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Moose
Joined: 02 Jan 2001
Posts: 24
Location: Fargo, ND |
 Sat Mar 10, 2001 3:05 pm
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Can one of you pilots out there tell me how an altimeter works? Does it use barometric pressure, electro-magnetic readings, radar, hydraulics or ? or a combination of the above to measure altitude? I'm interested especially in the altimeters used in an F-16 and/or a small private plane such as a Cessna or a Beachcraft.
Thank you. |
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Rt
Joined: 01 Feb 2001
Posts: 9
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Sat Mar 10, 2001 4:11 pm
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Historically altimeters have worked by barometric pressure. There is some instrumentation where with additional fast software GPS can be used. There also has been instrumentation where once zeroed for ground level, strain gauges have been used to compute altitude. |
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cydoniaquest
Joined: 12 Aug 2000
Posts: 797
Location: nowhere |
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Sat Mar 10, 2001 4:59 pm
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Your typical, basic pressure sensing altimeter in your typical "bug smasher" aircraft works by the mechanical expansion and contraction of sealed aneroid wafers within the altimeter case. These expand and contact sort of like an accordian.
The case is sealed except for a small hole that connects a tube to the static port of the aircraft. The static port is simply a hole on the outside of the aircraft usually flush with the fuselage. It doesn't pick up ram air (kinetic energy) like the pitot tube, but rather, the ambient air pressure and it translates this pressure through the tube to the altimeter case which equalizes with outside air pressure. This pressure in the altimeter case is the variable whereas the pressure within the aneroid wafers is the constant.
As the aircraft climbs in altitude, the ambient air pressure decreases which causes the aneroid wafers within the altimeter case to expand. This expansion is measured through a connected series of mechanical linkages and levers which turn gears which are connected to the altitude pointers that the pilot sees on the face of the altimeter dial.
There are usually three pointers that indicate increases in 100's of feet 1000's of feet and 10,000's of feet respectively. The pilot can adjust the instrument for accuracy by turning a knob which sets the atimeter at the current airport pressure setting (adjusted to sealevel). 29.92 in Hg. is standard sea level pressure, but the actual pressure is of course, usually higher or lower than this, and the pilot sets this reading in a small window in the altimeter's dial. Altimeters come from the factory calibrated to read true altitude at standard sealevel temperature and pressure, and a calibration knob on the lower left is used to adjust for non-standard pressure. As you set this, you can visually observe the 100 feet pointer move.
The altimeter setting is usually gained from the control tower, ATIS (airport terminal information service) or a FSS (flight service station enroute). Above 18,000 feet MSL the pilot sets the altimeter window to 29.92...
[Edited 4 times, lastly by cydoniaquest on 03-10-2001] |
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totallyreel
Joined: 10 Feb 2001
Posts: 2
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Sat Mar 10, 2001 6:02 pm
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I need hardcopy photos of sprayplanes.Can anyone supply photos for video? Also need hardcopy photos of trails and clouds, etc.totallyreel |
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Thermit
Joined: 08 Jul 2000
Posts: 3136
Location: Texas |
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Sat Mar 10, 2001 6:31 pm
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Good explaination Cy, thanks.
TotallyReel, what kind of project are you working on? |
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Moose
Joined: 02 Jan 2001
Posts: 24
Location: Fargo, ND |
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Sun Mar 11, 2001 9:55 pm
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Why thank you, CQ. Truth be told, you were the last person I thought might respond.
The "seals" you mentioned around the altimeter case...how exactly is the case sealed anyway? |
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cydoniaquest
Joined: 12 Aug 2000
Posts: 797
Location: nowhere |
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Mon Mar 12, 2001 3:23 am
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The case is just basically a solid unit (usually metal I think) with a hole in the back where the tube goes out to a manifold that connects to the static port.
The glass in the face makes up part of the seal usually set into place with a rubber grommet, so that basically the only air that is able to enter the case comes from the outside static port.
