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
|
|||
|
|||
Fuel contamination and other basic survival instincts
This is purely theoretical - it is not something I am planning for next
Saturday : If you are to fly over an expanse of water or other inhospitible terrain, for a distance long enough to require re-fueling immediately prior (US-Europe ferry, for example) - You watch to see that they put the right fuel in your plane, but you can really only see what's stenciled on the side of the truck, not what's inside (call me paranoid - what if the line guy is someone I owe money to). How long do you have to fly before a fuel contamination problem manifests itself? Does this depend on how empty your tanks were? I'm guessing no - I'm guessing this type of problem - any serious fuel contamination problem - would show up within minutes. Anyone really know this. Anyone here learn this the hard way? I've also noted, though far less certain, a number of vacuum or AI failures take place within the first minutes of flight, not to mention engines throwing rods etc. You can see what I'm getting at - how useful a survival instinct would it be to fly, say 20 minutes, up the Icelandic coast, then double back before setting out across the great void? (Obviously you've already taken the other measures, and you are wearing your survival gear etc). Another question : I read an official accident report (not a newspaper report) in which ground personnel refilled a small plane's oxygen tanks with compressed air before a mountain crossing. The pilot died in the ensuing accident, but miraculously the single passenger survived to confirm the oxygen-related unconciousness of the pilot as the cause of the crash. What could this pilot have done to defend against this "rare but not impossible" event? We assume that in aviation - unlike on the road - we may kill ourselves by our own mistakes, but the likliehood of being killed by the mistakes of others is very far removed. This is certainly justified, however very far removed does not mean impossible, and our preventive measures should try to preclude suce events if we can. G Faris |
#2
|
|||
|
|||
"Greg Farris" wrote in message
.... orginal message snipped: This is purely theoretical - it is not something I am planning for next Saturday : If you are to fly over an expanse of water or other inhospitible terrain, for a distance long enough////////////You can see what I'm getting at - how useful a survival instinct would it be to fly, say 20 minutes, up the Icelandic coast, then double back before setting out across the great void? ---------------------------reply---------------------------------- If you are flying from Florida to the Bahamas, you can circle up to 10,000 feet and follow the line of boats as you descend to the islands. Stephen F. Pearce Foley, Alabama |
#3
|
|||
|
|||
Greg Farris wrote:
If you are to fly over an expanse of water or other inhospitible terrain, for a distance long enough to require re-fueling immediately prior (US-Europe ferry, for example) - You watch to see that they put the right fuel in your plane, but you can really only see what's stenciled on the side of the truck, not what's inside (call me paranoid - what if the line guy is someone I owe money to). How long do you have to fly before a fuel contamination problem manifests itself? Does this depend on how empty your tanks were? I'm guessing no - I'm guessing this type of problem - any serious fuel contamination problem - would show up within minutes. Anyone really know this. Anyone here learn this the hard way? No way to know. It takes awhile for water to settle in avgas; it could manifest itself immediately, or a few minutes after takeoff. Factors such as fuel system layout, amount of water, and effectiveness of fuel filters would all play a role. I wasn't particularly thrilled about taking on fuel for a Hughes 500 I delivered from Florida to San Juan, Puerto Rico, in a number of, ah, "isolated" spots. I was least pleased about taking fuel in Providenciales and the Dominican Republic. However, your risk of contamination (due to water, anyway) in Jet-A is lower than avgas, because Jet-A (and turbine engines) are more tolerant of water than pistons. In any case, I did a little 500 ft. traffic pattern after departing my first fuel stop in the DR, Puerto Plata, then headed east over the mountains. I've also noted, though far less certain, a number of vacuum or AI failures take place within the first minutes of flight, not to