Speed Penalty for Removing Wheel Pants

Any DA40 related topics

Moderators: Rick, Lance Murray

Post Reply
User avatar
Scotsman58
3 Diamonds Member
3 Diamonds Member
Posts: 64
Joined: Fri Feb 24, 2012 9:38 pm
First Name: John
Aircraft Type: DA40
Aircraft Registration: N430JP
Airports: KBDR
Has thanked: 7 times
Been thanked: 8 times

Speed Penalty for Removing Wheel Pants

Post by Scotsman58 »

I have never been a fan of the Diamond wheel pants (not that I have that much experience with those on other makes). It is incredibly fiddly to line up the air valves with the tiny holes and then to get my fingers and the air chuck to the valves. As a result, I don't inflate the tires as faithfully as I should. It is also not easy to inspect the tires for wear. I sometimes see DA40s with their pants removed -- maybe not that great looking, but considerably more convenient. Has anybody got real-world experience of the cruise speed penalty involved with flying without them?
User avatar
Scotsman58
3 Diamonds Member
3 Diamonds Member
Posts: 64
Joined: Fri Feb 24, 2012 9:38 pm
First Name: John
Aircraft Type: DA40
Aircraft Registration: N430JP
Airports: KBDR
Has thanked: 7 times
Been thanked: 8 times

Re: Speed Penalty for Removing Wheel Pants

Post by Scotsman58 »

I just noticed that the DA40 AFM advises that the speed penalty for flying without the "fairings" is "approximately 5%." I guess that translates to almost 7 knots for my normal cruise of 135. That seems like a pretty big hit (although in truth it would not make much difference for most of my flights). Again, if anyone has any actual observations here I would appreciate hearing them.
User avatar
Colin
5 Diamonds Member
5 Diamonds Member
Posts: 1793
Joined: Sat Aug 21, 2010 8:37 pm
First Name: Colin
Aircraft Type: DA42
Aircraft Registration: N972RD
Airports: KFHR
Has thanked: 256 times
Been thanked: 420 times

Re: Speed Penalty for Removing Wheel Pants

Post by Colin »

I believe I noticed a 3kt penalty when I took mine off. I left on the nose wheel.

That was a fine penalty. I would rather be in the sky than on the ground anyway.
Colin Summers, PP Multi-Engine IFR, ~2,800hrs
colin@mightycheese.com
http://www.flyingsummers.com
N972RD DA42 G1000 2.0 s/n 42.AC100
N971RD DA40 G1000 s/n 40.508 (traded)
User avatar
MackAttack
3 Diamonds Member
3 Diamonds Member
Posts: 129
Joined: Thu Jan 23, 2020 6:20 pm
First Name: Joel
Aircraft Type: OTHER
Aircraft Registration: N79LG
Airports: KTME
Has thanked: 5 times
Been thanked: 51 times

Re: Speed Penalty for Removing Wheel Pants

Post by MackAttack »

The “Tundra” version has larger tires and no wheel pants, but has a small horizontal fairing on the wheels to smooth the airflow. It would be a good point of comparison to compare the cruise of a standard DA40 NG with the wheel pants and the Tundra version without, in terms of what Diamond thinks the difference is (I would expect the larger tires to take up 1-2 knots by themselves).
User avatar
haykinson
3 Diamonds Member
3 Diamonds Member
Posts: 79
Joined: Thu Apr 19, 2018 8:32 am
First Name: ilya
Aircraft Type: DA40NG
Aircraft Registration: N724LA
Airports: KSMO
Has thanked: 20 times
Been thanked: 27 times

Re: Speed Penalty for Removing Wheel Pants

Post by haykinson »

I just recently put my wheel pants back on. The difference seems to be at least 5 kts, and even more at low altitudes. Next time I'm at the plane I'll pull my logs and show some sample flights. The flip side of having pants on is now I more frequently need to put rudder input the entire time I'm flying, due to nosewheel corking issues.
brian5x5
1 Diamond Member
1 Diamond Member
Posts: 8
Joined: Fri May 08, 2020 7:05 pm
First Name: Brian
Aircraft Type: DA40NG
Aircraft Registration: N1234
Airports: KEMT
Has thanked: 4 times
Been thanked: 1 time

