Horatiu Goanta Aviation Photography
Boeing 747SP-27 A4O-SO Royal Flight of Oman | Hamburg Fuhlsbüttel HAM/EDDH
The Oman SP landing at EDDH on a sunny spring day. The noise of those four JT9Ds was amazing. The SP wing is different than the 747-100 series it was derived from. Instead of complex triple slotted Fowler flaps with external flap track and associated fairings, the SP has single slotted Fowler flaps that move on internal tracks. Also note the inboard ailerons directly behind engines 2 and 3. The leading edge high lift devices are unchanged from the -100: 1 section unslotted Kruger flaps inboard and 2 sections slotted Kruger flaps outboard. This measure sounds weird, but ensures that the wing roots suffer flow separation first at the beginning of a stall. As the wing tips still are further aft and still produce lift, this will cause the lift vector to shift rearwards and the nose-down moment caused will reduce the angle-of-attack of the aircraft, recovering from the stall.
By the same logic the horizontal tail planes (HTPs) have less sweep than the wings: if the wings stall first, the aircraft is still controllable in pitch so the pilots have a chance to recover.
Categories:
Boeing - 747 - 747 VIP - B747SP - Oman - HAM/EDDH
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Boeing 747SP-27 A4O-SO Royal Flight of Oman | Hamburg Fuhlsbüttel HAM/EDDH
The Oman SP landing at EDDH on a sunny spring day. The noise of those four JT9Ds was amazing. The SP wing is different than the 747-100 series it was derived from. Instead of complex triple slotted Fowler flaps with external flap track and associated fairings, the SP has single slotted Fowler flaps that move on internal tracks. Also note the inboard ailerons directly behind engines 2 and 3. The leading edge high lift devices are unchanged from the -100: 1 section unslotted Kruger flaps inboard and 2 sections slotted Kruger flaps outboard. This measure sounds weird, but ensures that the wing roots suffer flow separation first at the beginning of a stall. As the wing tips still are further aft and still produce lift, this will cause the lift vector to shift rearwards and the nose-down moment caused will reduce the angle-of-attack of the aircraft, recovering from the stall.
By the same logic the horizontal tail planes (HTPs) have less sweep than the wings: if the wings stall first, the aircraft is still controllable in pitch so the pilots have a chance to recover.
Categories:
Boeing - 747 - 747 VIP - B747SP - Oman - HAM/EDDH
Collections: