https://upload.wikimedia.org/wikipedia/commons/thumb/0/06/Boeing_707-321B_Pan_Am_Freer.jpg/220px-Boeing_707-321B_Pan_Am_Freer.jpg707-320B

A Boeing 707-320B of Pan American World Airways in 1979

The 707-320B had the application of the JT3D turbofan to the Intercontinental, but with aerodynamic refinements. The wing was modified from the −320 by adding a second inboard kink, a dog-toothed leading edge, and curved low-drag wingtips instead of the

earlier blunt ones.  These wingtips increased overall wingspan by 3.0 ft. Takeoff gross weight was increased to 328,000 lb (149,000 kg). The 175 707-320B aircraft were all new-build; no original −320 models were converted to fan engines in civilian use. First service was June 1962, with Pan Am.

The 707-320B Advanced is an improved version of the −320B, adding the three-section leading-edge flaps already seen on the −320C. These reduced takeoff and landing speeds and altered the lift distribution of the wing, allowing the ventral fin found on earlier 707s to be deleted. From 1965, -320Bs had the uprated −320C undercarriage allowing the same 335,000 lb (152,000 kg) MTOW.

These were often identified as 707-320BA-H.

 

https://upload.wikimedia.org/wikipedia/commons/thumb/2/24/BOAC_Boeing_707-436_Wheatley.jpg/220px-BOAC_Boeing_707-436_Wheatley.jpg 707-420

 

The 707-420 was identical to the −320, but fitted with Rolls-Royce Conway 508 (RCo.12) turbofans (or by-pass turbojets as Rolls-Royce called them) of 18,000 lb (79 kN) thrust each. The first announced customer was Lufthansa. BOAC's controversial order was announced six months later, but the British carrier got the first service-ready aircraft off the production line. The British Air Registration Board refused to give the aircraft a certificate of airworthiness, citing insufficient lateral control, excessive rudder forces, and the ability

to over-rotate on takeoff, stalling the wing on the ground (a fault of the de Havilland Comet 1). Boeing responded by adding 40 in to the vertical tail, applying full instead of partial rudder boost, and fitting an underfin to prevent over-rotation.

These modifications except to the fin under the tail became standard on all 707 variants

and were retrofitted to all earlier 707s. The 37 -420s were delivered to BOAC, Lufthansa, Air-India, El Al, and Varig through November 1963; Lufthansa was the first to carry passengers, in March 1960.

 

* BOEING 707-320B/420 REFERENCE INFORMATION *

 

 

*****Total Flight Simulator aircraft weight with full fuel*****           

316,000 lbs.

NOTE: To adjust fuel load, on the Aircraft menu, click Fuel.

 

**********SPEEDS**********

Vmo - Maximum Operating Speed (airspeed)

           370 KIAS

 

Mmo - Maximum Operating Speed (Mach)

           .90 Mach

 

Turbulent Air Penetration Speed

           280 KIAS/.73 Mach

 

Vlo - Maximum Gear Operating Speed

           270 KIAS

 

Vle - Maximum Landing Gear Extension Speed

           320 KIAS/.83 Mach

 

*****Maximum Flap Placard Speeds*****

Maximum Flap (Placard) KIAS Speeds

       5          230

      14          223

      25          215

      40          200

      50          185

 

*****Take-off*****

V1 - Takeoff Decision Speed (dry runway, flaps 14)

       Standard temperature, sea level pressure altitude

             154 KIAS (315,000 lbs.)

             145 KIAS (290,000 lbs.)

             136 KIAS (265,000 lbs.)

       Standard temperature, 5,000' pressure altitude

             151 KIAS (290,000 lbs.)

             143 KIAS (265,000 lbs.)

 

Vr - Rotation Speed (dry runway, flaps 14)

       Standard temperature, sea level pressure altitude

             160 KIAS (315,000 lbs.)

             152 KIAS (290,000 lbs.)

             143 KIAS (265,000 lbs.)

       Standard temperature, 5,000' pressure altitude

             158 KIAS (290,000 lbs.)

             147 KIAS (265,000 lbs.)

 

V2 - Takeoff Safety Speed (dry runway, flaps 14)

             177 KIAS (315,000 lbs.)

             171 KIAS (290,000 lbs.)

             163 KIAS (265,000 lbs.)

 

*****Landing*****

Vref - Landing Approach Speed (flaps 50, gear down)

             158 KIAS (290,000 lbs.)

             151 KIAS (265,000 lbs.)

             147 KIAS (250,000 lbs.)

             142 KIAS (235,000 lbs.)

 

NOTE:  For explanations of speeds used on this tab, see "V-speeds" in the Glossary section of Help.