mention engines throwing rods etc. You can see what I'm getting at - how useful a survival instinct would it be to fly, say 20 minutes, up the Icelandic coast, then double back before setting out across the great void? (Obviously you've already taken the other measures, and you are wearing your survival gear etc). Sure, that's useful. Prove out the equipment before you commit. Hopefully you've already had some trials or other proving runs so you have a big-picture idea of what you're dealing with; the last test run, just prior to flight, will be to catch any last-minute gotchas. Another question : I read an official accident report (not a newspaper report) in which ground personnel refilled a small plane's oxygen tanks with compressed air before a mountain crossing. The pilot died in the ensuing accident, but miraculously the single passenger survived to confirm the oxygen-related unconciousness of the pilot as the cause of the crash. What could this pilot have done to defend against this "rare but not impossible" event? Realistically? Nothing. We could probably make some guesses and theorize about ways to prevent that from happening, but in the real world, we trust that an O2 fill is an O2 fill. Supervise the recharging of the tanks, is all I could say. We assume that in aviation - unlike on the road - we may kill ourselves by our own mistakes, but the likliehood of being killed by the mistakes of others is very far removed. This is certainly justified, however very far removed does not mean impossible, and our preventive measures should try to preclude suce events if we can. Absolutely. I've "prevented" problems by supervising the refueling of the Hawker 700 which I fly. It's possible, via a refueling control panel, for the fueler to put fuel where it doesn't belong, i.e. ventral and dorsal tanks when all I asked for was the wings to be topped. Since T/O with partial fuel in those tanks is not allowed, I'd have a real problem if the fueler accidentally fueled those tanks. Even worse is when the fueler tries to fill tanks that are already full and the airplane starts discharging fuel onto the ramp via a surge overflow vent. The EPA comes runnin'! My policy is to always be present when the aircraft is fueled. Good thoughts, Greg. -Ryan |
#4
|
|||
|
|||
In article ,
Greg Farris wrote: depend on how empty your tanks were? I'm guessing no - I'm guessing this type of problem - any serious fuel contamination problem - would show up within minutes. Anyone really know this. Anyone here learn this the hard way? I know of a Seneca that was fuel with Jet fuel. Both engines failed within 1/2 mile of the airport on takeoff. I don't know how much avgas was in the tanks when the jet fuel was put in. I had a problem on takeoff with water in the fuel on a '57 182. I had been flying the airplane all day, I had fueled several times (all from the same source) and the problem occured on the last flight of the day. Another question : I read an official accident report (not a newspaper report) in which ground personnel refilled a small plane's oxygen tanks with compressed air before a mountain crossing. The pilot died in the ensuing accident, but miraculously the single passenger survived to confirm the oxygen-related unconciousness of the pilot as the cause of the crash. What could this pilot have done to defend against this "rare but not impossible" event? SCUBA divers use a test device to determine the amount of O2 in the tank when using mixed gas so I would have to say it is possible to test the O2 content of your a/c system. -- Dale L. Falk There is nothing - absolutely nothing - half so much worth doing as simply messing around with airplanes. http://home.gci.net/~sncdfalk/flying.html |
#5
|
|||
|
|||
Sounds like a good argument to check the sumps on your takes as part of
your preflight. My instructor told me explicitly not to trust the fuel truck, as PIC it's my responsibillity to make sure he didn't 'fill me up with water' (was one way he put it). He taught me to sump the tanks, then verify the color of the fuel against a white surface. I know that it can take a few minutes for contamination or wrong fuel to settle to the sumps, but if I _don't_ check, then I lose an opportunity to abort the flight I might have otherwise had. Basically, it's not a 100% guarentee I'll catch a problem, but it's certainly better then if I just go on 'faith' (a poor trait to have in the cockpit, it seems). First time I fueled at a nice FBO, I felt kinda funny when I sumped and checked the tank, like the look the fuel guy was giving me was sorta funny, but I remembered my responsibillity and finished the check. It's my butt on the line, not his. I've read stories of turbo normalized planes getting Jet-A because the fuel truck saw 'Turbo' and read 'Turboprop'. Anyone else have thoughts on this? |
