Sir Isaac comes a knockin

Discussion in 'Aviation' started by Virgil, Feb 18, 2006.

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  1. Hopefully this is OK to post here being a civilian chopper not military. Still it's fairly hair-raising to watch. I'm sure new underwear was needed by all after this one.

    Not an aviator, I jump from planes and helicopters, but any ideas what may have been wrong and what steps the pilot was trying to take besides not ending up as a stain on the side of a building?
     
  2. I think this was a news chopper that suffered a tail rotor failure. Amazingly, both the pilot and crewman survived the incident.
     
  3. I think this has been posted before, but perhaps I saw it somewhere else. I seem to recall it being a TV/radio news helicopter somewhere in the USA. Anyone remember more or better?
     
  4. They show you this one (amongst others) if you go to Shawbury on the pilots course.

    It's about the only footage they've got of a squirrel accident.

    I'm out on a long spindly limb here with a strong wind blowing, but with a tail rotor failure it depends if it was a loss of control or a drive shaft failure. If the former then he/she/it (Ex SARTU CRAB?!) should have been able to continue to a better landing area. If the latter then he had no choice but to plough in.

    He'd definitely have lost control when he lost his airspeed, you can see as he slows down it gets worse.

    Not a good day in anyones office that.

    Mind you they were journos....
     
  5. They had a problem with T/R pitch change links and I undestand there where a couple of failures world wide in the 80s/90s.
    john
     
  6. I found an interview with the pilot that was aired. It may take a bit to load.
     
  7. Thought I would chase up the cause of the crash....

    Not tail rotor failure or control input failure but a failure of a rubber belt that drives the hydraulic pump. It caused a rapid loss of hydraulic pressure resulting in reduced control.

    AS 350 FRCs say that you have to run it on at 40kts (I think...been a while). If you are Garth then you can actually hover a Squirrel Hyds out. Tricky though. That's when you're sat at Tern Hill with a QHI htough. Little different with 2 bods and 1200ft over a city. Reckon he did pretty well and was v lucky.

    http://www.ntsb.gov/Recs/letters/2005/A05_36_37.pdf

    Imagine trying a hyds out in a Lynx.... Maybe not. Whats a Gazelle like?
     
  8. The Gazelle has considerable control forces when hydraulics are switched off. However, it is totally manageable by any normal sized person. If one of my students was doing really really well on instrument flying practice I would praise him and then let him fly the beast in manaul control for a while..........always brought sweat out of the student. Prolonged flight in manual control should be avoided........1. Very tiring 2. What caused the failure? If there is a massive leak where is the hyd.oil flowing to?
     
  9. Lynx is benign with one Hyd system deselected (No 1 out gives you slightly stiffer yaw pedals due to the interlink friction and SBU issues), with both out you become a passenger. Gazelle is a bit heavier and is fairly easy to hover and land but no where near as heavy as a Squirrel. As you say, you would need to be Garth to hover or low speed land it. The accident in question was, as quickstop says, due to failed hydraulics but as you can see from the clip, it occured at fairly low speed. The onset of PIO (pilot induced occillation) can be seen just after the initial failure. The disc moving harshly fore and aft, and the aircraft yawing. They were very lucky to get away with only minor injuries.
     
  10. You did it to one or two crewmwn as well, didn't you Con?
     
  11. CONNEACH,

    there was no fluid leak thank goodness. The drive belt broke as it was installed inside out. Basically the same as a drive belt on your car to the alternator but a bit wider. Installed the wrong way the support on the bands wouldn't have been there.

    The report is interesting as it says that US squirrels have the problem that the belt has failed loads of times before its planned life. You would think that they would have sorted that out a while ago.

    It is good that a training aircraft like the Gazelle has that amount of control ;-). No room for that option in the mighty Lynx!
    Is there a way that you can download the video from the site rather than have it streaming? Flash?
     
  12. Wolf_Nipplechips.............Yes, but never done maliciously. If a crewman can handle the aircraft under the most difficult of conditions then the easy stuff is just that....easy.

    Quickstop.....I mentioned the hydraulic fluid purely because of its volatility on contact with hot surfaces.
     
  13. Quite right too, CONN. Most if not all aircraft have as an IA on Hyd failure 'Check for Signs of Fire'. 2000 PSI of vapourised, volitile hyd fluid being sprayed onto gearbox, engine and other rather warm things is not condusive to prolonged flight IMHO!