1. 2017 Annual Conference,
South Lake Tahoe
Rayvon Williams,
Airport Manager

4. Protection of Airport Approach/ Departure
Surfaces, including the 20:1 surface
Federal Aviation Administration

5. It’s not just a slope, it’s an adventure!

7. OBS ID
MSL
Description
Lat
Long
Accuracy
20:1 Penetration
Risk Category
Affected Procedures
KWVIT0289
266
TREE N W
20/3
23.2
HIGH
RNAV (GPS) RWY 02;LOC RWY 02;
KWVI0074
262 N W
19.11
164
POLE N W
16.37
KWVI0003
203 N W
10.2
MED
165 N W
3.84
KWVIT0530
234 N W
28.49
AIRPORT CIRCLING(R09);
KWVIT0532
228 N W
21.89
KWVI0026
226 N W
20.99
KWVI0025
220
ANT N W
17.24
TOWER
KWVI0086
533 N W
50/20
17.16
KWVI0027 N W
12.12
KWVIT0506
193 N W
11.1
KWVI0029
301 N W
8.39
KWVI0023
187 N W
5.11
KWVIT0509
188 N W
4.91
KWVIT0546
309 N W
2.65
LOW
KWVIT0538 N W
1.63
KWVIT0361
280 N W
54.58
AIRPORT CIRCLING(R20);
KWVI0059
253 N
27.5
KWVIT0328
231 N W
26.75 N W
24.04
KWVI0010
223 N W
18.73
KWVIT0367
243 N W
11.28
KWVI0014
238 N W
6.84
KWVIT0356
225 N W
2.5
KWVI0012 N W
0.78
KWVIT0908
192 N W
AIRPORT CIRCLING(R27);
181 N W
13.38
KWVI0035
183 N W
9.85
162 N W
0.93

9. What happened was… “Welcome to the 20:1 adventure!”

10. 20:1 Issue? Don’t know what you Don’t Know.
The 20:1 visual area surface is described in Section c of FAA Order B, United States Standard for Terminal Instrument Procedures (TERPS).
On November 15, 2013, FAA memorandum issued to provide Interim Guidance for mitigation of penetrations to the 20:1 Visual Area Surface.
In November 2013, ARP Regional Division Managers sent to NPIAS airports emphasizing responsibility to regularly review and maintain clearance to all approach and departure surfaces (beyond just the 20:1 surface)
The interim guidance became effective January 6, 2014 and contains a risk-based approach with varying action timeframes relative to the amount of penetration to the 20:1 surface.
In the notice to the airport owners/sponsors, the FAA highly recommends Airport Sponsors take a proactive approach by reviewing all approach surfaces in advance of any flight check schedule to ensure they are clear.
Federal Aviation Administration 7

11. 20:1 Risk Assessment
High Risk Area (Red) is evident when an obstruction Penetrates the 20:1 Visual Area Surface by more than 11 ft; there are at least 19 identified obstructions at Watsonville Municipal Airport
20:1 Visual Area Surface
More than 11 ft
More than 3ft up to 11ft
Obstruction
3ft
Runway
Medium Risk Area (Yellow) is evident when an obstruction penetrates the 20:1 Visual Area Surface by more than 3 ft but less than 11ft.
Low Risk Area (Green) is evident when a obstruction penetrates the 20:1 by no more than three feet.
There are at least 12 identified Medium and Low Risk obstructions at Watsonville Municipal Airport
200 ft
Start 20:1 slope
measurement 200 ft
from Runway end

12. 20:1 Decision Tree

13. 20:1 approach slopes: View from North

14. 20:1 approach slopes: View from Northeast

15. 20:1 approach slopes: View from Northwest

16. Flight Standards Policy requires an immediate NOTAM that “Not Authorizes (N/A)” night minimums when a 20:1 penetration is discovered upon biennial review or new procedure development.
Runways with 20:1 penetrations are highlighted to Airport Managers and/or consultants by the Flight Procedures Team.
What’s an Airport Manager to do?
Clear or light the 20:1 penetrators if feasible
If clearing has occurred, provide updated survey info to
the Flight Procedures Team
Is there a plan to remove/reduce in height/light the unlit penetration(s) and, if so, what is the plan?
If the unlit penetration(s) cannot be removed, reduced in height, or lighted, a properly sited, certified and maintained VGSI could be used to mitigate the effects of the unlit obstacles, if approved by FAA Flight Standards Division.

18. Impact on Flight Operations
Trees, Poles and Towers
Topping…a process not an event
Poles are communities
Private Towers?
Jurisdiction
City and County Zoning
Concept of Right-away
Parcel Owners vs. Residents
Rights of Entry
You can’t see it from the street
You can’t do it from the street
Who’s got the liability
Impact on the guy next door
Impact on Flight Operations
Corporate or Part 135 ops?
IAPs Not Authorized?
Losing your VGSI is a big deal
Financial Impact
Who should pay?
Who should maintain?
“Prosecutorial Discretion”
Average cost $2,000!
Environmental
Multiple possibilities
Arborists & Biologists
Seasonality
Impact on the guy next door

19. Annual Conference,
South Lake Tahoe
Rayvon Williams,
Airport Manager