official, new AF 1 selected.
I really don't think suggesting there are decent alternatives to an old design really puts me in front of the UnAmerican Activities Committee .......
the current VC-25 is quoted at a unit cost of $325 million cp the commercial cost of around $ 80mm per commercial aircraft so the extra cost look as if it is in proportion
HH, the $325 million is what the government paid, the actual Boeing cost was more like $500 million each (I was pretty deeply involved, including a couple weeks of 18 hr. days). Now much of the overrun was due to some super dumbass management, but even when they announced the contract it was pretty well understood that best case would be a 'break even' business case. It takes a lot of engineering development to put things like dual APUs, aerial refueling, and defensive countermeasures on a commercial airplane.
And what information would the OEM require? They certainly wouldn't need to know any specifics.
Caller: How much HIRF can the FADEC handle? (HIRF - High Intensity Radiated Fields)
Me: We tested to 200 volts/meter continuous wave across the frequency range.
Caller: But what can it take?
Me: We tested to 200 volts/meter and it passed, we didn't test to failure. What's the threat?
Caller: Can't tell you the threat - that's classified. What threat can you take?
The worst part was I had some variation of that conversation (with different callers) about a dozen times
I don't own this space under my name. I should have leased it while I still could
One could almost think HH bashing is derigour when my red cloak has been totally ignored.
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de ri·gueur
adjective \də-(ˌ)rē-ˈgər\ : necessary if you want to be fashionable, popular, socially acceptable, etc.
Pontius is all of the above......................... a true SAPEUR............
I think he's disappointed that no-one rose (very much ) to the post
"Leading, most powerful and arguably only superpower is true, but with the might to impose its will on any other power, by definition, means no other power is free."
PS getting priority in the "Hate" stakes is the price of fame...........................
adjective \də-(ˌ)rē-ˈgər\ : necessary if you want to be fashionable, popular, socially acceptable, etc.
Pontius is all of the above......................... a true SAPEUR............
I think he's disappointed that no-one rose (very much ) to the post
"Leading, most powerful and arguably only superpower is true, but with the might to impose its will on any other power, by definition, means no other power is free."
PS getting priority in the "Hate" stakes is the price of fame...........................
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TD RACER - thanks I was using the published figures (obviously)
I presume that quite a bit of the refueling probe design can be carried over from the VC-25 but then all the add-ons made on the VC-25 over their 30 year lives will all be lumped together in one big bill for the new AF1
I presume Mr B would give the USAF a decent deal on this one - the PR is worth a lot and they are getting rid of two airframes that otherwise will go to scrap or freighters
I presume that quite a bit of the refueling probe design can be carried over from the VC-25 but then all the add-ons made on the VC-25 over their 30 year lives will all be lumped together in one big bill for the new AF1
I presume Mr B would give the USAF a decent deal on this one - the PR is worth a lot and they are getting rid of two airframes that otherwise will go to scrap or freighters
It is no real surprise that a Boeing airliner has been chosen. The two key parts of the initial requirement that the aircraft have four engines and be assembled in the USA. Add to this a (I understand) requirement that the design offered have a pre-proven safe service history and the field is very limited.
The first part brings the field down to three types: Airbus A340, Boeing 747 & Airbus A380.
The second requirement eliminates the two Airbus types. It is simply impractical to set up a production facility several time zones away from the existing production facilities just to produce two, or at most three aircraft (see earlier posts).
What is really surprising to me, is that the US put this out to a pointless form of competitive tendering, rather than just take the "National Security - driven requirement" and just specify a 747, end of story.
But again, I don't follow the logic of needing 'four engines, more maintenance, more fuel burn & statistically a greater chance that an engine will drop out, due to the fact that there are more of them. The routes and locations flown by AF1 are well within ETOPS, even over nominally unfriendly territory.
The sceptic in me wonders if there is something missing in the [Boeing] twin airframes that is there in the 747 that drives the four engine requirement. The Airbus designs being irrelevant here. My suspicion is that it may be something related to the air to air refuelling capability. Perhaps the fuel management systems are older & simpler on the 747 & hence more robust for upset conditions than more evolved & sensitive systems in the twins. Pure speculation on my part.
The first part brings the field down to three types: Airbus A340, Boeing 747 & Airbus A380.
The second requirement eliminates the two Airbus types. It is simply impractical to set up a production facility several time zones away from the existing production facilities just to produce two, or at most three aircraft (see earlier posts).
What is really surprising to me, is that the US put this out to a pointless form of competitive tendering, rather than just take the "National Security - driven requirement" and just specify a 747, end of story.
But again, I don't follow the logic of needing 'four engines, more maintenance, more fuel burn & statistically a greater chance that an engine will drop out, due to the fact that there are more of them. The routes and locations flown by AF1 are well within ETOPS, even over nominally unfriendly territory.
