Density altitude is the effective altitude at which an aircraft performs as if it were at that altitude, even if the actual elevation is lower. It is a measure of air density and is affected by high temperatures, high humidity, and high actual altitude, all of which decrease air density. A high density altitude leads to reduced aircraft performance, resulting in a longer takeoff roll and slower climb rates, while a low density altitude improves performance. Pilots must always calculate the density altitude before flying, especially in hot, high-elevation environments, as it is a critical factor for safe takeoff and landing.
What is Density Altitude?
An indicator of performance:
Density altitude is not an actual altitude but a way to express how dense the air is, which directly affects how an aircraft will perform.
Corrected for temperature and humidity:
It's essentially the pressure altitude adjusted for the current temperature and humidity.
How High Temperatures, High Humidity, and High Elevation Affect Air Density
Warm air:
Warmer air has more energetic molecules and is less dense, leading to lower performance.
Humid air:
While humidity is less significant than temperature, it does reduce engine power.
High elevation:
At higher altitudes, there are fewer air molecules above, resulting in lower air density.
The Effect on Aircraft Performance
Low Density Altitude (e.g., Cold, Dry Air at Sea Level):
Air is denser, providing more lift and engine power.
This results in a shorter takeoff roll and better climb performance.
High Density Altitude (e.g., Hot, Humid Air at 5,000 ft):
Air is thinner, leading to less lift and engine power.
An aircraft will require a longer takeoff roll and have a reduced climb rate.
Pilot's Guide
Calculate density altitude:
Always check the density altitude before flying to understand how it will impact your aircraft.
Plan for performance limitations:
On a hot day at a high-altitude airport, you might need a longer runway or need to delay your flight until conditions are cooler and air density is higher.
Go-around if in doubt:
If takeoff or landing performance is questionable, perform a go-around to ensure safety.
What is Density Altitude?
An indicator of performance:
Density altitude is not an actual altitude but a way to express how dense the air is, which directly affects how an aircraft will perform.
Corrected for temperature and humidity:
It's essentially the pressure altitude adjusted for the current temperature and humidity.
How High Temperatures, High Humidity, and High Elevation Affect Air Density
Warm air:
Warmer air has more energetic molecules and is less dense, leading to lower performance.
Humid air:
While humidity is less significant than temperature, it does reduce engine power.
High elevation:
At higher altitudes, there are fewer air molecules above, resulting in lower air density.
The Effect on Aircraft Performance
Low Density Altitude (e.g., Cold, Dry Air at Sea Level):
Air is denser, providing more lift and engine power.
This results in a shorter takeoff roll and better climb performance.
High Density Altitude (e.g., Hot, Humid Air at 5,000 ft):
Air is thinner, leading to less lift and engine power.
An aircraft will require a longer takeoff roll and have a reduced climb rate.
Pilot's Guide
Calculate density altitude:
Always check the density altitude before flying to understand how it will impact your aircraft.
Plan for performance limitations:
On a hot day at a high-altitude airport, you might need a longer runway or need to delay your flight until conditions are cooler and air density is higher.
Go-around if in doubt:
If takeoff or landing performance is questionable, perform a go-around to ensure safety.
FINAL REPORT - A dark-night IFR into Gaithersburg, Maryland, turned into national news when a Mooney M20J ended up hanging from a powerline tower. On November 27, 2022, N201RF was inbound for the RNAV 14 approach in dense fog—ceilings around 200 feet and visibility barely a mile. Another airplane ahead had already gone missed. Still, the Mooney pressed on.
The pilot had about 1,475 hours with 500 in type, but not much recent actual IMC. He asked for the lower-minimums approach, but automation setup became a problem. Mis-programmed avionics meant no vertical guidance; effectively, he was flying LNAV-only, with higher minimums. ADS-B shows the airplane consistently low—crossing fixes hundreds of feet below published altitudes, and drifting left of course.
At 1.25 miles from the runway, in fog and off the centerline, the Mooney struck a powerline tower and came to rest suspended 100 feet in the air. Miraculously, both occupants survived and were rescued after hours on live TV.
The pilot later admitted he saw the ground out the side window and tried to “pull the airport out of the soup.” That mindset—continuation bias, chasing glimpses instead of flying the published numbers—turned a marginal approach into a trap.
The lessons aren’t new, but they’re sharp reminders: know your avionics, fly the published altitudes, respect DA/MDA, and if the runway isn’t there—go missed or divert. Safety is about margins, not convenience.
The pilot had about 1,475 hours with 500 in type, but not much recent actual IMC. He asked for the lower-minimums approach, but automation setup became a problem. Mis-programmed avionics meant no vertical guidance; effectively, he was flying LNAV-only, with higher minimums. ADS-B shows the airplane consistently low—crossing fixes hundreds of feet below published altitudes, and drifting left of course.
