Center Of Gravity Concerns Lead To Lufthansa Pulling Last Economy Row On A320neo

German flag carrier Lufthansa has stopped selling the last row of seats in its Airbus A320neos due to concerns over the aircraft’s center-of-gravity limitations.

A320neo-Lufthansa
Lufthansa has stopped passengers from sitting in the last row. Photo: Airbus

This move comes after Lufthansa pilots were reportedly given an internal memo that suggested blocking off the last row of seats. This is seen as a makeshift measure following an airworthiness directive from EASA, according to Air Transport World.

EASA finds center of gravity issues on the A320neo

Following concerns regarding the center of gravity issues with the A321neo, the European Union Aviation Safety Agency (EASA) has uncovered a similar problem with the A320neo.

After a series of tests, the A320neo is susceptible to angle-of-attack protection weakness. Under certain conditions and maneuvers, the aircraft’s aileron, elevator, and the elevator and aileron computer (ELAC) software compensator showed a defect.

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For the problem to occur two things must first happen: The A320neo must be set up for landing with a center of gravity near its limit at the rear of the aircraft. It then takes a sudden maneuver like an aborted landing to cause the nose of the aircraft to rear up more than it normally would in a go-around situation.

Lufthansa A320neo
The issue would only occur in a go-around situation. Photo: TJDarmstadt via Flickr

Normally under these conditions, ELAC would automatically correct the angle of attack to compensate, but it does not. Meanwhile, the pilot of the A320neo can correct the angle of rotation and reduce the pitch angle without any problems. 

At no time on the A320neo does the computer override the actions of the pilot flying the plane. This is in direct contrast to the Boeing 737 MAX and its MCAS anti-stall prevention system that inhibits a pilot’s intervention during an excessive pitch-up situation.

Airbus has updated the A320neo flight manual

This new finding comes on the back of a similar excessive pitch anomaly that occurs under the same circumstances with the A321neo.

Lufthansa A320neo
Airbus has updated the aircraft’s flight manual. Photo: Lufthansa

The Airworthiness Directive (AD), issued by the EASA and published by HMGaerospace reads:

“Reduced efficiency of the A320neo AOA protection under certain flight conditions, and in combination with specific command maneuvers from the flight crew, could lead to excessive pitch attitudes, possibly increasing cockpit workload conditions.

“This potentially unsafe condition, although never encountered during operations, was discovered during analysis and laboratory testing of the A320neo flight control laws.”

Airbus has contacted airlines flying the A320neo and has updated the aircraft’s flight manual with revisions to the center-of-gravity. The manufacturer has also provided new load recommendations.

According to Aviation Week, senior executives at Lufthansa say the center of gravity issue only relates to A320neos and A321neos that have been fitted out with Space Flex cabins.

What are Space Flex cabins?

Designed to accommodate passengers with reduced mobility aboard single-aisle Airbus aircraft the Space-Flex is a new galley and toilet set-up that takes advantage of previously unused space.

The new configuration can also accommodate six more seats or provide additional space for passenger comfort. With enough room for airlines to customize their galleys to their meal and drink requirements, the real innovation can be found in the lavatories. Now passengers in wheelchairs have enough room to maneuver and can transfer from their chair to a sideways positioned toilet. 

With EASA not issuing a critical directive, airlines are allowed to still fly the A320neo and are taking steps to temporarily address the problem until Airbus comes up with a solution.

How do you feel about Lufthansa correcting the center of gravity situation by not allowing passengers to sit in the back row? Let us know your thoughts in the comments section.

We wrote to Lufthansa about the center of gravity issues and they wrote back saying:

The European Union Aviation Safety Agency (EASA) published an airworthiness directive on 1 August 2019. According to the directive, in certain flight configurations and in combination with specific maneuvers, the “angle of attack protection” may become less efficient.