The sceptic in me wonders if there is something missing in the [Boeing] twin airframes that is there in the 747 that drives the four engine requirement. The Airbus designs being irrelevant here. My suspicion is that it may be something related to the air to air refuelling capability. Perhaps the fuel management systems are older & simpler on the 747 & hence more robust for upset conditions than more evolved & sensitive systems in the twins. Pure speculation on my part.
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This is a pretty good video on Air Force One and its mission. There are smaller aircraft that are used, mainly domestically for smaller airports such as Boeing 757s and business jet type aircraft.
I can guarantee that special attention is paid to every aspect of these aircraft including all the parts for the engines. Enjoy the presentation below:
https://www.youtube.com/watch?v=gd-yjm6uTYc
I can guarantee that special attention is paid to every aspect of these aircraft including all the parts for the engines. Enjoy the presentation below:
https://www.youtube.com/watch?v=gd-yjm6uTYc
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Originally Posted by Donkey497
But again, I don't follow the logic of needing 'four engines, more maintenance, more fuel burn & statistically a greater chance that an engine will drop out, due to the fact that there are more of them. The routes and locations flown by AF1 are well within ETOPS, even over nominally unfriendly territory.
The sceptic in me wonders if there is something missing in the [Boeing] twin airframes that is there in the 747 that drives the four engine requirement. The Airbus designs being irrelevant here. My suspicion is that it may be something related to the air to air refuelling capability. Perhaps the fuel management systems are older & simpler on the 747 & hence more robust for upset conditions than more evolved & sensitive systems in the twins. Pure speculation on my part.
The sceptic in me wonders if there is something missing in the [Boeing] twin airframes that is there in the 747 that drives the four engine requirement. The Airbus designs being irrelevant here. My suspicion is that it may be something related to the air to air refuelling capability. Perhaps the fuel management systems are older & simpler on the 747 & hence more robust for upset conditions than more evolved & sensitive systems in the twins. Pure speculation on my part.
That IS a specific item in the requirements - to continue to fly (even early in take-off) if one engine is disabled for any reason.
From what I can pick up from various discussions here & elsewhere the 777 is somewhat unchallenged losing an engine above V1. Below V1 it's a roll to a stop under normal circumstances. However, I would judge that from what is said in other threads that it would be possible to proceed to take off on only 1 engine.
BUT, in reality, if someone has just shot off one of your engines, be it 1 out of four or one out of two, your are very likely to have other more serious problems. & the safety of the Pres is probably best served by staying on the ground, evacuating & seeking cover from the rearguard security detachment.
....Just sayin'
BUT, in reality, if someone has just shot off one of your engines, be it 1 out of four or one out of two, your are very likely to have other more serious problems. & the safety of the Pres is probably best served by staying on the ground, evacuating & seeking cover from the rearguard security detachment.
....Just sayin'
Back during the VC-25 development, I was in some real entertaining meetings with the USAF. Lots of questions about taking off with various systems failed. Basically, they were worried about the ability to get the President out of Dodge in a hurry, even if they had a broken airplane.
While I doubt you'd ever get them to admit this - I do think they want the to ability to depart even if they have a failed engine. The 747 has AFM procedures for a 3 engine ferry - with aerial refueling they could take off light, then aerial refuel and fly to pretty much anywhere they wanted. I'm pretty sure you wouldn't want to try that with a 777.
HH - I certainly hope we still have the engineering for some of the special mods from the VC-25 that would be applicable to a new 747-8 based AF1, although it wouldn't surprise me if much of it's been lost to the sands of time (VC-25 also has a really trick airstairs setup that deploys out of the cargo deck, with stairs up to the main deck).
While I doubt you'd ever get them to admit this - I do think they want the to ability to depart even if they have a failed engine. The 747 has AFM procedures for a 3 engine ferry - with aerial refueling they could take off light, then aerial refuel and fly to pretty much anywhere they wanted. I'm pretty sure you wouldn't want to try that with a 777.
HH - I certainly hope we still have the engineering for some of the special mods from the VC-25 that would be applicable to a new 747-8 based AF1, although it wouldn't surprise me if much of it's been lost to the sands of time (VC-25 also has a really trick airstairs setup that deploys out of the cargo deck, with stairs up to the main deck).
Thread Starter
The USAF has other 747s on the roster besides those assigned for the President. Those are older -200s, perhaps they are being replaced as well.
Or maybe Michelle just wants her own ride.
Or maybe Michelle just wants her own ride.
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Cutting Edge?
PN said 787. I would have added A350 to that too.
It is my opinion that the whole notion of a "cutting edge image" is a red herring not at all applicable to the mission of this aircraft.
Last edited by KenV; 3rd Feb 2015 at 21:16.