If the outside port were to become iced over or clogged, now of course, the altimeter will not be able to measure changes as the aircraft changes altitude since the pressure at which the icing or clog occurred will remain trapped in the system and the pressure within the case will not be able to equalize with the outside ambient air pressure. The altimeter needles would be, in effect, locked at the altitude where the clog occurred regardless if the aircraft climbs or descends.
In this situation, it was usually recommended that pilots of non-pressurized aircraft break the glass on the face of the altimeter (or better yet, the vertical speed indicator VSI, since this is the least important of the pressure sensing instruments) . This allows air from the cabin to enter the altimeter case either directly or through the other instrument in which the glass is broken, and the altimeter will once again read accurate altitude (assuming that the pressure inside the cabin is equal to outside air pressure). Obviously, in a pressurized aircraft, this practice would not be of help.
This illustrates that the glass on the altimeter case, and the other pressure sensing instruments is a component that plays a part in the seal.
[Edited 2 times, lastly by cydoniaquest on 03-12-2001] |
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defender
Joined: 27 Oct 2000
Posts: 1113
Location: Level 64 |
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Tue Apr 10, 2001 9:20 pm
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Great altimeter photo!  |
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defender
Joined: 27 Oct 2000
Posts: 1113
Location: Level 64 |
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Fri Apr 13, 2001 5:25 pm
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Any other aviation experts want to comment on CIA/Evergreen operations?
[Edited 1 times, lastly by defender on 04-16-2001] |
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defender
Joined: 27 Oct 2000
Posts: 1113
Location: Level 64 |
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Wed Apr 25, 2001 5:44 am
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psylenced,
Here's that thread with lyrics to "It's a Beautiful Day".
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defender
Joined: 27 Oct 2000
Posts: 1113
Location: Level 64 |
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Sat Feb 23, 2002 2:37 am
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... |
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RICOinformant
Joined: 22 Nov 2002
Posts: 1
Location: Los Angeles, CA |
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Fri Nov 22, 2002 8:14 am
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Evergreen International Aviation is a CIA proprietary. I handed old man George's administration a check for $10 million (criminal intelligence - asset forfeitures) in 1990. There was only one string attached and it was mandated by the state law and federal laws which protect children. Poor ole George and his boys couldn't even protect a baby from a dope-fiend crack-head ho. When I approached and briefed Detroit special agents Greg Suhyjda (US Sercret Service) and John Stevens (US Customs Service in February 1990 about the mother's criminal activities and those of her associates I also dropped a small hint to agents concerning Evergreen's illegal operations (cocaine trafficking) down in Marana, Arizona. They obviously never got the hint. George panicked and the feds retaliated against me. I went public before the feds unsealed the racketeering indictments which targeted the mother's former business manager (pimp). My name was published in a local Detroit paper with my permission. After a year and half went by I was finally able to obtain protection for the baby girl. The feds engaged in a Civil Rights conspiracy to obstruct that baby girl's right to equal protection under the law (Michigan Child Protection Act). The feds also engaged in a R.I.C.O. conspiracy to Obstruct Justice by engaging in a pattern of misleading conduct and harassment against their own informant while also engaging in retaliation against their own informant because I happened to mention Evergreen Air. Ex-CIA Director George got booted out of office in 1992 and Bill took his place. I contacted Bill and his people in June of 1993. Similar corresspondence was sent to Bill and his people in 1997 and 1998. I filed a RICO civil action against the USSS, USCS, and IRS in December of 1996. References to Evergreen Aviation and narcotics trafficking by that CIA front were included in my legal briefs to explain the government's motive to engage in racketeering (Obstruction of Justice). Bill authorized a sting investigation which targeted Evergreen Aviation based on my allegations. That became OPERATION ICon (Internal Conspiracy). Employees from one of Evergreen Aviation's