'No speed'
Join Date: Feb 2007
Location: Scandinavia
Age: 47
Posts: 149
Likes: 0
Received 0 Likes
on
0 Posts
Birdstrike
I've hit a big bird over Mallorca (Europe) at FL180 / 300 KIAS. Plane OK, bird not OK.
250 below FL100 is only applied if you are flying in a TMA, at least in Sweden.
/Rookie
250 below FL100 is only applied if you are flying in a TMA, at least in Sweden.
/Rookie
NGKaptain
Nice to know someone here has a sense of history. There were several jet vs. other mid-airs that brought about the first 250 knot rule. That accident also brought about "report navigation equipment failure to ATC" rule and the "slow down to be at holding speed 3 minutes prior to the holding fix" rule.
GF
Nice to know someone here has a sense of history. There were several jet vs. other mid-airs that brought about the first 250 knot rule. That accident also brought about "report navigation equipment failure to ATC" rule and the "slow down to be at holding speed 3 minutes prior to the holding fix" rule.
GF
From a post on the 'bluecoat' forum a few years ago.
BACKGROUND OF THE 250 KT RULE
The Rule
FAR 91.117(a):
Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).
The above FAR 91.117(a) restricts all aircraft departing Class B airspace to maximum speeds of 250 kt indicated airspeed when they are below 10,000 ft altitude. This background section will describe the historical origins of this restriction, the current implementation and enforcement of the rule.
The Historical Evolution of the Rule
The current 250 kt restriction on U.S. aircraft departures in Class B airspace was a result of the historical air traffic control problem of aircraft separation in busy, terminal areas. In the earlier days of aviation, avoiding collisions by the "see and be seen" VFR rules and air traffic controller-enforced IFR rules was adequate, but as air traffic levels increased and aircraft performance improved, these safety rules were significantly augmented by airspace and speed restrictions. Beginning in 1926, the U.S. government started issuing federal regulations to enhance the safety of the "see and avoid" concept of air traffic separation (Note: an interesting account of the history of the "see and be seen" concept can be found in Appendix D of reference 1). However, federal inquiries into three mid-air collisions in the 1950s and 1960s more or less led to the imposition of the 250 kt restriction on aircraft departures in Class B airspace.
In June 30, 1956, a mid-air collision between two airline aircraft over the Grand Canyon in visual meteorological conditions occurred, resulting in significant Congressional inquiry. A result of the inquiry was the adoption of an amendment to the Civil Air Regulations on February 6, 1957.
This amendment established high-density air traffic zones around certain busy airports and aircraft in these zones were to be limited to indicated airspeeds of 160 knots. This indicated airspeed restriction was later increased to 200 knots and 250 knots as required by the higher operating speeds of the developing jet aircraft.
On December 16, 1960, two IFR-controlled airline aircraft collided near Staten Island, New York. The two aircraft were assigned the same altitude but were assigned to two different routes with safe separation. One of the contributing factors in the accident (see reference 2) was judged to be the high rate of speed of one of the aircraft that ventured outside of its cleared airspace.
One outcome of the accident over Staten Island was the publishing of Draft Release (D.R.) No. 61-9, a notice that the Federal Aviation Agency was considering the imposition of a rule to prohibit the flight of arriving aircraft at airspeeds in excess of 250 knots indicated airspeed while in the airspace below 14,500 feet mean sea level within 50 miles of the destination airport (see reference 3). The result of this draft release was both strong support for and opposition against such restrictions. Reference 3 describes the written comments that responded to the draft release, "...one civil aviation organization voiced strong opposition to the proposed rule, emphasizing the economic burden that it felt would be imposed by its adoption. A second organization advocated a speed limit more stringent than the one under consideration, while a third such organization tempered its endorsement with recommendations that the area of applicability be reduced and that the ceiling of applicable airspace be established at 10,000 feet a.m.s.l."
Later, an informal conference among the interested parties was held and further discussions were conducted. The ultimate ruling was a modified version of D.R. No. 61-9, enforcing a 250 knot indicated airspeed restriction with the reduced airspace affected by the rule being all airspace below 10,000 feet m.s.l. and within 30 nautical miles of the destination airport.
The next significant development in the evolution of FAR 91.117(a) was a mid-air collision on March 9, 1967, between an airliner and a private pilot in clear daylight. In the accident report, after acknowledging the inability of "see and be seen" rules to suffice for separation of high-speed VFR traffic and rejecting the potential of increasing the amount of positive control airspace that exists (due to impact of airspace users and economic considerations), the newly-designated Federal Aviation
Administration decided to prescribe the conditions of FAR 91.117(a). The rule was enacted to "...provide a more realistic "see and avoid" environment in the airspace below 10,000 feet mean sea level (MSL) where traffic congestion is greatest..." Furthermore, the National Transportation Safety Board investigating the accident recognized the limitations of the speed restriction and, in the accident report,
recommended "the studying of the feasibility of climb and descent corridors for use by high performance aircraft at major air terminals," as well as, the consideration of collision avoidance systems "until a fail-safe system is developed that applies to all types of aircraft operating under both IFR and VFR weather conditions".
REFERENCES
1. National Transportation Safety Board, "Aircraft Accident Report: Allegheny Airlines, Inc., DC-9, N968VJ and a Forth Corporation, Piper PA-28, N7374J, Near Fairland, Indiana, September 9, 1969," SA-417, Adopted: July 15, 1970. (Report Number NTSB-AAR-70-15)
2. Civil Aeronautics Board, "Aircraft Accident Report: United Air Lines, Inc., DC-8, N 8013U, and Trans World Airlines, Inc., Constellation 1049A, N 6907C, Near Staten Island, New York, December 16, 1960," SA-361, Adopted: June 18, 1962.
