![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
![]()
One of the questions in the FAA exam (I don't have the number in front of me)
Shows a panel where the altimeter and VSI are both still and the Airspeed is very low. The Attitude indicator looks normal for pitch. The "Correct" answer is that the pitot system or the airspeed indicator has failed. Could'nt you get exactly the same indication with a frozen or plugged static line and a climb? Thought experiment: 1)Plug the static port. Altimeter and VSI will never ever move again. 2)The Pitot pressure is ambient pressure + impact pressure. If you climb then the ambient pressure goes down, but the ambient pressure in the static system stays where it was because of #1 above air speed indicator becomes a backwards altimeter biased by IAS. So in insturment flight how would you differentiate from these failures? Try to do some climbs decents and see if the Altimeter /VSI moves? Obviously if you have an alternate static source that would be tried early on. P.S. Closest I ever came to dying in a plane was beacuse of a plugged static port. I grew up in Alaska, my dad ran a part 135 bush airline. One summer vacation from college I went for a flight in my Dad's C206T on anphib floats. I was a bit rusty and way behind the airplane. The weather was rotten foggy and low clouds. (Like it normally is in South East Alaska.) There was ZERO wind, and I was making a glassy water landing. The clouds where low and patchy obscuring the tops of the mountains and creating an indistinct horizon. In a Seaplane one of the subtle problems is that if the water is glassy you can't flair, you can not tell how high above the water you are. On Glassy water you set up an attitude and controlled rate of descent and just wait until you hit the water. I was trying to land, the VSI made no sense, the weather made visual references difficult and the airspeed made no sense, The harder I pulled back the faster the airspeed went. I knew I was in trouble, but I had no idea what to do, nothing made sense. I will never forget that feeling of knowing you were doing something wrong and not being able to figure out what it was. I eventually stalled the plane at an altitude of about 10 feet and it just ploped on the the water and stopped. No damage other than to me ego. IF that had happened 100feet higher I would have killed everyone in the plane.(4 of us) As I sat there on the water moving about 5mph I looked down and the airspeed was reading 130 knots. I reached down pulled the alternate static selector and all the gauges went back to normal. Like most aviation incidents this was a combination of factors If I was more current I would have had a better feel for the plane. If the water had not been glassy I would not have had an issue. If the weather had been better I would not have had an issue. If the static pott had not clogged I would not have had an issue. If the plane did not have a STOL kit the Part 135 pilots that flew it regularly would not have "accidently" stuck a twig in the stall warning horn and I would have had warning. |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Instrument mounting question | Rob Turk | Home Built | 4 | July 19th 04 10:33 PM |
Instrument Question | Dick | Home Built | 10 | May 30th 04 12:05 AM |
Instrument Rating Ground School at Central Jersey Regional (47N) | john price | Instrument Flight Rules | 0 | October 12th 03 12:25 PM |
Got my Instrument Rating! | Jazzy_Pilot | Instrument Flight Rules | 4 | August 21st 03 02:35 AM |
Instrument Fix Question (student) | Cecil E. Chapman | Instrument Flight Rules | 6 | August 11th 03 07:15 PM |