company's (EAGLE) were arrested in September of 1999 by DEA and US Customs Service agents at the Miami International Airport. Old man George regained control over the Evergreen situation by sending a whore into the White House. Bill got set-up by Monica and the EOP's e-mail archives were mysteriously deleted at the end of Bill's final term in office. The Taliban cut the CIA and George's good'ole boys out of the opium market. Afghanistan supplies 90% of the world's opium (which is used to manufacture heroin). The CIA having past ties to the Afghan resistance set up a "black op" and set out to recruit Islamic fundamentalists to be trained as pilots in a scheme which was never fully made know to the Agency's Islamic cut-outs by their control officer(s). The pilots were given the "green light" to carry out their mission last September. The pilots were led to believe that they were going to be part of a multi-sychronous skyjacking which would draw the world media to the attention of the conflict between Israel and the Palestinians. The Islamic skyjackers were not told that their mission would end in their deaths. The CIA had installed remote control electronics in the target commercail aircraft which over-rode the plane's own avionics systems. CIA assets on the ground used remote control to guide the target commercial aircraft to their final targets after they had taken control of those planes. The Pentagon's anti-terroists department was targeted because it would have investigated the event and would have led to the exposure of the CIA's black-op which was designed to destroy the Taliban so a much needed source of raw opium would begin to flow again into the black coffers of the CIA's off-shore banks. The existing police state which has emerged within the past year is a method which will insure that the CIA will continue to rule with added help from the just legalized domestic spying which is to be conducted in the name of the WAR ON TERRORISM (ie. WAR ON AMERICAN FREEDOM & CIVIL LIBERTIES). Welcome to America's version of the Gestapo and SS brought to by old man George and the good ole boys from Texas. Heil George!.....
CIA's Evergreen Aviation Ground Logistics Enterprises employees being arrested by DEA and Customs agents as part of operation ICon and Operation Ramp Rats II
CIAo !
[Edited 3 times, lastly by RICOinformant on 11-22-2002] |
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Mech
Joined: 06 Jun 2001
Posts: 8237
Location: THE 4th REICH USA |
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Fri Nov 22, 2002 7:05 pm
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BOING!!!!! Wow. I knew that georgie poo (the first) helped set up the death sqauds in South America and overthrow the Sandanista government to control the Cocaine to finance the war there...which in turn..during the mid-80's set up a crack epidemic in most major cities here in the U.S., but I always wondered who was behind all the heroin coming in here.
I've heard that since the Northern Alliance (NOT a nice bunch) was helped to take over Afganistan...Poppies are sprouting up everywhere there. I wonder if this sagging economy will help bring in a huge lot of heroin this spring to put on the street of economically depressed inner cities.
2 days after Sept. 11th I began to have my doubts about the whole thing...especially when I considered the history of dirty tricks our own government has employed as a means to an end. I don't think sleeping, TV watching America would believe that their own government was responsible for flying 2 planes into lower Manhattan skyscrapers.Much less the Pentagon. I think they are desensitized enough to believe everything that comes out of Son of Bush's mouth. I know better.
Thanks for the confirmations and for some info I didn't have a clue about. This definately fills in some missing pieces.
Thanks for the links.
http://www.whatreallyhappened.com
[Edited 5 times, lastly by Mech on 11-22-2002] |
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Mech
Joined: 06 Jun 2001
Posts: 8237
Location: THE 4th REICH USA |
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Fri Nov 22, 2002 7:20 pm
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Here is an example of the desensitization I was speaking of.....NAME OMITTED cause' I'm a nice guy.
"---- I will say that I am riding the storm out after 8 years of Clinton and Gore, and have my faith in George W. to get us through the most important amd immediate event of my life time - the war on terror. ------"
That's scary when people start embracing fascism. Very reminicent of Germany in the late 30's...but much more frightening when it happens here.
People love to still assume that all of our problems are being caused by USAma Bin Laden
or Bush SR's ex buddy Saddam Hussein.
[Edited 4 times, lastly by Mech on 11-22-2002] |
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