3. National Transportation Safety Board, "Aircraft Accident Report: Trans World Airlines, Inc., Douglas DC-9, Tann Company Beechcraft Baron B-55, In-Flight Collision, Near Urbana, Ohio, March 9, 1967," SA-396, Adopted: June 19, 1968.
Cheers,
D.S.
Senior Systems Engineer
Seagull Technology, Inc.
BACKGROUND OF THE 250 KT RULE
The Rule
FAR 91.117(a):
Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).
The above FAR 91.117(a) restricts all aircraft departing Class B airspace to maximum speeds of 250 kt indicated airspeed when they are below 10,000 ft altitude. This background section will describe the historical origins of this restriction, the current implementation and enforcement of the rule.
The Historical Evolution of the Rule
The current 250 kt restriction on U.S. aircraft departures in Class B airspace was a result of the historical air traffic control problem of aircraft separation in busy, terminal areas. In the earlier days of aviation, avoiding collisions by the "see and be seen" VFR rules and air traffic controller-enforced IFR rules was adequate, but as air traffic levels increased and aircraft performance improved, these safety rules were significantly augmented by airspace and speed restrictions. Beginning in 1926, the U.S. government started issuing federal regulations to enhance the safety of the "see and avoid" concept of air traffic separation (Note: an interesting account of the history of the "see and be seen" concept can be found in Appendix D of reference 1). However, federal inquiries into three mid-air collisions in the 1950s and 1960s more or less led to the imposition of the 250 kt restriction on aircraft departures in Class B airspace.
In June 30, 1956, a mid-air collision between two airline aircraft over the Grand Canyon in visual meteorological conditions occurred, resulting in significant Congressional inquiry. A result of the inquiry was the adoption of an amendment to the Civil Air Regulations on February 6, 1957.
This amendment established high-density air traffic zones around certain busy airports and aircraft in these zones were to be limited to indicated airspeeds of 160 knots. This indicated airspeed restriction was later increased to 200 knots and 250 knots as required by the higher operating speeds of the developing jet aircraft.
On December 16, 1960, two IFR-controlled airline aircraft collided near Staten Island, New York. The two aircraft were assigned the same altitude but were assigned to two different routes with safe separation. One of the contributing factors in the accident (see reference 2) was judged to be the high rate of speed of one of the aircraft that ventured outside of its cleared airspace.
One outcome of the accident over Staten Island was the publishing of Draft Release (D.R.) No. 61-9, a notice that the Federal Aviation Agency was considering the imposition of a rule to prohibit the flight of arriving aircraft at airspeeds in excess of 250 knots indicated airspeed while in the airspace below 14,500 feet mean sea level within 50 miles of the destination airport (see reference 3). The result of this draft release was both strong support for and opposition against such restrictions. Reference 3 describes the written comments that responded to the draft release, "...one civil aviation organization voiced strong opposition to the proposed rule, emphasizing the economic burden that it felt would be imposed by its adoption. A second organization advocated a speed limit more stringent than the one under consideration, while a third such organization tempered its endorsement with recommendations that the area of applicability be reduced and that the ceiling of applicable airspace be established at 10,000 feet a.m.s.l."
Later, an informal conference among the interested parties was held and further discussions were conducted. The ultimate ruling was a modified version of D.R. No. 61-9, enforcing a 250 knot indicated airspeed restriction with the reduced airspace affected by the rule being all airspace below 10,000 feet m.s.l. and within 30 nautical miles of the destination airport.
The next significant development in the evolution of FAR 91.117(a) was a mid-air collision on March 9, 1967, between an airliner and a private pilot in clear daylight. In the accident report, after acknowledging the inability of "see and be seen" rules to suffice for separation of high-speed VFR traffic and rejecting the potential of increasing the amount of positive control airspace that exists (due to impact of airspace users and economic considerations), the newly-designated Federal Aviation
Administration decided to prescribe the conditions of FAR 91.117(a). The rule was enacted to "...provide a more realistic "see and avoid" environment in the airspace below 10,000 feet mean sea level (MSL) where traffic congestion is greatest..." Furthermore, the National Transportation Safety Board investigating the accident recognized the limitations of the speed restriction and, in the accident report,
recommended "the studying of the feasibility of climb and descent corridors for use by high performance aircraft at major air terminals," as well as, the consideration of collision avoidance systems "until a fail-safe system is developed that applies to all types of aircraft operating under both IFR and VFR weather conditions".
REFERENCES
1. National Transportation Safety Board, "Aircraft Accident Report: Allegheny Airlines, Inc., DC-9, N968VJ and a Forth Corporation, Piper PA-28, N7374J, Near Fairland, Indiana, September 9, 1969," SA-417, Adopted: July 15, 1970. (Report Number NTSB-AAR-70-15)
2. Civil Aeronautics Board, "Aircraft Accident Report: United Air Lines, Inc., DC-8, N 8013U, and Trans World Airlines, Inc., Constellation 1049A, N 6907C, Near Staten Island, New York, December 16, 1960," SA-361, Adopted: June 18, 1962.
3. National Transportation Safety Board, "Aircraft Accident Report: Trans World Airlines, Inc., Douglas DC-9, Tann Company Beechcraft Baron B-55, In-Flight Collision, Near Urbana, Ohio, March 9, 1967," SA-396, Adopted: June 19, 1968.
Cheers,
D.S.
Senior Systems Engineer
Seagull Technology, Inc.
