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Author Topic: Airworthiness Certificate(s); fuel capacity  (Read 83586 times)

Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #75 on: December 28, 2011, 05:45:20 PM »

Thanks John but its the fuel load thats expected to be loaded at Howland for trip to Hawaii. Not Lae to Howland.  Gary did some takeoff distance calculations and indicated that AE was going with a lighter fuel load from Howland to Hawaii but I can't find the references to that.  It flies in the face of what the pilots have said in this forum before about leaving for a flight with less than full tanks. 
You have that slightly wrong. To be sure of the amount of fuel in any particular fuel tank a pilot needs that tank to be full since he can't trust the fuel gauge for that particular fuel tank. This doesn't mean that he always fills every fuel tank in the plane for every flight because it costs money to "tanker" excess fuel around the sky and the excess weight makes the plane go slower. The heavier the plane the more fuel it takes to go any particular distance so you do not want to carry fuel in excess of that needed for the flight leg plus required reserves, fuel to get to the point of first intended landing, thence to the alternate airport and then sufficient fuel for forty five minutes of flight at normal cruising fuel consumption. That is the requirement for domestic operations. For airlines operating internationally the fuel requirement for propeller driven airplanes is spelled out in Federal Aviation Regulations, 14 CFR § 121.641
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" Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Flag operations.

(a) No person may dispatch or take off a nonturbine or turbo-propeller-powered airplane unless, considering the wind and other weather conditions expected, it has enough fuel—

(1) To fly to and land at the airport to which it is dispatched;

(2) Thereafter, to fly to and land at the most distant alternate airport specified in the dispatch release; and

(3) Thereafter, to fly for 30 minutes plus 15 percent of the total time required to fly at normal cruising fuel consumption to the airports specified in paragraphs (a) (1) and (2) of this section or to fly for 90 minutes at normal cruising fuel consumption, whichever is less.

(b) No person may dispatch a nonturbine or turbo-propeller-powered airplane to an airport for which an alternate is not specified under §121.621(a)(2), unless it has enough fuel, considering wind and forecast weather conditions, to fly to that airport and thereafter to fly for three hours at normal cruising fuel consumption."
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Paragraph (b) is the one that applies to an airline flying to a location where there is no geographically available alternate airport, like flying to Howland Island. So today, a scheduled passenger carrying airline flying to Howland would only need to carry a three hour reserve of fuel.

In commercial operations you only put aboard the required fuel which then allows you to put on more payload. It is called "payload" for a reason, you charge by the pound, the more pounds of cargo, mail, or passengers you can put aboard the more money you make.

Even if flying a small plane you may not fill all the tanks in the plane if you do not need the extra fuel for the flight leg. For example, a Cherokee Six has two 25 gallons tanks and two 17 gallon wing tip tanks, total of 84 gallons. If 50 gallons is enough for your flight leg then you leave the tips empty (34 gallons, 204 pounds) so you can carry an extra passenger. But you fill the two inboard 25 gallon tanks so that you know that they are full when you take off.

Amelia did not always fill all her tanks, in fact she never did! The takeoff at Lae was with the most fuel she ever had in the plane and even then all the tanks were not full. On the leg from OAK to HON she only took 947 gallons. Hmmm... that's an odd number, why not an even number like 950 gallons. Let's see, the total capacity was 1151 gallons so 947 gallons is 204 gallons less than completely full tanks. The tanks behind the wing spars each held 102 gallons so Earhart filled completely all the fuselage tanks and the forward wing tanks and left the aft wing tanks empty. This 947 gallons was enough for the 2400 SM flight to Hawaii, only 156 SM shorter than the Lae to Howland leg, and Earhart said she had four hours of fuel left when she landed.

gl
« Last Edit: January 02, 2012, 01:05:44 AM by Gary LaPook »
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #76 on: December 28, 2011, 05:58:10 PM »

No guys. Gary has suggested that AE was going to only load 825 gallons when she ARRIVED at Howland. We know she didn't so it's a moot point. I asked if Gary or anyone has information as to how much she was planning on taking off with from Howland.

Marty I know the Chater report is re the fuel taken on at Lae to Howland. What about Howland to Hawaii?  I have searched Ameliapedia, this forum and the Internet in general. No luck. How does Gary know she only planned to load 825 gallons at Howland?

If I'm missing something then I sincerely apologize.
Two ways. She took 1100 gallons for a 2556 statute mile flight against a 15 to 25 mph headwind so how much would be required for the much shorter 1900 SM leg to Hawaii against similar headwinds? 1900/2556 X 1100 = 817.86 gallons. The second way is that, according to Long, page 97, they put 825 gallons on board for the flight from Hawaii to Howland. Later they added another 75 gallons so that they would have the capability to return to Hawaii after flying for eight hours on course to Howland.

gl
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Irvine John Donald

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #77 on: December 28, 2011, 06:05:37 PM »

Gary, as always, a very comprehensive answer.  Thank you.  As a non pilot I don't even know the right questions to ask but I hope that other non pilots learn from my questions. 

So determining the required fuel is really nothing more than following a formula that is used by all pilots. 

Another question however. This is purely from curiosity. Why did the coast guard deliver 200 gallons of 100 octane to Howland. Not the "boost" question again, but why 200 gallons. Seems she had carried 100 octane in a much smaller tank on leaving Lae. I'm sure this is meaningless in the whole scheme but it just peaked my interest. Just the Coast Guard making sure they had enough in case of spills?  I appreciate your time to answer this.
Respectfully Submitted;

Irv
 
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #78 on: December 28, 2011, 06:09:49 PM »

Gary, as always, a very comprehensive answer.  Thank you.  As a non pilot I don't even know the right questions to ask but I hope that other non pilots learn from my questions. 

So determining the required fuel is really nothing more than following a formula that is used by all pilots. 

Another question however. This is purely from curiosity. Why did the coast guard deliver 200 gallons of 100 octane to Howland. Not the "boost" question again, but why 200 gallons. Seems she had carried 100 octane in a much smaller tank on leaving Lae. I'm sure this is meaningless in the whole scheme but it just peaked my interest. Just the Coast Guard making sure they had enough in case of spills?  I appreciate your time to answer this.
Oh, it piqued your interest.  ;)
No idea, four barrels of 100 octane and 12 barrels of 87 octane.

gl
« Last Edit: December 28, 2011, 06:13:44 PM by Gary LaPook »
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Irvine John Donald

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #79 on: December 28, 2011, 07:15:03 PM »

Thanks Gary. I appreciate the spelling lesson too. LOL!
Respectfully Submitted;

Irv
 
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