dear old Gazelle has been through a complete overhaul, amazingly increased in value from 30k - 120+k, and still you won't be able to fly your granny on her birthday without giving her a groundcrew certificate.. . . . <small>[ 03 March 2002, 23:26: Message edited by: Jeep ]</small>
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Loose Nut - the Gazelle is a sportscar and has, as you are aware, a sportscar price tag for the running of it. I would beg to differ on a demo regarding YAW DIVERGENCE, it is possible to demonstrate this characteristic and it is possible to do it in a low key manner that easily demonstrates the problem. 'Jacques Stall' is a simple characteristic to overcome but does need demonstrating incipiently. The beautiful machine needs a couple of other demos with regard to performance but best left out of this forums discussion lest I get spanked hard! If you wish to know more drop me an email? I am dead jealous and wish you every once of fun with your GAZPIECE.. .. .There's alot of experience out there on these beasts so you're likely to get some good info'. .. .eden(energy driven eccentric nirvana). .. .(ex- RN QHI and 'Shark')
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WTF are you talking about, 'Yaw Divergence'?. .Please enlighten us all, I think that most Gazelle pilots probably haven't heard about such a phenomenon.. .Reaching the limit of effectiveness of the tail rotor(feneston), Yes. Yaw divergence???????????
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Reg 'conehead' - I'll tell U wot the F**K I'm talking about! If you perceive there to be anything other than this affecting the Gazelle performance then you are mistaken or content that your experience is different and I aint gonna argue with you. BUT - and it's a big BUT! . .. .History - all of the 3 UK services suffered several, ney multiple accidents involving low speed handling manoeuvres in turns to the left or in spot turns to the left. It boiled down to a consideration that the fenestron was causing the tail rotor to stall. Aerospatiale and the RN eventually got together to do some radical testing of the Gaz performance. It put the an Aerospatiale pilot in with Lt Cdr Paul Shawcross RN, who I believe, had not long before had just such an awkward flight. . .. .It demonstrated on video that in high rotational spot turns of increasing magnitude, and I can't recall the final rotation rate but it was in the order of 180 deg per second that the rotation was divergent or increased in amplitude upon application of pedal. When I say divergent - I mean that with 'X' amount of pedal the rotation to the left increased even though the pedal position remained constant. The rotation was however halted with the application of FULL opposite pedal, which provided a massive overtorque. This was all captured on video (as mentioned in an earlier post). . .. .The deduction was that due to the incidents/accidents that had occurred in the past. The PERCEPTION was that pilots had lost tail rotor authority, tail rotor effectiveness or that the tail rotor had stalled. It was assessed that in the extreme attitudes and high rotation that the pilots never achieved FULL opposite pedal deflection during any recovery action that they may have taken. . .. .The term 'fenestron stall' was erased, certainly the RN (and I think the other services also - happy to be corrected) replaced it with YAW DIVERGENCE - it was fairly late in the Gazelle miltary career that this evidence was brought to bear and therefore only fairly recent QHI's and Gazelle pilots were very familiar with this terminology. Furthermore, it was of great interest to me as a display pilot that i understood the implications of this problem and the recovery action should I end up being so hamfooted as to give myself a self induced enema manoeuvre. . .. .I did have occasion with a handful of students to exercise incipient recovery action to this effect . .. . I am satisfied that the explanation regarding Fenestron Stall - falls squarely in the seat of YAW DIVERGENCE with a reaction akin to...... '**** I've lost tailrotor control, hack the lever' without ever attempting to use the FULL opposite boot or something similar.. .. .I hope this clarifies where I'm coming from .....
eden, Paul Shawcross was on my QHI course. Got best stude if I remember.. .Yaw divergence...been there, done that. Scary stuff. <img border="0" title="" alt="[Eek!]" src="eek.gif" />
eden, if I remember correctly, only those ac fitted with SAS (stability augmentation system) have ever suffered crashes/incidents that were alleged to have been caused by Fenestron stall. The French video, as you mentioned showed that even at rates of yaw to the left far in excess of those reported in the incidents could be halted by the full application of right pedal. The overtorque will happen in any helicopter you try this with, it is not peculiar to the Gazelle.. .The yaw channel in the SAS makes Gazelle pilots lazy at low speeds because it does some of the work for you, the problem come when it saturates - the required yaw pedal position is nowhere near where it needs to be and most pilots used to SAS are reluctant to apply the correct amount of pedal because they are not used to having the controls in that configuration and are very wary of overtorquing. A pilot in a non-SAS equipped Gaz is far more sensitive to the twitchiness in yaw, especially in the rear-right wind condition - if the rate of yaw increases he instinctively corrects with pedal and the rapid rate of yaw associated with "fenestron stall" never builds. I have flown extensively in RAF and AAC Gazelles and once you get used to not having SAS, the AAC version is better in the low speed environment.