1 week Ago By Steve Miller
It might be surprising to know that the Air Force's VC-25A "Air Force One" (AFO) and the Boeing 747-200B jumbo jet (the base level aircraft that the VC-25A is derived from) do not have as much in common as people might think. The two B747-200Bs converted to the AFO configuration, started life as finished passenger planes. After the two planes were delivered to the AFO production shop, the technicians started removing everything that was not on the VC-25A's bill-of-materials.
Checkout Simple Flying's additional Air Force One content The two gutted planes were ready to begin the VC-25A fabrication process. Simply put, the stripped-down planes did not retain much more than the aluminum skin panels and landing gear! Even the airframe and internal wing structure would be modified. What is the difference between the B747-200B airliner and the VC-25A Air Force One? Pan American World Airways was the first carrier to put a Boeing 747-100 into service in January 1970.
Pan Am had a long-running tradition of naming its planes. The honor of being the first Pan Am B747 to enter service, and the first one overall, was the " Clipper Ocean Telegraph " shown above landing at London's Heathrow Airport. When the Clipper Ocean Telegraph entered service, Boeing was already in the midst of designing and testing the first major B747 upgrade, the B747-200.
This major upgrade was the baseline B747 that became the VC-25A " Air Force One." Model/ Feature -100 -200 -300 -400 -8i/f Cockpit Crew Three (pilot, co-pilot, flight engineer) Two (pilot, co-pilot) MTOW 375 tons 416 tons 416 tons 455 tons 493 tons Fuel Capacity 48,000 gal 52,000 gal 52,000 gal 63,000 gal 63,000 gal Thrust (4 eng) 51,600 lbf 54,000 lbf 57,000 lbf 63,000 lbf 66,500 lbf Range 5,320 mi. 7,550 mi.
7,280 mi. 8,826 mi. 8,900 mi.
In 1985, the 89th Airlift Wing, then a component of the Air Force's Military Airlift Command, identified the need to begin studying and planning for a new Presidential Special Airlift Mission Aircraft, known informally as "Air Force One." It will be more costly than expected due to a time-consuming modification process, supply disruptions, and other challenges. Both McDonnell Douglas and Boeing submitted proposals.
McDonnell Douglas put forward their DC-10, and Boeing proposed the B747-200B. Boeing won the contract. The first VC-25A started flight testing in 1987 and began Presidential service in August 1990.
Although the B747-100 was still in production when the 89th Airlift Wing began its new AFO planning, Boeing purposely focused on the B747-200B because the -100 model did not meet the VC-25A procurement specification. The VC-25A procurement specification required higher engine thrust, greater fuel capacity, longer range, and increased payload. The B747-200B met all of the baseline features the USAF required.
Aircrew requirements for the VC-25A Aircrew Position Minimum Number of Airmen for a Basic Crew Minimum Number of Airmen for an Augmented Crew (for overnight and intercontinental flights) Aircraft Commander 1 2 Co-Pilot 1 1 Navigator 1 2 Flight Engineer 1 2 Communications Technician 4 4 Flight Attendant 10 10 Flying Crew Chief 2 2 Phoenix Raven Security Forces 4 6 VC-25A-specific aircraft operations and aircrew training & evaluation A commercial B747-200B has a cockpit aircrew of pilot, co-pilot, and flight engineer, but no navigator. The reason a VC-25A carries a navigator is to facilitate continued flight if computerized navigation equipment is inoperative or being jammed, satellite GPS is unavailable, or ground navigation aids are unavailable. The VC-25A has more than 30 different communications and navigation devices.
These problems can be the result of equipment failure, or hostile actions. In either case, the pilots are not trained to perform manual navigation work or troubleshoot the issues disrupting normal navigation. The navigator also handles the specialized defensive and electronic warfare equipment.
The crew navigator functioned much like navigators used to do before navigation avionics became so automated in the 1990s and new planes eliminated the navigator position. The Boeing E-4B "Nightwatch" National Emergency Airborne Command Post is being refueled by a KC-135 tanker. The E-4B is a modified Boeing 747-200B, just like the VC-25A.
A significant number of avionics systems are common to the VC-25A and E-4B. Another position of note is the flying crew chief. Crew chiefs are the primary maintenance technicians who "own" the plane on the ground and either do the maintenance themselves, or arrange for a specialist to come out to check the plane.
Crew chiefs normally do not fly on other large aircraft, unless the plane is going overseas. They fly on Air Force One in order to handle emergency repairs, and they are responsible for any ground servicing en route. Tech.
Sgt. Mark Graveline performs an operational check on a C-17 Globemaster III aircraft fuel control panel. Flying crew chiefs are specially trained maintenance personnel who attend a six-week maintenance special operations course in addition to the hundreds of hours of training it takes to become 7-level aircraft maintenance supervisor.
Lastly, the Phoenix Raven Security Forces are airmen from the Joint Base Andrews' 89th Security Forces Squadron. Phoenix Ravens have advanced training that addresses the unique circumstances of Air Force One flight operations. During any special airlift mission, the Phoenix Raven team reports solely to the Aircraft Commander, and their jurisdiction is everyone and everything aboard Air Force One, and the same rules apply when the plane is on the ground anywhere in the world.
Special Purpose Navigation/Communications Equipment on VC-25A (unclassified) For future reference in interpreting the many acronyms used in flight operations, the FAA publishes a Pilot/Controller Glossary . At first glance, this equipment list seems like a lot of redundancy; it is intentional. It permits Air Force One to literally travel anywhere in the world, and be able to comply with the varied systems that might be dissimilar from one country to another.
Category Operational Capability Equipment Purpose Communication & Navigation Radios 8.33 KHz VHF Radios Narrowband, jam-resistant receivers AN/ARN-147 FM Immunity ILS/VOR jam-resistant receiver Datalink Systems FANS 1/A Future Air Navigation System introduced by the International Civil Aviation Organization (ICAO) [international equivalent of the FAA]. ATC/pilot datalink used to communicate when flying over open water.
FANS 1/A+ ATN B1 (Link 2000+) Aeronautical Telecom Network - introduced in the 1990s by ICAO for Europe - ATC datalink communications ATN B2 ACARS ATS (DCL, OCL, TWIP, D-ATIS) Aircraft Communications Addressing and Reporting System - introduced in 1970s, ATC/pilot datalink system transmitting a variety of data, like, cargo manifests, distress calls, weather updates, flight plans, position reports, aircraft performance info, passenger issues and automated alerts for system failures. TDLS (D-ATIS, PDC, CPDLC -DCL) Tower Data Link Services - per the FAA, TDLS is a system that provides Digital Automatic Terminal Information Service (D-ATIS) both on a specified radio frequency and also, for subscribers, in a text message via data link to the cockpit or to a gate printer. TDLS also provides Pre-departure Clearances (PDC), at selected airports, to subscribers, through a service provider, in text to the cockpit or to a gate printer.
In addition, TDLS will emulate the Flight Data Input/Output (FDIO) information within the control tower. Surveillance ADS-B In Automatic Dependent Surveillance–Broadcast. FAA mandated for all aircraft flying in the NAS.
In and outbound signals are through the plane's transponder. ADS-B notifies each aircraft in the air of other traffic in its vicinity. ADS-B Out Version 2 Elementary Mode S A function of the plane's transponder that provides aircraft identification and altitude information to air traffic controllers.
Enhanced Mode S Facilitates additional data in the transponder outbound signal. TCAS II Version 7.1 Traffic Alert and Collision Avoidance System.
Mandatory system in the EU. In U.S.
airspace, only required for commercial planes of 30 seats or more, or a max takeoff weight over 33,000 lbs., or planes that fly in Reduced Vertical Separation Minimum designated airspaces. Provides visual and auditory Resolution Advisories (RAs), including such warnings as "Adjust Vertical Speed, "Level Off, Level Off".
IFF Mode 5 Identify Friend or Foe was developed in W.W. II to reduce the number of friendly ground fire.
Certain IFF modes are used by airlines and private aviation. Mode 5 is U.S.
military only. Vertical Navigation RVSM Reduced Vertical Separation Minimum. It allows for reduced vertical separation between aircraft from 2,000 feet to 1,000 feet between Flight Level 29,000 feet.
MSL and 41,000 ft. MSL. Aircraft are allowed to use RVSM if it has two independent altitude measurement systems.
The advantage of RVSM capable aircraft is avoiding the congested airspace using 2,000 ft separation. Lateral Navigation NAT HLA North Atlantic High-Level Airspace is a restricted corridor across the North Atlantic. Requires FANS 1/A, two independent Long Range Navigation Systems, transponder TCASD 7.
1, and HF radios. An aircraft cannot use the NAT HLA corridor without an FAA written authorization. RNAV 5 (B-RNAV, RNP 5) Area Navigation, Basic (requires onboard system that tracks an aircraft's location along it's planned route, and must show a minimum of being within 5 miles , 95% of the time.
Aircraft capable of this system are authorized to be routed by ATC on a point-to-point direct basis instead of using designated airways, which are not a direct route. RNAV 2 (nas ONLY) Q & T Routes navigation performance has to be within 2 miles instead of 5. This category is only available in the U.
S. Q routes are 18,000 to 45,000 ft. altitude.
T routes are 1,200 to 18,000 ft. altitude. RNAV 1 (P-RNAV) The most precise navigation performance has to be within 1 mile instead of 2 or 5.
