Why are tags on an aircraft and why are they coloured?

A pitot tube cover tag.

The purpose of tags

All pilots know that there are tags that cover the pitot tube, and that the tag must be removed before flight, otherwise the airspeed indicator and other associated instruments will not operate or give the correct readings.

Tags are also used for engine inlet covers to prevent animals such as birds from nesting inside the engine nacelle or bay.

Engine inlet plugs and tags.

Some come as different size and shape plugs that cover various holes and openings of the aircraft.

Pins with tags can also help prevent movement of mechanical assemblies such as propellers, control surfaces and landing gear.

“Remove before flight” tags themselves are just markers on the components that need to be removed. Sometimes you may see a pilot or groundcrew walking around, inspecting the aircraft and removing these tags.

Tags in aviation are designed to enhance safety. It is worth mentioning that due to international regulations “Remove before flight” warnings appear only in English.

Tags are always in English.

Military aircraft

Military tags cover critical air inlets for sensors and/or air flow powered generators. Tags used in ammunitions indicate whether the weapon or munition is live or not, and must be removed before flight. Tags also help prevent damage from accidently knocking or hitting the item as it is more visable.

An armament technician removes safety pins from CBU-58 cluster bombs mounted on the wing pylon of an F-4G Wild Weasel Phantom II aircraft from the 37th Tactical Fighter Wing.
US Marine Corps (USMC) Corporal (CPL) Kristen Myrick, Marine Fighter Attack Squadron ÒAll WeatherÓ 225 (VMFA ÒAWÓ-225), checks a safety pin on an AIM-9 Sidewinder missile attached to the wing pylon of a USMC F/A-18 Hornet aircraft at Al Jaber Airbase (AB), Kuwait, during Operation ENDURING FREEDOM.

Tags kept in place help prevent accidental discharge or arming of a weapon.

Commercial aircraft
Tags over sensors keep dirt, ice and bugs from working into the inlets and blocking the devices from functioning. Tags are also used with control locks to prevent damage to control surfaces, especially in windy conditions.

Damaged aircraft

Generally all tags are red to make them noticeable to pilots and ground crews. However, tags are also known to be bright yellow or orange and even neon coloured, but this is rather the exception than the rule.

Additionally ‘tagging’ is a term used in US Aviation to indicate if a part is serviceable and airworthy as evaluated by an FAA certified repair station.

It is important to note that this term is an industry term and is not an FAA requirement or even mentioned in the Federal Aviation Regulation (FAR).

  • Red Tag: component is scrap or unusable
  • Yellow Tag: component is serviceable and airworthy
  • Green Tag: component is not airworthy but is repairable

In Canada, a green tag is used for a serviceable and airworthy part, but as in the US, the presence of the tag does not guarantee that the part is legal for use in certificated aircraft.

This is the ill-fated Boeing 757 that crashed after takeoff from Puerto Plata, Dominican Republic, on February 6, 1996.

Accidents as a result of tags

On February 6, 1996, a Boeing 757-200 crashed after takeoff from Puerto Plata, Dominican Republic. Birgenair Flight 301 was a flight chartered by Turkish-managed Birginair partner Alas Nacionales from Peurto Plata in the Dominican Republic to Frankfurt, Germany.  The flight was supposed to route  via Gandar, Canada.

Shortly after take-off from Puerto Plata’s Gregorio Luperon International Airport the aircraft crashed under unknown circumstances at the time. All 189 people on board died. The cause was traced back to pilot error after receiving incorrect airspeed information from one of the pitot tubes.

Investigators believe the pitot tube was blocked by a wasp nest built inside it. The aircraft had been sitting unused for 20 days without pitot tube covers in place for the preceding 2 days before the crash. If tags had been used, the accident probarly would not have occured.

Flight 301 shares the title of deadliest aviation crash involving a Boeing 757 alongside American Airlines Flight 77; both having 189 total fatalities. Furthermore, Flight 301 is the deadliest aviation accident ever to have occurred in the Dominican Republic.

The “Remove before flight” tag has become one of the amateur souvenirs.


  1. I think this is a real great blog.Much thanks again. Will read on…

Leave a Reply

Your email address will not be published. Required fields are marked *