Picture of product GDL-88

Part #:

Model: GDL-88




GDL 88 System

Part Number :

  • Provides certified ADS-B “In” for access to subscription-free weather and traffic on compatible Garmin displays
  • Satisfies FAA ADS-B “Out” mandate requirements, using the 978 MHz transmitter, for operations under 18,000 feet
  • Shows other ADS-B equipped aircraft, as well as traffic from ground station uplinks, on compatible displays
  • Generates both aural and visual traffic advisories
  • Expanded aural alerts can specify relative target bearing, relative altitude (above/below) and range, when data is available
  • Displays up to 30 intruder threats
  • TargetTrend™ relative display aids in projecting potential traffic conflicts
  • Automatically displays the highest integrity traffic data when receiving ADS-B, TIS-B, ADS-R or TAS/TCAS from compatible sources
  • The Surface Feature (or SURF), which is available only with SafeTaxi®, displays taxiways and runways to enhance pilot awareness of on-surface traffic
  • Interfaces with compatible Garmin cockpit displays


unit size: 1.75 x 6.17 x 7.12 inches Includes mounting rack and connectors weight: 2.4 lbs LRU only; 3.75 lbs with mounting rack and connectors
temperature: -55°C to +70°C operating altitude: To 55,000 feet
power input: 14 or 28 VDC; 20 watts max Cooling input: Intergrated
environmental compliance: DO-160F software compliance: DO-178 Level D and Level B
hardware compliance: DO-254 Level C TSO compliance: GDL 88: TSO-C145c (B2), TSO-C154c (A1S/A1H), TSO-C157A, TSO-C166b (A1/A1S), TSO-C195a (C1,C2,C3)
part number: description:
010-00859-30 GDL 88; 3.75 lbs
010-00860-30 GDL 88 Diversity; 3.87 lbs
010-00861-30 GDL 88 with WAAS GPS; 4.13 lbs
010-00862-30 GDL 88 Diversity with WAAS GPS; 4.25 lbs


- Datalink System
Price Condition Status
- WAAS ADS-B Data Link System
Price Condition Status
- ADS-B Data Link Sensor with WAAS GPS
Price Condition Status
- Datalink Transceiver
Price Condition Status
- Datalink Transceiver
Price Condition Status
- Datalink Transceiver
Price Condition Status

Click on a question below to see the answer. If you have a question about this model that is not answered below, please contact questions@seaerospace.com

In relation to NE (New) parts, many OEMs change their prices and availability without any notice to dealers or the industry. Therefore, through the REQUEST or RFQ indication, we ask that customers contact us for the most accurate price and availability.

In relation to SV & OH parts, the used parts aftermarket in the aviation industry is not an infinite supply. It is a dynamic, constantly changing market that is significantly affected by and susceptible to highs and lows in supply and demand. Therefore, although we attempt to, at times, we are unable to predict the exact moment when an item may be available. Once again, through the REQUEST or RFQ indication on our website, we ask that customers contact us for the most current and accurate price and availability.

In regards to your RV-6A, upgrading to the GTX 330ES will take care of your 2020 requirements for ADS-B. As you already have a GTX 327 and a GNS 430W, you may be more pleased with the installation of a GDL 88 standard. The prices of the units are similar even once you add the new antenna for the GDL-88 (give or take about $150). The labor to install the GDL 88 will be more, but with the GDL 88 you will get free weather and traffic on the GNS 430W. This would then free up the Garmin 696 and the GDL 39 for your Luscombe.

In regards to your 1947 Luscombe 8-E, your options are not as straight forward. You have no WAAS/GPS receiver in the aircraft so one of the UAT units like the GDL 88/84 from Garmin, NGT-2500 from L-3, or the RANGR 978 from Freeflight will be your best option to give the ADS-B Out. The RANGR 978, with its control head (required per the installation manual), may be the least expensive option but all three will have a fair amount of labor for the installation.

In most cases, if you already have Garmin equipment, the easiest route to comply with ADS-B is to stay with Garmin. Based on what you gave me below, you would need to upgrade your GNS530 to the 530W (WAAS) and replace your GTX327 with the GTX330ES (Extended Squitter). Most shops will give you a trade-in value for the GTX327 and there are some used GTX330ES units out there on the market. This route will make you compliant with the 1090ES part of ADS-B compliance.