Airbus ran simulations of go-around maneuvers on the A320neo and the A321neo and observed that an intensive control command can cause an accentuated rise in the aircraft’s longitudinal axis during an approach and landing configuration when the following combination of conditions are met: a specific loading, flying at low altitude and the flight control computer being set in certain flight modes.

According to Airbus, this maneuver is only possible when all specific conditions coincide at the same time. On the A320neo, for example, in such situation, the sidestick would have to be pulled to the fullest to maximum thrust.

EASA gave the operating airlines 30 days to implement the directive – and Lufthansa took the consequences. As a countermeasure, there will now be a restriction of the rear centre of gravity limit, by up to four percent depending on the weight of the aircraft.

As an ad-hoc-measure, Lufthansa will block the last row of seats on all of its 20 A320neo aircraft. As of 12 September, row 32 will therefore no longer be assigned to passengers – not even to staff travelling with ID tickets. This change will already be programmed in the check-in system. A Lufthansa A320neo is configured with 180 seats.

Lufthansa’s A320ceo is not affected by this directive.

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Matthew in PDX

I think that if this is an issue that can be corrected in this way, the airline should, if it is safe to do so, remove the last row of seats adjust the pitch on the other rows to take up that space. It may be necessary to leave that space empty, or the aircraft may need the weight of the row of seats to achieve the safest trim. I feel that if safety requires the seats be empty, removing them completely prevents anyone overriding the airline’s directive and sitting there, or even assigning passengers to sit there – although… Read more »

Vedant Ganesh

The point is I’ll be happy on an any Airbus Aircraft (until March would’ve been happy with Boeing also for obvious reasons) because Airbus isn’t hiding prices of malware under the hood. 😉
Edit: the A320neo has gotten a system like MCAS but it is pretty benign as the “captain over computer” system seems to be working for Airbus.

David

They build an airframe and it functions properly. Then the greedy airlines demand more seating capacity…so the manufacturers stretch the original frame design. The air frame is now out of balance. Airline demands placed on the manufacturers creates usafe issues.

Nate Dogg

You’ll find that the issue is similarly related to the 737 MAX. Because they have put larger engines on the NEO’s and the MAX, there is a tendency for the increased drag to lift up the nose. The equivalent system on Airbus as the MCAS on the MAX is not quite correcting this nose up as it should whereas on the MAX it was over-correcting it and forcing the nose down against pilot commands

Marc McReynolds

Things to think about: Go-arounds may be rare, but needing to correct a too-high sink rate with pitch just before touchdown is not; Counting on the pilot to salvage things when thrown a new wrinkle below 100 ft — say in the midst of a crosswind-limits landing — isn’t much of a game plan; Nature abhors vacuums and empty spaces at the back of crowded airliners, especially in some parts of the world; Airliner CG is typically calculated (not directly measured) using assumptions about cargo (sometimes) and passenger weight/distribution (always). See for example Airbus document http://www.smartcockpit.com/docs/Getting_To_Grips_With_Weight_and_Balance.pdf starting at p. 138… Read more »

Kevin Anderson

Sounds a reasonable common sense solution to the problem

Marc McReynolds

“Ladies and gentlemen, in preparation for landing please return your seatback to its full and upright position.  Make sure your seatbelt is fastened, and then lean your torso all the way forward as far as you can.  We will be landing shortly.  Thank you for flying Lufthansa.”

On a full aircraft, having everyone lean forward will shift the CG enough that only four people have to be cut from the flight instead of six.  You’re welcome, Airbus! : )

Dan

So 1500 lbs takes this plane to a critical CG! I am shocked at how tail heavy the plane must be in this current configuration. As an ex USAF loadmaster I think I can speak with some authority on CG :). I wold not fly on a plane of this size where the CG envelop is so critical.

Dan

Would…

Antonio Talluri

What about storing more luggage forward and leaving empty or removing overhead bins aft?

Chris

“…the sidestick would have to be pulled to the fullest to maximum thrust.” the sidestick does not control thrust, do you mean “pitch”?