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I was involved in the last AF1 proposal on the losing side: Douglas with the DC-10.
Without going into sensitive technical details, single engine out performance was a BIG deal. The DC-10 could barely, sort of meet the requirements. The 747 met them handily.
Electric power generation requirements were immense and were a huge deal to USAF. Two APUs were required. Providing the required power in flight with an engine out was problematic for the DC-10. Not so the 747. There were other issues.
Douglas had plans to meet all the requirements, but early on it was clear that USAF wanted a four engine jet. Douglas' role was to keep Boeing focussed while looking over their shoulder and the Douglas strategy became to force Boeing to underbid the contract to win it. It worked. Boeing took a financial bath on the last Air Force One project and tied up a bunch of their best engineers for years to solve all the issues.
And as a reminder, the DC-10 had three engines. A twin could not hope to meet those long ago requirements. And the new requirements are MUCH more challenging.
And as an aside, the 747-8 uses GenX engines, same as the 787. These engines and their accessory gear drive have the ability to drive two 250KVA generators EACH. (That is not what is installed on the 747-8, but could be.) With four engines and eight generators, that means 2 gigawatts of installed power, NOT including the APUs (yes, two APUs are required, each also with BIG generators.). I'll leave it up to the reader to conjecture on what all this power is for, but, yes, all that power is needed to power some of the stuff that will be installed on the new Air Force Ones.
As a reminder, the VH-71 was WAY bigger than the VH-3 it was to replace. Yet it was not big enough to handle all the stuff USAF wanted to include. The same with the new Air Force One. The 747-8 is bigger and more powerful than the 747-200 it is replacing, but meeting all the requirements with that bigger airplane will be challenging. Meeting those requirements with a twin cannot be done. It has NOTHING to do with ETOPS or other engine reliability considerations.
Without going into sensitive technical details, single engine out performance was a BIG deal. The DC-10 could barely, sort of meet the requirements. The 747 met them handily.
Electric power generation requirements were immense and were a huge deal to USAF. Two APUs were required. Providing the required power in flight with an engine out was problematic for the DC-10. Not so the 747. There were other issues.
Douglas had plans to meet all the requirements, but early on it was clear that USAF wanted a four engine jet. Douglas' role was to keep Boeing focussed while looking over their shoulder and the Douglas strategy became to force Boeing to underbid the contract to win it. It worked. Boeing took a financial bath on the last Air Force One project and tied up a bunch of their best engineers for years to solve all the issues.
And as a reminder, the DC-10 had three engines. A twin could not hope to meet those long ago requirements. And the new requirements are MUCH more challenging.
And as an aside, the 747-8 uses GenX engines, same as the 787. These engines and their accessory gear drive have the ability to drive two 250KVA generators EACH. (That is not what is installed on the 747-8, but could be.) With four engines and eight generators, that means 2 gigawatts of installed power, NOT including the APUs (yes, two APUs are required, each also with BIG generators.). I'll leave it up to the reader to conjecture on what all this power is for, but, yes, all that power is needed to power some of the stuff that will be installed on the new Air Force Ones.
As a reminder, the VH-71 was WAY bigger than the VH-3 it was to replace. Yet it was not big enough to handle all the stuff USAF wanted to include. The same with the new Air Force One. The 747-8 is bigger and more powerful than the 747-200 it is replacing, but meeting all the requirements with that bigger airplane will be challenging. Meeting those requirements with a twin cannot be done. It has NOTHING to do with ETOPS or other engine reliability considerations.
And as an aside, the 747-8 uses GenX engines, same as the 787. These engines and their accessory gear drive have the ability to drive two 250KVA generators EACH. (That is not what is installed on the 747-8, but could be.) With four engines and eight generators, that means 2 gigawatts of installed power, NOT including the APUs (yes, two APUs are required, each also with BIG generators.). I'll leave it up to the reader to conjecture on what all this power is for, but, yes, all that power is needed to power some of the stuff that will be installed on the new Air Force Ones.
I think what may be more likely if they need lots of electricity would be to install 120 KVA IDGs (the 747-8 currently has 96 KVA IDGs which appears to have been a penny wise/pound foolish decision by management very early in the 747-8 program).
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It is my opinion that the whole notion of a "cutting edge image" is a red herring not at all applicable to the mission of this aircraft.
If cutting edge image isn't too important then I would imagine a C17 would be ideal.
S-D
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Seems to me it was you who made a big deal over cutting edge. You asked a question, got a couple of answers. You didn't like those though, didn't fit with your thinking
If cutting edge image isn't too important then I would imagine a C-17 would be ideal.
Although technically, a few C-17s have ALREADY been Air Force One. Air Force One is the call sign of ANY airplane with POTUS aboard, and Clinton, Bush, and Obama have all flown on C-17s.