At 1.25 miles from the runway, in fog and off the centerline, the Mooney struck a powerline tower and came to rest suspended 100 feet in the air. Miraculously, both occupants survived and were rescued after hours on live TV.
The pilot later admitted he saw the ground out the side window and tried to “pull the airport out of the soup.” That mindset—continuation bias, chasing glimpses instead of flying the published numbers—turned a marginal approach into a trap.
The lessons aren’t new, but they’re sharp reminders: know your avionics, fly the published altitudes, respect DA/MDA, and if the runway isn’t there—go missed or divert. Safety is about margins, not convenience.
* Final Report * Ground Collision
N420AW CRJ-200 Air Wisconsin Flight 6181 Chicago Illinois 01 FEB 2025
1 Serious Injury
Pilot Flight Time:
PIC - 17000 hours (Total, all aircraft), 14500 hours (Total, this make and model)
Copilot - 1190 hours (Total, all aircraft), 259 hours (Total, this make and model)
A serious injury was sustained by a tug driver following a collision with the left wing of Air Wisconsin flight 6181, a CRJ-200, during taxi operations at Chicago O’Hare International Airport (ORD). No injuries were reported among the airplane’s crew or passengers. Night visual meteorological conditions (VMC) prevailed at the time of the accident.
Flight 6181 landed at ORD and was initially held at the B Pad for an open gate. Once cleared, the aircraft proceeded southbound on Taxiway A under a standard clearance. The first officer was actively monitoring both ramp and ground control frequencies during the taxi.
The captain reported first observing the tug on Taxiway B as the tug began crossing at the access road. The tug appeared to be slowing down suggesting an intent to stop. The captain could not recall whether the tug’s headlights were illuminated and believed he saw the vehicle using ambient lighting.
After briefly diverting attention toward the gate area, the captain looked back and recognized an imminent collision with the tug. Braking was initiated immediately by the captain, but the impact occurred shortly thereafter. The captain described the impact as “not that bad” and believed the tug had struck the wingtip. The flight crew then communicated with the flight attendants, followed by dispatch via the Aircraft Communications Addressing and Reporting System (ACARS).
According to the tug driver, while returning from the international terminal, the vehicle approached the service road leading to the L gates. Before entering the road and crossing taxiway B, the tug came to a complete stop at the designated stop sign and the driver observed an airplane taxiing outbound on Taxiway B. The driver checked both directions and waited until the outbound aircraft cleared the taxiway. The driver also verified that no aircraft were approaching from behind or the opposite direction before proceeding to cross the taxiways (A&B).
The driver stated that as the tug was crossing the taxiways, the left wing of flight 6181, approaching on taxiway A, was not visible until the last moment, leaving insufficient time to react. He also noted the absence of a nose-gear light on flight 6181, which may have contributed to the tug driver not detecting the presence of flight 6181 before the collision.
The collision resulted in the tug overturning and trapping the driver, leading to serious injury. Post-flight inspection revealed substantial damage to the leading-edge front spar of the airplane’s left wing. The tug driver emphasized that had he been aware of the airplane’s presence, he would not have entered the intersection.
According to the Chicago Department of Aviation (CDA) ground motor vehicle operating regulations manual, dated August 2023, a driver must stop prior to initiating the crossing of the taxiways A, B, and V to determine if the crossing could be accomplished without stopping in the islands between the taxiways. Vehicles on service roads must yield to vehicles crossing taxiways.
Probable Cause and Findings:
The tug driver’s failure to ensure the taxiway was clear of aircraft prior to crossing, resulting in a collision with the left wing of the taxiing aircraft. Contributing to the accident was the limited visibility of the aircraft due to ambient lighting conditions and the absence of the aircraft’s nose-gear light, which reduced the tug driver’s ability to detect the aircraft’s presence in time to avoid the collision.
N420AW CRJ-200 Air Wisconsin Flight 6181 Chicago Illinois 01 FEB 2025
1 Serious Injury
Pilot Flight Time:
PIC - 17000 hours (Total, all aircraft), 14500 hours (Total, this make and model)
Copilot - 1190 hours (Total, all aircraft), 259 hours (Total, this make and model)
A serious injury was sustained by a tug driver following a collision with the left wing of Air Wisconsin flight 6181, a CRJ-200, during taxi operations at Chicago O’Hare International Airport (ORD). No injuries were reported among the airplane’s crew or passengers. Night visual meteorological conditions (VMC) prevailed at the time of the accident.