RNP 4 Required Navigation Performance - ICAO navigation performance over water or intercontinental flights of 4 miles, 95% of the time. RNP 2 a combination of NAT HLA and RNAV 2. Requires two independent Long Range Navigation Systems.
Flight navigation performance is 2 miles, 95% of the time. RNP 1 a combination of NAT HLA and RNAV 2. Requires two independent Long Range Navigation Systems.
Flight navigation performance is 1 mile, 95% of the time. Advanced RNP (A-RNP) Similar to RNP 2, but it is not limited to en route segments. Adds in arrival, approach, and departure routes.
[ICAO] RNP Approach [NAS] RNAV (GPS) Similar to RNP 2, but for just departures, and navigation accuracy can only be based on GPS or other satellite navigation systems. LNAV/VNAV (Baro VNAV) LPV LP Navigation system used for approaches based on data coming from onboard systems Special Aircrew & Aircraft PRM ILS Precision Runway Monitor (PRM) approach for airports with parallel runways separated by 2,500 ft. to 4,300 ft.
Pilots require specialized training, must be familiar with relevant AIM sections, and have dual VHF radio capability to monitor both the tower and PRM monitor frequencies. SA CAT I ILS Special authorization category I means an approach with a decision height not lower than 150 ft. and a Runway Visual Range not less than 600 yds.
Pilots require specialized training and must use a HUD. SA CAT II ILS Special authorization category II means an approach with a decision height not lower than 100 ft. and a Runway Visual Range not less than 330 yds.
Pilots require specialized training and must use a radar altimeter and HUD. CAT IIIa ILS Category IIIa means an approach with a no-mandated decision height and a Runway Visual Range not less than 190 yds. Pilots require specialized training and must use a radar altimeter and HUD.
CAT IIIb ILS Category IIIb means an approach with a no-mandated decision height and a Runway Visual Range not less than 55 yds. Pilots require specialized training and must use a radar altimeter and HUD. CAT IIIc ILS Category IIIc means an approach with a non-mandated decision height and no Runway Visual Range limitation.
Pilots require specialized training and must use a radar altimeter and HUD. High Latitude Navigation Specialized techniques and challenges are involved in navigating near the poles, where traditional navigation is less reliable due to the convergence of meridians and the effects on magnetic compasses. Requires a trained navigator and Stellar Inertial Navigation System.
Classified Voice/Data/Network Encryption Device HAVE QUICK II or SATURN An ECM-resistant frequency hopping system used to protect military radio traffic related to airborne operations. SINCGARS - RT-1702 Single Channel Ground and Airborne Radio System (SINCGARS) is a VHF combat network radio (CNR) used by U.S.
and allied military forces. In the CNR network, the SINCGARS’ primary role is voice transmission between surface and airborne command and control (C2) assets. SIPRNet and JWICS The Secret Internet Protocol Router Network (SIPRNet) and Joint Worldwide Intelligence Communications System (JWICS), are systems of interconnected computer networks used by the U.
S. Department of Defense and the U.S.
Department of State to transmit classified information. SIPRNet is used for information that is classified up to and including SECRET, and JWICS is for TOP SECRET information. General Dynamics TACLANE-1G (KG-175G) Jam-resistant HAIPE Encryptor Additional information about navigation systems can be accessed at Jetcraft, Inc.
The chart embedded above is a summary of Jetcraft's content. Other features and equipment aboard the VC-25A Airstairs - Two airstairs were added to the VC-25A. One set of airstairs is on the left side of the plane, forward.
President George Bush Jr. is shown using the forward airstairs. An aft set of airstairs is also on the left side.
VIPs use the forward airstairs, and all others (i.e., the plane's aircrew, traveling press pool) use the aft airstairs.
Onboard compartments - The President's executive suite, conference room with teleconferencing ability, several office compartments, and other enclosed areas, like the medical suite, are all located on the right side, and a long corridor runs down the left side. The unofficial protocol for passengers (aircrew not applicable) is that wherever your assigned seat is located, you can move around the cabin, but only for areas aft of your seat. Passengers should not go forward beyond their seats.
Medical personnel - All Air Force One missions carry a flight surgeon and registered nurse. Telecom systems - For general unclassified communications for anyone onboard, the VC-25A has 87 telephones and 19 televisions. Baggage loader - The VC-25A has a self-contained baggage loader.
Aerial refueling system - The VC-25A was given this feature from beginning, but the need for it has not occurred. This feature has been removed from the engineering baseline of the new VC-25Bs. Electronic countermeasures (ECM) and electronic warfare - The plane carries radar warning gear and infrared detection.
The plane has an automated ECM jamming system - the AN/ALQ-204 - with chaff and flare dispensers. The graphic shown above depicts the components of the Infrared/heat-seeking missile countermeasures system made by Northrop Grumman. Gas Turbine Compressor (auxiliary power unit) - Part of the VC-25A's operational concept is to be self-contained.