#6
|
|||
|
|||
In rec.aviation.ifr Ben Hallert wrote:
First time I fueled at a nice FBO, I felt kinda funny when I sumped and checked the tank, like the look the fuel guy was giving me was sorta funny, but I remembered my responsibillity and finished the check. Remember, you're checking for a few things: 1) Is the fuel the right grade (as indicated by the color)? 2) Is there water in the fuel? 3) Is there other contamination? There's no reason for the fuel guy to interpret your check as criticism or suspicion of his actions. An error in the fuel grade could be introduced by somebody else (e.g., whoever filled the truck, whoever filled your tanks the previous time), and the other problems could have other causes (e.g., maybe your previous fill had water in it, but it didn't have time to settle out and be visible before you took off). It's my butt on the line, not his. Very true. Don't let funny looks deter you. (Not to mention that the funny look might not even be related to what you're doing.) .... Alan -- Alan Gerber gerber AT panix DOT com |
#7
|
|||
|
|||
The odds of someone filling your O2 tanks with air instead of O2 is
just as deadly and just as likley to happen as someone putting Drain-O on your sandwitch instead of mustard at a Subway restraunt. Well, maybe not as likley, but you get the idea. Some things in life you just have to risk. Thats not to say fuel sumps need not be checked, or simple inspections shouldn't be made, but there exists a line which seperates reasonable precautions and insanity. |
#8
|
|||
|
|||
"buttman" wrote in message ps.com... The odds of someone filling your O2 tanks with air instead of O2 is just as deadly and just as likley to happen as someone putting Drain-O on your sandwitch instead of mustard at a Subway restraunt. Well, maybe not as likley, but you get the idea. Some things in life you just have to risk. Thats not to say fuel sumps need not be checked, or simple inspections shouldn't be made, but there exists a line which seperates reasonable precautions and insanity. I'm aware of a story similar to what the original poster mentioned regarding filling an 02 tank with regular compressed air. It was a C-337 on a photography mission. The passenger (who was in the back, ready to shoot photos) passed out at ~20k ft, and the pilot lost consciousness somewhat higher. The airplane departed from controlled flight, and came apart on the way down. The wings, tail, etc. came down miles from the fuselage. The fuselage came down in a tree, killing the pilot. When the fire department came to pull the body out of the aircraft, the passenger woke up and climbed down the ladder with the firemen with minor injuries. True story. I have met the NTSB guy who was the lead investigator. He indicated that the FBO had been filling O2 tanks with regular compressed air for a lengthy time. They had to notify the FBO's recent O2 customers on an emergency basis to let them know that their oxygen tanks needed to be purged and re-filled. A very interesting tale which goes to show that there are many, many ways to die quickly in an airplane. Some of them unforseen. KB |
#9
|
|||
|
|||
An Instructor once told me that it takes 5 minutes per inch of fuel in the
tank for all the water (if any) to show up in the sumps. Don't know where he got that from, but I thought I'd pass it on. |
#10
|
|||
|
|||
In rec.aviation.ifr lardsoup wrote:
An Instructor once told me that it takes 5 minutes per inch of fuel in the tank for all the water (if any) to show up in the sumps. Don't know where he got that from, but I thought I'd pass it on. CRC Chemistry. I believe the settling rate of water in 100LL is 1" per minute. Figure your tanks are 9" deep... check after 9 minutes. Adjust for the depth of your tanks. Best regards, Jer/ "Flight instruction and mountain flying are my vocation!" Eberhard -- Jer/ (Slash) Eberhard, Mountain Flying Aviation, LTD, Ft Collins, CO CELL 970 231-6325 EMAIL jer'at'frii.com WEB http://users.frii.com/jer/ C-206 N9513G, CFII Airplane&Glider, FAA-DEN Aviation Safety Counselor CAP-CO Mission&Aircraft CheckPilot, BM218 HAM N0FZD, 228 Young Eagles! |
|
Thread Tools | |
Display Modes | |
|
|