Flight 6181 landed at ORD and was initially held at the B Pad for an open gate. Once cleared, the aircraft proceeded southbound on Taxiway A under a standard clearance. The first officer was actively monitoring both ramp and ground control frequencies during the taxi.
The captain reported first observing the tug on Taxiway B as the tug began crossing at the access road. The tug appeared to be slowing down suggesting an intent to stop. The captain could not recall whether the tug’s headlights were illuminated and believed he saw the vehicle using ambient lighting.
After briefly diverting attention toward the gate area, the captain looked back and recognized an imminent collision with the tug. Braking was initiated immediately by the captain, but the impact occurred shortly thereafter. The captain described the impact as “not that bad” and believed the tug had struck the wingtip. The flight crew then communicated with the flight attendants, followed by dispatch via the Aircraft Communications Addressing and Reporting System (ACARS).
According to the tug driver, while returning from the international terminal, the vehicle approached the service road leading to the L gates. Before entering the road and crossing taxiway B, the tug came to a complete stop at the designated stop sign and the driver observed an airplane taxiing outbound on Taxiway B. The driver checked both directions and waited until the outbound aircraft cleared the taxiway. The driver also verified that no aircraft were approaching from behind or the opposite direction before proceeding to cross the taxiways (A&B).
The driver stated that as the tug was crossing the taxiways, the left wing of flight 6181, approaching on taxiway A, was not visible until the last moment, leaving insufficient time to react. He also noted the absence of a nose-gear light on flight 6181, which may have contributed to the tug driver not detecting the presence of flight 6181 before the collision.
The collision resulted in the tug overturning and trapping the driver, leading to serious injury. Post-flight inspection revealed substantial damage to the leading-edge front spar of the airplane’s left wing. The tug driver emphasized that had he been aware of the airplane’s presence, he would not have entered the intersection.
According to the Chicago Department of Aviation (CDA) ground motor vehicle operating regulations manual, dated August 2023, a driver must stop prior to initiating the crossing of the taxiways A, B, and V to determine if the crossing could be accomplished without stopping in the islands between the taxiways. Vehicles on service roads must yield to vehicles crossing taxiways.
Probable Cause and Findings:
The tug driver’s failure to ensure the taxiway was clear of aircraft prior to crossing, resulting in a collision with the left wing of the taxiing aircraft. Contributing to the accident was the limited visibility of the aircraft due to ambient lighting conditions and the absence of the aircraft’s nose-gear light, which reduced the tug driver’s ability to detect the aircraft’s presence in time to avoid the collision.
2003 Iranian Air Force IL-76 Crash – 275 Lost in Fog & Silence | Pro Plane Pilot
https://proplanepilot.com/2003-iranian-air-force-il-76-crash/
https://proplanepilot.com/2003-iranian-air-force-il-76-crash/
pro plane pilot
2003 Iranian Air Force IL-76 Crash – 275 Lost in Fog & Silence | Pro Plane Pilot
Read about the 2003 Iranian Air Force IL-76 crash in Kerman that killed 275 people. Full details, timeline, and key facts.
Cyber attack on several European airports, including London and Brussels... Many flights disrupted, Heathrow Airport issues advisory
Flight delays are reported at London, Brussels, and several major European airports. It is being reported that many flights have been disrupted due to a cyber attack. Heathrow Airport stated that efforts are being made to resolve the problem as quickly as possible. Passengers are advised to check flight status before travel and arrive at the airport on time
Flight delays are reported at London, Brussels, and several major European airports. It is being reported that many flights have been disrupted due to a cyber attack. Heathrow Airport stated that efforts are being made to resolve the problem as quickly as possible. Passengers are advised to check flight status before travel and arrive at the airport on time
Attempted to open the cockpit, suspected hijacking; all nine youths released after 11 hours
The nine youths who were detained on suspicion of hijacking after attempting to open the cockpit of a plane flying from Bengaluru to Varanasi were released after 11 hours.
The nine youths who were detained on suspicion of hijacking after attempting to open the cockpit of a plane flying from Bengaluru to Varanasi were released after 11 hours.
The FIP pilots' body has accused the authorities of trying to find fault with the pilots.
FIP : This is not acceptable
The Federation of Indian Pilots (FIP) has written a letter to the Ministry of Civil Aviation demanding a judicial probe into the June 12 crash of Air India Flight AI 171, alleging that the officials are prematurely pushing a "pilot error" narrative.
air india plane crash 171– Pilot’s Father Calls for Probe, Families Sue Boeing and Honeywell
What did the Supreme Court say about this investigation?
