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I noticed that nothing was mentioned in the AAIB preliminary report about the integrity of the fenestron, only that the main rotor gearbox was capable of driving the driveshaft.
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Fenestron intact?
From the clear photo in http://www.pprune.org/8244492-post1677.html the chances of it being in a pre-crash state don't look good. However, if I remember correctly, the AAIB statement did say that all components were found at the crash site.
There are photos online of substantial parts of an un-enshrouded, yet substantially complete, fenestron fan being hoisted away from the crash site: one is currently illustrating a charmless tale here: Glasgow Pub Crash: Teen Arrested for 'Sectarian' Comments [VIDEO]. Whether it landed in a working condition of course remains a question. Its hub being hoisted away substantially intact is perhaps consistent with it not turning on impact (as probably noted previously in the thread). |
If the tank was "brimmed", then the weight carried would be the tank maximum volume divided by the fuel density.
Multiplied not divided: 100L weighs ~81kg. Weight and balance is one of the first things a student pilot learns, before going cross country. But I do wonder how people can read that and apparently not notice. |
Oops, yes. Exactly the sort of error that needs to be avoided.
I shall edit my original post to show I did it wrong. |
Ornis - You sure about the 0.81? Your student won't get very far if he needed 100L AVGAS....
Ah, in retrospect I think you mean 100 litres ....but his aircraft is more likely to be non-turbine and need AVGAS, not Jet A1. So he would use 0.7 SG as his conversion factor. |
Probably no relevance but a picture has been found on Flickr with a good view of the roof of the pub in 2012. The tryst bar and the clutha bar Glasgow_ASN2235 where a police Helicopter - A Eurocopter EC135 T2 crashed | Flickr - Photo Sharing!
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One hundred litres is written 100L or 100l. Both are correct. I prefer "l" but I thought some helicopter pilot might read "l" as "1" and argue the point about 1001 bananas.
Or possibly go off on a tangent about avgas when the EC135 we have been discussing all this time uses JetA1 or whatever. A pilot must see the crux of an issue or problem immediately and the problem I saw was a wrong conversion from volume to mass. The fact is, quantity or capacity can be measure by volume or mass, both are correct. It's usual to buy fuel by volume and mandatory to flight plan by mass. The relationship is given by the specific gravity. We all know this. |
Yes, we do all know this. But incorrect conversion of litres to kilograms or vice versa is likely to be irrelevant to the cause of this accident, as per my earlier post.
BTW, in my tech log, I use the annotation "LTRS" for litres, to avoid any confusion. Another possible gotcha is engine oil quantity. The oil contents (and maximum usage rates) are quoted in litres. The oil is packaged in US Quart cans. |
But conversion of litres to kilograms or vice versa is likely to be irrelevant to the cause of this accident. |
So it might be. Or then again, possibly not.
The circumstances are most unusual, possibly unprecedented. Certainly I know of no similar RW accident on a twin engined helicopter and I've been flying helicopters for a living for thirty five years. The point is, there was fuel in the aircraft, that has been proven beyond doubt. although a relatively small quantity, it would normally have been enough to make a safe landing with. Not a stopped rotor "arrival", as this evidently was. |
A turbine engine flows much more air than is needed for combustion, unlike a piston engine burning AVGAS, where the ratio of air and fuel are more critical.
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The closest I can find on anything remotely similar.
NTSB Looks At Cranes In Potomac Crash | Aero-News Network Press Release [January 12, 2005] - NTSB - National Transportation Safety Board NYC05MA039 Full report According to the flight nurse, after the helicopter flew over the southern half of the Woodrow Wilson Bridge, the next thing he recalled was being submerged in water with his seatbelt on and his helmet off. He stated that the helicopter's master caution lights and panel segment lights did not illuminate and that he did not hear any audio alarms sound before the crash. He stated that the pilot did not execute any evasive maneuvers or communicate any difficulties, either verbally or nonverbally. According to witnesses in vehicles on the Woodrow Wilson Bridge, the helicopter crossed over the bridge before it descended and then impacted the water. None of the witnesses reported seeing the helicopter impact any objects before its descent. The wreckage was located in the Potomac River about 0.5 nm south of the Woodrow Wilson Bridge. According to the DCA automated surface observing system, located about 3.5 nm north of the accident site, the reported conditions at 2251 were winds calm, visibility 10 statute miles, broken clouds at 13,000 feet and 20,000 feet, temperature 45 degrees Fahrenheit (F), dew point 36 degrees F, and altimeter setting 30.25 inches of mercury. Wreckage was scattered along a north-south oriented debris path. The wreckage was recovered, and examination indicated no evidence of a collision with a bird or other object, fatigue fractures, or other anomalies. The main rotor mast was in place and intact in the main transmission. The root ends of the four main rotor blades remained attached to the main rotor hub on the mast. The main transmission remained attached to the center section of the upper airframe structure, and all four mounting points were intact. The main transmission turned freely, no chips were found on the detectors, and the transmission appeared intact and functional. The tail boom was separated at the aft fuselage frame. The tail section included the complete fenestron assembly [11] with the tail rotor gearbox and tail rotor. The tail rotor driveshaft was displaced forward about 1.5 inches. The aft portion of the driveshaft, which was carbon composite, was found fractured, torsionally cracked, and deformed. All tail rotor blades remained complete and attached to the hub. The fenestron shroud around the tail rotor showed a rotational scrape at the 5 o'clock position. The width of the scrape corresponded with the tail rotor-blade width. Both engines showed little damage, and the gas generator (N1 compressor and turbine) and power turbine (N2 turbine) for each engine rotated freely. Nonvolatile memory data extracted from the electronic engine control units for each engine revealed no evidence of preimpact faults. |
SS -- very similar, when you look for the similarities not the differences. I looked at the 'full' report and can't see what the cause was ruled to be.
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For the above referenced LifeNet EC-135 crash the NTSB concluded:
PROBABLE CAUSE The National Transportation Safety Board determines that the probable cause of this accident was the pilot’s failure to identify and arrest the helicopter’s descent, which resulted in controlled flight into terrain. Contributing to the accident were the dark night conditions, limited outside visual references, and the lack of an operable radar altimeter in the helicopter. |
Shy? is there a significant difference between Us Quarts and Litres?
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Shy? is there a significant difference between Us Quarts and Litres? So no. Not significant. A scientist and an engineer are at a dance. The girls are all standing by the wall opposite, 20 ft away. Someone asks the two guys "if you cross the floor with each step half the distance left to go, how many steps will it take to reach the girls?" The scientist sadly says that he'll never get there. The engineer confidently replies, "Five, for all practical purposes". QED! |
For all practical purposes, five. Of course, the mathematician would say the number of steps is not important, the question is how long it will take you to get there. Provided each successive step is taken twice as quickly as the last you should get there in a reasonable time! The real answer of course is "I though I would just wait here until they came over" - moving from feet to metres is not the only change! |
Converting feet to meters:
http://lamar.colostate.edu/~hillger/...o-meters_2.gif |
Agaricus, albeit small, 6% could make a difference with regard to whether the engine requires an overhaul or not. Oil used figures are logged and the rate monitored; it should not exceed the maximum allowed by the manufacturer.
I suppose I could do the 6% conversion every day but it makes better sense to log the units in use and do the conversion once. |
Could someone briefly sum up the known facts please ?
Also, is anyone allowed to say what the aircraft was doing there ? |
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