Boeing 737-900ER tail tip issues

[northbynorthwest]

Having just seen Frank Nichols classic pictures of the Ace Freighters Constellation on the ramp at Speke in 1966 in the Liverpool Airport Accidents and Incidents thread, this article from Aviation Week popped up in a recent Aviation Daily email blog I subscribe to. The timing was impeccable.


United Faces Boeing 737-
900ER Tail Tip Problem

United Airlines is concerned about possible tail-tip problems
with its Boeing 737-900ERs on arrival when aircraft
are not loaded according to the initial plan, the carrier
told pilots in an Aug. 28 flight operations pilot bulletin.
United has started delivering pilots a pre-arrival message through
the Aircraft Communications Addressing and Reporting System
(ACARS) if planners are concerned about a possible tail tip. If a 737-
900ER is not loaded in accordance with the load plan, United said,
the aircraft can still be within center-of-gravity limits for arrival and
departure. However, improper loading can cause problems at the gate.
“If the bags are not deplaned in an expeditious manner and
passengers stop moving forward to deplane, the nose wheel may
come off the ground,” United told pilots.

As a solution during these situations, ground agents are supposed
to wait to connect the jet bridge until at least 25 bags have
been unloaded from the rear cargo bin. Only after that happens
can passengers begin disembarking.

United says it can solve the problem in two ways: First, airport
operations is trying to minimize how often the 737-900ER is
loaded incorrectly. Second, the airline has started to add tail stands
wherever the aircraft operates.

This problem is not unique to United, which blames the issue
on “the design of the 737-900ER.”

—Brian Sumers, [e-mail]

[calflier]

United should have thought of this when they ordered the aircraft,this has always been the problem with stretched designs,operators of the A321,are also concerned of tipping if pax and cargo are not loaded according to the standard loading plan,and even the DC8 series 60,s were prone to this,as well as tail strikes on landing and take off,this could be due to United configuration of the 900ER,thats causing the problem,IE not enough pax and bags up front! etc,compared to all economy versions such as the Lion air examples in Indonesia.

[Deleted]

The EL-AL service into LTN is sometimes operated by a -900 and the loading crew have specific instructions as to how to off and on load the bags and cargo based on the hold loading plan which is sent in advance by EL AL. The flight is normally packed with both, so it is particularly important to get it right. No problems with airbridges at LTN of course, but still the potential for a tail-tip!

Improper loading will also make the aircraft difficult to trim and thus potentially increase fuel consumption. I didn't realise that there was provision for a tail stand on a 737-900, or is this a retro-mod?

[northbynorthwest]

Sept 6, 2015 14:38:21 GMT 1 calflier said:

United should have thought of this when they ordered the aircraft,this has always been the problem with stretched designs,operators of the A321,are also concerned of tipping if pax and cargo are not loaded according to the standard loading plan,and even the DC8 series 60,s were prone to this,as well as tail strikes on landing and take off,this could be due to United configuration of the 900ER,thats causing the problem,IE not enough pax and bags up front! etc,compared to all economy versions such as the Lion air examples in Indonesia.

Certainly, with the desire to have a First Class cabin in the U.S. domestic market, the number of passengers seated forward is reduced. I know I have heard of fairly lightly loaded 737-900's needing to have some passengers moved forward to keep within Center of Gravity limits. This happens with other aircraft too, but I have heard it more frequently with regard to this aircraft.


Any time there is a stretch of an aircraft design, there is a lot of compromising involved. Lack of power, lack of performance, possibility of tail strikes on take-off are all common themes. Having been involved with flight planning for the 727 family, the 757 family, and most of the derivatives of the DC9, I have had to deal with these limitations first hand. So far, I have only had limited exposure to the 737-900, but I always hear coworkers who deal with this aircraft every day complaining about it constantly. Trouble is that the decision makers love the promised economics of the aircraft, with operational issues apparently far lower on the list of priorities.


Loading the aircraft, with all the issues raised by garstonboy concerning the El Al -900s, is a real challenge for those involved with Weight and Balance. I knew that tail-tipping was an potential issue, but I had no idea that United have to do this work around. A knee-jerk reaction? Perhaps. I will be interested to see whether Delta and/or others follows suit. Not sure about whether a tail stand is incorporated. Will have to check into this. With the issues from this article, you would think it would be standard!

[calflier]

Good information there North by Northwest,maybe a tail stand is the answer,but if it is a stand rather than a pogo stick,(I remember the Shorts 360),it would be a fair weight to carry in the hold,it would have to be at the stand or gate,this then reduces how many airports you can use that are not an equipped or line stations with personnel trained on the use etc,ie diversions,charters etc would be problematic,just added complications of operating the subtype in my view.When you say the planners like the economics and dont factor in any minus points,I know what you mean.