Use the table of contents direct to the point
Read full here https://proplanepilot.com/air-india-plane-crash-171/
FIP : This is not acceptable
The Federation of Indian Pilots (FIP) has written a letter to the Ministry of Civil Aviation demanding a judicial probe into the June 12 crash of Air India Flight AI 171, alleging that the officials are prematurely pushing a "pilot error" narrative.
air india plane crash 171– Pilot’s Father Calls for Probe, Families Sue Boeing and Honeywell
What did the Supreme Court say about this investigation?
Use the table of contents direct to the point
Read full here https://proplanepilot.com/air-india-plane-crash-171/
pro plane pilot
air india plane crash 171
air india plane crash 171 Pilot’s father Pushkarraj seeks a formal AAIB probe, while four victims’ families sue Boeing & Honeywell in U.S. court.
Kabul To Delhi Flight News : 13-Year-Old Afghan Boy Survives Freezing Flight From Kabul To Delhi Hidden In Landing Gear
https://proplanepilot.com/kabul-to-delhi-flight-news/
https://proplanepilot.com/kabul-to-delhi-flight-news/
pro plane pilot
Kabul To Delhi Flight News : 13-Year-Old Afghan Boy Survives Freezing Flight From Kabul To Delhi Hidden In Landing Gear
Stowaway Miracle Kabul to Delhi flight news : A 13-year-old Afghan boy miraculously survives freezing -50°C, no oxygen, and deafening noise while hiding in Kam Air’s Kabul to Delhi flight landing gear.
Midnight Chaos At LaGuardia: Delta Flight Attendant Injured In Taxiway Collision
https://proplanepilot.com/delta-flight-attendant-injured-in-taxiway-collision/
https://proplanepilot.com/delta-flight-attendant-injured-in-taxiway-collision/
AI171 Crash Investigation: AAIB Invites Airline Pilots
https://proplanepilot.com/aaib-invites-alpa-for-ai171-crash-investigation-meeting-delhi/
https://proplanepilot.com/aaib-invites-alpa-for-ai171-crash-investigation-meeting-delhi/
pro plane pilot
AI171 Crash Investigation: AAIB Invites Airline Pilots
AAIB invites the Airline Pilots’ Association of India (ALPA) for a crucial meeting in Delhi to discuss the AI171 crash investigation , pilot participation, and aviation safety transparency.
AAIB Rejects ALPA India’s Request To Join AI171 Crash Probe, Cites Government Rules
https://proplanepilot.com/aaib-denies-alpa-request-join-ai171-crash-investigation/
https://proplanepilot.com/aaib-denies-alpa-request-join-ai171-crash-investigation/
pro plane pilot
AAIB Rejects ALPA India’s Request To Join AI171 Crash Probe, Cites Government Rules
AAIB rejects ALPA India’s request to include its member in the AI171 crash probe, citing government rules. The pilot body remains hopeful of future collaboration.
B-787 RAT Deployment: Amritsar To Birmingham , FIP Pilots' Association Demands Thorough Inspection Of All Aircrafts
https://proplanepilot.com/b-787-rat-deployment-amritsar-to-birmingham-fip-pilots-association-demands-thorough-inspection-of-all-aircrafts/
https://proplanepilot.com/b-787-rat-deployment-amritsar-to-birmingham-fip-pilots-association-demands-thorough-inspection-of-all-aircrafts/
pro plane pilot
B-787 RAT Deployment: Amritsar To Birmingham , FIP Pilots' Association Demands Thorough Inspection Of All Aircrafts
B-787 RAT Deployment: Amritsar to Birmingham , FIP Pilots' Association Demands Thorough Inspection of All Aircrafts The pilots' body also highlighted the June 12, 2025 crash of Air India flight AI171, flying from Ahmedabad to London. Since that incident,…
American Government Shutdown's Real Truth: Pilots, Passengers, And Public Reactions
https://proplanepilot.com/american-government-shutdowns-real-truth-pilots-passengers-and-public-reactions/#
https://proplanepilot.com/american-government-shutdowns-real-truth-pilots-passengers-and-public-reactions/#
pro plane pilot
American Government Shutdown's Real Truth: Pilots, Passengers, And Public Reactions
The American government shutdown's real truth is starting to unfold as the crisis enters its eighth day. The effects are no longer confined to Washington;
The Matter Of Flight 117 : Ram Air Turbine Deployment Neither Pilot Error Nor System Failure
https://proplanepilot.com/ram-air-turbine-deployment/
https://proplanepilot.com/ram-air-turbine-deployment/
pro plane pilot
The Matter Of Flight 117 : Ram Air Turbine Deployment Neither Pilot Error Nor System Failure
Ram Air Turbine Deployment Neither Pilot Error Nor System Failure then Whose spirit is in the equipments of B-787 aircraft ?