Flash Products

Vanguard® Medium FTS 370d LED Tower Lighting System

Dual L-864 / L-865 Obstruction Lighting System

Designed for ease of installation, the Vanguard Medium FTS 370d LED tower lighting system is a dual (red and white) FAA L-864/L-865 or catenary (L-866/L-885) medium intensity LED aviation obstruction lighting system. It is suitable for structures between 200′ and 700′ AGL (FAA E-type towers). Efficiencies are engineered throughout the system, such as a single flashhead and marker cable for power and communication as well as a single enclosure for power, control and monitoring. Vanguard Medium beacons offer standard 850 nm infrared LEDs, in compliance with FAA AC 150/5345-43J.


Vanguard Medium offers numerous monitoring and control options and is one of the most versatile lighting systems on the market.



Lightning Protection

The Vanguard Medium product line protects against 99% of lightning strikes, including the most intense strikes. It has a surge suppression rating of 25kA, validated by multiple lightning test laboratories. A properly grounded tower should take 55% of the lightning energy through the steel tower and to the ground, leaving 45% to be distributed amongst the cables. An average lightning strike is 28kA, with a 200kA strike happening less than 1% of the time. A 200kA strike on a tower using an average of 4 cables will deliver 22.5kA to the flashhead cable, much less than the FTS 370d’s 25kA rating.


Data Connectivity

Choose from many options to customize monitoring to your needs, whether performed by your NOC or by Flash Technology. Connectivity options include AT&T and Verizon LTE with supplied monitoring devices as well as an ethernet port. Modbus and SNMP protocols support third-party monitoring.


Easier Installation

Flash Technology’s LED L-810 marker is an integral part of the FTS 370d solution. At less than a pound in weight and requiring only two adjustable straps to mount, it’s the easiest marker to install on the market.


Made of powder-coated, lightweight aluminum, the versatile enclosure makes installation easier and reduces operating temperatures. Two lockable twist knobs provide easy access. A water channel diverts water away from the door opening. And knock-out holes in the bottom of the enclosure simplify cable installation.


FTS 370d Vanguard Medium Features

  • Infrared lighting – NVG and NVIS compatibility using 850nm infrared (IR) LEDs on the flashhead per FAA AC 150/5345-43J
  • Interleaved LEDs and by-pass circuitry provide longer life by allowing the loss of individual LEDs up to the 25% limit
  • Industry-leading IEC 61000-4-5 surge immunity to 25kA
  • LTE modem for greater reliability
  • Ruggedized photodiode in metal housing with shielded cable
  • Input power breaker switch eliminates replaceable fuses
  • Outdoor Wi-Fi antenna for diagnostics and lighting inspections
  • Patented Fresnel optics to minimize ground scatter
  • Aircraft Detection Lighting Systems (ADLS) interface
  • Automatic failsafe switches to day mode after 19 hours of no mode change; can be disabled if necessary
  • Configurable to meet AC 70/7460-1L
  • 4-line OLED backlit display for visibility in any lighting conditions
  • Dry contact monitoring (day, night, marker, PED, GPS, comm alarms and mode status)
  • 5-year warranty


FTS 370d Vanguard Medium Options

  • Infrared LEDs on L-810 marker lights
  • SMART Card – monitor and control the system remotely and receive full diagnostic information through LTE modem or ethernet-based connectivity. SNMP, Modbus or Eagle Protocols can be used.
  • GPS synchronization
  • Upgrade firmware remotely
  • TECK90 Support – provides protection from RF interference and damage on high-power broadcast towers up to 700′ AGL


Please fill out the form below or call 615.503.2000 with questions or to order this product.

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Input Voltage

100-240 VAC
±24 VDC (optional)
±48 VDC (optional)


50-60 Hz

Marker Power Consumption

2.1 watts per marker*
3.4 watts per marker with IR

Marker Dimensions

9” x 2.75” x 2.13” (228.6 x 69.9 x 54.1 mm)

Marker Weight

1.6 lbs. (0.7 kg)

FH Dimensions

15.75″ dia. x 7.31″

FH Aerodynamic Wind Area

99.125 in2

Controller Dimensions

23″ x 17.13″ x 6.44″

Controller Weight

44 lbs (20kg)

Protection Rating

IP65, NEMA 4x

* Not included in system consumption


L-864/L-865 System Power Consumption

White Day

80 watts (70 watts with IR)
40 fpm
20,000 ± 25% ECD

Red Night

40 watts (40 watts with IR)
20/30/40 fpm
2,000 ± 25% ECD

White Night

40 watts (40 watts with IR)
40 fpm
2,000 ± 25% ECD


L-866/L-885 System Power Consumption

White Day

110 watts (100 watts with IR)
60 fpm
20,000 ± 25% ECD

Red Night

50 watts (50 watts with IR)
60 fpm
2,000 ± 25% ECD

White Night

50 watts (50 watts with IR)
60 fpm
2,000 ± 25% ECD


* Only 30 fpm flash rate is applicable for FAA certified applications filed under AC 70/7460-1L, and requires the use of L-810(F) depending on the height of the structure


Intertek FAA L-864 FTS 370d certification
Intertek FAA L-865 FTS 370d certification
Intertek L-885 FTS 370d/r catenary certification
Intertek L-866 FTS 370d catenary certification
Intertek CAR 621 (with infrared)
ICAO 6th Edition
DGAC L-864
DGAC L-865
CSA Certificate of Compliance FTS 370d/r/w and FTS 370d/r/w IR
CE Declaration of Conformity FTS 370d



FTS 370d Vanguard Medium Datasheet
FTS 370d Vanguard Medium Wind Datasheet
FTS 370d Vanguard Medium Wind Datasheet – Spanish
FTS 370c Vanguard Medium Catenary Datasheet


Current Manual

Vanguard Medium FTS 370d / FTS 370w / FTS 370r / FTS 370c Rev 19 (5.7MB)
Quick Start Guide
Manuals for older product revisions can be found in the Knowledge Base.


Vanguard Medium Firmware
Vanguard Medium SNMP MIB


Flash Technology Vanguard Medium-HD