The gas turbine compressor (GTC) is an example of the plane's self-service capability. The plane can land in locations with no ground support from FBO personnel. The GTC facilitates the engine start-up and can provide electricity to power all of the onboard systems while on the ground.
SatCom systems - In 2017, both VC-25As completed a major depot overhaul, which included dual SatCom antennas and receivers. Satellites are becoming an ever-critical part of the way the United States fights and dominates its opponents. Airframe and wings strengthening - A commercial B747 aircraft is limited in its ability to make aggressive airborne maneuvers.
A VC-25A may be a target of airborne attack. The plane would have to make radical moves to evade an adversary. To enable the plane's ability to withstand the stress of evasive maneuvering, the longerons and wing roots had to be strengthened.
Taking care of the passengers - Not counting the aircrew, the VC-25A accommodates 71 passengers. On the lower level there are two large kitchens, one forward and one aft. Combined together, the kitchens can feed 100 people at each meal.
Onboard cold storage and dry storage contains enough food for 3,000 meals. Defense against an Electro-Magnetic Pulse (EMP) - All electronics used on the VC-25A are susceptible to an EMP. Without proper protection, exposed electronic equipment will be damaged and unserviceable.
The most effective deterrence to EMP damage is the " Faraday Cage ." One of the prominent scientists to discover key factors in the behavior of electricity and its effects in an electronic circuit was Michael Faraday (1791-1867). The three key factors that determine how electrical current and electronic signals behave in a circuit are: Resistance Inductance Capacitance - Michael Faraday discovered how capacitance works in an electrical/electronic circuit.
In honor of Faraday's discovery, the unit of measure for capacitance was named the "Farad." Decades later, scientists discovered that capacitors blocked direct current, but alternating current passes through a capacitor. Research determined that if an alternating current signal flows through a capacitor, but you do not want the signal to go further into the circuit, a connection from the capacitor's output wire to an electrical ground will short the signal to ground, and it stops right there.
This poses a problem if the alternating current signal is not hardwired to a circuit, but is propagated through the air like a radio or radar signal. An EMP is an alternating current signal that is propagated through the air. To prevent the propagated EMP signal from entering an electronic circuit, a Faraday Cage is used.
In simple terms, the physical exterior of the electronic device you want to protect needs to become one continuous capacitor covering all of the external surface area. This is a Faraday Cage. If a propagated EMP signal touches any part of the external surface, the signal is shorted to ground.
The Marine Corps EA-6B Prowler Electronic Attack platform shown here, is a good example of a Faraday caged aircraft. Since the skin and airframe are made of metal, and is electrically conductive, incorporating a Faraday cage is not a simple design and manufacturing work product, yet it is a well-known, expensive process. But, what about an aircraft's windows? Regardless of whether a window is made of glass or plastic, a propagated EMP signal passes through with ease.
Windows must also be protected with a Faraday cage. This is accomplished by embedding a fine metal mesh made of a gold alloy. This is visible in the EA-6B's photo.
The windows have a gold tint. The VC-25A uses the same method. Since it is imperative for Air Force One to survive any catastrophic situation, like an EMP, it has a double Faraday Cage.
The entire external surface of the VC-25A has been configured as a huge Faraday Cage. If any part of the external surface has been damaged, allowing leakage of the EMP signal into the plane's interior, it could cause one or more onboard electronic devices to be permanently inoperative. To prevent the possibility of a single point of failure due to the damaged exterior surface, all critical VC-25A systems (i.
e., "black boxes") are designed and built with their own Faraday Cage. A quick update from the USAF Executive Program Manager for the VC-25B This linked document is a bit outdated, but only in the sense of the program schedule and cost.
The contents covering what features and modifications are to be done to the two Boeing 747- 8i to produce the VC-25B are accurate, and cover far more information than can be found in an internet search. Musk is helping in several ways. There's a Boom to this story, wait for it.
Once again, the Air Force issued a firm, fixed price (FFP) contract to Boeing, including a fixed amount for systems design and development (SDD). Those funds have been expended, and it is unlikely for USAF program leadership to add more SDD funding. This outcome is not unexpected by Boeing, and any incurred over-budget costs will be a tax write-off.
If Boeing declined to accept the contract in anticipation of a financial loss, the Air Force would not have been too concerned. Since the two B747-8i planes are completely functional commercial airliners, it was not as if the Air Force lacked other defense contractors with experience doing aircraft build-out modifications. Three contractors immediately come to mind: Vertex Aerospace, L3-Harris, and the Sierra-Nevada Corp.
Sierra-Nevada is currently the prime contractor for the new E-4C airborne command post, also a B747-8i conversion. Boeing chose to accept the contract with the expected financial loss. Their rationale kept competitors out of the program and better positioned them for follow-on sustainability, including technical manuals, spare parts, technical support, and major overhauls.
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