Otherwise, if you choose to keep the GTX327 and go with the GDL88 or GDL84 UAT (978 compliance), you will still have to get your GNS530 upgraded to WAAS and then handle some additional considerations.

First, we would recommend contacting a local Garmin dealer to discuss the following:

  • Upgrading your existing nav/com to a used GNS-530W or the newer GTN-750.
  • If you already have a Garmin transponder (i.e. GTX-330), then you should simply get the ES upgrade, interface to GNS-530W or GTN-750, along with a few other minor installation considerations, and get the shop to do the appropriate paperwork based on Garmin's AML STC.
  • If you do not have the GTX-330, then you should just consider pursuing one of the GDL systems from Garmin. Most likely the GDL88 which will give you In/Out capability. Same interface and installation considerations as above apply. Please note ADS-B In is not required for the mandate.

The GDL-88 is capable of receiving and transmitting on both 978 MHz (UAT) and 1090 MHz (Mode S Transponder). This will allow the GDL-88 to send position data on both 978 MHz and 1090 MHz. It is also capable of receiving FIS-B weather data on 978 MHz. The GDL-88 is also capable of interfacing with TCAD/TAS/TCAS I systems for a "fused" situational awareness display for the flight crew.

Yes, the GDL-88 is a dual transceiver, which means that it is capable of transmitting your ADS-B position. Most typical installations will be configured to be ADS-B out compliant, thereby satisfying the FAA's mandate. Your existing equipment and how the installation is performed may affect your ADS-B out capability.

While a GNS or GTN series product (with the proper software level) is what is most often used as a qualified position source, there are versions of the GDL-88 that include an internal WAAS receiver. Having a WAAS receiver is a requirement for ADS-B compliance. This will allow your exact position, speed, etc., to be broadcasted to other aircraft. Four versions of the GDL-88 are available:

GDL-88 Standard
GDL-88 with Diversity
GDL-88 with internal WAAS receiver
GDL-88 with Diversity and internal WAAS receiver

In a minimal installation, the GDL-88 provides the required ADS-B Out functionality with a standalone set of annunciators and control switches installed in the cockpit. When a GDL-88 is installed without interface to an external display, some ADS-B In functionality is still retained. A traffic annunciation light is installed in the cockpit for CSA (Conflict Situational Awareness) alerts and aural alerts are provided for these threat aircraft, to include directionality from the ownship and range.

Audio Panel  -  Traffic alert audio output is interfaced to a required audio panel with a compatible unswitched, unmuted audio input

Altitude Source -The GDL-88 requires the use of an ownship pressure altitude for transmission of required ADS-B Out data values and to calculate the vertical separation and vertical closure from target aircraft.


TAS/TCAS Traffic Systems - The GDL-88 will interface with the GTS-800/820/850, Skywatch, Skywatch HP, and Avidyne TCAD.


Heading Source (optional) - The GDL-88 can optionally use heading for the purpose of correlating ADS-B traffic and traffic received from the external traffic system. HSDB and ARINC 429 digital heading is provided to the GDL 88 from any compatible magnetic heading source. Multiple heading sources may be connected to the GDL-88.


GPS Position Source - The GDL-88 uses the ownship GPS position for creation of the ADS-B Out messages as well as the receipt and tracking of ADS-B In targets. The GDL-88 without the internal GPS WAAS requires at least one compatible GPS position source be installed, while the GDL-88 with the internal GPS WAAS engine may optionally be interfaced with compatible sources.


Radar Altimeter (optional) - The GDL-88 can optionally be interfaced with a radar altimeter to drive the sensitivity level of the Conflict Situational Awareness (CSA) application.


Traffic Mute (optional) - The GDL-88 can optionally interface with a pilot controlled switch to acknowledge an active Conflict Situational Awareness (CSA) alert and mute the associated aural alert. This momentary switch only mutes the current CSAs and does not act as an inhibit for future CSA aural annunciations.

PLEASE NOTE - Publications are for Reference Only