Turbine traffic pattern

[C-5 MEM]

Flying one day into a airport where there is a large number of student pilots in the pattern. The field elevation is 401 feet and I was flying into the pattern at 2000 feet. 1500 AGL. I was told by a few pilots in the pattern that turbine aircraft is required to fly at 1400 feet. Now, I remember in the FAR/AIM there was wording about what the traffic pattern altitude would be for piston and turbine aircraft. I have looked through the 2003 and can not locate it.

Can anyone tell me where it is.

 

[Pilot877]

They are just jealous, Terry!

 

[Michael Knight]

This is what I found:

c. It is recommended that airplanes observe a 1000 foot above ground level (AGL) traffic pattern altitude. Large and turbine powered airplanes should enter the traffic pattern at an altitude of 1,500 feet AGL or 500 feet above the established pattern altitude. A pilot may vary the size of the traffic pattern depending on the aircraft's performance characteristics.

My interpretation is that it is recommended and not regulatory so I try to adhere to the overall intent. I have always based my pattern altitude on my aircrafts performance characteristics mainly and in particular my airspeed on downwind. If I'm flying a turbine/turboprop at 150 kts I'd use 1500' but if I was flying a turborop at 100kts I'd use 1000'. That is what I typically do anyway.

I copied above from: http://www1.faa.gov/avr/afs/acs/90-66a.txt

 

[C-5 MEM]

I think your right 877, later this same individuals wanted me to walk in their resume. As for the airport I have flown in there and that is where we have the king airs parked. I know it states it in Class D airspace but I remember seeing it in bold letters in the FAR/AIM but no dice.

 

[DLF8108]

Turbine Pattern

Were the student pilots flying the T-1 Jayhawk (Beechjet 400)?

The AF SUPT programs use civilian fields for pattern training in the T-1. Columbus AFB used HSV, MEI, NQA, MGM, GLH. 30Flap, 10Flap, 0 Flap, & SE rectangular patterns were taught/flown at 1000' AGL. Only the Tactical Pattern (similiar to a fighter overhead pttn) was flown at 1500 agl.

Instructors often debated the reason why we didn't use the "Aim recommended 1500 ft agl" ...my best guess...1000 agl patterns required students to "manage the power setting" instead of simply pulling the throttles to idle during the base turn.

My $.02

 

[C-5 MEM]

ditch,

I found that about the airspace, but this airport is class E.

I recall along time ago that there was something in the regs about if going into a uncontrolled airport the piston traffic pattern is 1000AGL and turbine is 1500AGL. Now I cant find it.

DLF,
No they were not T-1 drivers just local flight school

 

[SPBRIAN]

My interpretation and please tell me if i'm looking at it wrong.

Starting with operations in class G airspace CFR 91.126 does not mention anything about turbine altitudes, my interpretation is that 91.126 is the basic rules, and each airspace thereon takes the rules from 91.126 and piles more and more on top of it. That indicates to me that they want the turbine aircraft at the established altitudes as specified in the A/FD. The first mentioning of 1,500' MINIMUM altitude for turbine operations is CFR 91.129 operations in class D airspace, this indicates to me that when you are at a controlled airfield they would like you to fly at the higher altitude. Of course by looking in the A/FD there are some uncontrolled airports that have a turbine TPA established. I have some ideas of my own but they don't coincide with what the regulations say, i'm interested to hear anybody else's conclusions.

-Brian

 

[Richie]

The conclusion is…

TRAFFIC PATTERN ALTITUDE at AIRPORTS WITHOUT an OPERATING CONTROL TOWER:
Ref: 91.126 thru 91.131, 91.155, AIM 4-3-3d.1., AIM 4-3-4, AC 90-66A, Airplane Flying Handbook FAA H-8083-3
1. At most airports and military air bases, traffic pattern altitudes for propeller-driven aircraft generally extend from 600 feet to as high as 1,500 feet AGL. Also, traffic pattern altitudes for military turbojet aircraft sometimes extend up to 2,500 feet AGL. Therefore, pilots of en route aircraft should be constantly on the alert for other aircraft in traffic patterns and avoid these areas whenever possible. Traffic pattern altitudes should be maintained unless otherwise required by the applicable distance from cloud criteria (NOTE: there is different VFR distance from cloud criteria for Class G or Class E airspace).
2. 1,000 feet AGL is the recommended pattern altitude unless established otherwise… (AIM 4-3-4 [1])
3. There is a “RECOMMENDATION” (in AC 90-66A) that large and turbine powered airplanes should enter the traffic pattern at 1,500 AGL or 500 feet above the established pattern altitude. Apparently someone at the FAA feels it’s OK for a large aircraft to descend on top of a smaller aircraft (very possibly moving at a similar speed) during base to final.
4. Traffic pattern altitudes are occasionally listed in the Airport/Facility Directory, in which case the published altitudes would be somewhat regulatory. In some cases these airports actually have different altitudes for small and large or turbine-powered aircraft. In other cases there is only one altitude published, and that would be the altitude for ALL aircraft (unless you accept the recommendation of AC 90-66A and fly your large and invincible turbine 500 feet above everybody else — until you turn base to final — then descend on top of the other aircraft that was in the pattern below you the whole time flying at just about the same speed!).
5. Other “unofficially published” sources of traffic pattern altitude are the “Flight Guide” produced by Airguide Publications for VFR pilots; and the two different “Airport Directories” produced by Jeppesen and AOPA. These commercial publications list far more pattern altitudes than the A/FD, but very often disagree as to what these altitudes actually are!
6. The majority of Class G or E airports do not have “officially published” (in the A/FD) pattern altitudes. In which case you have your choice of the 1,000 AGL (for ALL aircraft) as recommended by the AIM — and/or 1,500 AGL for large and turbine powered as recommended by AC 90-66A — or personally calling the airport manager and asking if he has “established” a “recommended” altitude for “his” airport (an obviously imperfect system).
7. Large and turbojet aircraft are also governed by 91.515 which states those aircraft are required to maintain at least 1,000 feet AGL during the day and the altitudes prescribed in 91.177 at night. However this rule does not apply during takeoff or landing. When does “during takeoff or landing” begin? That is a good question that could be debated either way. There is another reference to minimum safe altitudes in 91.119 that states “Except when NECESSARY for takeoff or landing…”
8. Aircraft remaining in the traffic pattern should not commence a turn to the crosswind leg until beyond the departure end of the runway and within 300 feet below traffic pattern altitude, with the pilot ensuring that the turn to downwind leg will be made at the traffic pattern altitude. (AIM FIG 4-3-3)
9. “Recommended” traffic pattern speed limit is 200 kts.

That’s all I’ve got for ya.

The key document is AC 90-66A which is the (only) source of the “recommended” 1500 feet for large and turbine powered aircraft.

I hope this helps.