What is the safe speed to use highspeed turnoff?

I understand that high speed turnoff is for the plane to exit the runway asap. What is its design specification and how fast can a plane use highspeed turnoff? Assuming only A320,737 and larger.

• I don't have a reference, but I have always been told that high speed turn offs are designed for 60 knots, assuming a dry uncontaminated surface. – Lnafziger Dec 20 '14 at 16:12
• are all high-speed turnoffs at the same angle to the RW? 30 degrees? 45? – rbp Dec 20 '14 at 20:39
• Okay safe speed to be a blanket and highly dependent on the type of plane. How about the disign aspect? 30 or 45 degree? How wide it must be? Any special marking? Out of memory answer is fine by me. – vasin1987 Dec 22 '14 at 2:26

Please be careful applying a blanket figure during high speed turnoff. There are many variables which you should consider. These are:

• Exact angle of the taxiway(you're turning onto): If it's a very shallow angle off the runway and therefore does not require much turning, high-speed turnoffs are easier and manageable, and vice versa.

• Rate of deceleration

• Side load limitations on the CRJ

• Tolerance of the nose gear

• Traffic situation on taxiway

Generally speaking you need both sets of eyes outside, especially if you are joining or crossing another Taxi Way.

According to AC 150/5300-13A, section 409:

b. High-speed exit taxiways. A specific case of an acute angle runway exit taxiway that forms a 30-degree angle with the runway centerline is commonly referred to as a “highspeed” exit taxiway. The purpose of a high speed exit is to enhance airport capacity.

Since the parameters of high-speed taxiway design is the angle at which the taxiway intersects the runway, and does not take into account the aircraft speed, then the answer will be different for every aircraft.

From the Jeppesen glossary, page 14 of this PDF:

HIGH SPEED TAXIWAY / TURNOFF (HST) — A long radius taxiway designed and provided with lighting or marking to define the path of an aircraft, traveling at high speed (up to 60KT), from therunway center to a point on the center of a taxiway. Also referred to as long radius exit or turnoff taxiway. The high speed taxiway is designed to expedite aircraft turning off the runway after landing, thus reducing runway occupancy time.

• Can you provide a link to where this came from? – fooot May 10 '16 at 22:30
• Well, @fooot, he did provide some sort of reference jeppessen page 76 GLOSSARY, but a link would have been much nicer. Does Jeppessen put out more than one document? (Rhetorical question.) – FreeMan May 11 '16 at 12:34