Re: Speed Penalty for Removing Wheel Pants

Post by brian5x5 »

I think a good compromise it remove the nose wheel pant only. It seems to cost about 3 knots. But for that you get much less corking and an one easier to inspect wheel.
User avatar
Karl
4 Diamonds Member
4 Diamonds Member
Posts: 270
Joined: Wed Aug 04, 2010 3:58 am
First Name: Karl
Aircraft Type: DA40
Airports:
Has thanked: 53 times
Been thanked: 70 times

Re: Speed Penalty for Removing Wheel Pants

Post by Karl »

Scotsman58 wrote: Wed May 04, 2022 7:48 pm I just noticed that the DA40 AFM advises that the speed penalty for flying without the "fairings" is "approximately 5%." I guess that translates to almost 7 knots for my normal cruise of 135. That seems like a pretty big hit (although in truth it would not make much difference for most of my flights). Again, if anyone has any actual observations here I would appreciate hearing them.
It depends on what you are using the aircraft for.

If you are flying just for fun or logging hours then a loss of 5% has no impact on what you are doing.
If you fly short trips it is insignificant. A 1 hr trip with wheel pants will now take 1hr 3m without them.
If it is so fiddly trying to check tires and pressures that it takes more than 3 mins to check them you might actually save time on a 1 hr trip with them off.
Even on a 4 hr trip, 5% will only add 12 mins to the flight.

It is only really a factor if you plan to fly very long trips or looks are more important than the ease of checking the tyres.
User avatar
jwx96
3 Diamonds Member
3 Diamonds Member
Posts: 60
Joined: Mon Jul 22, 2019 9:54 pm
First Name: John
Aircraft Type: DA40
Aircraft Registration: N193JP
Airports: KFCM
Has thanked: 24 times
Been thanked: 12 times

Re: Speed Penalty for Removing Wheel Pants

Post by jwx96 »

When I bought my plane 3 years ago the wheel fairings were on. As others have written it’s hard to check the tires for wear and proper inflation. Also the brakes are not visible. I didn’t think much about it until I had a flat one day when I was landing. It was a clean smooth asphalt runway so I think the fault was with the tire. The fairing was now touching the ground and there was no way to move the plane. It was a Saturday but fortunately there was a mechanic on the field and it wasn’t a busy airport. He was able remove the wheel on the runway, change the tire in his shop, and then reinstall the wheel back out on the runway. I stayed with the plane and alerted a few other planes with my hand-held radio. After that experience I keep my tires pretty new and I keep the wheel fairings off for a good preflight inspection. It’s not a big deal for me because they have to come off for the winter anyway.
User avatar
Don
4 Diamonds Member
4 Diamonds Member
Posts: 359
Joined: Tue Jul 06, 2010 9:15 pm
First Name: Don
Aircraft Type: DA40
Aircraft Registration: N623DS
Airports: KTOA
Has thanked: 111 times
Been thanked: 143 times

Re: Speed Penalty for Removing Wheel Pants

Post by Don »

Not sure why so many Diamonds have a corked nose wheel issues. I do keep my wheel pants on. Maybe I am lucky as I have had only 3 or 4 occasions with a corked nose wheel in the past 10 years. This only has happened when taking off in a strong crosswind. In each case, I would immediate ask the tower to do a touch and go which resets the nose wheel back straight again. That said, during the annuals we have never had to readjust the nose wheel tension so I am guessing they got it right at the factory.
Diamond Star XLS, N623DS, SN40.1076
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 3865
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 114 times
Been thanked: 820 times

Re: Speed Penalty for Removing Wheel Pants

Post by Rich »

Don wrote: Thu May 12, 2022 6:04 pm Not sure why so many Diamonds have a corked nose wheel issues. I do keep my wheel pants on. Maybe I am lucky as I have had only 3 or 4 occasions with a corked nose wheel in the past 10 years. This only has happened when taking off in a strong crosswind. In each case, I would immediate ask the tower to do a touch and go which resets the nose wheel back straight again. That said, during the annuals we have never had to readjust the nose wheel tension so I am guessing they got it right at the factory.
Keep in mind that every time the nose wheel arm comes off for the inspection AD the tension setting has to be reset/rechecked.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
Post Reply